Merge branch 'dev' of https://github.com/prusa3d/Slic3r into dev

xs/CMakeLists.txt

@@ -2,6 +2,10 @@
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+# Enable C11 language standard.
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+
 # Add our own cmake module path.
 list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/modules/)
 
@@ -156,6 +160,7 @@ add_library(libslic3r STATIC
     ${LIBDIR}/libslic3r/PolylineCollection.hpp
     ${LIBDIR}/libslic3r/Print.cpp
     ${LIBDIR}/libslic3r/Print.hpp
+    ${LIBDIR}/libslic3r/PrintExport.hpp
     ${LIBDIR}/libslic3r/PrintConfig.cpp
     ${LIBDIR}/libslic3r/PrintConfig.hpp
     ${LIBDIR}/libslic3r/PrintObject.cpp
@@ -174,8 +179,11 @@ add_library(libslic3r STATIC
     ${LIBDIR}/libslic3r/SVG.hpp
     ${LIBDIR}/libslic3r/TriangleMesh.cpp
     ${LIBDIR}/libslic3r/TriangleMesh.hpp
+    ${LIBDIR}/libslic3r/SLABasePool.hpp
+    ${LIBDIR}/libslic3r/SLABasePool.cpp
 #    ${LIBDIR}/libslic3r/utils.cpp
     ${LIBDIR}/libslic3r/Utils.hpp
+
 )
 
 add_library(libslic3r_gui STATIC
@@ -271,6 +279,8 @@ add_library(libslic3r_gui STATIC
     ${LIBDIR}/slic3r/Utils/PresetUpdater.hpp
     ${LIBDIR}/slic3r/Utils/Time.cpp
     ${LIBDIR}/slic3r/Utils/Time.hpp
+    ${LIBDIR}/slic3r/GUI/PngExportDialog.hpp
+    ${LIBDIR}/slic3r/GUI/PngExportDialog.cpp
     ${LIBDIR}/slic3r/Utils/HexFile.cpp
     ${LIBDIR}/slic3r/Utils/HexFile.hpp
     ${LIBDIR}/slic3r/IProgressIndicator.hpp
@@ -373,6 +383,49 @@ add_library(semver STATIC
     ${LIBDIR}/semver/semver.c
 )
 
+# ##############################################################################
+# Configure rasterizer target
+# ##############################################################################
+
+find_package(PNG QUIET)
+
+option(RASTERIZER_FORCE_BUILTIN_LIBPNG "Force the usage of builting libpng instead of the system version." OFF)
+
+add_library(rasterizer STATIC
+    ${LIBDIR}/libslic3r/Rasterizer/Rasterizer.hpp
+    ${LIBDIR}/libslic3r/Rasterizer/Rasterizer.cpp
+)
+
+if(PNG_FOUND AND NOT RASTERIZER_FORCE_BUILTIN_LIBPNG)
+    message(STATUS "Using system libpng.")
+    target_link_libraries(rasterizer PRIVATE ${PNG_LIBRARIES})
+    target_include_directories(rasterizer PRIVATE ${PNG_INCLUDE_DIRS})
+    target_compile_definitions(rasterizer PRIVATE ${PNG_DEFINITIONS})
+else()
+    set(ZLIB_LIBRARY "")
+    message(WARNING "Using builtin libpng. This can cause crashes on some platforms.")
+    add_subdirectory( ${LIBDIR}/png/zlib)
+
+    set(ZLIB_INCLUDE_DIR
+        ${LIBDIR}/png/zlib
+        ${CMAKE_CURRENT_BINARY_DIR}/src/png/zlib
+        )
+
+    add_subdirectory( ${LIBDIR}/png/libpng )
+    set_target_properties(zlibstatic PROPERTIES POSITION_INDEPENDENT_CODE ON)
+    set_target_properties(png_static PROPERTIES POSITION_INDEPENDENT_CODE ON)
+
+    target_include_directories(rasterizer PRIVATE
+        ${LIBDIR}/png/libpng
+        ${CMAKE_CURRENT_BINARY_DIR}/src/png/libpng
+        )
+    target_link_libraries(rasterizer PRIVATE png_static zlibstatic)
+
+endif()
+
+target_link_libraries(libslic3r rasterizer )
+
+# ##############################################################################
 
 # Generate the Slic3r Perl module (XS) typemap file.
 set(MyTypemap ${CMAKE_CURRENT_BINARY_DIR}/typemap)
@@ -715,9 +768,14 @@ if(APPLE)
 endif()
 
 # Create a slic3r executable
-add_executable(slic3r ${PROJECT_SOURCE_DIR}/src/slic3r.cpp)
+add_executable(slic3r EXCLUDE_FROM_ALL ${PROJECT_SOURCE_DIR}/src/slic3r.cpp)
 target_include_directories(XS PRIVATE src src/libslic3r)
 target_link_libraries(slic3r libslic3r libslic3r_gui admesh miniz ${Boost_LIBRARIES} clipper ${EXPAT_LIBRARIES} ${GLEW_LIBRARIES} polypartition poly2tri ${TBB_LIBRARIES} ${wxWidgets_LIBRARIES})
+
+add_executable(slabasebed ${PROJECT_SOURCE_DIR}/src/slabasebed.cpp)
+target_include_directories(slabasebed PRIVATE src src/libslic3r)
+target_link_libraries(slabasebed libslic3r libslic3r_gui qhull admesh miniz ${Boost_LIBRARIES} clipper ${EXPAT_LIBRARIES} ${GLEW_LIBRARIES} polypartition poly2tri ${TBB_LIBRARIES} ${wxWidgets_LIBRARIES})
+
 if(SLIC3R_PROFILE)
     target_link_libraries(Shiny)
 endif()

xs/src/agg/AUTHORS

@@ -0,0 +1,2 @@
+Anti-Grain Geometry - Version 2.4
+Copyright (C) 2002-2005 Maxim Shemanarev (McSeem) 

xs/src/agg/VERSION

@@ -0,0 +1,2 @@
+2.4
+svn revision 128

xs/src/agg/agg_basics.h

@@ -0,0 +1,574 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_BASICS_INCLUDED
+#define AGG_BASICS_INCLUDED
+
+#include <cmath>
+#include "agg_config.h"
+
+//---------------------------------------------------------AGG_CUSTOM_ALLOCATOR
+#ifdef AGG_CUSTOM_ALLOCATOR
+#include "agg_allocator.h"
+#else
+namespace agg
+{
+    // The policy of all AGG containers and memory allocation strategy 
+    // in general is that no allocated data requires explicit construction.
+    // It means that the allocator can be really simple; you can even
+    // replace new/delete to malloc/free. The constructors and destructors 
+    // won't be called in this case, however everything will remain working. 
+    // The second argument of deallocate() is the size of the allocated 
+    // block. You can use this information if you wish.
+    //------------------------------------------------------------pod_allocator
+    template<class T> struct pod_allocator
+    {
+        static T*   allocate(unsigned num)       { return new T [num]; }
+        static void deallocate(T* ptr, unsigned) { delete [] ptr;      }
+    };
+
+    // Single object allocator. It's also can be replaced with your custom
+    // allocator. The difference is that it can only allocate a single 
+    // object and the constructor and destructor must be called. 
+    // In AGG there is no need to allocate an array of objects with
+    // calling their constructors (only single ones). So that, if you
+    // replace these new/delete to malloc/free make sure that the in-place
+    // new is called and take care of calling the destructor too.
+    //------------------------------------------------------------obj_allocator
+    template<class T> struct obj_allocator
+    {
+        static T*   allocate()         { return new T; }
+        static void deallocate(T* ptr) { delete ptr;   }
+    };
+}
+#endif
+
+
+//-------------------------------------------------------- Default basic types
+//
+// If the compiler has different capacity of the basic types you can redefine
+// them via the compiler command line or by generating agg_config.h that is
+// empty by default.
+//
+#ifndef AGG_INT8
+#define AGG_INT8 signed char
+#endif
+
+#ifndef AGG_INT8U
+#define AGG_INT8U unsigned char
+#endif
+
+#ifndef AGG_INT16
+#define AGG_INT16 short
+#endif
+
+#ifndef AGG_INT16U
+#define AGG_INT16U unsigned short
+#endif
+
+#ifndef AGG_INT32
+#define AGG_INT32 int
+#endif
+
+#ifndef AGG_INT32U
+#define AGG_INT32U unsigned
+#endif
+
+#ifndef AGG_INT64
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+#define AGG_INT64 signed __int64
+#else
+#define AGG_INT64 signed long long
+#endif
+#endif
+
+#ifndef AGG_INT64U
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+#define AGG_INT64U unsigned __int64
+#else
+#define AGG_INT64U unsigned long long
+#endif
+#endif
+
+//------------------------------------------------ Some fixes for MS Visual C++
+#if defined(_MSC_VER)
+#pragma warning(disable:4786) // Identifier was truncated...
+#endif
+
+#if defined(_MSC_VER)
+#define AGG_INLINE __forceinline
+#else
+#define AGG_INLINE inline
+#endif
+
+namespace agg
+{
+    //-------------------------------------------------------------------------
+    typedef AGG_INT8   int8;         //----int8
+    typedef AGG_INT8U  int8u;        //----int8u
+    typedef AGG_INT16  int16;        //----int16
+    typedef AGG_INT16U int16u;       //----int16u
+    typedef AGG_INT32  int32;        //----int32
+    typedef AGG_INT32U int32u;       //----int32u
+    typedef AGG_INT64  int64;        //----int64
+    typedef AGG_INT64U int64u;       //----int64u
+
+#if defined(AGG_FISTP)
+#pragma warning(push)
+#pragma warning(disable : 4035) //Disable warning "no return value"
+    AGG_INLINE int iround(double v)              //-------iround
+    {
+        int t;
+        __asm fld   qword ptr [v]
+        __asm fistp dword ptr [t]
+        __asm mov eax, dword ptr [t]
+    }
+    AGG_INLINE unsigned uround(double v)         //-------uround
+    {
+        unsigned t;
+        __asm fld   qword ptr [v]
+        __asm fistp dword ptr [t]
+        __asm mov eax, dword ptr [t]
+    }
+#pragma warning(pop)
+    AGG_INLINE int ifloor(double v)
+    {
+        return int(floor(v));
+    }
+    AGG_INLINE unsigned ufloor(double v)         //-------ufloor
+    {
+        return unsigned(floor(v));
+    }
+    AGG_INLINE int iceil(double v)
+    {
+        return int(ceil(v));
+    }
+    AGG_INLINE unsigned uceil(double v)          //--------uceil
+    {
+        return unsigned(ceil(v));
+    }
+#elif defined(AGG_QIFIST)
+    AGG_INLINE int iround(double v)
+    {
+        return int(v);
+    }
+    AGG_INLINE int uround(double v)
+    {
+        return unsigned(v);
+    }
+    AGG_INLINE int ifloor(double v)
+    {
+        return int(floor(v));
+    }
+    AGG_INLINE unsigned ufloor(double v)
+    {
+        return unsigned(floor(v));
+    }
+    AGG_INLINE int iceil(double v)
+    {
+        return int(ceil(v));
+    }
+    AGG_INLINE unsigned uceil(double v)
+    {
+        return unsigned(ceil(v));
+    }
+#else
+    AGG_INLINE int iround(double v)
+    {
+        return int((v < 0.0) ? v - 0.5 : v + 0.5);
+    }
+    AGG_INLINE int uround(double v)
+    {
+        return unsigned(v + 0.5);
+    }
+    AGG_INLINE int ifloor(double v)
+    {
+        int i = int(v);
+        return i - (i > v);
+    }
+    AGG_INLINE unsigned ufloor(double v)
+    {
+        return unsigned(v);
+    }
+    AGG_INLINE int iceil(double v)
+    {
+        return int(ceil(v));
+    }
+    AGG_INLINE unsigned uceil(double v)
+    {
+        return unsigned(ceil(v));
+    }
+#endif
+
+    //---------------------------------------------------------------saturation
+    template<int Limit> struct saturation
+    {
+        AGG_INLINE static int iround(double v)
+        {
+            if(v < double(-Limit)) return -Limit;
+            if(v > double( Limit)) return  Limit;
+            return agg::iround(v);
+        }
+    };
+
+    //------------------------------------------------------------------mul_one
+    template<unsigned Shift> struct mul_one
+    {
+        AGG_INLINE static unsigned mul(unsigned a, unsigned b)
+        {
+            unsigned q = a * b + (1 << (Shift-1));
+            return (q + (q >> Shift)) >> Shift;
+        }
+    };
+
+    //-------------------------------------------------------------------------
+    typedef unsigned char cover_type;    //----cover_type
+    enum cover_scale_e
+    {
+        cover_shift = 8,                 //----cover_shift
+        cover_size  = 1 << cover_shift,  //----cover_size 
+        cover_mask  = cover_size - 1,    //----cover_mask 
+        cover_none  = 0,                 //----cover_none 
+        cover_full  = cover_mask         //----cover_full 
+    };
+
+    //----------------------------------------------------poly_subpixel_scale_e
+    // These constants determine the subpixel accuracy, to be more precise, 
+    // the number of bits of the fractional part of the coordinates. 
+    // The possible coordinate capacity in bits can be calculated by formula:
+    // sizeof(int) * 8 - poly_subpixel_shift, i.e, for 32-bit integers and
+    // 8-bits fractional part the capacity is 24 bits.
+    enum poly_subpixel_scale_e
+    {
+        poly_subpixel_shift = 8,                      //----poly_subpixel_shift
+        poly_subpixel_scale = 1<<poly_subpixel_shift, //----poly_subpixel_scale 
+        poly_subpixel_mask  = poly_subpixel_scale-1   //----poly_subpixel_mask 
+    };
+
+    //----------------------------------------------------------filling_rule_e
+    enum filling_rule_e
+    {
+        fill_non_zero,
+        fill_even_odd
+    };
+
+    //-----------------------------------------------------------------------pi
+    const double pi = 3.14159265358979323846;
+
+    //------------------------------------------------------------------deg2rad
+    inline double deg2rad(double deg)
+    {
+        return deg * pi / 180.0;
+    }
+
+    //------------------------------------------------------------------rad2deg
+    inline double rad2deg(double rad)
+    {
+        return rad * 180.0 / pi;
+    }
+ 
+    //----------------------------------------------------------------rect_base
+    template<class T> struct rect_base
+    {
+        typedef T            value_type;
+        typedef rect_base<T> self_type;
+        T x1, y1, x2, y2;
+
+        rect_base() {}
+        rect_base(T x1_, T y1_, T x2_, T y2_) :
+            x1(x1_), y1(y1_), x2(x2_), y2(y2_) {}
+
+        void init(T x1_, T y1_, T x2_, T y2_) 
+        {
+            x1 = x1_; y1 = y1_; x2 = x2_; y2 = y2_; 
+        }
+
+        const self_type& normalize()
+        {
+            T t;
+            if(x1 > x2) { t = x1; x1 = x2; x2 = t; }
+            if(y1 > y2) { t = y1; y1 = y2; y2 = t; }
+            return *this;
+        }
+
+        bool clip(const self_type& r)
+        {
+            if(x2 > r.x2) x2 = r.x2;
+            if(y2 > r.y2) y2 = r.y2;
+            if(x1 < r.x1) x1 = r.x1;
+            if(y1 < r.y1) y1 = r.y1;
+            return x1 <= x2 && y1 <= y2;
+        }
+
+        bool is_valid() const
+        {
+            return x1 <= x2 && y1 <= y2;
+        }
+
+        bool hit_test(T x, T y) const
+        {
+            return (x >= x1 && x <= x2 && y >= y1 && y <= y2);
+        }
+        
+        bool overlaps(const self_type& r) const
+        {
+            return !(r.x1 > x2 || r.x2 < x1
+                  || r.y1 > y2 || r.y2 < y1);
+        }
+    };
+
+    //-----------------------------------------------------intersect_rectangles
+    template<class Rect> 
+    inline Rect intersect_rectangles(const Rect& r1, const Rect& r2)
+    {
+        Rect r = r1;
+
+        // First process x2,y2 because the other order 
+        // results in Internal Compiler Error under 
+        // Microsoft Visual C++ .NET 2003 69462-335-0000007-18038 in 
+        // case of "Maximize Speed" optimization option.
+        //-----------------
+        if(r.x2 > r2.x2) r.x2 = r2.x2; 
+        if(r.y2 > r2.y2) r.y2 = r2.y2;
+        if(r.x1 < r2.x1) r.x1 = r2.x1;
+        if(r.y1 < r2.y1) r.y1 = r2.y1;
+        return r;
+    }
+
+
+    //---------------------------------------------------------unite_rectangles
+    template<class Rect> 
+    inline Rect unite_rectangles(const Rect& r1, const Rect& r2)
+    {
+        Rect r = r1;
+        if(r.x2 < r2.x2) r.x2 = r2.x2;
+        if(r.y2 < r2.y2) r.y2 = r2.y2;
+        if(r.x1 > r2.x1) r.x1 = r2.x1;
+        if(r.y1 > r2.y1) r.y1 = r2.y1;
+        return r;
+    }
+
+    typedef rect_base<int>    rect_i; //----rect_i
+    typedef rect_base<float>  rect_f; //----rect_f
+    typedef rect_base<double> rect_d; //----rect_d
+
+    //---------------------------------------------------------path_commands_e
+    enum path_commands_e
+    {
+        path_cmd_stop     = 0,        //----path_cmd_stop    
+        path_cmd_move_to  = 1,        //----path_cmd_move_to 
+        path_cmd_line_to  = 2,        //----path_cmd_line_to 
+        path_cmd_curve3   = 3,        //----path_cmd_curve3  
+        path_cmd_curve4   = 4,        //----path_cmd_curve4  
+        path_cmd_curveN   = 5,        //----path_cmd_curveN
+        path_cmd_catrom   = 6,        //----path_cmd_catrom
+        path_cmd_ubspline = 7,        //----path_cmd_ubspline
+        path_cmd_end_poly = 0x0F,     //----path_cmd_end_poly
+        path_cmd_mask     = 0x0F      //----path_cmd_mask    
+    };
+
+    //------------------------------------------------------------path_flags_e
+    enum path_flags_e
+    {
+        path_flags_none  = 0,         //----path_flags_none 
+        path_flags_ccw   = 0x10,      //----path_flags_ccw  
+        path_flags_cw    = 0x20,      //----path_flags_cw   
+        path_flags_close = 0x40,      //----path_flags_close
+        path_flags_mask  = 0xF0       //----path_flags_mask 
+    };
+
+    //---------------------------------------------------------------is_vertex
+    inline bool is_vertex(unsigned c)
+    {
+        return c >= path_cmd_move_to && c < path_cmd_end_poly;
+    }
+
+    //--------------------------------------------------------------is_drawing
+    inline bool is_drawing(unsigned c)
+    {
+        return c >= path_cmd_line_to && c < path_cmd_end_poly;
+    }
+
+    //-----------------------------------------------------------------is_stop
+    inline bool is_stop(unsigned c)
+    { 
+        return c == path_cmd_stop;
+    }
+
+    //--------------------------------------------------------------is_move_to
+    inline bool is_move_to(unsigned c)
+    {
+        return c == path_cmd_move_to;
+    }
+
+    //--------------------------------------------------------------is_line_to
+    inline bool is_line_to(unsigned c)
+    {
+        return c == path_cmd_line_to;
+    }
+
+    //----------------------------------------------------------------is_curve
+    inline bool is_curve(unsigned c)
+    {
+        return c == path_cmd_curve3 || c == path_cmd_curve4;
+    }
+
+    //---------------------------------------------------------------is_curve3
+    inline bool is_curve3(unsigned c)
+    {
+        return c == path_cmd_curve3;
+    }
+
+    //---------------------------------------------------------------is_curve4
+    inline bool is_curve4(unsigned c)
+    {
+        return c == path_cmd_curve4;
+    }
+
+    //-------------------------------------------------------------is_end_poly
+    inline bool is_end_poly(unsigned c)
+    {
+        return (c & path_cmd_mask) == path_cmd_end_poly;
+    }
+
+    //----------------------------------------------------------------is_close
+    inline bool is_close(unsigned c)
+    {
+        return (c & ~(path_flags_cw | path_flags_ccw)) ==
+               (path_cmd_end_poly | path_flags_close); 
+    }
+
+    //------------------------------------------------------------is_next_poly
+    inline bool is_next_poly(unsigned c)
+    {
+        return is_stop(c) || is_move_to(c) || is_end_poly(c);
+    }
+
+    //-------------------------------------------------------------------is_cw
+    inline bool is_cw(unsigned c)
+    {
+        return (c & path_flags_cw) != 0;
+    }
+
+    //------------------------------------------------------------------is_ccw
+    inline bool is_ccw(unsigned c)
+    {
+        return (c & path_flags_ccw) != 0;
+    }
+
+    //-------------------------------------------------------------is_oriented
+    inline bool is_oriented(unsigned c)
+    {
+        return (c & (path_flags_cw | path_flags_ccw)) != 0; 
+    }
+
+    //---------------------------------------------------------------is_closed
+    inline bool is_closed(unsigned c)
+    {
+        return (c & path_flags_close) != 0; 
+    }
+
+    //----------------------------------------------------------get_close_flag
+    inline unsigned get_close_flag(unsigned c)
+    {
+        return c & path_flags_close; 
+    }
+
+    //-------------------------------------------------------clear_orientation
+    inline unsigned clear_orientation(unsigned c)
+    {
+        return c & ~(path_flags_cw | path_flags_ccw);
+    }
+
+    //---------------------------------------------------------get_orientation
+    inline unsigned get_orientation(unsigned c)
+    {
+        return c & (path_flags_cw | path_flags_ccw);
+    }
+
+    //---------------------------------------------------------set_orientation
+    inline unsigned set_orientation(unsigned c, unsigned o)
+    {
+        return clear_orientation(c) | o;
+    }
+
+    //--------------------------------------------------------------point_base
+    template<class T> struct point_base
+    {
+        typedef T value_type;
+        T x,y;
+        point_base() {}
+        point_base(T x_, T y_) : x(x_), y(y_) {}
+    };
+    typedef point_base<int>    point_i; //-----point_i
+    typedef point_base<float>  point_f; //-----point_f
+    typedef point_base<double> point_d; //-----point_d
+
+    //-------------------------------------------------------------vertex_base
+    template<class T> struct vertex_base
+    {
+        typedef T value_type;
+        T x,y;
+        unsigned cmd;
+        vertex_base() {}
+        vertex_base(T x_, T y_, unsigned cmd_) : x(x_), y(y_), cmd(cmd_) {}
+    };
+    typedef vertex_base<int>    vertex_i; //-----vertex_i
+    typedef vertex_base<float>  vertex_f; //-----vertex_f
+    typedef vertex_base<double> vertex_d; //-----vertex_d
+
+    //----------------------------------------------------------------row_info
+    template<class T> struct row_info
+    {
+        int x1, x2;
+        T* ptr;
+        row_info() {}
+        row_info(int x1_, int x2_, T* ptr_) : x1(x1_), x2(x2_), ptr(ptr_) {}
+    };
+
+    //----------------------------------------------------------const_row_info
+    template<class T> struct const_row_info
+    {
+        int x1, x2;
+        const T* ptr;
+        const_row_info() {}
+        const_row_info(int x1_, int x2_, const T* ptr_) : 
+            x1(x1_), x2(x2_), ptr(ptr_) {}
+    };
+
+    //------------------------------------------------------------is_equal_eps
+    template<class T> inline bool is_equal_eps(T v1, T v2, T epsilon)
+    {
+	bool neg1 = v1 < 0.0;
+	bool neg2 = v2 < 0.0;
+
+	if (neg1 != neg2)
+	    return std::fabs(v1) < epsilon && std::fabs(v2) < epsilon;
+
+        int int1, int2;
+	std::frexp(v1, &int1);
+	std::frexp(v2, &int2);
+	int min12 = int1 < int2 ? int1 : int2;
+
+	v1 = std::ldexp(v1, -min12);
+	v2 = std::ldexp(v2, -min12);
+
+	return std::fabs(v1 - v2) < epsilon;
+    }
+}
+
+
+#endif
+

xs/src/agg/agg_bezier_arc.h

@@ -0,0 +1,159 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Arc generator. Produces at most 4 consecutive cubic bezier curves, i.e., 
+// 4, 7, 10, or 13 vertices.
+//
+//----------------------------------------------------------------------------
+
+#ifndef AGG_BEZIER_ARC_INCLUDED
+#define AGG_BEZIER_ARC_INCLUDED
+
+#include "agg_conv_transform.h"
+
+namespace agg
+{
+
+    //-----------------------------------------------------------------------
+    void arc_to_bezier(double cx, double cy, double rx, double ry, 
+                       double start_angle, double sweep_angle,
+                       double* curve);
+
+
+    //==============================================================bezier_arc
+    // 
+    // See implemantaion agg_bezier_arc.cpp
+    //
+    class bezier_arc
+    {
+    public:
+        //--------------------------------------------------------------------
+        bezier_arc() : m_vertex(26), m_num_vertices(0), m_cmd(path_cmd_line_to) {}
+        bezier_arc(double x,  double y, 
+                   double rx, double ry, 
+                   double start_angle, 
+                   double sweep_angle)
+        {
+            init(x, y, rx, ry, start_angle, sweep_angle);
+        }
+
+        //--------------------------------------------------------------------
+        void init(double x,  double y, 
+                  double rx, double ry, 
+                  double start_angle, 
+                  double sweep_angle);
+
+        //--------------------------------------------------------------------
+        void rewind(unsigned)
+        {
+            m_vertex = 0;
+        }
+
+        //--------------------------------------------------------------------
+        unsigned vertex(double* x, double* y)
+        {
+            if(m_vertex >= m_num_vertices) return path_cmd_stop;
+            *x = m_vertices[m_vertex];
+            *y = m_vertices[m_vertex + 1];
+            m_vertex += 2;
+            return (m_vertex == 2) ? unsigned(path_cmd_move_to) : m_cmd;
+        }
+
+        // Supplemantary functions. num_vertices() actually returns doubled 
+        // number of vertices. That is, for 1 vertex it returns 2.
+        //--------------------------------------------------------------------
+        unsigned  num_vertices() const { return m_num_vertices; }
+        const double* vertices() const { return m_vertices;     }
+        double*       vertices()       { return m_vertices;     }
+ 
+    private:
+        unsigned m_vertex;
+        unsigned m_num_vertices;
+        double   m_vertices[26];
+        unsigned m_cmd;
+    };
+
+
+
+    //==========================================================bezier_arc_svg
+    // Compute an SVG-style bezier arc. 
+    //
+    // Computes an elliptical arc from (x1, y1) to (x2, y2). The size and 
+    // orientation of the ellipse are defined by two radii (rx, ry) 
+    // and an x-axis-rotation, which indicates how the ellipse as a whole 
+    // is rotated relative to the current coordinate system. The center 
+    // (cx, cy) of the ellipse is calculated automatically to satisfy the 
+    // constraints imposed by the other parameters. 
+    // large-arc-flag and sweep-flag contribute to the automatic calculations 
+    // and help determine how the arc is drawn.
+    class bezier_arc_svg
+    {
+    public:
+        //--------------------------------------------------------------------
+        bezier_arc_svg() : m_arc(), m_radii_ok(false) {}
+
+        bezier_arc_svg(double x1, double y1, 
+                       double rx, double ry, 
+                       double angle,
+                       bool large_arc_flag,
+                       bool sweep_flag,
+                       double x2, double y2) : 
+            m_arc(), m_radii_ok(false)
+        {
+            init(x1, y1, rx, ry, angle, large_arc_flag, sweep_flag, x2, y2);
+        }
+
+        //--------------------------------------------------------------------
+        void init(double x1, double y1, 
+                  double rx, double ry, 
+                  double angle,
+                  bool large_arc_flag,
+                  bool sweep_flag,
+                  double x2, double y2);
+
+        //--------------------------------------------------------------------
+        bool radii_ok() const { return m_radii_ok; }
+
+        //--------------------------------------------------------------------
+        void rewind(unsigned)
+        {
+            m_arc.rewind(0);
+        }
+
+        //--------------------------------------------------------------------
+        unsigned vertex(double* x, double* y)
+        {
+            return m_arc.vertex(x, y);
+        }
+
+        // Supplemantary functions. num_vertices() actually returns doubled 
+        // number of vertices. That is, for 1 vertex it returns 2.
+        //--------------------------------------------------------------------
+        unsigned  num_vertices() const { return m_arc.num_vertices(); }
+        const double* vertices() const { return m_arc.vertices();     }
+        double*       vertices()       { return m_arc.vertices();     }
+
+    private:
+        bezier_arc m_arc;
+        bool       m_radii_ok;
+    };
+
+
+
+
+}
+
+
+#endif

xs/src/agg/agg_clip_liang_barsky.h

@@ -0,0 +1,333 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Liang-Barsky clipping 
+//
+//----------------------------------------------------------------------------
+#ifndef AGG_CLIP_LIANG_BARSKY_INCLUDED
+#define AGG_CLIP_LIANG_BARSKY_INCLUDED
+
+#include "agg_basics.h"
+
+namespace agg
+{
+
+    //------------------------------------------------------------------------
+    enum clipping_flags_e
+    {
+        clipping_flags_x1_clipped = 4,
+        clipping_flags_x2_clipped = 1,
+        clipping_flags_y1_clipped = 8,
+        clipping_flags_y2_clipped = 2,
+        clipping_flags_x_clipped = clipping_flags_x1_clipped | clipping_flags_x2_clipped,
+        clipping_flags_y_clipped = clipping_flags_y1_clipped | clipping_flags_y2_clipped
+    };
+
+    //----------------------------------------------------------clipping_flags
+    // Determine the clipping code of the vertex according to the 
+    // Cyrus-Beck line clipping algorithm
+    //
+    //        |        |
+    //  0110  |  0010  | 0011
+    //        |        |
+    // -------+--------+-------- clip_box.y2
+    //        |        |
+    //  0100  |  0000  | 0001
+    //        |        |
+    // -------+--------+-------- clip_box.y1
+    //        |        |
+    //  1100  |  1000  | 1001
+    //        |        |
+    //  clip_box.x1  clip_box.x2
+    //
+    // 
+    template<class T>
+    inline unsigned clipping_flags(T x, T y, const rect_base<T>& clip_box)
+    {
+        return  (x > clip_box.x2) |
+               ((y > clip_box.y2) << 1) |
+               ((x < clip_box.x1) << 2) |
+               ((y < clip_box.y1) << 3);
+    }
+
+    //--------------------------------------------------------clipping_flags_x
+    template<class T>
+    inline unsigned clipping_flags_x(T x, const rect_base<T>& clip_box)
+    {
+        return  (x > clip_box.x2) | ((x < clip_box.x1) << 2);
+    }
+
+
+    //--------------------------------------------------------clipping_flags_y
+    template<class T>
+    inline unsigned clipping_flags_y(T y, const rect_base<T>& clip_box)
+    {
+        return ((y > clip_box.y2) << 1) | ((y < clip_box.y1) << 3);
+    }
+
+
+    //-------------------------------------------------------clip_liang_barsky
+    template<class T>
+    inline unsigned clip_liang_barsky(T x1, T y1, T x2, T y2,
+                                      const rect_base<T>& clip_box,
+                                      T* x, T* y)
+    {
+        const double nearzero = 1e-30;
+
+        double deltax = x2 - x1;
+        double deltay = y2 - y1; 
+        double xin;
+        double xout;
+        double yin;
+        double yout;
+        double tinx;
+        double tiny;
+        double toutx;
+        double touty;  
+        double tin1;
+        double tin2;
+        double tout1;
+        unsigned np = 0;
+
+        if(deltax == 0.0) 
+        {   
+            // bump off of the vertical
+            deltax = (x1 > clip_box.x1) ? -nearzero : nearzero;
+        }
+
+        if(deltay == 0.0) 
+        { 
+            // bump off of the horizontal 
+            deltay = (y1 > clip_box.y1) ? -nearzero : nearzero;
+        }
+        
+        if(deltax > 0.0) 
+        {                
+            // points to right
+            xin  = clip_box.x1;
+            xout = clip_box.x2;
+        }
+        else 
+        {
+            xin  = clip_box.x2;
+            xout = clip_box.x1;
+        }
+
+        if(deltay > 0.0) 
+        {
+            // points up
+            yin  = clip_box.y1;
+            yout = clip_box.y2;
+        }
+        else 
+        {
+            yin  = clip_box.y2;
+            yout = clip_box.y1;
+        }
+        
+        tinx = (xin - x1) / deltax;
+        tiny = (yin - y1) / deltay;
+        
+        if (tinx < tiny) 
+        {
+            // hits x first
+            tin1 = tinx;
+            tin2 = tiny;
+        }
+        else
+        {
+            // hits y first
+            tin1 = tiny;
+            tin2 = tinx;
+        }
+        
+        if(tin1 <= 1.0) 
+        {
+            if(0.0 < tin1) 
+            {
+                *x++ = (T)xin;
+                *y++ = (T)yin;
+                ++np;
+            }
+
+            if(tin2 <= 1.0)
+            {
+                toutx = (xout - x1) / deltax;
+                touty = (yout - y1) / deltay;
+                
+                tout1 = (toutx < touty) ? toutx : touty;
+                
+                if(tin2 > 0.0 || tout1 > 0.0) 
+                {
+                    if(tin2 <= tout1) 
+                    {
+                        if(tin2 > 0.0) 
+                        {
+                            if(tinx > tiny) 
+                            {
+                                *x++ = (T)xin;
+                                *y++ = (T)(y1 + tinx * deltay);
+                            }
+                            else 
+                            {
+                                *x++ = (T)(x1 + tiny * deltax);
+                                *y++ = (T)yin;
+                            }
+                            ++np;
+                        }
+
+                        if(tout1 < 1.0) 
+                        {
+                            if(toutx < touty) 
+                            {
+                                *x++ = (T)xout;
+                                *y++ = (T)(y1 + toutx * deltay);
+                            }
+                            else 
+                            {
+                                *x++ = (T)(x1 + touty * deltax);
+                                *y++ = (T)yout;
+                            }
+                        }
+                        else 
+                        {
+                            *x++ = x2;
+                            *y++ = y2;
+                        }
+                        ++np;
+                    }
+                    else 
+                    {
+                        if(tinx > tiny) 
+                        {
+                            *x++ = (T)xin;
+                            *y++ = (T)yout;
+                        }
+                        else 
+                        {
+                            *x++ = (T)xout;
+                            *y++ = (T)yin;
+                        }
+                        ++np;
+                    }
+                }
+            }
+        }
+        return np;
+    }
+
+
+    //----------------------------------------------------------------------------
+    template<class T>
+    bool clip_move_point(T x1, T y1, T x2, T y2, 
+                         const rect_base<T>& clip_box, 
+                         T* x, T* y, unsigned flags)
+    {
+       T bound;
+
+       if(flags & clipping_flags_x_clipped)
+       {
+           if(x1 == x2)
+           {
+               return false;
+           }
+           bound = (flags & clipping_flags_x1_clipped) ? clip_box.x1 : clip_box.x2;
+           *y = (T)(double(bound - x1) * (y2 - y1) / (x2 - x1) + y1);
+           *x = bound;
+       }
+
+       flags = clipping_flags_y(*y, clip_box);
+       if(flags & clipping_flags_y_clipped)
+       {
+           if(y1 == y2)
+           {
+               return false;
+           }
+           bound = (flags & clipping_flags_y1_clipped) ? clip_box.y1 : clip_box.y2;
+           *x = (T)(double(bound - y1) * (x2 - x1) / (y2 - y1) + x1);
+           *y = bound;
+       }
+       return true;
+    }
+
+    //-------------------------------------------------------clip_line_segment
+    // Returns: ret >= 4        - Fully clipped
+    //          (ret & 1) != 0  - First point has been moved
+    //          (ret & 2) != 0  - Second point has been moved
+    //
+    template<class T>
+    unsigned clip_line_segment(T* x1, T* y1, T* x2, T* y2,
+                               const rect_base<T>& clip_box)
+    {
+        unsigned f1 = clipping_flags(*x1, *y1, clip_box);
+        unsigned f2 = clipping_flags(*x2, *y2, clip_box);
+        unsigned ret = 0;
+
+        if((f2 | f1) == 0)
+        {
+            // Fully visible
+            return 0;
+        }
+
+        if((f1 & clipping_flags_x_clipped) != 0 && 
+           (f1 & clipping_flags_x_clipped) == (f2 & clipping_flags_x_clipped))
+        {
+            // Fully clipped
+            return 4;
+        }
+
+        if((f1 & clipping_flags_y_clipped) != 0 && 
+           (f1 & clipping_flags_y_clipped) == (f2 & clipping_flags_y_clipped))
+        {
+            // Fully clipped
+            return 4;
+        }
+
+        T tx1 = *x1;
+        T ty1 = *y1;
+        T tx2 = *x2;
+        T ty2 = *y2;
+        if(f1) 
+        {   
+            if(!clip_move_point(tx1, ty1, tx2, ty2, clip_box, x1, y1, f1)) 
+            {
+                return 4;
+            }
+            if(*x1 == *x2 && *y1 == *y2) 
+            {
+                return 4;
+            }
+            ret |= 1;
+        }
+        if(f2) 
+        {
+            if(!clip_move_point(tx1, ty1, tx2, ty2, clip_box, x2, y2, f2))
+            {
+                return 4;
+            }
+            if(*x1 == *x2 && *y1 == *y2) 
+            {
+                return 4;
+            }
+            ret |= 2;
+        }
+        return ret;
+    }
+
+
+}
+
+
+#endif

xs/src/agg/agg_config.h

@@ -0,0 +1,44 @@
+#ifndef AGG_CONFIG_INCLUDED
+#define AGG_CONFIG_INCLUDED
+
+// This file can be used to redefine certain data types.
+
+//---------------------------------------
+// 1. Default basic types such as:
+// 
+// AGG_INT8
+// AGG_INT8U
+// AGG_INT16
+// AGG_INT16U
+// AGG_INT32
+// AGG_INT32U
+// AGG_INT64
+// AGG_INT64U
+//
+// Just replace this file with new defines if necessary. 
+// For example, if your compiler doesn't have a 64 bit integer type
+// you can still use AGG if you define the follows:
+//
+// #define AGG_INT64  int
+// #define AGG_INT64U unsigned
+//
+// It will result in overflow in 16 bit-per-component image/pattern resampling
+// but it won't result any crash and the rest of the library will remain 
+// fully functional.
+
+
+//---------------------------------------
+// 2. Default rendering_buffer type. Can be:
+//
+// Provides faster access for massive pixel operations, 
+// such as blur, image filtering:
+// #define AGG_RENDERING_BUFFER row_ptr_cache<int8u>
+// 
+// Provides cheaper creation and destruction (no mem allocs):
+// #define AGG_RENDERING_BUFFER row_accessor<int8u>
+//
+// You can still use both of them simultaneously in your applications 
+// This #define is used only for default rendering_buffer type,
+// in short hand typedefs like pixfmt_rgba32.
+
+#endif

xs/src/agg/agg_conv_transform.h

@@ -0,0 +1,68 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// class conv_transform
+//
+//----------------------------------------------------------------------------
+#ifndef AGG_CONV_TRANSFORM_INCLUDED
+#define AGG_CONV_TRANSFORM_INCLUDED
+
+#include "agg_basics.h"
+#include "agg_trans_affine.h"
+
+namespace agg
+{
+
+    //----------------------------------------------------------conv_transform
+    template<class VertexSource, class Transformer=trans_affine> class conv_transform
+    {
+    public:
+        conv_transform(VertexSource& source, Transformer& tr) :
+            m_source(&source), m_trans(&tr) {}
+        void attach(VertexSource& source) { m_source = &source; }
+
+        void rewind(unsigned path_id) 
+        { 
+            m_source->rewind(path_id); 
+        }
+
+        unsigned vertex(double* x, double* y)
+        {
+            unsigned cmd = m_source->vertex(x, y);
+            if(is_vertex(cmd))
+            {
+                m_trans->transform(x, y);
+            }
+            return cmd;
+        }
+
+        void transformer(Transformer& tr)
+        {
+            m_trans = &tr;
+        }
+
+    private:
+        conv_transform(const conv_transform<VertexSource>&);
+        const conv_transform<VertexSource>& 
+            operator = (const conv_transform<VertexSource>&);
+
+        VertexSource*      m_source;
+        Transformer* m_trans;
+    };
+
+
+}
+
+#endif

xs/src/agg/agg_gamma_functions.h

@@ -0,0 +1,132 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_GAMMA_FUNCTIONS_INCLUDED
+#define AGG_GAMMA_FUNCTIONS_INCLUDED
+
+#include <math.h>
+#include "agg_basics.h"
+
+namespace agg
+{
+    //===============================================================gamma_none
+    struct gamma_none
+    {
+        double operator()(double x) const { return x; }
+    };
+
+
+    //==============================================================gamma_power
+    class gamma_power
+    {
+    public:
+        gamma_power() : m_gamma(1.0) {}
+        gamma_power(double g) : m_gamma(g) {}
+
+        void gamma(double g) { m_gamma = g; }
+        double gamma() const { return m_gamma; }
+
+        double operator() (double x) const
+        {
+            return pow(x, m_gamma);
+        }
+
+    private:
+        double m_gamma;
+    };
+
+
+    //==========================================================gamma_threshold
+    class gamma_threshold
+    {
+    public:
+        gamma_threshold() : m_threshold(0.5) {}
+        gamma_threshold(double t) : m_threshold(t) {}
+
+        void threshold(double t) { m_threshold = t; }
+        double threshold() const { return m_threshold; }
+
+        double operator() (double x) const
+        {
+            return (x < m_threshold) ? 0.0 : 1.0;
+        }
+
+    private:
+        double m_threshold;
+    };
+
+
+    //============================================================gamma_linear
+    class gamma_linear
+    {
+    public:
+        gamma_linear() : m_start(0.0), m_end(1.0) {}
+        gamma_linear(double s, double e) : m_start(s), m_end(e) {}
+
+        void set(double s, double e) { m_start = s; m_end = e; }
+        void start(double s) { m_start = s; }
+        void end(double e) { m_end = e; }
+        double start() const { return m_start; }
+        double end() const { return m_end; }
+
+        double operator() (double x) const
+        {
+            if(x < m_start) return 0.0;
+            if(x > m_end) return 1.0;
+            return (x - m_start) / (m_end - m_start);
+        }
+
+    private:
+        double m_start;
+        double m_end;
+    };
+
+
+    //==========================================================gamma_multiply
+    class gamma_multiply
+    {
+    public:
+        gamma_multiply() : m_mul(1.0) {}
+        gamma_multiply(double v) : m_mul(v) {}
+
+        void value(double v) { m_mul = v; }
+        double value() const { return m_mul; }
+
+        double operator() (double x) const
+        {
+            double y = x * m_mul;
+            if(y > 1.0) y = 1.0;
+            return y;
+        }
+
+    private:
+        double m_mul;
+    };
+
+    inline double sRGB_to_linear(double x)
+    {
+        return (x <= 0.04045) ? (x / 12.92) : pow((x + 0.055) / (1.055), 2.4);
+    }
+
+    inline double linear_to_sRGB(double x)
+    {
+        return (x <= 0.0031308) ? (x * 12.92) : (1.055 * pow(x, 1 / 2.4) - 0.055);
+    }
+}
+
+#endif
+
+
+

xs/src/agg/agg_gamma_lut.h

@@ -0,0 +1,300 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_GAMMA_LUT_INCLUDED
+#define AGG_GAMMA_LUT_INCLUDED
+
+#include <math.h>
+#include "agg_basics.h"
+#include "agg_gamma_functions.h"
+
+namespace agg
+{
+    template<class LoResT=int8u, 
+             class HiResT=int8u, 
+             unsigned GammaShift=8, 
+             unsigned HiResShift=8> class gamma_lut
+    {
+    public:
+        typedef gamma_lut<LoResT, HiResT, GammaShift, HiResShift> self_type;
+
+        enum gamma_scale_e
+        {
+            gamma_shift = GammaShift,
+            gamma_size  = 1 << gamma_shift,
+            gamma_mask  = gamma_size - 1
+        };
+
+        enum hi_res_scale_e
+        {
+            hi_res_shift = HiResShift,
+            hi_res_size  = 1 << hi_res_shift,
+            hi_res_mask  = hi_res_size - 1
+        };
+
+        ~gamma_lut()
+        {
+            pod_allocator<LoResT>::deallocate(m_inv_gamma, hi_res_size);
+            pod_allocator<HiResT>::deallocate(m_dir_gamma, gamma_size);
+        }
+
+        gamma_lut() : 
+            m_gamma(1.0), 
+            m_dir_gamma(pod_allocator<HiResT>::allocate(gamma_size)),
+            m_inv_gamma(pod_allocator<LoResT>::allocate(hi_res_size))
+        {
+            unsigned i;
+            for(i = 0; i < gamma_size; i++)
+            {
+                m_dir_gamma[i] = HiResT(i << (hi_res_shift - gamma_shift));
+            }
+
+            for(i = 0; i < hi_res_size; i++)
+            {
+                m_inv_gamma[i] = LoResT(i >> (hi_res_shift - gamma_shift));
+            }
+        }
+
+        gamma_lut(double g) :
+            m_gamma(1.0), 
+            m_dir_gamma(pod_allocator<HiResT>::allocate(gamma_size)),
+            m_inv_gamma(pod_allocator<LoResT>::allocate(hi_res_size))
+        {
+            gamma(g);
+        }
+
+        void gamma(double g) 
+        {
+            m_gamma = g;
+
+            unsigned i;
+            for(i = 0; i < gamma_size; i++)
+            {
+                m_dir_gamma[i] = (HiResT)
+                    uround(pow(i / double(gamma_mask), m_gamma) * double(hi_res_mask));
+            }
+
+            double inv_g = 1.0 / g;
+            for(i = 0; i < hi_res_size; i++)
+            {
+                m_inv_gamma[i] = (LoResT)
+                    uround(pow(i / double(hi_res_mask), inv_g) * double(gamma_mask));
+            }
+        }
+
+        double gamma() const
+        {
+            return m_gamma;
+        }
+
+        HiResT dir(LoResT v) const 
+        { 
+            return m_dir_gamma[unsigned(v)]; 
+        }
+
+        LoResT inv(HiResT v) const 
+        { 
+            return m_inv_gamma[unsigned(v)];
+        }
+
+    private:
+        gamma_lut(const self_type&);
+        const self_type& operator = (const self_type&);
+
+        double m_gamma;
+        HiResT* m_dir_gamma;
+        LoResT* m_inv_gamma;
+    };
+
+    //
+    // sRGB support classes
+    //
+
+    // sRGB_lut - implements sRGB conversion for the various types.
+    // Base template is undefined, specializations are provided below.
+    template<class LinearType>
+    class sRGB_lut;
+
+    template<>
+    class sRGB_lut<float>
+    {
+    public:
+		sRGB_lut()
+		{
+			// Generate lookup tables.
+			for (int i = 0; i <= 255; ++i)
+			{
+				m_dir_table[i] = float(sRGB_to_linear(i / 255.0));
+			}
+			for (int i = 0; i <= 65535; ++i)
+			{
+				m_inv_table[i] = uround(255.0 * linear_to_sRGB(i / 65535.0));
+			}
+		}
+
+		float dir(int8u v) const
+		{
+			return m_dir_table[v];
+		}
+
+		int8u inv(float v) const
+		{
+			return m_inv_table[int16u(0.5 + v * 65535)];
+		}
+
+	private:
+		float m_dir_table[256];
+		int8u m_inv_table[65536];
+    };
+
+    template<>
+    class sRGB_lut<int16u>
+    {
+    public:
+        sRGB_lut()
+        {
+            // Generate lookup tables.
+            for (int i = 0; i <= 255; ++i)
+            {
+                m_dir_table[i] = uround(65535.0 * sRGB_to_linear(i / 255.0));
+            }
+			for (int i = 0; i <= 65535; ++i)
+			{
+				m_inv_table[i] = uround(255.0 * linear_to_sRGB(i / 65535.0));
+			}
+		}
+
+		int16u dir(int8u v) const
+		{
+			return m_dir_table[v];
+		}
+
+		int8u inv(int16u v) const
+		{
+			return m_inv_table[v];
+		}
+
+	private:
+		int16u m_dir_table[256];
+		int8u m_inv_table[65536];
+	};
+
+    template<>
+    class sRGB_lut<int8u>
+    {
+    public:
+        sRGB_lut()
+        {
+            // Generate lookup tables. 
+            for (int i = 0; i <= 255; ++i)
+            {
+                m_dir_table[i] = uround(255.0 * sRGB_to_linear(i / 255.0));
+                m_inv_table[i] = uround(255.0 * linear_to_sRGB(i / 255.0));
+            }
+        }
+
+		int8u dir(int8u v) const
+		{
+			return m_dir_table[v];
+		}
+
+		int8u inv(int8u v) const
+        {
+            return m_inv_table[v];
+        }
+
+	private:
+		int8u m_dir_table[256];
+		int8u m_inv_table[256];
+	};
+
+    // Common base class for sRGB_conv objects. Defines an internal 
+    // sRGB_lut object so that users don't have to.
+    template<class T>
+    class sRGB_conv_base
+    {
+    public:
+        static T rgb_from_sRGB(int8u x)
+        {
+            return lut.dir(x);
+        }
+
+        static int8u rgb_to_sRGB(T x)
+        {
+            return lut.inv(x);
+        }
+
+    private:
+        static sRGB_lut<T> lut;
+    };
+
+    // Definition of sRGB_conv_base::lut. Due to the fact that this a template, 
+    // we don't need to place the definition in a cpp file. Hurrah.
+    template<class T>
+    sRGB_lut<T> sRGB_conv_base<T>::lut;
+
+    // Wrapper for sRGB-linear conversion. 
+    // Base template is undefined, specializations are provided below.
+    template<class T>
+    class sRGB_conv;
+
+    template<>
+    class sRGB_conv<float> : public sRGB_conv_base<float>
+    {
+    public:
+        static float alpha_from_sRGB(int8u x)
+        {
+			static const double y = 1 / 255.0;
+            return float(x * y);
+        }
+
+        static int8u alpha_to_sRGB(float x)
+        {
+            return int8u(0.5 + x * 255);
+        }
+    };
+
+    template<>
+    class sRGB_conv<int16u> : public sRGB_conv_base<int16u>
+    {
+    public:
+        static int16u alpha_from_sRGB(int8u x)
+        {
+            return (x << 8) | x;
+        }
+
+        static int8u alpha_to_sRGB(int16u x)
+        {
+            return x >> 8;
+        }
+    };
+
+    template<>
+    class sRGB_conv<int8u> : public sRGB_conv_base<int8u>
+    {
+    public:
+        static int8u alpha_from_sRGB(int8u x)
+        {
+            return x;
+        }
+
+        static int8u alpha_to_sRGB(int8u x)
+        {
+            return x;
+        }
+    };
+}
+
+#endif

xs/src/agg/agg_math.h

@@ -0,0 +1,437 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+// Bessel function (besj) was adapted for use in AGG library by Andy Wilk 
+// Contact: castor.vulgaris@gmail.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_MATH_INCLUDED
+#define AGG_MATH_INCLUDED
+
+#include <math.h>
+#include "agg_basics.h"
+
+namespace agg
+{
+
+    //------------------------------------------------------vertex_dist_epsilon
+    // Coinciding points maximal distance (Epsilon)
+    const double vertex_dist_epsilon = 1e-14;
+
+    //-----------------------------------------------------intersection_epsilon
+    // See calc_intersection
+    const double intersection_epsilon = 1.0e-30;
+
+    //------------------------------------------------------------cross_product
+    AGG_INLINE double cross_product(double x1, double y1, 
+                                    double x2, double y2, 
+                                    double x,  double y)
+    {
+        return (x - x2) * (y2 - y1) - (y - y2) * (x2 - x1);
+    }
+
+    //--------------------------------------------------------point_in_triangle
+    AGG_INLINE bool point_in_triangle(double x1, double y1, 
+                                      double x2, double y2, 
+                                      double x3, double y3, 
+                                      double x,  double y)
+    {
+        bool cp1 = cross_product(x1, y1, x2, y2, x, y) < 0.0;
+        bool cp2 = cross_product(x2, y2, x3, y3, x, y) < 0.0;
+        bool cp3 = cross_product(x3, y3, x1, y1, x, y) < 0.0;
+        return cp1 == cp2 && cp2 == cp3 && cp3 == cp1;
+    }
+
+    //-----------------------------------------------------------calc_distance
+    AGG_INLINE double calc_distance(double x1, double y1, double x2, double y2)
+    {
+        double dx = x2-x1;
+        double dy = y2-y1;
+        return sqrt(dx * dx + dy * dy);
+    }
+
+    //--------------------------------------------------------calc_sq_distance
+    AGG_INLINE double calc_sq_distance(double x1, double y1, double x2, double y2)
+    {
+        double dx = x2-x1;
+        double dy = y2-y1;
+        return dx * dx + dy * dy;
+    }
+
+    //------------------------------------------------calc_line_point_distance
+    AGG_INLINE double calc_line_point_distance(double x1, double y1, 
+                                               double x2, double y2, 
+                                               double x,  double y)
+    {
+        double dx = x2-x1;
+        double dy = y2-y1;
+        double d = sqrt(dx * dx + dy * dy);
+        if(d < vertex_dist_epsilon)
+        {
+            return calc_distance(x1, y1, x, y);
+        }
+        return ((x - x2) * dy - (y - y2) * dx) / d;
+    }
+
+    //-------------------------------------------------------calc_line_point_u
+    AGG_INLINE double calc_segment_point_u(double x1, double y1, 
+                                           double x2, double y2, 
+                                           double x,  double y)
+    {
+        double dx = x2 - x1;
+        double dy = y2 - y1;
+
+        if(dx == 0 && dy == 0)
+        {
+	        return 0;
+        }
+
+        double pdx = x - x1;
+        double pdy = y - y1;
+
+        return (pdx * dx + pdy * dy) / (dx * dx + dy * dy);
+    }
+
+    //---------------------------------------------calc_line_point_sq_distance
+    AGG_INLINE double calc_segment_point_sq_distance(double x1, double y1, 
+                                                     double x2, double y2, 
+                                                     double x,  double y,
+                                                     double u)
+    {
+        if(u <= 0)
+        {
+	        return calc_sq_distance(x, y, x1, y1);
+        }
+        else 
+        if(u >= 1)
+        {
+	        return calc_sq_distance(x, y, x2, y2);
+        }
+        return calc_sq_distance(x, y, x1 + u * (x2 - x1), y1 + u * (y2 - y1));
+    }
+
+    //---------------------------------------------calc_line_point_sq_distance
+    AGG_INLINE double calc_segment_point_sq_distance(double x1, double y1, 
+                                                     double x2, double y2, 
+                                                     double x,  double y)
+    {
+        return 
+            calc_segment_point_sq_distance(
+                x1, y1, x2, y2, x, y,
+                calc_segment_point_u(x1, y1, x2, y2, x, y));
+    }
+
+    //-------------------------------------------------------calc_intersection
+    AGG_INLINE bool calc_intersection(double ax, double ay, double bx, double by,
+                                      double cx, double cy, double dx, double dy,
+                                      double* x, double* y)
+    {
+        double num = (ay-cy) * (dx-cx) - (ax-cx) * (dy-cy);
+        double den = (bx-ax) * (dy-cy) - (by-ay) * (dx-cx);
+        if(fabs(den) < intersection_epsilon) return false;
+        double r = num / den;
+        *x = ax + r * (bx-ax);
+        *y = ay + r * (by-ay);
+        return true;
+    }
+
+    //-----------------------------------------------------intersection_exists
+    AGG_INLINE bool intersection_exists(double x1, double y1, double x2, double y2,
+                                        double x3, double y3, double x4, double y4)
+    {
+        // It's less expensive but you can't control the 
+        // boundary conditions: Less or LessEqual
+        double dx1 = x2 - x1;
+        double dy1 = y2 - y1;
+        double dx2 = x4 - x3;
+        double dy2 = y4 - y3;
+        return ((x3 - x2) * dy1 - (y3 - y2) * dx1 < 0.0) != 
+               ((x4 - x2) * dy1 - (y4 - y2) * dx1 < 0.0) &&
+               ((x1 - x4) * dy2 - (y1 - y4) * dx2 < 0.0) !=
+               ((x2 - x4) * dy2 - (y2 - y4) * dx2 < 0.0);
+
+        // It's is more expensive but more flexible 
+        // in terms of boundary conditions.
+        //--------------------
+        //double den  = (x2-x1) * (y4-y3) - (y2-y1) * (x4-x3);
+        //if(fabs(den) < intersection_epsilon) return false;
+        //double nom1 = (x4-x3) * (y1-y3) - (y4-y3) * (x1-x3);
+        //double nom2 = (x2-x1) * (y1-y3) - (y2-y1) * (x1-x3);
+        //double ua = nom1 / den;
+        //double ub = nom2 / den;
+        //return ua >= 0.0 && ua <= 1.0 && ub >= 0.0 && ub <= 1.0;
+    }
+
+    //--------------------------------------------------------calc_orthogonal
+    AGG_INLINE void calc_orthogonal(double thickness,
+                                    double x1, double y1,
+                                    double x2, double y2,
+                                    double* x, double* y)
+    {
+        double dx = x2 - x1;
+        double dy = y2 - y1;
+        double d = sqrt(dx*dx + dy*dy); 
+        *x =  thickness * dy / d;
+        *y = -thickness * dx / d;
+    }
+
+    //--------------------------------------------------------dilate_triangle
+    AGG_INLINE void dilate_triangle(double x1, double y1,
+                                    double x2, double y2,
+                                    double x3, double y3,
+                                    double *x, double* y,
+                                    double d)
+    {
+        double dx1=0.0;
+        double dy1=0.0; 
+        double dx2=0.0;
+        double dy2=0.0; 
+        double dx3=0.0;
+        double dy3=0.0; 
+        double loc = cross_product(x1, y1, x2, y2, x3, y3);
+        if(fabs(loc) > intersection_epsilon)
+        {
+            if(cross_product(x1, y1, x2, y2, x3, y3) > 0.0) 
+            {
+                d = -d;
+            }
+            calc_orthogonal(d, x1, y1, x2, y2, &dx1, &dy1);
+            calc_orthogonal(d, x2, y2, x3, y3, &dx2, &dy2);
+            calc_orthogonal(d, x3, y3, x1, y1, &dx3, &dy3);
+        }
+        *x++ = x1 + dx1;  *y++ = y1 + dy1;
+        *x++ = x2 + dx1;  *y++ = y2 + dy1;
+        *x++ = x2 + dx2;  *y++ = y2 + dy2;
+        *x++ = x3 + dx2;  *y++ = y3 + dy2;
+        *x++ = x3 + dx3;  *y++ = y3 + dy3;
+        *x++ = x1 + dx3;  *y++ = y1 + dy3;
+    }
+
+    //------------------------------------------------------calc_triangle_area
+    AGG_INLINE double calc_triangle_area(double x1, double y1,
+                                         double x2, double y2,
+                                         double x3, double y3)
+    {
+        return (x1*y2 - x2*y1 + x2*y3 - x3*y2 + x3*y1 - x1*y3) * 0.5;
+    }
+
+    //-------------------------------------------------------calc_polygon_area
+    template<class Storage> double calc_polygon_area(const Storage& st)
+    {
+        unsigned i;
+        double sum = 0.0;
+        double x  = st[0].x;
+        double y  = st[0].y;
+        double xs = x;
+        double ys = y;
+
+        for(i = 1; i < st.size(); i++)
+        {
+            const typename Storage::value_type& v = st[i];
+            sum += x * v.y - y * v.x;
+            x = v.x;
+            y = v.y;
+        }
+        return (sum + x * ys - y * xs) * 0.5;
+    }
+
+    //------------------------------------------------------------------------
+    // Tables for fast sqrt
+    extern int16u g_sqrt_table[1024];
+    extern int8   g_elder_bit_table[256];
+
+
+    //---------------------------------------------------------------fast_sqrt
+    //Fast integer Sqrt - really fast: no cycles, divisions or multiplications
+    #if defined(_MSC_VER)
+    #pragma warning(push)
+    #pragma warning(disable : 4035) //Disable warning "no return value"
+    #endif
+    AGG_INLINE unsigned fast_sqrt(unsigned val)
+    {
+    #if defined(_M_IX86) && defined(_MSC_VER) && !defined(AGG_NO_ASM)
+        //For Ix86 family processors this assembler code is used. 
+        //The key command here is bsr - determination the number of the most 
+        //significant bit of the value. For other processors
+        //(and maybe compilers) the pure C "#else" section is used.
+        __asm
+        {
+            mov ebx, val
+            mov edx, 11
+            bsr ecx, ebx
+            sub ecx, 9
+            jle less_than_9_bits
+            shr ecx, 1
+            adc ecx, 0
+            sub edx, ecx
+            shl ecx, 1
+            shr ebx, cl
+    less_than_9_bits:
+            xor eax, eax
+            mov  ax, g_sqrt_table[ebx*2]
+            mov ecx, edx
+            shr eax, cl
+        }
+    #else
+
+        //This code is actually pure C and portable to most 
+        //arcitectures including 64bit ones. 
+        unsigned t = val;
+        int bit=0;
+        unsigned shift = 11;
+
+        //The following piece of code is just an emulation of the
+        //Ix86 assembler command "bsr" (see above). However on old
+        //Intels (like Intel MMX 233MHz) this code is about twice 
+        //faster (sic!) then just one "bsr". On PIII and PIV the
+        //bsr is optimized quite well.
+        bit = t >> 24;
+        if(bit)
+        {
+            bit = g_elder_bit_table[bit] + 24;
+        }
+        else
+        {
+            bit = (t >> 16) & 0xFF;
+            if(bit)
+            {
+                bit = g_elder_bit_table[bit] + 16;
+            }
+            else
+            {
+                bit = (t >> 8) & 0xFF;
+                if(bit)
+                {
+                    bit = g_elder_bit_table[bit] + 8;
+                }
+                else
+                {
+                    bit = g_elder_bit_table[t];
+                }
+            }
+        }
+
+        //This code calculates the sqrt.
+        bit -= 9;
+        if(bit > 0)
+        {
+            bit = (bit >> 1) + (bit & 1);
+            shift -= bit;
+            val >>= (bit << 1);
+        }
+        return g_sqrt_table[val] >> shift;
+    #endif
+    }
+    #if defined(_MSC_VER)
+    #pragma warning(pop)
+    #endif
+
+
+
+
+    //--------------------------------------------------------------------besj
+    // Function BESJ calculates Bessel function of first kind of order n
+    // Arguments:
+    //     n - an integer (>=0), the order
+    //     x - value at which the Bessel function is required
+    //--------------------
+    // C++ Mathematical Library
+    // Convereted from equivalent FORTRAN library
+    // Converetd by Gareth Walker for use by course 392 computational project
+    // All functions tested and yield the same results as the corresponding
+    // FORTRAN versions.
+    //
+    // If you have any problems using these functions please report them to
+    // M.Muldoon@UMIST.ac.uk
+    //
+    // Documentation available on the web
+    // http://www.ma.umist.ac.uk/mrm/Teaching/392/libs/392.html
+    // Version 1.0   8/98
+    // 29 October, 1999
+    //--------------------
+    // Adapted for use in AGG library by Andy Wilk (castor.vulgaris@gmail.com)
+    //------------------------------------------------------------------------
+    inline double besj(double x, int n)
+    {
+        if(n < 0)
+        {
+            return 0;
+        }
+        double d = 1E-6;
+        double b = 0;
+        if(fabs(x) <= d) 
+        {
+            if(n != 0) return 0;
+            return 1;
+        }
+        double b1 = 0; // b1 is the value from the previous iteration
+        // Set up a starting order for recurrence
+        int m1 = (int)fabs(x) + 6;
+        if(fabs(x) > 5) 
+        {
+            m1 = (int)(fabs(1.4 * x + 60 / x));
+        }
+        int m2 = (int)(n + 2 + fabs(x) / 4);
+        if (m1 > m2) 
+        {
+            m2 = m1;
+        }
+    
+        // Apply recurrence down from curent max order
+        for(;;) 
+        {
+            double c3 = 0;
+            double c2 = 1E-30;
+            double c4 = 0;
+            int m8 = 1;
+            if (m2 / 2 * 2 == m2) 
+            {
+                m8 = -1;
+            }
+            int imax = m2 - 2;
+            for (int i = 1; i <= imax; i++) 
+            {
+                double c6 = 2 * (m2 - i) * c2 / x - c3;
+                c3 = c2;
+                c2 = c6;
+                if(m2 - i - 1 == n)
+                {
+                    b = c6;
+                }
+                m8 = -1 * m8;
+                if (m8 > 0)
+                {
+                    c4 = c4 + 2 * c6;
+                }
+            }
+            double c6 = 2 * c2 / x - c3;
+            if(n == 0)
+            {
+                b = c6;
+            }
+            c4 += c6;
+            b /= c4;
+            if(fabs(b - b1) < d)
+            {
+                return b;
+            }
+            b1 = b;
+            m2 += 3;
+        }
+    }
+
+}
+
+
+#endif

xs/src/agg/agg_pixfmt_base.h

@@ -0,0 +1,97 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_PIXFMT_BASE_INCLUDED
+#define AGG_PIXFMT_BASE_INCLUDED
+
+#include "agg_basics.h"
+#include "agg_color_gray.h"
+#include "agg_color_rgba.h"
+
+namespace agg
+{
+    struct pixfmt_gray_tag
+    {
+    };
+
+    struct pixfmt_rgb_tag
+    {
+    };
+
+    struct pixfmt_rgba_tag
+    {
+    };
+
+    //--------------------------------------------------------------blender_base
+    template<class ColorT, class Order = void> 
+    struct blender_base
+    {
+        typedef ColorT color_type;
+        typedef Order order_type;
+        typedef typename color_type::value_type value_type;
+
+        static rgba get(value_type r, value_type g, value_type b, value_type a, cover_type cover = cover_full)
+        {
+            if (cover > cover_none)
+            {
+                rgba c(
+                    color_type::to_double(r), 
+                    color_type::to_double(g), 
+                    color_type::to_double(b), 
+                    color_type::to_double(a));
+
+                if (cover < cover_full)
+                {
+                    double x = double(cover) / cover_full;
+                    c.r *= x;
+                    c.g *= x;
+                    c.b *= x;
+                    c.a *= x;
+                }
+
+                return c;
+            }
+            else return rgba::no_color();
+        }
+
+        static rgba get(const value_type* p, cover_type cover = cover_full)
+        {
+            return get(
+                p[order_type::R], 
+                p[order_type::G], 
+                p[order_type::B], 
+                p[order_type::A], 
+                cover);
+        }
+
+        static void set(value_type* p, value_type r, value_type g, value_type b, value_type a)
+        {
+            p[order_type::R] = r;
+            p[order_type::G] = g;
+            p[order_type::B] = b;
+            p[order_type::A] = a;
+        }
+
+        static void set(value_type* p, const rgba& c)
+        {
+            p[order_type::R] = color_type::from_double(c.r);
+            p[order_type::G] = color_type::from_double(c.g);
+            p[order_type::B] = color_type::from_double(c.b);
+            p[order_type::A] = color_type::from_double(c.a);
+        }
+    };
+}
+
+#endif

xs/src/agg/agg_pixfmt_gray.h

@@ -0,0 +1,738 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Adaptation for high precision colors has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+
+#ifndef AGG_PIXFMT_GRAY_INCLUDED
+#define AGG_PIXFMT_GRAY_INCLUDED
+
+#include <string.h>
+#include "agg_pixfmt_base.h"
+#include "agg_rendering_buffer.h"
+
+namespace agg
+{
+ 
+    //============================================================blender_gray
+    template<class ColorT> struct blender_gray
+    {
+        typedef ColorT color_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        typedef typename color_type::long_type long_type;
+
+        // Blend pixels using the non-premultiplied form of Alvy-Ray Smith's
+        // compositing function. Since the render buffer is opaque we skip the
+        // initial premultiply and final demultiply.
+
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cv, value_type alpha, cover_type cover)
+        {
+            blend_pix(p, cv, color_type::mult_cover(alpha, cover));
+        }
+
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cv, value_type alpha)
+        {
+            *p = color_type::lerp(*p, cv, alpha);
+        }
+    };
+
+
+    //======================================================blender_gray_pre
+    template<class ColorT> struct blender_gray_pre
+    {
+        typedef ColorT color_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        typedef typename color_type::long_type long_type;
+
+        // Blend pixels using the premultiplied form of Alvy-Ray Smith's
+        // compositing function. 
+
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cv, value_type alpha, cover_type cover)
+        {
+            blend_pix(p, color_type::mult_cover(cv, cover), color_type::mult_cover(alpha, cover));
+        }
+
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cv, value_type alpha)
+        {
+            *p = color_type::prelerp(*p, cv, alpha);
+        }
+    };
+    
+
+
+    //=====================================================apply_gamma_dir_gray
+    template<class ColorT, class GammaLut> class apply_gamma_dir_gray
+    {
+    public:
+        typedef typename ColorT::value_type value_type;
+
+        apply_gamma_dir_gray(const GammaLut& gamma) : m_gamma(gamma) {}
+
+        AGG_INLINE void operator () (value_type* p)
+        {
+            *p = m_gamma.dir(*p);
+        }
+
+    private:
+        const GammaLut& m_gamma;
+    };
+
+
+
+    //=====================================================apply_gamma_inv_gray
+    template<class ColorT, class GammaLut> class apply_gamma_inv_gray
+    {
+    public:
+        typedef typename ColorT::value_type value_type;
+
+        apply_gamma_inv_gray(const GammaLut& gamma) : m_gamma(gamma) {}
+
+        AGG_INLINE void operator () (value_type* p)
+        {
+            *p = m_gamma.inv(*p);
+        }
+
+    private:
+        const GammaLut& m_gamma;
+    };
+
+
+
+    //=================================================pixfmt_alpha_blend_gray
+    template<class Blender, class RenBuf, unsigned Step = 1, unsigned Offset = 0>
+    class pixfmt_alpha_blend_gray
+    {
+    public:
+        typedef pixfmt_gray_tag pixfmt_category;
+        typedef RenBuf   rbuf_type;
+        typedef typename rbuf_type::row_data row_data;
+        typedef Blender  blender_type;
+        typedef typename blender_type::color_type color_type;
+        typedef int                               order_type; // A fake one
+        typedef typename color_type::value_type   value_type;
+        typedef typename color_type::calc_type    calc_type;
+        enum 
+        {
+            num_components = 1,
+            pix_width = sizeof(value_type) * Step,
+            pix_step = Step,
+            pix_offset = Offset,
+        };
+        struct pixel_type
+        {
+            value_type c[num_components];
+
+            void set(value_type v)
+            {
+                c[0] = v;
+            }
+
+            void set(const color_type& color)
+            {
+                set(color.v);
+            }
+
+            void get(value_type& v) const
+            {
+                v = c[0];
+            }
+
+            color_type get() const
+            {
+                return color_type(c[0]);
+            }
+
+            pixel_type* next()
+            {
+                return (pixel_type*)(c + pix_step);
+            }
+
+            const pixel_type* next() const
+            {
+                return (const pixel_type*)(c + pix_step);
+            }
+
+            pixel_type* advance(int n)
+            {
+                return (pixel_type*)(c + n * pix_step);
+            }
+
+            const pixel_type* advance(int n) const
+            {
+                return (const pixel_type*)(c + n * pix_step);
+            }
+        };
+
+    private:
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, 
+            value_type v, value_type a, 
+            unsigned cover)
+        {
+            blender_type::blend_pix(p->c, v, a, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, value_type v, value_type a)
+        {
+            blender_type::blend_pix(p->c, v, a);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c, unsigned cover)
+        {
+            blender_type::blend_pix(p->c, c.v, c.a, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c)
+        {
+            blender_type::blend_pix(p->c, c.v, c.a);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c, unsigned cover)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    p->set(c);
+                }
+                else
+                {
+                    blend_pix(p, c, cover);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque())
+                {
+                    p->set(c);
+                }
+                else
+                {
+                    blend_pix(p, c);
+                }
+            }
+        }
+
+    public:
+        //--------------------------------------------------------------------
+        explicit pixfmt_alpha_blend_gray(rbuf_type& rb) :
+            m_rbuf(&rb)
+        {}
+        void attach(rbuf_type& rb) { m_rbuf = &rb; }
+        //--------------------------------------------------------------------
+
+        template<class PixFmt>
+        bool attach(PixFmt& pixf, int x1, int y1, int x2, int y2)
+        {
+            rect_i r(x1, y1, x2, y2);
+            if (r.clip(rect_i(0, 0, pixf.width()-1, pixf.height()-1)))
+            {
+                int stride = pixf.stride();
+                m_rbuf->attach(pixf.pix_ptr(r.x1, stride < 0 ? r.y2 : r.y1), 
+                               (r.x2 - r.x1) + 1,
+                               (r.y2 - r.y1) + 1,
+                               stride);
+                return true;
+            }
+            return false;
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE unsigned width()  const { return m_rbuf->width();  }
+        AGG_INLINE unsigned height() const { return m_rbuf->height(); }
+        AGG_INLINE int      stride() const { return m_rbuf->stride(); }
+
+        //--------------------------------------------------------------------
+        int8u* row_ptr(int y)       { return m_rbuf->row_ptr(y); }
+        const int8u* row_ptr(int y) const { return m_rbuf->row_ptr(y); }
+        row_data     row(int y)     const { return m_rbuf->row(y); }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE int8u* pix_ptr(int x, int y) 
+        { 
+            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step + pix_offset);
+        }
+
+        AGG_INLINE const int8u* pix_ptr(int x, int y) const 
+        { 
+            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step + pix_offset);
+        }
+
+        // Return pointer to pixel value, forcing row to be allocated.
+        AGG_INLINE pixel_type* pix_value_ptr(int x, int y, unsigned len) 
+        {
+            return (pixel_type*)(m_rbuf->row_ptr(x, y, len) + sizeof(value_type) * (x * pix_step + pix_offset));
+        }
+
+        // Return pointer to pixel value, or null if row not allocated.
+        AGG_INLINE const pixel_type* pix_value_ptr(int x, int y) const 
+        {
+            int8u* p = m_rbuf->row_ptr(y);
+            return p ? (pixel_type*)(p + sizeof(value_type) * (x * pix_step + pix_offset)) : 0;
+        }
+
+        // Get pixel pointer from raw buffer pointer.
+        AGG_INLINE static pixel_type* pix_value_ptr(void* p) 
+        {
+            return (pixel_type*)((value_type*)p + pix_offset);
+        }
+
+        // Get pixel pointer from raw buffer pointer.
+        AGG_INLINE static const pixel_type* pix_value_ptr(const void* p) 
+        {
+            return (const pixel_type*)((const value_type*)p + pix_offset);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static void write_plain_color(void* p, color_type c)
+        {
+            // Grayscale formats are implicitly premultiplied.
+            c.premultiply();
+            pix_value_ptr(p)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static color_type read_plain_color(const void* p)
+        {
+            return pix_value_ptr(p)->get();
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static void make_pix(int8u* p, const color_type& c)
+        {
+            ((pixel_type*)p)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE color_type pixel(int x, int y) const
+        {
+            if (const pixel_type* p = pix_value_ptr(x, y))
+            {
+                return p->get();
+            }
+            return color_type::no_color();
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
+        {
+            pix_value_ptr(x, y, 1)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pixel(int x, int y, const color_type& c, int8u cover)
+        {
+            copy_or_blend_pix(pix_value_ptr(x, y, 1), c, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_hline(int x, int y, 
+                                   unsigned len, 
+                                   const color_type& c)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+            do
+            {
+                p->set(c);
+                p = p->next();
+            }
+            while(--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_vline(int x, int y,
+                                   unsigned len, 
+                                   const color_type& c)
+        {
+            do
+            {
+                pix_value_ptr(x, y++, 1)->set(c);
+            }
+            while (--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_hline(int x, int y,
+                         unsigned len, 
+                         const color_type& c,
+                         int8u cover)
+        {
+            if (!c.is_transparent())
+            {
+                pixel_type* p = pix_value_ptr(x, y, len);
+
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    do
+                    {
+                        p->set(c);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do
+                    {
+                        blend_pix(p, c, cover);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_vline(int x, int y,
+                         unsigned len, 
+                         const color_type& c,
+                         int8u cover)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    do
+                    {
+                        pix_value_ptr(x, y++, 1)->set(c);
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do
+                    {
+                        blend_pix(pix_value_ptr(x, y++, 1), c, cover);
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_solid_hspan(int x, int y,
+                               unsigned len, 
+                               const color_type& c,
+                               const int8u* covers)
+        {
+            if (!c.is_transparent())
+            {
+                pixel_type* p = pix_value_ptr(x, y, len);
+
+                do 
+                {
+                    if (c.is_opaque() && *covers == cover_mask)
+                    {
+                        p->set(c);
+                    }
+                    else
+                    {
+                        blend_pix(p, c, *covers);
+                    }
+                    p = p->next();
+                    ++covers;
+                }
+                while (--len);
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_solid_vspan(int x, int y,
+                               unsigned len, 
+                               const color_type& c,
+                               const int8u* covers)
+        {
+            if (!c.is_transparent())
+            {
+                do 
+                {
+                    pixel_type* p = pix_value_ptr(x, y++, 1);
+
+                    if (c.is_opaque() && *covers == cover_mask)
+                    {
+                        p->set(c);
+                    }
+                    else
+                    {
+                        blend_pix(p, c, *covers);
+                    }
+                    ++covers;
+                }
+                while (--len);
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_color_hspan(int x, int y,
+                              unsigned len, 
+                              const color_type* colors)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+
+            do 
+            {
+                p->set(*colors++);
+                p = p->next();
+            }
+            while (--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_color_vspan(int x, int y,
+                              unsigned len, 
+                              const color_type* colors)
+        {
+            do 
+            {
+                pix_value_ptr(x, y++, 1)->set(*colors++);
+            }
+            while (--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_color_hspan(int x, int y,
+                               unsigned len, 
+                               const color_type* colors,
+                               const int8u* covers,
+                               int8u cover)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+
+            if (covers)
+            {
+                do 
+                {
+                    copy_or_blend_pix(p, *colors++, *covers++);
+                    p = p->next();
+                }
+                while (--len);
+            }
+            else
+            {
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(p, *colors++);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(p, *colors++, cover);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+        
+
+        //--------------------------------------------------------------------
+        void blend_color_vspan(int x, int y,
+                               unsigned len, 
+                               const color_type* colors,
+                               const int8u* covers,
+                               int8u cover)
+        {
+            if (covers)
+            {
+                do 
+                {
+                    copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, *covers++);
+                }
+                while (--len);
+            }
+            else
+            {
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++);
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, cover);
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class Function> void for_each_pixel(Function f)
+        {
+            unsigned y;
+            for (y = 0; y < height(); ++y)
+            {
+                row_data r = m_rbuf->row(y);
+                if (r.ptr)
+                {
+                    unsigned len = r.x2 - r.x1 + 1;
+                    pixel_type* p = pix_value_ptr(r.x1, y, len);
+                    do
+                    {
+                        f(p->c);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class GammaLut> void apply_gamma_dir(const GammaLut& g)
+        {
+            for_each_pixel(apply_gamma_dir_gray<color_type, GammaLut>(g));
+        }
+
+        //--------------------------------------------------------------------
+        template<class GammaLut> void apply_gamma_inv(const GammaLut& g)
+        {
+            for_each_pixel(apply_gamma_inv_gray<color_type, GammaLut>(g));
+        }
+
+        //--------------------------------------------------------------------
+        template<class RenBuf2>
+        void copy_from(const RenBuf2& from, 
+                       int xdst, int ydst,
+                       int xsrc, int ysrc,
+                       unsigned len)
+        {
+            if (const int8u* p = from.row_ptr(ysrc))
+            {
+                memmove(m_rbuf->row_ptr(xdst, ydst, len) + xdst * pix_width, 
+                        p + xsrc * pix_width, 
+                        len * pix_width);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        // Blend from single color, using grayscale surface as alpha channel.
+        template<class SrcPixelFormatRenderer>
+        void blend_from_color(const SrcPixelFormatRenderer& from, 
+                              const color_type& color,
+                              int xdst, int ydst,
+                              int xsrc, int ysrc,
+                              unsigned len,
+                              int8u cover)
+        {
+            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
+            typedef typename SrcPixelFormatRenderer::color_type src_color_type;
+
+            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
+            {
+                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
+
+                do 
+                {
+                    copy_or_blend_pix(pdst, color, src_color_type::scale_cover(cover, psrc->c[0]));
+                    psrc = psrc->next();
+                    pdst = pdst->next();
+                }
+                while (--len);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        // Blend from color table, using grayscale surface as indexes into table.
+        // Obviously, this only works for integer value types.
+        template<class SrcPixelFormatRenderer>
+        void blend_from_lut(const SrcPixelFormatRenderer& from, 
+                            const color_type* color_lut,
+                            int xdst, int ydst,
+                            int xsrc, int ysrc,
+                            unsigned len,
+                            int8u cover)
+        {
+            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
+
+            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
+            {
+                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
+
+                do 
+                {
+                    copy_or_blend_pix(pdst, color_lut[psrc->c[0]], cover);
+                    psrc = psrc->next();
+                    pdst = pdst->next();
+                }
+                while (--len);
+            }
+        }
+
+    private:
+        rbuf_type* m_rbuf;
+    };
+
+    typedef blender_gray<gray8> blender_gray8;
+    typedef blender_gray<sgray8> blender_sgray8;
+    typedef blender_gray<gray16> blender_gray16;
+    typedef blender_gray<gray32> blender_gray32;
+
+    typedef blender_gray_pre<gray8> blender_gray8_pre;
+    typedef blender_gray_pre<sgray8> blender_sgray8_pre;
+    typedef blender_gray_pre<gray16> blender_gray16_pre;
+    typedef blender_gray_pre<gray32> blender_gray32_pre;
+
+    typedef pixfmt_alpha_blend_gray<blender_gray8, rendering_buffer> pixfmt_gray8;
+    typedef pixfmt_alpha_blend_gray<blender_sgray8, rendering_buffer> pixfmt_sgray8;
+    typedef pixfmt_alpha_blend_gray<blender_gray16, rendering_buffer> pixfmt_gray16;
+    typedef pixfmt_alpha_blend_gray<blender_gray32, rendering_buffer> pixfmt_gray32;
+
+    typedef pixfmt_alpha_blend_gray<blender_gray8_pre, rendering_buffer> pixfmt_gray8_pre;
+    typedef pixfmt_alpha_blend_gray<blender_sgray8_pre, rendering_buffer> pixfmt_sgray8_pre;
+    typedef pixfmt_alpha_blend_gray<blender_gray16_pre, rendering_buffer> pixfmt_gray16_pre;
+    typedef pixfmt_alpha_blend_gray<blender_gray32_pre, rendering_buffer> pixfmt_gray32_pre;
+}
+
+#endif
+

xs/src/agg/agg_pixfmt_rgb.h

@@ -0,0 +1,995 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Adaptation for high precision colors has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+
+#ifndef AGG_PIXFMT_RGB_INCLUDED
+#define AGG_PIXFMT_RGB_INCLUDED
+
+#include <string.h>
+#include "agg_pixfmt_base.h"
+#include "agg_rendering_buffer.h"
+
+namespace agg
+{
+
+    //=====================================================apply_gamma_dir_rgb
+    template<class ColorT, class Order, class GammaLut> class apply_gamma_dir_rgb
+    {
+    public:
+        typedef typename ColorT::value_type value_type;
+
+        apply_gamma_dir_rgb(const GammaLut& gamma) : m_gamma(gamma) {}
+
+        AGG_INLINE void operator () (value_type* p)
+        {
+            p[Order::R] = m_gamma.dir(p[Order::R]);
+            p[Order::G] = m_gamma.dir(p[Order::G]);
+            p[Order::B] = m_gamma.dir(p[Order::B]);
+        }
+
+    private:
+        const GammaLut& m_gamma;
+    };
+
+
+
+    //=====================================================apply_gamma_inv_rgb
+    template<class ColorT, class Order, class GammaLut> class apply_gamma_inv_rgb
+    {
+    public:
+        typedef typename ColorT::value_type value_type;
+
+        apply_gamma_inv_rgb(const GammaLut& gamma) : m_gamma(gamma) {}
+
+        AGG_INLINE void operator () (value_type* p)
+        {
+            p[Order::R] = m_gamma.inv(p[Order::R]);
+            p[Order::G] = m_gamma.inv(p[Order::G]);
+            p[Order::B] = m_gamma.inv(p[Order::B]);
+        }
+
+    private:
+        const GammaLut& m_gamma;
+    };
+
+
+    //=========================================================blender_rgb
+    template<class ColorT, class Order> 
+    struct blender_rgb
+    {
+        typedef ColorT color_type;
+        typedef Order order_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        typedef typename color_type::long_type long_type;
+
+        // Blend pixels using the non-premultiplied form of Alvy-Ray Smith's
+        // compositing function. Since the render buffer is opaque we skip the
+        // initial premultiply and final demultiply.
+
+        //--------------------------------------------------------------------
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
+        {
+            blend_pix(p, cr, cg, cb, color_type::mult_cover(alpha, cover));
+        }
+        
+        //--------------------------------------------------------------------
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha)
+        {
+            p[Order::R] = color_type::lerp(p[Order::R], cr, alpha);
+            p[Order::G] = color_type::lerp(p[Order::G], cg, alpha);
+            p[Order::B] = color_type::lerp(p[Order::B], cb, alpha);
+        }
+    };
+
+    //======================================================blender_rgb_pre
+    template<class ColorT, class Order> 
+    struct blender_rgb_pre
+    {
+        typedef ColorT color_type;
+        typedef Order order_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        typedef typename color_type::long_type long_type;
+
+        // Blend pixels using the premultiplied form of Alvy-Ray Smith's
+        // compositing function. 
+
+        //--------------------------------------------------------------------
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
+        {
+            blend_pix(p, 
+                color_type::mult_cover(cr, cover), 
+                color_type::mult_cover(cg, cover), 
+                color_type::mult_cover(cb, cover), 
+                color_type::mult_cover(alpha, cover));
+        }
+
+        //--------------------------------------------------------------------
+        static AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha)
+        {
+            p[Order::R] = color_type::prelerp(p[Order::R], cr, alpha);
+            p[Order::G] = color_type::prelerp(p[Order::G], cg, alpha);
+            p[Order::B] = color_type::prelerp(p[Order::B], cb, alpha);
+        }
+    };
+
+    //===================================================blender_rgb_gamma
+    template<class ColorT, class Order, class Gamma> 
+    class blender_rgb_gamma : public blender_base<ColorT, Order>
+    {
+    public:
+        typedef ColorT color_type;
+        typedef Order order_type;
+        typedef Gamma gamma_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        typedef typename color_type::long_type long_type;
+
+        //--------------------------------------------------------------------
+        blender_rgb_gamma() : m_gamma(0) {}
+        void gamma(const gamma_type& g) { m_gamma = &g; }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
+        {
+            blend_pix(p, cr, cg, cb, color_type::mult_cover(alpha, cover));
+        }
+        
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(value_type* p, 
+            value_type cr, value_type cg, value_type cb, value_type alpha)
+        {
+            calc_type r = m_gamma->dir(p[Order::R]);
+            calc_type g = m_gamma->dir(p[Order::G]);
+            calc_type b = m_gamma->dir(p[Order::B]);
+            p[Order::R] = m_gamma->inv(color_type::downscale((m_gamma->dir(cr) - r) * alpha) + r);
+            p[Order::G] = m_gamma->inv(color_type::downscale((m_gamma->dir(cg) - g) * alpha) + g);
+            p[Order::B] = m_gamma->inv(color_type::downscale((m_gamma->dir(cb) - b) * alpha) + b);
+        }
+        
+    private:
+        const gamma_type* m_gamma;
+    };
+
+
+    //==================================================pixfmt_alpha_blend_rgb
+    template<class Blender, class RenBuf, unsigned Step, unsigned Offset = 0> 
+    class pixfmt_alpha_blend_rgb
+    {
+    public:
+        typedef pixfmt_rgb_tag pixfmt_category;
+        typedef RenBuf   rbuf_type;
+        typedef Blender  blender_type;
+        typedef typename rbuf_type::row_data row_data;
+        typedef typename blender_type::color_type color_type;
+        typedef typename blender_type::order_type order_type;
+        typedef typename color_type::value_type value_type;
+        typedef typename color_type::calc_type calc_type;
+        enum 
+        {
+            num_components = 3,
+            pix_step = Step,
+            pix_offset = Offset,
+            pix_width = sizeof(value_type) * pix_step
+        };
+        struct pixel_type
+        {
+            value_type c[num_components];
+
+            void set(value_type r, value_type g, value_type b)
+            {
+                c[order_type::R] = r;
+                c[order_type::G] = g;
+                c[order_type::B] = b;
+            }
+
+            void set(const color_type& color)
+            {
+                set(color.r, color.g, color.b);
+            }
+
+            void get(value_type& r, value_type& g, value_type& b) const
+            {
+                r = c[order_type::R];
+                g = c[order_type::G];
+                b = c[order_type::B];
+            }
+
+            color_type get() const
+            {
+                return color_type(
+                    c[order_type::R], 
+                    c[order_type::G], 
+                    c[order_type::B]);
+            }
+
+            pixel_type* next()
+            {
+                return (pixel_type*)(c + pix_step);
+            }
+
+            const pixel_type* next() const
+            {
+                return (const pixel_type*)(c + pix_step);
+            }
+
+            pixel_type* advance(int n)
+            {
+                return (pixel_type*)(c + n * pix_step);
+            }
+
+            const pixel_type* advance(int n) const
+            {
+                return (const pixel_type*)(c + n * pix_step);
+            }
+        };
+
+    private:
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, 
+            value_type r, value_type g, value_type b, value_type a, 
+            unsigned cover)
+        {
+            m_blender.blend_pix(p->c, r, g, b, a, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, 
+            value_type r, value_type g, value_type b, value_type a)
+        {
+            m_blender.blend_pix(p->c, r, g, b, a);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c, unsigned cover)
+        {
+            m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c)
+        {
+            m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c, unsigned cover)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    p->set(c);
+                }
+                else
+                {
+                    blend_pix(p, c, cover);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque())
+                {
+                    p->set(c);
+                }
+                else
+                {
+                    blend_pix(p, c);
+                }
+            }
+        }
+
+    public:
+        //--------------------------------------------------------------------
+        explicit pixfmt_alpha_blend_rgb(rbuf_type& rb) :
+            m_rbuf(&rb)
+        {}
+        void attach(rbuf_type& rb) { m_rbuf = &rb; }
+
+        //--------------------------------------------------------------------
+        template<class PixFmt>
+        bool attach(PixFmt& pixf, int x1, int y1, int x2, int y2)
+        {
+            rect_i r(x1, y1, x2, y2);
+            if (r.clip(rect_i(0, 0, pixf.width()-1, pixf.height()-1)))
+            {
+                int stride = pixf.stride();
+                m_rbuf->attach(pixf.pix_ptr(r.x1, stride < 0 ? r.y2 : r.y1), 
+                               (r.x2 - r.x1) + 1,
+                               (r.y2 - r.y1) + 1,
+                               stride);
+                return true;
+            }
+            return false;
+        }
+
+        //--------------------------------------------------------------------
+        Blender& blender() { return m_blender; }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE unsigned width()  const { return m_rbuf->width();  }
+        AGG_INLINE unsigned height() const { return m_rbuf->height(); }
+        AGG_INLINE int      stride() const { return m_rbuf->stride(); }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE       int8u* row_ptr(int y)       { return m_rbuf->row_ptr(y); }
+        AGG_INLINE const int8u* row_ptr(int y) const { return m_rbuf->row_ptr(y); }
+        AGG_INLINE row_data     row(int y)     const { return m_rbuf->row(y); }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE int8u* pix_ptr(int x, int y) 
+        { 
+            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step + pix_offset);
+        }
+
+        AGG_INLINE const int8u* pix_ptr(int x, int y) const 
+        { 
+            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step + pix_offset);
+        }
+
+        // Return pointer to pixel value, forcing row to be allocated.
+        AGG_INLINE pixel_type* pix_value_ptr(int x, int y, unsigned len) 
+        {
+            return (pixel_type*)(m_rbuf->row_ptr(x, y, len) + sizeof(value_type) * (x * pix_step + pix_offset));
+        }
+
+        // Return pointer to pixel value, or null if row not allocated.
+        AGG_INLINE const pixel_type* pix_value_ptr(int x, int y) const 
+        {
+            int8u* p = m_rbuf->row_ptr(y);
+            return p ? (pixel_type*)(p + sizeof(value_type) * (x * pix_step + pix_offset)) : 0;
+        }
+
+        // Get pixel pointer from raw buffer pointer.
+        AGG_INLINE static pixel_type* pix_value_ptr(void* p) 
+        {
+            return (pixel_type*)((value_type*)p + pix_offset);
+        }
+
+        // Get pixel pointer from raw buffer pointer.
+        AGG_INLINE static const pixel_type* pix_value_ptr(const void* p) 
+        {
+            return (const pixel_type*)((const value_type*)p + pix_offset);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static void write_plain_color(void* p, color_type c)
+        {
+            // RGB formats are implicitly premultiplied.
+            c.premultiply();
+            pix_value_ptr(p)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static color_type read_plain_color(const void* p)
+        {
+            return pix_value_ptr(p)->get();
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE static void make_pix(int8u* p, const color_type& c)
+        {
+            ((pixel_type*)p)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE color_type pixel(int x, int y) const
+        {
+            if (const pixel_type* p = pix_value_ptr(x, y))
+            {
+                return p->get();
+            }
+            return color_type::no_color();
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
+        {
+            pix_value_ptr(x, y, 1)->set(c);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void blend_pixel(int x, int y, const color_type& c, int8u cover)
+        {
+            copy_or_blend_pix(pix_value_ptr(x, y, 1), c, cover);
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_hline(int x, int y, 
+                                   unsigned len, 
+                                   const color_type& c)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+            do
+            {
+                p->set(c);
+                p = p->next();
+            }
+            while(--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        AGG_INLINE void copy_vline(int x, int y,
+                                   unsigned len, 
+                                   const color_type& c)
+        {
+            do
+            {
+                pix_value_ptr(x, y++, 1)->set(c);
+            }
+            while (--len);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_hline(int x, int y,
+                         unsigned len, 
+                         const color_type& c,
+                         int8u cover)
+        {
+            if (!c.is_transparent())
+            {
+                pixel_type* p = pix_value_ptr(x, y, len);
+
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    do
+                    {
+                        p->set(c);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do
+                    {
+                        blend_pix(p, c, cover);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_vline(int x, int y,
+                         unsigned len, 
+                         const color_type& c,
+                         int8u cover)
+        {
+            if (!c.is_transparent())
+            {
+                if (c.is_opaque() && cover == cover_mask)
+                {
+                    do
+                    {
+                        pix_value_ptr(x, y++, 1)->set(c);
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do
+                    {
+                        blend_pix(pix_value_ptr(x, y++, 1), c, cover);
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void blend_solid_hspan(int x, int y,
+                               unsigned len, 
+                               const color_type& c,
+                               const int8u* covers)
+        {
+            if (!c.is_transparent())
+            {
+                pixel_type* p = pix_value_ptr(x, y, len);
+
+                do 
+                {
+                    if (c.is_opaque() && *covers == cover_mask)
+                    {
+                        p->set(c);
+                    }
+                    else
+                    {
+                        blend_pix(p, c, *covers);
+                    }
+                    p = p->next();
+                    ++covers;
+                }
+                while (--len);
+            }
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_solid_vspan(int x, int y,
+                               unsigned len, 
+                               const color_type& c,
+                               const int8u* covers)
+        {
+            if (!c.is_transparent())
+            {
+                do 
+                {
+                    pixel_type* p = pix_value_ptr(x, y++, 1);
+
+                    if (c.is_opaque() && *covers == cover_mask)
+                    {
+                        p->set(c);
+                    }
+                    else
+                    {
+                        blend_pix(p, c, *covers);
+                    }
+                    ++covers;
+                }
+                while (--len);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void copy_color_hspan(int x, int y,
+                              unsigned len, 
+                              const color_type* colors)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+
+            do 
+            {
+                p->set(*colors++);
+                p = p->next();
+            }
+            while (--len);
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_color_vspan(int x, int y,
+                              unsigned len, 
+                              const color_type* colors)
+        {
+            do 
+            {
+                pix_value_ptr(x, y++, 1)->set(*colors++);
+            }
+            while (--len);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_color_hspan(int x, int y,
+                               unsigned len, 
+                               const color_type* colors,
+                               const int8u* covers,
+                               int8u cover)
+        {
+            pixel_type* p = pix_value_ptr(x, y, len);
+
+            if (covers)
+            {
+                do 
+                {
+                    copy_or_blend_pix(p, *colors++, *covers++);
+                    p = p->next();
+                }
+                while (--len);
+            }
+            else
+            {
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(p, *colors++);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(p, *colors++, cover);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void blend_color_vspan(int x, int y,
+                               unsigned len, 
+                               const color_type* colors,
+                               const int8u* covers,
+                               int8u cover)
+        {
+            if (covers)
+            {
+                do 
+                {
+                    copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, *covers++);
+                }
+                while (--len);
+            }
+            else
+            {
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++);
+                    }
+                    while (--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, cover);
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class Function> void for_each_pixel(Function f)
+        {
+            for (unsigned y = 0; y < height(); ++y)
+            {
+                row_data r = m_rbuf->row(y);
+                if (r.ptr)
+                {
+                    unsigned len = r.x2 - r.x1 + 1;
+                    pixel_type* p = pix_value_ptr(r.x1, y, len);
+                    do
+                    {
+                        f(p->c);
+                        p = p->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class GammaLut> void apply_gamma_dir(const GammaLut& g)
+        {
+            for_each_pixel(apply_gamma_dir_rgb<color_type, order_type, GammaLut>(g));
+        }
+
+        //--------------------------------------------------------------------
+        template<class GammaLut> void apply_gamma_inv(const GammaLut& g)
+        {
+            for_each_pixel(apply_gamma_inv_rgb<color_type, order_type, GammaLut>(g));
+        }
+
+        //--------------------------------------------------------------------
+        template<class RenBuf2>
+        void copy_from(const RenBuf2& from, 
+                       int xdst, int ydst,
+                       int xsrc, int ysrc,
+                       unsigned len)
+        {
+            if (const int8u* p = from.row_ptr(ysrc))
+            {
+                memmove(m_rbuf->row_ptr(xdst, ydst, len) + xdst * pix_width, 
+                        p + xsrc * pix_width, 
+                        len * pix_width);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        // Blend from an RGBA surface.
+        template<class SrcPixelFormatRenderer>
+        void blend_from(const SrcPixelFormatRenderer& from, 
+                        int xdst, int ydst,
+                        int xsrc, int ysrc,
+                        unsigned len,
+                        int8u cover)
+        {
+            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
+            typedef typename SrcPixelFormatRenderer::order_type src_order;
+
+            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
+            {
+                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
+
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        value_type alpha = psrc->c[src_order::A];
+                        if (alpha <= color_type::empty_value())
+                        {
+                            if (alpha >= color_type::full_value())
+                            {
+                                pdst->c[order_type::R] = psrc->c[src_order::R];
+                                pdst->c[order_type::G] = psrc->c[src_order::G];
+                                pdst->c[order_type::B] = psrc->c[src_order::B];
+                            }
+                            else
+                            {
+                                blend_pix(pdst, 
+                                    psrc->c[src_order::R],
+                                    psrc->c[src_order::G],
+                                    psrc->c[src_order::B],
+                                    alpha);
+                            }
+                        }
+                        psrc = psrc->next();
+                        pdst = pdst->next();
+                    }
+                    while(--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pdst, psrc->get(), cover);
+                        psrc = psrc->next();
+                        pdst = pdst->next();
+                    }
+                    while (--len);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        // Blend from single color, using grayscale surface as alpha channel.
+        template<class SrcPixelFormatRenderer>
+        void blend_from_color(const SrcPixelFormatRenderer& from, 
+                              const color_type& color,
+                              int xdst, int ydst,
+                              int xsrc, int ysrc,
+                              unsigned len,
+                              int8u cover)
+        {
+            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
+            typedef typename SrcPixelFormatRenderer::color_type src_color_type;
+
+            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
+            {
+                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
+
+                do 
+                {
+                    copy_or_blend_pix(pdst, color, src_color_type::scale_cover(cover, psrc->c[0]));
+                    psrc = psrc->next();
+                    pdst = pdst->next();
+                }
+                while (--len);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        // Blend from color table, using grayscale surface as indexes into table. 
+        // Obviously, this only works for integer value types.
+        template<class SrcPixelFormatRenderer>
+        void blend_from_lut(const SrcPixelFormatRenderer& from, 
+                            const color_type* color_lut,
+                            int xdst, int ydst,
+                            int xsrc, int ysrc,
+                            unsigned len,
+                            int8u cover)
+        {
+            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
+
+            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
+            {
+                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
+
+                if (cover == cover_mask)
+                {
+                    do 
+                    {
+                        const color_type& color = color_lut[psrc->c[0]];
+                        blend_pix(pdst, color);
+                        psrc = psrc->next();
+                        pdst = pdst->next();
+                    }
+                    while(--len);
+                }
+                else
+                {
+                    do 
+                    {
+                        copy_or_blend_pix(pdst, color_lut[psrc->c[0]], cover);
+                        psrc = psrc->next();
+                        pdst = pdst->next();
+                    }
+                    while(--len);
+                }
+            }
+        }
+
+    private:
+        rbuf_type* m_rbuf;
+        Blender    m_blender;
+    };
+    
+    //-----------------------------------------------------------------------
+    typedef blender_rgb<rgba8, order_rgb> blender_rgb24;
+    typedef blender_rgb<rgba8, order_bgr> blender_bgr24;
+    typedef blender_rgb<srgba8, order_rgb> blender_srgb24;
+    typedef blender_rgb<srgba8, order_bgr> blender_sbgr24;
+    typedef blender_rgb<rgba16, order_rgb> blender_rgb48;
+    typedef blender_rgb<rgba16, order_bgr> blender_bgr48;
+    typedef blender_rgb<rgba32, order_rgb> blender_rgb96;
+    typedef blender_rgb<rgba32, order_bgr> blender_bgr96;
+
+    typedef blender_rgb_pre<rgba8, order_rgb> blender_rgb24_pre;
+    typedef blender_rgb_pre<rgba8, order_bgr> blender_bgr24_pre;
+    typedef blender_rgb_pre<srgba8, order_rgb> blender_srgb24_pre;
+    typedef blender_rgb_pre<srgba8, order_bgr> blender_sbgr24_pre;
+    typedef blender_rgb_pre<rgba16, order_rgb> blender_rgb48_pre;
+    typedef blender_rgb_pre<rgba16, order_bgr> blender_bgr48_pre;
+    typedef blender_rgb_pre<rgba32, order_rgb> blender_rgb96_pre;
+    typedef blender_rgb_pre<rgba32, order_bgr> blender_bgr96_pre;
+
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24, rendering_buffer, 3> pixfmt_rgb24;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24, rendering_buffer, 3> pixfmt_bgr24;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24, rendering_buffer, 3> pixfmt_srgb24;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24, rendering_buffer, 3> pixfmt_sbgr24;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48, rendering_buffer, 3> pixfmt_rgb48;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48, rendering_buffer, 3> pixfmt_bgr48;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96, rendering_buffer, 3> pixfmt_rgb96;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96, rendering_buffer, 3> pixfmt_bgr96;
+
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24_pre, rendering_buffer, 3> pixfmt_rgb24_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24_pre, rendering_buffer, 3> pixfmt_bgr24_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24_pre, rendering_buffer, 3> pixfmt_srgb24_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24_pre, rendering_buffer, 3> pixfmt_sbgr24_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48_pre, rendering_buffer, 3> pixfmt_rgb48_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48_pre, rendering_buffer, 3> pixfmt_bgr48_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96_pre, rendering_buffer, 3> pixfmt_rgb96_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96_pre, rendering_buffer, 3> pixfmt_bgr96_pre;
+
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24, rendering_buffer, 4, 0> pixfmt_rgbx32;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24, rendering_buffer, 4, 1> pixfmt_xrgb32;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24, rendering_buffer, 4, 1> pixfmt_xbgr32;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24, rendering_buffer, 4, 0> pixfmt_bgrx32;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24, rendering_buffer, 4, 0> pixfmt_srgbx32;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24, rendering_buffer, 4, 1> pixfmt_sxrgb32;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24, rendering_buffer, 4, 1> pixfmt_sxbgr32;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24, rendering_buffer, 4, 0> pixfmt_sbgrx32;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48, rendering_buffer, 4, 0> pixfmt_rgbx64;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48, rendering_buffer, 4, 1> pixfmt_xrgb64;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48, rendering_buffer, 4, 1> pixfmt_xbgr64;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48, rendering_buffer, 4, 0> pixfmt_bgrx64;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96, rendering_buffer, 4, 0> pixfmt_rgbx128;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96, rendering_buffer, 4, 1> pixfmt_xrgb128;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96, rendering_buffer, 4, 1> pixfmt_xbgr128;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96, rendering_buffer, 4, 0> pixfmt_bgrx128;
+
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24_pre, rendering_buffer, 4, 0> pixfmt_rgbx32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb24_pre, rendering_buffer, 4, 1> pixfmt_xrgb32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24_pre, rendering_buffer, 4, 1> pixfmt_xbgr32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr24_pre, rendering_buffer, 4, 0> pixfmt_bgrx32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24_pre, rendering_buffer, 4, 0> pixfmt_srgbx32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_srgb24_pre, rendering_buffer, 4, 1> pixfmt_sxrgb32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24_pre, rendering_buffer, 4, 1> pixfmt_sxbgr32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_sbgr24_pre, rendering_buffer, 4, 0> pixfmt_sbgrx32_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48_pre, rendering_buffer, 4, 0> pixfmt_rgbx64_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb48_pre, rendering_buffer, 4, 1> pixfmt_xrgb64_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48_pre, rendering_buffer, 4, 1> pixfmt_xbgr64_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr48_pre, rendering_buffer, 4, 0> pixfmt_bgrx64_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96_pre, rendering_buffer, 4, 0> pixfmt_rgbx128_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_rgb96_pre, rendering_buffer, 4, 1> pixfmt_xrgb128_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96_pre, rendering_buffer, 4, 1> pixfmt_xbgr128_pre;
+    typedef pixfmt_alpha_blend_rgb<blender_bgr96_pre, rendering_buffer, 4, 0> pixfmt_bgrx128_pre;
+    
+
+    //-----------------------------------------------------pixfmt_rgb24_gamma
+    template<class Gamma> class pixfmt_rgb24_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba8, order_rgb, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_rgb24_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba8, order_rgb, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+        
+    //-----------------------------------------------------pixfmt_srgb24_gamma
+    template<class Gamma> class pixfmt_srgb24_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<srgba8, order_rgb, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_srgb24_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<srgba8, order_rgb, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+        
+    //-----------------------------------------------------pixfmt_bgr24_gamma
+    template<class Gamma> class pixfmt_bgr24_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba8, order_bgr, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_bgr24_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba8, order_bgr, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+
+    //-----------------------------------------------------pixfmt_sbgr24_gamma
+    template<class Gamma> class pixfmt_sbgr24_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<srgba8, order_bgr, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_sbgr24_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<srgba8, order_bgr, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+
+    //-----------------------------------------------------pixfmt_rgb48_gamma
+    template<class Gamma> class pixfmt_rgb48_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba16, order_rgb, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_rgb48_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba16, order_rgb, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+        
+    //-----------------------------------------------------pixfmt_bgr48_gamma
+    template<class Gamma> class pixfmt_bgr48_gamma : 
+    public pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba16, order_bgr, Gamma>, rendering_buffer, 3>
+    {
+    public:
+        pixfmt_bgr48_gamma(rendering_buffer& rb, const Gamma& g) :
+            pixfmt_alpha_blend_rgb<blender_rgb_gamma<rgba16, order_bgr, Gamma>, rendering_buffer, 3>(rb) 
+        {
+            this->blender().gamma(g);
+        }
+    };
+    
+}
+
+#endif
+

xs/src/agg/agg_rasterizer_cells_aa.h

@@ -0,0 +1,741 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+//
+// The author gratefully acknowleges the support of David Turner, 
+// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType 
+// libray - in producing this work. See http://www.freetype.org for details.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Adaptation for 32-bit screen coordinates has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+#ifndef AGG_RASTERIZER_CELLS_AA_INCLUDED
+#define AGG_RASTERIZER_CELLS_AA_INCLUDED
+
+#include <string.h>
+#include <cstdlib>
+#include <limits>
+#include "agg_math.h"
+#include "agg_array.h"
+
+
+namespace agg
+{
+
+    //-----------------------------------------------------rasterizer_cells_aa
+    // An internal class that implements the main rasterization algorithm.
+    // Used in the rasterizer. Should not be used direcly.
+    template<class Cell> class rasterizer_cells_aa
+    {
+        enum cell_block_scale_e
+        {
+            cell_block_shift = 12,
+            cell_block_size  = 1 << cell_block_shift,
+            cell_block_mask  = cell_block_size - 1,
+            cell_block_pool  = 256,
+            cell_block_limit = 1024
+        };
+
+        struct sorted_y
+        {
+            unsigned start;
+            unsigned num;
+        };
+
+    public:
+        typedef Cell cell_type;
+        typedef rasterizer_cells_aa<Cell> self_type;
+
+        ~rasterizer_cells_aa();
+        rasterizer_cells_aa();
+
+        void reset();
+        void style(const cell_type& style_cell);
+        void line(int x1, int y1, int x2, int y2);
+
+        int min_x() const { return m_min_x; }
+        int min_y() const { return m_min_y; }
+        int max_x() const { return m_max_x; }
+        int max_y() const { return m_max_y; }
+
+        void sort_cells();
+
+        unsigned total_cells() const 
+        {
+            return m_num_cells;
+        }
+
+        unsigned scanline_num_cells(unsigned y) const 
+        { 
+            return m_sorted_y[y - m_min_y].num; 
+        }
+
+        const cell_type* const* scanline_cells(unsigned y) const
+        { 
+            return m_sorted_cells.data() + m_sorted_y[y - m_min_y].start; 
+        }
+
+        bool sorted() const { return m_sorted; }
+
+    private:
+        rasterizer_cells_aa(const self_type&);
+        const self_type& operator = (const self_type&);
+
+        void set_curr_cell(int x, int y);
+        void add_curr_cell();
+        void render_hline(int ey, int x1, int y1, int x2, int y2);
+        void allocate_block();
+        
+    private:
+        unsigned                m_num_blocks;
+        unsigned                m_max_blocks;
+        unsigned                m_curr_block;
+        unsigned                m_num_cells;
+        cell_type**             m_cells;
+        cell_type*              m_curr_cell_ptr;
+        pod_vector<cell_type*>  m_sorted_cells;
+        pod_vector<sorted_y>    m_sorted_y;
+        cell_type               m_curr_cell;
+        cell_type               m_style_cell;
+        int                     m_min_x;
+        int                     m_min_y;
+        int                     m_max_x;
+        int                     m_max_y;
+        bool                    m_sorted;
+    };
+
+
+
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    rasterizer_cells_aa<Cell>::~rasterizer_cells_aa()
+    {
+        if(m_num_blocks)
+        {
+            cell_type** ptr = m_cells + m_num_blocks - 1;
+            while(m_num_blocks--)
+            {
+                pod_allocator<cell_type>::deallocate(*ptr, cell_block_size);
+                ptr--;
+            }
+            pod_allocator<cell_type*>::deallocate(m_cells, m_max_blocks);
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    rasterizer_cells_aa<Cell>::rasterizer_cells_aa() :
+        m_num_blocks(0),
+        m_max_blocks(0),
+        m_curr_block(0),
+        m_num_cells(0),
+        m_cells(0),
+        m_curr_cell_ptr(0),
+        m_sorted_cells(),
+        m_sorted_y(),
+        m_min_x(std::numeric_limits<int>::max()),
+        m_min_y(std::numeric_limits<int>::max()),
+        m_max_x(std::numeric_limits<int>::min()),
+        m_max_y(std::numeric_limits<int>::min()),
+        m_sorted(false)
+    {
+        m_style_cell.initial();
+        m_curr_cell.initial();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    void rasterizer_cells_aa<Cell>::reset()
+    {
+        m_num_cells = 0; 
+        m_curr_block = 0;
+        m_curr_cell.initial();
+        m_style_cell.initial();
+        m_sorted = false;
+        m_min_x = std::numeric_limits<int>::max();
+        m_min_y = std::numeric_limits<int>::max();
+        m_max_x = std::numeric_limits<int>::min();
+        m_max_y = std::numeric_limits<int>::min();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    AGG_INLINE void rasterizer_cells_aa<Cell>::add_curr_cell()
+    {
+        if(m_curr_cell.area | m_curr_cell.cover)
+        {
+            if((m_num_cells & cell_block_mask) == 0)
+            {
+                if(m_num_blocks >= cell_block_limit) return;
+                allocate_block();
+            }
+            *m_curr_cell_ptr++ = m_curr_cell;
+            ++m_num_cells;
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    AGG_INLINE void rasterizer_cells_aa<Cell>::set_curr_cell(int x, int y)
+    {
+        if(m_curr_cell.not_equal(x, y, m_style_cell))
+        {
+            add_curr_cell();
+            m_curr_cell.style(m_style_cell);
+            m_curr_cell.x     = x;
+            m_curr_cell.y     = y;
+            m_curr_cell.cover = 0;
+            m_curr_cell.area  = 0;
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    AGG_INLINE void rasterizer_cells_aa<Cell>::render_hline(int ey, 
+                                                            int x1, int y1, 
+                                                            int x2, int y2)
+    {
+        int ex1 = x1 >> poly_subpixel_shift;
+        int ex2 = x2 >> poly_subpixel_shift;
+        int fx1 = x1 & poly_subpixel_mask;
+        int fx2 = x2 & poly_subpixel_mask;
+
+        int delta, p, first;
+        long long dx;
+        int incr, lift, mod, rem;
+
+        //trivial case. Happens often
+        if(y1 == y2)
+        {
+            set_curr_cell(ex2, ey);
+            return;
+        }
+
+        //everything is located in a single cell.  That is easy!
+        if(ex1 == ex2)
+        {
+            delta = y2 - y1;
+            m_curr_cell.cover += delta;
+            m_curr_cell.area  += (fx1 + fx2) * delta;
+            return;
+        }
+
+        //ok, we'll have to render a run of adjacent cells on the same
+        //hline...
+        p     = (poly_subpixel_scale - fx1) * (y2 - y1);
+        first = poly_subpixel_scale;
+        incr  = 1;
+
+        dx = (long long)x2 - (long long)x1;
+
+        if(dx < 0)
+        {
+            p     = fx1 * (y2 - y1);
+            first = 0;
+            incr  = -1;
+            dx    = -dx;
+        }
+
+        delta = (int)(p / dx);
+        mod   = (int)(p % dx);
+
+        if(mod < 0)
+        {
+            delta--;
+            mod += static_cast<int>(dx);
+        }
+
+        m_curr_cell.cover += delta;
+        m_curr_cell.area  += (fx1 + first) * delta;
+
+        ex1 += incr;
+        set_curr_cell(ex1, ey);
+        y1  += delta;
+
+        if(ex1 != ex2)
+        {
+            p     = poly_subpixel_scale * (y2 - y1 + delta);
+            lift  = (int)(p / dx);
+            rem   = (int)(p % dx);
+
+            if (rem < 0)
+            {
+                lift--;
+                rem += static_cast<int>(dx);
+            }
+
+            mod -= static_cast<int>(dx);
+
+            while (ex1 != ex2)
+            {
+                delta = lift;
+                mod  += rem;
+                if(mod >= 0)
+                {
+                    mod -= static_cast<int>(dx);
+                    delta++;
+                }
+
+                m_curr_cell.cover += delta;
+                m_curr_cell.area  += poly_subpixel_scale * delta;
+                y1  += delta;
+                ex1 += incr;
+                set_curr_cell(ex1, ey);
+            }
+        }
+        delta = y2 - y1;
+        m_curr_cell.cover += delta;
+        m_curr_cell.area  += (fx2 + poly_subpixel_scale - first) * delta;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    AGG_INLINE void rasterizer_cells_aa<Cell>::style(const cell_type& style_cell)
+    { 
+        m_style_cell.style(style_cell); 
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    void rasterizer_cells_aa<Cell>::line(int x1, int y1, int x2, int y2)
+    {
+        enum dx_limit_e { dx_limit = 16384 << poly_subpixel_shift };
+
+        long long dx = (long long)x2 - (long long)x1;
+
+        if(dx >= dx_limit || dx <= -dx_limit)
+        {
+            int cx = (int)(((long long)x1 + (long long)x2) >> 1);
+            int cy = (int)(((long long)y1 + (long long)y2) >> 1);
+            line(x1, y1, cx, cy);
+            line(cx, cy, x2, y2);
+        }
+
+        long long dy = (long long)y2 - (long long)y1;
+        int ex1 = x1 >> poly_subpixel_shift;
+        int ex2 = x2 >> poly_subpixel_shift;
+        int ey1 = y1 >> poly_subpixel_shift;
+        int ey2 = y2 >> poly_subpixel_shift;
+        int fy1 = y1 & poly_subpixel_mask;
+        int fy2 = y2 & poly_subpixel_mask;
+
+        int x_from, x_to;
+        int rem, mod, lift, delta, first, incr;
+        long long p;
+
+        if(ex1 < m_min_x) m_min_x = ex1;
+        if(ex1 > m_max_x) m_max_x = ex1;
+        if(ey1 < m_min_y) m_min_y = ey1;
+        if(ey1 > m_max_y) m_max_y = ey1;
+        if(ex2 < m_min_x) m_min_x = ex2;
+        if(ex2 > m_max_x) m_max_x = ex2;
+        if(ey2 < m_min_y) m_min_y = ey2;
+        if(ey2 > m_max_y) m_max_y = ey2;
+
+        set_curr_cell(ex1, ey1);
+
+        //everything is on a single hline
+        if(ey1 == ey2)
+        {
+            render_hline(ey1, x1, fy1, x2, fy2);
+            return;
+        }
+
+        //Vertical line - we have to calculate start and end cells,
+        //and then - the common values of the area and coverage for
+        //all cells of the line. We know exactly there's only one 
+        //cell, so, we don't have to call render_hline().
+        incr  = 1;
+        if(dx == 0)
+        {
+            int ex = x1 >> poly_subpixel_shift;
+            int two_fx = (x1 - (ex << poly_subpixel_shift)) << 1;
+            int area;
+
+            first = poly_subpixel_scale;
+            if(dy < 0)
+            {
+                first = 0;
+                incr  = -1;
+            }
+
+            x_from = x1;
+
+            //render_hline(ey1, x_from, fy1, x_from, first);
+            delta = first - fy1;
+            m_curr_cell.cover += delta;
+            m_curr_cell.area  += two_fx * delta;
+
+            ey1 += incr;
+            set_curr_cell(ex, ey1);
+
+            delta = first + first - poly_subpixel_scale;
+            area = two_fx * delta;
+            while(ey1 != ey2)
+            {
+                //render_hline(ey1, x_from, poly_subpixel_scale - first, x_from, first);
+                m_curr_cell.cover = delta;
+                m_curr_cell.area  = area;
+                ey1 += incr;
+                set_curr_cell(ex, ey1);
+            }
+            //render_hline(ey1, x_from, poly_subpixel_scale - first, x_from, fy2);
+            delta = fy2 - poly_subpixel_scale + first;
+            m_curr_cell.cover += delta;
+            m_curr_cell.area  += two_fx * delta;
+            return;
+        }
+
+        //ok, we have to render several hlines
+        p     = (poly_subpixel_scale - fy1) * dx;
+        first = poly_subpixel_scale;
+
+        if(dy < 0)
+        {
+            p     = fy1 * dx;
+            first = 0;
+            incr  = -1;
+            dy    = -dy;
+        }
+
+        delta = (int)(p / dy);
+        mod   = (int)(p % dy);
+
+        if(mod < 0)
+        {
+            delta--;
+            mod += static_cast<int>(dy);
+        }
+
+        x_from = x1 + delta;
+        render_hline(ey1, x1, fy1, x_from, first);
+
+        ey1 += incr;
+        set_curr_cell(x_from >> poly_subpixel_shift, ey1);
+
+        if(ey1 != ey2)
+        {
+            p     = poly_subpixel_scale * dx;
+            lift  = (int)(p / dy);
+            rem   = (int)(p % dy);
+
+            if(rem < 0)
+            {
+                lift--;
+                rem += static_cast<int>(dy);
+            }
+            mod -= static_cast<int>(dy);
+
+            while(ey1 != ey2)
+            {
+                delta = lift;
+                mod  += rem;
+                if (mod >= 0)
+                {
+                    mod -= static_cast<int>(dy);
+                    delta++;
+                }
+
+                x_to = x_from + delta;
+                render_hline(ey1, x_from, poly_subpixel_scale - first, x_to, first);
+                x_from = x_to;
+
+                ey1 += incr;
+                set_curr_cell(x_from >> poly_subpixel_shift, ey1);
+            }
+        }
+        render_hline(ey1, x_from, poly_subpixel_scale - first, x2, fy2);
+    }
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    void rasterizer_cells_aa<Cell>::allocate_block()
+    {
+        if(m_curr_block >= m_num_blocks)
+        {
+            if(m_num_blocks >= m_max_blocks)
+            {
+                cell_type** new_cells = 
+                    pod_allocator<cell_type*>::allocate(m_max_blocks + 
+                                                        cell_block_pool);
+
+                if(m_cells)
+                {
+                    memcpy(new_cells, m_cells, m_max_blocks * sizeof(cell_type*));
+                    pod_allocator<cell_type*>::deallocate(m_cells, m_max_blocks);
+                }
+                m_cells = new_cells;
+                m_max_blocks += cell_block_pool;
+            }
+
+            m_cells[m_num_blocks++] = 
+                pod_allocator<cell_type>::allocate(cell_block_size);
+
+        }
+        m_curr_cell_ptr = m_cells[m_curr_block++];
+    }
+
+
+
+    //------------------------------------------------------------------------
+    template <class T> static AGG_INLINE void swap_cells(T* a, T* b)
+    {
+        T temp = *a;
+        *a = *b;
+        *b = temp;
+    }
+
+
+    //------------------------------------------------------------------------
+    enum
+    {
+        qsort_threshold = 9
+    };
+
+
+    //------------------------------------------------------------------------
+    template<class Cell>
+    void qsort_cells(Cell** start, unsigned num)
+    {
+        Cell**  stack[80];
+        Cell*** top; 
+        Cell**  limit;
+        Cell**  base;
+
+        limit = start + num;
+        base  = start;
+        top   = stack;
+
+        for (;;)
+        {
+            int len = int(limit - base);
+
+            Cell** i;
+            Cell** j;
+            Cell** pivot;
+
+            if(len > qsort_threshold)
+            {
+                // we use base + len/2 as the pivot
+                pivot = base + len / 2;
+                swap_cells(base, pivot);
+
+                i = base + 1;
+                j = limit - 1;
+
+                // now ensure that *i <= *base <= *j 
+                if((*j)->x < (*i)->x)
+                {
+                    swap_cells(i, j);
+                }
+
+                if((*base)->x < (*i)->x)
+                {
+                    swap_cells(base, i);
+                }
+
+                if((*j)->x < (*base)->x)
+                {
+                    swap_cells(base, j);
+                }
+
+                for(;;)
+                {
+                    int x = (*base)->x;
+                    do i++; while( (*i)->x < x );
+                    do j--; while( x < (*j)->x );
+
+                    if(i > j)
+                    {
+                        break;
+                    }
+
+                    swap_cells(i, j);
+                }
+
+                swap_cells(base, j);
+
+                // now, push the largest sub-array
+                if(j - base > limit - i)
+                {
+                    top[0] = base;
+                    top[1] = j;
+                    base   = i;
+                }
+                else
+                {
+                    top[0] = i;
+                    top[1] = limit;
+                    limit  = j;
+                }
+                top += 2;
+            }
+            else
+            {
+                // the sub-array is small, perform insertion sort
+                j = base;
+                i = j + 1;
+
+                for(; i < limit; j = i, i++)
+                {
+                    for(; j[1]->x < (*j)->x; j--)
+                    {
+                        swap_cells(j + 1, j);
+                        if (j == base)
+                        {
+                            break;
+                        }
+                    }
+                }
+
+                if(top > stack)
+                {
+                    top  -= 2;
+                    base  = top[0];
+                    limit = top[1];
+                }
+                else
+                {
+                    break;
+                }
+            }
+        }
+    }
+
+
+    //------------------------------------------------------------------------
+    template<class Cell> 
+    void rasterizer_cells_aa<Cell>::sort_cells()
+    {
+        if(m_sorted) return; //Perform sort only the first time.
+
+        add_curr_cell();
+        m_curr_cell.x     = std::numeric_limits<int>::max();
+        m_curr_cell.y     = std::numeric_limits<int>::max();
+        m_curr_cell.cover = 0;
+        m_curr_cell.area  = 0;
+
+        if(m_num_cells == 0) return;
+
+// DBG: Check to see if min/max works well.
+//for(unsigned nc = 0; nc < m_num_cells; nc++)
+//{
+//    cell_type* cell = m_cells[nc >> cell_block_shift] + (nc & cell_block_mask);
+//    if(cell->x < m_min_x || 
+//       cell->y < m_min_y || 
+//       cell->x > m_max_x || 
+//       cell->y > m_max_y)
+//    {
+//        cell = cell; // Breakpoint here
+//    }
+//}
+        // Allocate the array of cell pointers
+        m_sorted_cells.allocate(m_num_cells, 16);
+
+        // Allocate and zero the Y array
+        m_sorted_y.allocate(m_max_y - m_min_y + 1, 16);
+        m_sorted_y.zero();
+
+        // Create the Y-histogram (count the numbers of cells for each Y)
+        cell_type** block_ptr = m_cells;
+        cell_type*  cell_ptr;
+        unsigned nb = m_num_cells;
+        unsigned i;
+        while(nb)
+        {
+            cell_ptr = *block_ptr++;
+            i = (nb > cell_block_size) ? unsigned(cell_block_size) : nb;
+            nb -= i;
+            while(i--) 
+            {
+                m_sorted_y[cell_ptr->y - m_min_y].start++;
+                ++cell_ptr;
+            }
+        }
+
+        // Convert the Y-histogram into the array of starting indexes
+        unsigned start = 0;
+        for(i = 0; i < m_sorted_y.size(); i++)
+        {
+            unsigned v = m_sorted_y[i].start;
+            m_sorted_y[i].start = start;
+            start += v;
+        }
+
+        // Fill the cell pointer array sorted by Y
+        block_ptr = m_cells;
+        nb = m_num_cells;
+        while(nb)
+        {
+            cell_ptr = *block_ptr++;
+            i = (nb > cell_block_size) ? unsigned(cell_block_size) : nb;
+            nb -= i;
+            while(i--)
+            {
+                sorted_y& curr_y = m_sorted_y[cell_ptr->y - m_min_y];
+                m_sorted_cells[curr_y.start + curr_y.num] = cell_ptr;
+                ++curr_y.num;
+                ++cell_ptr;
+            }
+        }
+        
+        // Finally arrange the X-arrays
+        for(i = 0; i < m_sorted_y.size(); i++)
+        {
+            const sorted_y& curr_y = m_sorted_y[i];
+            if(curr_y.num)
+            {
+                qsort_cells(m_sorted_cells.data() + curr_y.start, curr_y.num);
+            }
+        }
+        m_sorted = true;
+    }
+
+
+
+    //------------------------------------------------------scanline_hit_test
+    class scanline_hit_test
+    {
+    public:
+        scanline_hit_test(int x) : m_x(x), m_hit(false) {}
+
+        void reset_spans() {}
+        void finalize(int) {}
+        void add_cell(int x, int)
+        {
+            if(m_x == x) m_hit = true;
+        }
+        void add_span(int x, int len, int)
+        {
+            if(m_x >= x && m_x < x+len) m_hit = true;
+        }
+        unsigned num_spans() const { return 1; }
+        bool hit() const { return m_hit; }
+
+    private:
+        int  m_x;
+        bool m_hit;
+    };
+
+
+}
+
+#endif

xs/src/agg/agg_rasterizer_scanline_aa.h

@@ -0,0 +1,481 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+//
+// The author gratefully acknowleges the support of David Turner, 
+// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType 
+// libray - in producing this work. See http://www.freetype.org for details.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Adaptation for 32-bit screen coordinates has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+#ifndef AGG_RASTERIZER_SCANLINE_AA_INCLUDED
+#define AGG_RASTERIZER_SCANLINE_AA_INCLUDED
+
+#include "agg_rasterizer_cells_aa.h"
+#include "agg_rasterizer_sl_clip.h"
+#include "agg_rasterizer_scanline_aa_nogamma.h"
+#include "agg_gamma_functions.h"
+
+
+namespace agg
+{
+    //==================================================rasterizer_scanline_aa
+    // Polygon rasterizer that is used to render filled polygons with 
+    // high-quality Anti-Aliasing. Internally, by default, the class uses 
+    // integer coordinates in format 24.8, i.e. 24 bits for integer part 
+    // and 8 bits for fractional - see poly_subpixel_shift. This class can be 
+    // used in the following  way:
+    //
+    // 1. filling_rule(filling_rule_e ft) - optional.
+    //
+    // 2. gamma() - optional.
+    //
+    // 3. reset()
+    //
+    // 4. move_to(x, y) / line_to(x, y) - make the polygon. One can create 
+    //    more than one contour, but each contour must consist of at least 3
+    //    vertices, i.e. move_to(x1, y1); line_to(x2, y2); line_to(x3, y3);
+    //    is the absolute minimum of vertices that define a triangle.
+    //    The algorithm does not check either the number of vertices nor
+    //    coincidence of their coordinates, but in the worst case it just 
+    //    won't draw anything.
+    //    The orger of the vertices (clockwise or counterclockwise) 
+    //    is important when using the non-zero filling rule (fill_non_zero).
+    //    In this case the vertex order of all the contours must be the same
+    //    if you want your intersecting polygons to be without "holes".
+    //    You actually can use different vertices order. If the contours do not 
+    //    intersect each other the order is not important anyway. If they do, 
+    //    contours with the same vertex order will be rendered without "holes" 
+    //    while the intersecting contours with different orders will have "holes".
+    //
+    // filling_rule() and gamma() can be called anytime before "sweeping".
+    //------------------------------------------------------------------------
+    template<class Clip=rasterizer_sl_clip_int> class rasterizer_scanline_aa
+    {
+        enum status
+        {
+            status_initial,
+            status_move_to,
+            status_line_to,
+            status_closed
+        };
+
+    public:
+        typedef Clip                      clip_type;
+        typedef typename Clip::conv_type  conv_type;
+        typedef typename Clip::coord_type coord_type;
+
+        enum aa_scale_e
+        {
+            aa_shift  = 8,
+            aa_scale  = 1 << aa_shift,
+            aa_mask   = aa_scale - 1,
+            aa_scale2 = aa_scale * 2,
+            aa_mask2  = aa_scale2 - 1
+        };
+
+        //--------------------------------------------------------------------
+        rasterizer_scanline_aa() : 
+            m_outline(),
+            m_clipper(),
+            m_filling_rule(fill_non_zero),
+            m_auto_close(true),
+            m_start_x(0),
+            m_start_y(0),
+            m_status(status_initial)
+        {
+            int i;
+            for(i = 0; i < aa_scale; i++) m_gamma[i] = i;
+        }
+
+        //--------------------------------------------------------------------
+        template<class GammaF> 
+        rasterizer_scanline_aa(const GammaF& gamma_function) : 
+            m_outline(),
+            m_clipper(m_outline),
+            m_filling_rule(fill_non_zero),
+            m_auto_close(true),
+            m_start_x(0),
+            m_start_y(0),
+            m_status(status_initial)
+        {
+            gamma(gamma_function);
+        }
+
+        //--------------------------------------------------------------------
+        void reset(); 
+        void reset_clipping();
+        void clip_box(double x1, double y1, double x2, double y2);
+        void filling_rule(filling_rule_e filling_rule);
+        void auto_close(bool flag) { m_auto_close = flag; }
+
+        //--------------------------------------------------------------------
+        template<class GammaF> void gamma(const GammaF& gamma_function)
+        { 
+            int i;
+            for(i = 0; i < aa_scale; i++)
+            {
+                m_gamma[i] = uround(gamma_function(double(i) / aa_mask) * aa_mask);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        unsigned apply_gamma(unsigned cover) const 
+        { 
+            return m_gamma[cover]; 
+        }
+
+        //--------------------------------------------------------------------
+        void move_to(int x, int y);
+        void line_to(int x, int y);
+        void move_to_d(double x, double y);
+        void line_to_d(double x, double y);
+        void close_polygon();
+        void add_vertex(double x, double y, unsigned cmd);
+
+        void edge(int x1, int y1, int x2, int y2);
+        void edge_d(double x1, double y1, double x2, double y2);
+
+        //-------------------------------------------------------------------
+        template<class VertexSource>
+        void add_path(VertexSource& vs, unsigned path_id=0)
+        {
+            double x;
+            double y;
+
+            unsigned cmd;
+            vs.rewind(path_id);
+            if(m_outline.sorted()) reset();
+            while(!is_stop(cmd = vs.vertex(&x, &y)))
+            {
+                add_vertex(x, y, cmd);
+            }
+        }
+        
+        //--------------------------------------------------------------------
+        int min_x() const { return m_outline.min_x(); }
+        int min_y() const { return m_outline.min_y(); }
+        int max_x() const { return m_outline.max_x(); }
+        int max_y() const { return m_outline.max_y(); }
+
+        //--------------------------------------------------------------------
+        void sort();
+        bool rewind_scanlines();
+        bool navigate_scanline(int y);
+
+        //--------------------------------------------------------------------
+        AGG_INLINE unsigned calculate_alpha(int area) const
+        {
+            int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
+
+            if(cover < 0) cover = -cover;
+            if(m_filling_rule == fill_even_odd)
+            {
+                cover &= aa_mask2;
+                if(cover > aa_scale)
+                {
+                    cover = aa_scale2 - cover;
+                }
+            }
+            if(cover > aa_mask) cover = aa_mask;
+            return m_gamma[cover];
+        }
+
+        //--------------------------------------------------------------------
+        template<class Scanline> bool sweep_scanline(Scanline& sl)
+        {
+            for(;;)
+            {
+                if(m_scan_y > m_outline.max_y()) return false;
+                sl.reset_spans();
+                unsigned num_cells = m_outline.scanline_num_cells(m_scan_y);
+                const cell_aa* const* cells = m_outline.scanline_cells(m_scan_y);
+                int cover = 0;
+
+                while(num_cells)
+                {
+                    const cell_aa* cur_cell = *cells;
+                    int x    = cur_cell->x;
+                    int area = cur_cell->area;
+                    unsigned alpha;
+
+                    cover += cur_cell->cover;
+
+                    //accumulate all cells with the same X
+                    while(--num_cells)
+                    {
+                        cur_cell = *++cells;
+                        if(cur_cell->x != x) break;
+                        area  += cur_cell->area;
+                        cover += cur_cell->cover;
+                    }
+
+                    if(area)
+                    {
+                        alpha = calculate_alpha((cover << (poly_subpixel_shift + 1)) - area);
+                        if(alpha)
+                        {
+                            sl.add_cell(x, alpha);
+                        }
+                        x++;
+                    }
+
+                    if(num_cells && cur_cell->x > x)
+                    {
+                        alpha = calculate_alpha(cover << (poly_subpixel_shift + 1));
+                        if(alpha)
+                        {
+                            sl.add_span(x, cur_cell->x - x, alpha);
+                        }
+                    }
+                }
+        
+                if(sl.num_spans()) break;
+                ++m_scan_y;
+            }
+
+            sl.finalize(m_scan_y);
+            ++m_scan_y;
+            return true;
+        }
+
+        //--------------------------------------------------------------------
+        bool hit_test(int tx, int ty);
+
+
+    private:
+        //--------------------------------------------------------------------
+        // Disable copying
+        rasterizer_scanline_aa(const rasterizer_scanline_aa<Clip>&);
+        const rasterizer_scanline_aa<Clip>& 
+        operator = (const rasterizer_scanline_aa<Clip>&);
+
+    private:
+        rasterizer_cells_aa<cell_aa> m_outline;
+        clip_type      m_clipper;
+        int            m_gamma[aa_scale];
+        filling_rule_e m_filling_rule;
+        bool           m_auto_close;
+        coord_type     m_start_x;
+        coord_type     m_start_y;
+        unsigned       m_status;
+        int            m_scan_y;
+    };
+
+
+
+
+
+
+
+
+
+
+
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::reset() 
+    { 
+        m_outline.reset(); 
+        m_status = status_initial;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::filling_rule(filling_rule_e filling_rule) 
+    { 
+        m_filling_rule = filling_rule; 
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::clip_box(double x1, double y1, 
+                                                double x2, double y2)
+    {
+        reset();
+        m_clipper.clip_box(conv_type::upscale(x1), conv_type::upscale(y1), 
+                           conv_type::upscale(x2), conv_type::upscale(y2));
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::reset_clipping()
+    {
+        reset();
+        m_clipper.reset_clipping();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::close_polygon()
+    {
+        if(m_status == status_line_to)
+        {
+            m_clipper.line_to(m_outline, m_start_x, m_start_y);
+            m_status = status_closed;
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::move_to(int x, int y)
+    {
+        if(m_outline.sorted()) reset();
+        if(m_auto_close) close_polygon();
+        m_clipper.move_to(m_start_x = conv_type::downscale(x), 
+                          m_start_y = conv_type::downscale(y));
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::line_to(int x, int y)
+    {
+        m_clipper.line_to(m_outline, 
+                          conv_type::downscale(x), 
+                          conv_type::downscale(y));
+        m_status = status_line_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::move_to_d(double x, double y) 
+    { 
+        if(m_outline.sorted()) reset();
+        if(m_auto_close) close_polygon();
+        m_clipper.move_to(m_start_x = conv_type::upscale(x), 
+                          m_start_y = conv_type::upscale(y)); 
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::line_to_d(double x, double y) 
+    { 
+        m_clipper.line_to(m_outline, 
+                          conv_type::upscale(x), 
+                          conv_type::upscale(y)); 
+        m_status = status_line_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::add_vertex(double x, double y, unsigned cmd)
+    {
+        if(is_move_to(cmd)) 
+        {
+            move_to_d(x, y);
+        }
+        else 
+        if(is_vertex(cmd))
+        {
+            line_to_d(x, y);
+        }
+        else
+        if(is_close(cmd))
+        {
+            close_polygon();
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::edge(int x1, int y1, int x2, int y2)
+    {
+        if(m_outline.sorted()) reset();
+        m_clipper.move_to(conv_type::downscale(x1), conv_type::downscale(y1));
+        m_clipper.line_to(m_outline, 
+                          conv_type::downscale(x2), 
+                          conv_type::downscale(y2));
+        m_status = status_move_to;
+    }
+    
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::edge_d(double x1, double y1, 
+                                              double x2, double y2)
+    {
+        if(m_outline.sorted()) reset();
+        m_clipper.move_to(conv_type::upscale(x1), conv_type::upscale(y1)); 
+        m_clipper.line_to(m_outline, 
+                          conv_type::upscale(x2), 
+                          conv_type::upscale(y2)); 
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa<Clip>::sort()
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    AGG_INLINE bool rasterizer_scanline_aa<Clip>::rewind_scanlines()
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+        if(m_outline.total_cells() == 0) 
+        {
+            return false;
+        }
+        m_scan_y = m_outline.min_y();
+        return true;
+    }
+
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    AGG_INLINE bool rasterizer_scanline_aa<Clip>::navigate_scanline(int y)
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+        if(m_outline.total_cells() == 0 || 
+           y < m_outline.min_y() || 
+           y > m_outline.max_y()) 
+        {
+            return false;
+        }
+        m_scan_y = y;
+        return true;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    bool rasterizer_scanline_aa<Clip>::hit_test(int tx, int ty)
+    {
+        if(!navigate_scanline(ty)) return false;
+        scanline_hit_test sl(tx);
+        sweep_scanline(sl);
+        return sl.hit();
+    }
+
+
+
+}
+
+
+
+#endif
+

xs/src/agg/agg_rasterizer_scanline_aa_nogamma.h

@@ -0,0 +1,483 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+//
+// The author gratefully acknowleges the support of David Turner, 
+// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType 
+// libray - in producing this work. See http://www.freetype.org for details.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Adaptation for 32-bit screen coordinates has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+#ifndef AGG_RASTERIZER_SCANLINE_AA_NOGAMMA_INCLUDED
+#define AGG_RASTERIZER_SCANLINE_AA_NOGAMMA_INCLUDED
+
+#include <limits>
+#include "agg_rasterizer_cells_aa.h"
+#include "agg_rasterizer_sl_clip.h"
+
+
+namespace agg
+{
+
+
+    //-----------------------------------------------------------------cell_aa
+    // A pixel cell. There're no constructors defined and it was done 
+    // intentionally in order to avoid extra overhead when allocating an 
+    // array of cells.
+    struct cell_aa
+    {
+        int x;
+        int y;
+        int cover;
+        int area;
+
+        void initial()
+        {
+            x = std::numeric_limits<int>::max();
+            y = std::numeric_limits<int>::max();
+            cover = 0;
+            area  = 0;
+        }
+
+        void style(const cell_aa&) {}
+
+        int not_equal(int ex, int ey, const cell_aa&) const
+        {
+            return ((unsigned)ex - (unsigned)x) | ((unsigned)ey - (unsigned)y);
+        }
+    };
+
+
+    //==================================================rasterizer_scanline_aa_nogamma
+    // Polygon rasterizer that is used to render filled polygons with 
+    // high-quality Anti-Aliasing. Internally, by default, the class uses 
+    // integer coordinates in format 24.8, i.e. 24 bits for integer part 
+    // and 8 bits for fractional - see poly_subpixel_shift. This class can be 
+    // used in the following  way:
+    //
+    // 1. filling_rule(filling_rule_e ft) - optional.
+    //
+    // 2. gamma() - optional.
+    //
+    // 3. reset()
+    //
+    // 4. move_to(x, y) / line_to(x, y) - make the polygon. One can create 
+    //    more than one contour, but each contour must consist of at least 3
+    //    vertices, i.e. move_to(x1, y1); line_to(x2, y2); line_to(x3, y3);
+    //    is the absolute minimum of vertices that define a triangle.
+    //    The algorithm does not check either the number of vertices nor
+    //    coincidence of their coordinates, but in the worst case it just 
+    //    won't draw anything.
+    //    The orger of the vertices (clockwise or counterclockwise) 
+    //    is important when using the non-zero filling rule (fill_non_zero).
+    //    In this case the vertex order of all the contours must be the same
+    //    if you want your intersecting polygons to be without "holes".
+    //    You actually can use different vertices order. If the contours do not 
+    //    intersect each other the order is not important anyway. If they do, 
+    //    contours with the same vertex order will be rendered without "holes" 
+    //    while the intersecting contours with different orders will have "holes".
+    //
+    // filling_rule() and gamma() can be called anytime before "sweeping".
+    //------------------------------------------------------------------------
+    template<class Clip=rasterizer_sl_clip_int> class rasterizer_scanline_aa_nogamma
+    {
+        enum status
+        {
+            status_initial,
+            status_move_to,
+            status_line_to,
+            status_closed
+        };
+
+    public:
+        typedef Clip                      clip_type;
+        typedef typename Clip::conv_type  conv_type;
+        typedef typename Clip::coord_type coord_type;
+
+        enum aa_scale_e
+        {
+            aa_shift  = 8,
+            aa_scale  = 1 << aa_shift,
+            aa_mask   = aa_scale - 1,
+            aa_scale2 = aa_scale * 2,
+            aa_mask2  = aa_scale2 - 1
+        };
+
+        //--------------------------------------------------------------------
+        rasterizer_scanline_aa_nogamma() : 
+            m_outline(),
+            m_clipper(),
+            m_filling_rule(fill_non_zero),
+            m_auto_close(true),
+            m_start_x(0),
+            m_start_y(0),
+            m_status(status_initial)
+        {
+        }
+
+        //--------------------------------------------------------------------
+        void reset(); 
+        void reset_clipping();
+        void clip_box(double x1, double y1, double x2, double y2);
+        void filling_rule(filling_rule_e filling_rule);
+        void auto_close(bool flag) { m_auto_close = flag; }
+
+        //--------------------------------------------------------------------
+        unsigned apply_gamma(unsigned cover) const 
+        { 
+            return cover;
+        }
+
+        //--------------------------------------------------------------------
+        void move_to(int x, int y);
+        void line_to(int x, int y);
+        void move_to_d(double x, double y);
+        void line_to_d(double x, double y);
+        void close_polygon();
+        void add_vertex(double x, double y, unsigned cmd);
+
+        void edge(int x1, int y1, int x2, int y2);
+        void edge_d(double x1, double y1, double x2, double y2);
+
+        //-------------------------------------------------------------------
+        template<class VertexSource>
+        void add_path(VertexSource& vs, unsigned path_id=0)
+        {
+            double x;
+            double y;
+
+            unsigned cmd;
+            vs.rewind(path_id);
+            if(m_outline.sorted()) reset();
+            while(!is_stop(cmd = vs.vertex(&x, &y)))
+            {
+                add_vertex(x, y, cmd);
+            }
+        }
+        
+        //--------------------------------------------------------------------
+        int min_x() const { return m_outline.min_x(); }
+        int min_y() const { return m_outline.min_y(); }
+        int max_x() const { return m_outline.max_x(); }
+        int max_y() const { return m_outline.max_y(); }
+
+        //--------------------------------------------------------------------
+        void sort();
+        bool rewind_scanlines();
+        bool navigate_scanline(int y);
+
+        //--------------------------------------------------------------------
+        AGG_INLINE unsigned calculate_alpha(int area) const
+        {
+            int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
+
+            if(cover < 0) cover = -cover;
+            if(m_filling_rule == fill_even_odd)
+            {
+                cover &= aa_mask2;
+                if(cover > aa_scale)
+                {
+                    cover = aa_scale2 - cover;
+                }
+            }
+            if(cover > aa_mask) cover = aa_mask;
+            return cover;
+        }
+
+        //--------------------------------------------------------------------
+        template<class Scanline> bool sweep_scanline(Scanline& sl)
+        {
+            for(;;)
+            {
+                if(m_scan_y > m_outline.max_y()) return false;
+                sl.reset_spans();
+                unsigned num_cells = m_outline.scanline_num_cells(m_scan_y);
+                const cell_aa* const* cells = m_outline.scanline_cells(m_scan_y);
+                int cover = 0;
+
+                while(num_cells)
+                {
+                    const cell_aa* cur_cell = *cells;
+                    int x    = cur_cell->x;
+                    int area = cur_cell->area;
+                    unsigned alpha;
+
+                    cover += cur_cell->cover;
+
+                    //accumulate all cells with the same X
+                    while(--num_cells)
+                    {
+                        cur_cell = *++cells;
+                        if(cur_cell->x != x) break;
+                        area  += cur_cell->area;
+                        cover += cur_cell->cover;
+                    }
+
+                    if(area)
+                    {
+                        alpha = calculate_alpha((cover << (poly_subpixel_shift + 1)) - area);
+                        if(alpha)
+                        {
+                            sl.add_cell(x, alpha);
+                        }
+                        x++;
+                    }
+
+                    if(num_cells && cur_cell->x > x)
+                    {
+                        alpha = calculate_alpha(cover << (poly_subpixel_shift + 1));
+                        if(alpha)
+                        {
+                            sl.add_span(x, cur_cell->x - x, alpha);
+                        }
+                    }
+                }
+        
+                if(sl.num_spans()) break;
+                ++m_scan_y;
+            }
+
+            sl.finalize(m_scan_y);
+            ++m_scan_y;
+            return true;
+        }
+
+        //--------------------------------------------------------------------
+        bool hit_test(int tx, int ty);
+
+
+    private:
+        //--------------------------------------------------------------------
+        // Disable copying
+        rasterizer_scanline_aa_nogamma(const rasterizer_scanline_aa_nogamma<Clip>&);
+        const rasterizer_scanline_aa_nogamma<Clip>& 
+        operator = (const rasterizer_scanline_aa_nogamma<Clip>&);
+
+    private:
+        rasterizer_cells_aa<cell_aa> m_outline;
+        clip_type      m_clipper;
+        filling_rule_e m_filling_rule;
+        bool           m_auto_close;
+        coord_type     m_start_x;
+        coord_type     m_start_y;
+        unsigned       m_status;
+        int            m_scan_y;
+    };
+
+
+
+
+
+
+
+
+
+
+
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::reset() 
+    { 
+        m_outline.reset(); 
+        m_status = status_initial;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::filling_rule(filling_rule_e filling_rule) 
+    { 
+        m_filling_rule = filling_rule; 
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::clip_box(double x1, double y1, 
+                                                double x2, double y2)
+    {
+        reset();
+        m_clipper.clip_box(conv_type::upscale(x1), conv_type::upscale(y1), 
+                           conv_type::upscale(x2), conv_type::upscale(y2));
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::reset_clipping()
+    {
+        reset();
+        m_clipper.reset_clipping();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::close_polygon()
+    {
+        if(m_status == status_line_to)
+        {
+            m_clipper.line_to(m_outline, m_start_x, m_start_y);
+            m_status = status_closed;
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::move_to(int x, int y)
+    {
+        if(m_outline.sorted()) reset();
+        if(m_auto_close) close_polygon();
+        m_clipper.move_to(m_start_x = conv_type::downscale(x), 
+                          m_start_y = conv_type::downscale(y));
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::line_to(int x, int y)
+    {
+        m_clipper.line_to(m_outline, 
+                          conv_type::downscale(x), 
+                          conv_type::downscale(y));
+        m_status = status_line_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::move_to_d(double x, double y) 
+    { 
+        if(m_outline.sorted()) reset();
+        if(m_auto_close) close_polygon();
+        m_clipper.move_to(m_start_x = conv_type::upscale(x), 
+                          m_start_y = conv_type::upscale(y)); 
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::line_to_d(double x, double y) 
+    { 
+        m_clipper.line_to(m_outline, 
+                          conv_type::upscale(x), 
+                          conv_type::upscale(y)); 
+        m_status = status_line_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::add_vertex(double x, double y, unsigned cmd)
+    {
+        if(is_move_to(cmd)) 
+        {
+            move_to_d(x, y);
+        }
+        else 
+        if(is_vertex(cmd))
+        {
+            line_to_d(x, y);
+        }
+        else
+        if(is_close(cmd))
+        {
+            close_polygon();
+        }
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::edge(int x1, int y1, int x2, int y2)
+    {
+        if(m_outline.sorted()) reset();
+        m_clipper.move_to(conv_type::downscale(x1), conv_type::downscale(y1));
+        m_clipper.line_to(m_outline, 
+                          conv_type::downscale(x2), 
+                          conv_type::downscale(y2));
+        m_status = status_move_to;
+    }
+    
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::edge_d(double x1, double y1, 
+                                              double x2, double y2)
+    {
+        if(m_outline.sorted()) reset();
+        m_clipper.move_to(conv_type::upscale(x1), conv_type::upscale(y1)); 
+        m_clipper.line_to(m_outline, 
+                          conv_type::upscale(x2), 
+                          conv_type::upscale(y2)); 
+        m_status = status_move_to;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    void rasterizer_scanline_aa_nogamma<Clip>::sort()
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    AGG_INLINE bool rasterizer_scanline_aa_nogamma<Clip>::rewind_scanlines()
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+        if(m_outline.total_cells() == 0) 
+        {
+            return false;
+        }
+        m_scan_y = m_outline.min_y();
+        return true;
+    }
+
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    AGG_INLINE bool rasterizer_scanline_aa_nogamma<Clip>::navigate_scanline(int y)
+    {
+        if(m_auto_close) close_polygon();
+        m_outline.sort_cells();
+        if(m_outline.total_cells() == 0 || 
+           y < m_outline.min_y() || 
+           y > m_outline.max_y()) 
+        {
+            return false;
+        }
+        m_scan_y = y;
+        return true;
+    }
+
+    //------------------------------------------------------------------------
+    template<class Clip> 
+    bool rasterizer_scanline_aa_nogamma<Clip>::hit_test(int tx, int ty)
+    {
+        if(!navigate_scanline(ty)) return false;
+        scanline_hit_test sl(tx);
+        sweep_scanline(sl);
+        return sl.hit();
+    }
+
+
+
+}
+
+
+
+#endif
+

xs/src/agg/agg_rasterizer_sl_clip.h

@@ -0,0 +1,351 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+#ifndef AGG_RASTERIZER_SL_CLIP_INCLUDED
+#define AGG_RASTERIZER_SL_CLIP_INCLUDED
+
+#include "agg_clip_liang_barsky.h"
+
+namespace agg
+{
+    //--------------------------------------------------------poly_max_coord_e
+    enum poly_max_coord_e
+    {
+        poly_max_coord = (1 << 30) - 1 //----poly_max_coord
+    };
+    
+    //------------------------------------------------------------ras_conv_int
+    struct ras_conv_int
+    {
+        typedef int coord_type;
+        static AGG_INLINE int mul_div(double a, double b, double c)
+        {
+            return iround(a * b / c);
+        }
+        static int xi(int v) { return v; }
+        static int yi(int v) { return v; }
+        static int upscale(double v) { return iround(v * poly_subpixel_scale); }
+        static int downscale(int v)  { return v; }
+    };
+
+    //--------------------------------------------------------ras_conv_int_sat
+    struct ras_conv_int_sat
+    {
+        typedef int coord_type;
+        static AGG_INLINE int mul_div(double a, double b, double c)
+        {
+            return saturation<poly_max_coord>::iround(a * b / c);
+        }
+        static int xi(int v) { return v; }
+        static int yi(int v) { return v; }
+        static int upscale(double v) 
+        { 
+            return saturation<poly_max_coord>::iround(v * poly_subpixel_scale); 
+        }
+        static int downscale(int v) { return v; }
+    };
+
+    //---------------------------------------------------------ras_conv_int_3x
+    struct ras_conv_int_3x
+    {
+        typedef int coord_type;
+        static AGG_INLINE int mul_div(double a, double b, double c)
+        {
+            return iround(a * b / c);
+        }
+        static int xi(int v) { return v * 3; }
+        static int yi(int v) { return v; }
+        static int upscale(double v) { return iround(v * poly_subpixel_scale); }
+        static int downscale(int v)  { return v; }
+    };
+
+    //-----------------------------------------------------------ras_conv_dbl
+    struct ras_conv_dbl
+    {
+        typedef double coord_type;
+        static AGG_INLINE double mul_div(double a, double b, double c)
+        {
+            return a * b / c;
+        }
+        static int xi(double v) { return iround(v * poly_subpixel_scale); }
+        static int yi(double v) { return iround(v * poly_subpixel_scale); }
+        static double upscale(double v) { return v; }
+        static double downscale(int v)  { return v / double(poly_subpixel_scale); }
+    };
+
+    //--------------------------------------------------------ras_conv_dbl_3x
+    struct ras_conv_dbl_3x
+    {
+        typedef double coord_type;
+        static AGG_INLINE double mul_div(double a, double b, double c)
+        {
+            return a * b / c;
+        }
+        static int xi(double v) { return iround(v * poly_subpixel_scale * 3); }
+        static int yi(double v) { return iround(v * poly_subpixel_scale); }
+        static double upscale(double v) { return v; }
+        static double downscale(int v)  { return v / double(poly_subpixel_scale); }
+    };
+
+
+
+
+
+    //------------------------------------------------------rasterizer_sl_clip
+    template<class Conv> class rasterizer_sl_clip
+    {
+    public:
+        typedef Conv                      conv_type;
+        typedef typename Conv::coord_type coord_type;
+        typedef rect_base<coord_type>     rect_type;
+
+        //--------------------------------------------------------------------
+        rasterizer_sl_clip() :  
+            m_clip_box(0,0,0,0),
+            m_x1(0),
+            m_y1(0),
+            m_f1(0),
+            m_clipping(false) 
+        {}
+
+        //--------------------------------------------------------------------
+        void reset_clipping()
+        {
+            m_clipping = false;
+        }
+
+        //--------------------------------------------------------------------
+        void clip_box(coord_type x1, coord_type y1, coord_type x2, coord_type y2)
+        {
+            m_clip_box = rect_type(x1, y1, x2, y2);
+            m_clip_box.normalize();
+            m_clipping = true;
+        }
+
+        //--------------------------------------------------------------------
+        void move_to(coord_type x1, coord_type y1)
+        {
+            m_x1 = x1;
+            m_y1 = y1;
+            if(m_clipping) m_f1 = clipping_flags(x1, y1, m_clip_box);
+        }
+
+    private:
+        //------------------------------------------------------------------------
+        template<class Rasterizer>
+        AGG_INLINE void line_clip_y(Rasterizer& ras,
+                                    coord_type x1, coord_type y1, 
+                                    coord_type x2, coord_type y2, 
+                                    unsigned   f1, unsigned   f2) const
+        {
+            f1 &= 10;
+            f2 &= 10;
+            if((f1 | f2) == 0)
+            {
+                // Fully visible
+                ras.line(Conv::xi(x1), Conv::yi(y1), Conv::xi(x2), Conv::yi(y2)); 
+            }
+            else
+            {
+                if(f1 == f2)
+                {
+                    // Invisible by Y
+                    return;
+                }
+
+                coord_type tx1 = x1;
+                coord_type ty1 = y1;
+                coord_type tx2 = x2;
+                coord_type ty2 = y2;
+
+                if(f1 & 8) // y1 < clip.y1
+                {
+                    tx1 = x1 + Conv::mul_div(m_clip_box.y1-y1, x2-x1, y2-y1);
+                    ty1 = m_clip_box.y1;
+                }
+
+                if(f1 & 2) // y1 > clip.y2
+                {
+                    tx1 = x1 + Conv::mul_div(m_clip_box.y2-y1, x2-x1, y2-y1);
+                    ty1 = m_clip_box.y2;
+                }
+
+                if(f2 & 8) // y2 < clip.y1
+                {
+                    tx2 = x1 + Conv::mul_div(m_clip_box.y1-y1, x2-x1, y2-y1);
+                    ty2 = m_clip_box.y1;
+                }
+
+                if(f2 & 2) // y2 > clip.y2
+                {
+                    tx2 = x1 + Conv::mul_div(m_clip_box.y2-y1, x2-x1, y2-y1);
+                    ty2 = m_clip_box.y2;
+                }
+                ras.line(Conv::xi(tx1), Conv::yi(ty1), 
+                         Conv::xi(tx2), Conv::yi(ty2)); 
+            }
+        }
+
+
+    public:
+        //--------------------------------------------------------------------
+        template<class Rasterizer>
+        void line_to(Rasterizer& ras, coord_type x2, coord_type y2)
+        {
+            if(m_clipping)
+            {
+                unsigned f2 = clipping_flags(x2, y2, m_clip_box);
+
+                if((m_f1 & 10) == (f2 & 10) && (m_f1 & 10) != 0)
+                {
+                    // Invisible by Y
+                    m_x1 = x2;
+                    m_y1 = y2;
+                    m_f1 = f2;
+                    return;
+                }
+
+                coord_type x1 = m_x1;
+                coord_type y1 = m_y1;
+                unsigned   f1 = m_f1;
+                coord_type y3, y4;
+                unsigned   f3, f4;
+
+                switch(((f1 & 5) << 1) | (f2 & 5))
+                {
+                case 0: // Visible by X
+                    line_clip_y(ras, x1, y1, x2, y2, f1, f2);
+                    break;
+
+                case 1: // x2 > clip.x2
+                    y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    line_clip_y(ras, x1, y1, m_clip_box.x2, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x2, y3, m_clip_box.x2, y2, f3, f2);
+                    break;
+
+                case 2: // x1 > clip.x2
+                    y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x2, y3, x2, y2, f3, f2);
+                    break;
+
+                case 3: // x1 > clip.x2 && x2 > clip.x2
+                    line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y2, f1, f2);
+                    break;
+
+                case 4: // x2 < clip.x1
+                    y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    line_clip_y(ras, x1, y1, m_clip_box.x1, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x1, y3, m_clip_box.x1, y2, f3, f2);
+                    break;
+
+                case 6: // x1 > clip.x2 && x2 < clip.x1
+                    y3 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
+                    y4 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    f4 = clipping_flags_y(y4, m_clip_box);
+                    line_clip_y(ras, m_clip_box.x2, y1, m_clip_box.x2, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x2, y3, m_clip_box.x1, y4, f3, f4);
+                    line_clip_y(ras, m_clip_box.x1, y4, m_clip_box.x1, y2, f4, f2);
+                    break;
+
+                case 8: // x1 < clip.x1
+                    y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x1, y3, x2, y2, f3, f2);
+                    break;
+
+                case 9:  // x1 < clip.x1 && x2 > clip.x2
+                    y3 = y1 + Conv::mul_div(m_clip_box.x1-x1, y2-y1, x2-x1);
+                    y4 = y1 + Conv::mul_div(m_clip_box.x2-x1, y2-y1, x2-x1);
+                    f3 = clipping_flags_y(y3, m_clip_box);
+                    f4 = clipping_flags_y(y4, m_clip_box);
+                    line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y3, f1, f3);
+                    line_clip_y(ras, m_clip_box.x1, y3, m_clip_box.x2, y4, f3, f4);
+                    line_clip_y(ras, m_clip_box.x2, y4, m_clip_box.x2, y2, f4, f2);
+                    break;
+
+                case 12: // x1 < clip.x1 && x2 < clip.x1
+                    line_clip_y(ras, m_clip_box.x1, y1, m_clip_box.x1, y2, f1, f2);
+                    break;
+                }
+                m_f1 = f2;
+            }
+            else
+            {
+                ras.line(Conv::xi(m_x1), Conv::yi(m_y1), 
+                         Conv::xi(x2),   Conv::yi(y2)); 
+            }
+            m_x1 = x2;
+            m_y1 = y2;
+        }
+
+
+    private:
+        rect_type        m_clip_box;
+        coord_type       m_x1;
+        coord_type       m_y1;
+        unsigned         m_f1;
+        bool             m_clipping;
+    };
+
+
+
+
+    //---------------------------------------------------rasterizer_sl_no_clip
+    class rasterizer_sl_no_clip
+    {
+    public:
+        typedef ras_conv_int conv_type;
+        typedef int          coord_type;
+
+        rasterizer_sl_no_clip() : m_x1(0), m_y1(0) {}
+
+        void reset_clipping() {}
+        void clip_box(coord_type, coord_type, coord_type, coord_type) {}
+        void move_to(coord_type x1, coord_type y1) { m_x1 = x1; m_y1 = y1; }
+
+        template<class Rasterizer>
+        void line_to(Rasterizer& ras, coord_type x2, coord_type y2) 
+        { 
+            ras.line(m_x1, m_y1, x2, y2); 
+            m_x1 = x2; 
+            m_y1 = y2;
+        }
+
+    private:
+        int m_x1, m_y1;
+    };
+
+
+    //                                         -----rasterizer_sl_clip_int
+    //                                         -----rasterizer_sl_clip_int_sat
+    //                                         -----rasterizer_sl_clip_int_3x
+    //                                         -----rasterizer_sl_clip_dbl
+    //                                         -----rasterizer_sl_clip_dbl_3x
+    //------------------------------------------------------------------------
+    typedef rasterizer_sl_clip<ras_conv_int>     rasterizer_sl_clip_int;
+    typedef rasterizer_sl_clip<ras_conv_int_sat> rasterizer_sl_clip_int_sat;
+    typedef rasterizer_sl_clip<ras_conv_int_3x>  rasterizer_sl_clip_int_3x;
+    typedef rasterizer_sl_clip<ras_conv_dbl>     rasterizer_sl_clip_dbl;
+    typedef rasterizer_sl_clip<ras_conv_dbl_3x>  rasterizer_sl_clip_dbl_3x;
+
+
+}
+
+#endif

xs/src/agg/agg_renderer_base.h

@@ -0,0 +1,731 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// class renderer_base
+//
+//----------------------------------------------------------------------------
+
+#ifndef AGG_RENDERER_BASE_INCLUDED
+#define AGG_RENDERER_BASE_INCLUDED
+
+#include "agg_basics.h"
+#include "agg_rendering_buffer.h"
+
+namespace agg
+{
+
+    //-----------------------------------------------------------renderer_base
+    template<class PixelFormat> class renderer_base
+    {
+    public:
+        typedef PixelFormat pixfmt_type;
+        typedef typename pixfmt_type::color_type color_type;
+        typedef typename pixfmt_type::row_data row_data;
+
+        //--------------------------------------------------------------------
+        renderer_base() : m_ren(0), m_clip_box(1, 1, 0, 0) {}
+        explicit renderer_base(pixfmt_type& ren) :
+            m_ren(&ren),
+            m_clip_box(0, 0, ren.width() - 1, ren.height() - 1)
+        {}
+        void attach(pixfmt_type& ren)
+        {
+            m_ren = &ren;
+            m_clip_box = rect_i(0, 0, ren.width() - 1, ren.height() - 1);
+        }
+
+        //--------------------------------------------------------------------
+        const pixfmt_type& ren() const { return *m_ren;  }
+        pixfmt_type& ren() { return *m_ren;  }
+          
+        //--------------------------------------------------------------------
+        unsigned width()  const { return m_ren->width();  }
+        unsigned height() const { return m_ren->height(); }
+
+        //--------------------------------------------------------------------
+        bool clip_box(int x1, int y1, int x2, int y2)
+        {
+            rect_i cb(x1, y1, x2, y2);
+            cb.normalize();
+            if(cb.clip(rect_i(0, 0, width() - 1, height() - 1)))
+            {
+                m_clip_box = cb;
+                return true;
+            }
+            m_clip_box.x1 = 1;
+            m_clip_box.y1 = 1;
+            m_clip_box.x2 = 0;
+            m_clip_box.y2 = 0;
+            return false;
+        }
+
+        //--------------------------------------------------------------------
+        void reset_clipping(bool visibility)
+        {
+            if(visibility)
+            {
+                m_clip_box.x1 = 0;
+                m_clip_box.y1 = 0;
+                m_clip_box.x2 = width() - 1;
+                m_clip_box.y2 = height() - 1;
+            }
+            else
+            {
+                m_clip_box.x1 = 1;
+                m_clip_box.y1 = 1;
+                m_clip_box.x2 = 0;
+                m_clip_box.y2 = 0;
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void clip_box_naked(int x1, int y1, int x2, int y2)
+        {
+            m_clip_box.x1 = x1;
+            m_clip_box.y1 = y1;
+            m_clip_box.x2 = x2;
+            m_clip_box.y2 = y2;
+        }
+
+        //--------------------------------------------------------------------
+        bool inbox(int x, int y) const
+        {
+            return x >= m_clip_box.x1 && y >= m_clip_box.y1 &&
+                   x <= m_clip_box.x2 && y <= m_clip_box.y2;
+        }
+
+        //--------------------------------------------------------------------
+        const rect_i& clip_box() const { return m_clip_box;    }
+        int           xmin()     const { return m_clip_box.x1; }
+        int           ymin()     const { return m_clip_box.y1; }
+        int           xmax()     const { return m_clip_box.x2; }
+        int           ymax()     const { return m_clip_box.y2; }
+
+        //--------------------------------------------------------------------
+        const rect_i& bounding_clip_box() const { return m_clip_box;    }
+        int           bounding_xmin()     const { return m_clip_box.x1; }
+        int           bounding_ymin()     const { return m_clip_box.y1; }
+        int           bounding_xmax()     const { return m_clip_box.x2; }
+        int           bounding_ymax()     const { return m_clip_box.y2; }
+
+        //--------------------------------------------------------------------
+        void clear(const color_type& c)
+        {
+            unsigned y;
+            if(width())
+            {
+                for(y = 0; y < height(); y++)
+                {
+                    m_ren->copy_hline(0, y, width(), c);
+                }
+            }
+        }
+          
+
+        //--------------------------------------------------------------------
+        void fill(const color_type& c)
+        {
+            unsigned y;
+            if(width())
+            {
+                for(y = 0; y < height(); y++)
+                {
+                    m_ren->blend_hline(0, y, width(), c, cover_mask);
+                }
+            }
+        }
+        
+        //--------------------------------------------------------------------
+        void copy_pixel(int x, int y, const color_type& c)
+        {
+            if(inbox(x, y))
+            {
+                m_ren->copy_pixel(x, y, c);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void blend_pixel(int x, int y, const color_type& c, cover_type cover)
+        {
+            if(inbox(x, y))
+            {
+                m_ren->blend_pixel(x, y, c, cover);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        color_type pixel(int x, int y) const
+        {
+            return inbox(x, y) ? 
+                   m_ren->pixel(x, y) :
+                   color_type::no_color();
+        }
+
+        //--------------------------------------------------------------------
+        void copy_hline(int x1, int y, int x2, const color_type& c)
+        {
+            if(x1 > x2) { int t = x2; x2 = x1; x1 = t; }
+            if(y  > ymax()) return;
+            if(y  < ymin()) return;
+            if(x1 > xmax()) return;
+            if(x2 < xmin()) return;
+
+            if(x1 < xmin()) x1 = xmin();
+            if(x2 > xmax()) x2 = xmax();
+
+            m_ren->copy_hline(x1, y, x2 - x1 + 1, c);
+        }
+
+        //--------------------------------------------------------------------
+        void copy_vline(int x, int y1, int y2, const color_type& c)
+        {
+            if(y1 > y2) { int t = y2; y2 = y1; y1 = t; }
+            if(x  > xmax()) return;
+            if(x  < xmin()) return;
+            if(y1 > ymax()) return;
+            if(y2 < ymin()) return;
+
+            if(y1 < ymin()) y1 = ymin();
+            if(y2 > ymax()) y2 = ymax();
+
+            m_ren->copy_vline(x, y1, y2 - y1 + 1, c);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_hline(int x1, int y, int x2, 
+                         const color_type& c, cover_type cover)
+        {
+            if(x1 > x2) { int t = x2; x2 = x1; x1 = t; }
+            if(y  > ymax()) return;
+            if(y  < ymin()) return;
+            if(x1 > xmax()) return;
+            if(x2 < xmin()) return;
+
+            if(x1 < xmin()) x1 = xmin();
+            if(x2 > xmax()) x2 = xmax();
+
+            m_ren->blend_hline(x1, y, x2 - x1 + 1, c, cover);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_vline(int x, int y1, int y2, 
+                         const color_type& c, cover_type cover)
+        {
+            if(y1 > y2) { int t = y2; y2 = y1; y1 = t; }
+            if(x  > xmax()) return;
+            if(x  < xmin()) return;
+            if(y1 > ymax()) return;
+            if(y2 < ymin()) return;
+
+            if(y1 < ymin()) y1 = ymin();
+            if(y2 > ymax()) y2 = ymax();
+
+            m_ren->blend_vline(x, y1, y2 - y1 + 1, c, cover);
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_bar(int x1, int y1, int x2, int y2, const color_type& c)
+        {
+            rect_i rc(x1, y1, x2, y2);
+            rc.normalize();
+            if(rc.clip(clip_box()))
+            {
+                int y;
+                for(y = rc.y1; y <= rc.y2; y++)
+                {
+                    m_ren->copy_hline(rc.x1, y, unsigned(rc.x2 - rc.x1 + 1), c);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void blend_bar(int x1, int y1, int x2, int y2, 
+                       const color_type& c, cover_type cover)
+        {
+            rect_i rc(x1, y1, x2, y2);
+            rc.normalize();
+            if(rc.clip(clip_box()))
+            {
+                int y;
+                for(y = rc.y1; y <= rc.y2; y++)
+                {
+                    m_ren->blend_hline(rc.x1,
+                                       y,
+                                       unsigned(rc.x2 - rc.x1 + 1), 
+                                       c, 
+                                       cover);
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void blend_solid_hspan(int x, int y, int len, 
+                               const color_type& c, 
+                               const cover_type* covers)
+        {
+            if(y > ymax()) return;
+            if(y < ymin()) return;
+
+            if(x < xmin())
+            {
+                len -= xmin() - x;
+                if(len <= 0) return;
+                covers += xmin() - x;
+                x = xmin();
+            }
+            if(x + len > xmax())
+            {
+                len = xmax() - x + 1;
+                if(len <= 0) return;
+            }
+            m_ren->blend_solid_hspan(x, y, len, c, covers);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_solid_vspan(int x, int y, int len, 
+                               const color_type& c, 
+                               const cover_type* covers)
+        {
+            if(x > xmax()) return;
+            if(x < xmin()) return;
+
+            if(y < ymin())
+            {
+                len -= ymin() - y;
+                if(len <= 0) return;
+                covers += ymin() - y;
+                y = ymin();
+            }
+            if(y + len > ymax())
+            {
+                len = ymax() - y + 1;
+                if(len <= 0) return;
+            }
+            m_ren->blend_solid_vspan(x, y, len, c, covers);
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_color_hspan(int x, int y, int len, const color_type* colors)
+        {
+            if(y > ymax()) return;
+            if(y < ymin()) return;
+
+            if(x < xmin())
+            {
+                int d = xmin() - x;
+                len -= d;
+                if(len <= 0) return;
+                colors += d;
+                x = xmin();
+            }
+            if(x + len > xmax())
+            {
+                len = xmax() - x + 1;
+                if(len <= 0) return;
+            }
+            m_ren->copy_color_hspan(x, y, len, colors);
+        }
+
+
+        //--------------------------------------------------------------------
+        void copy_color_vspan(int x, int y, int len, const color_type* colors)
+        {
+            if(x > xmax()) return;
+            if(x < xmin()) return;
+
+            if(y < ymin())
+            {
+                int d = ymin() - y;
+                len -= d;
+                if(len <= 0) return;
+                colors += d;
+                y = ymin();
+            }
+            if(y + len > ymax())
+            {
+                len = ymax() - y + 1;
+                if(len <= 0) return;
+            }
+            m_ren->copy_color_vspan(x, y, len, colors);
+        }
+
+
+        //--------------------------------------------------------------------
+        void blend_color_hspan(int x, int y, int len, 
+                               const color_type* colors, 
+                               const cover_type* covers,
+                               cover_type cover = agg::cover_full)
+        {
+            if(y > ymax()) return;
+            if(y < ymin()) return;
+
+            if(x < xmin())
+            {
+                int d = xmin() - x;
+                len -= d;
+                if(len <= 0) return;
+                if(covers) covers += d;
+                colors += d;
+                x = xmin();
+            }
+            if(x + len > xmax())
+            {
+                len = xmax() - x + 1;
+                if(len <= 0) return;
+            }
+            m_ren->blend_color_hspan(x, y, len, colors, covers, cover);
+        }
+
+        //--------------------------------------------------------------------
+        void blend_color_vspan(int x, int y, int len, 
+                               const color_type* colors, 
+                               const cover_type* covers,
+                               cover_type cover = agg::cover_full)
+        {
+            if(x > xmax()) return;
+            if(x < xmin()) return;
+
+            if(y < ymin())
+            {
+                int d = ymin() - y;
+                len -= d;
+                if(len <= 0) return;
+                if(covers) covers += d;
+                colors += d;
+                y = ymin();
+            }
+            if(y + len > ymax())
+            {
+                len = ymax() - y + 1;
+                if(len <= 0) return;
+            }
+            m_ren->blend_color_vspan(x, y, len, colors, covers, cover);
+        }
+
+        //--------------------------------------------------------------------
+        rect_i clip_rect_area(rect_i& dst, rect_i& src, int wsrc, int hsrc) const
+        {
+            rect_i rc(0,0,0,0);
+            rect_i cb = clip_box();
+            ++cb.x2;
+            ++cb.y2;
+
+            if(src.x1 < 0)
+            {
+                dst.x1 -= src.x1;
+                src.x1 = 0;
+            }
+            if(src.y1 < 0)
+            {
+                dst.y1 -= src.y1;
+                src.y1 = 0;
+            }
+
+            if(src.x2 > wsrc) src.x2 = wsrc;
+            if(src.y2 > hsrc) src.y2 = hsrc;
+
+            if(dst.x1 < cb.x1)
+            {
+                src.x1 += cb.x1 - dst.x1;
+                dst.x1 = cb.x1;
+            }
+            if(dst.y1 < cb.y1)
+            {
+                src.y1 += cb.y1 - dst.y1;
+                dst.y1 = cb.y1;
+            }
+
+            if(dst.x2 > cb.x2) dst.x2 = cb.x2;
+            if(dst.y2 > cb.y2) dst.y2 = cb.y2;
+
+            rc.x2 = dst.x2 - dst.x1;
+            rc.y2 = dst.y2 - dst.y1;
+
+            if(rc.x2 > src.x2 - src.x1) rc.x2 = src.x2 - src.x1;
+            if(rc.y2 > src.y2 - src.y1) rc.y2 = src.y2 - src.y1;
+            return rc;
+        }
+
+        //--------------------------------------------------------------------
+        template<class RenBuf>
+        void copy_from(const RenBuf& src, 
+                       const rect_i* rect_src_ptr = 0, 
+                       int dx = 0, 
+                       int dy = 0)
+        {
+            rect_i rsrc(0, 0, src.width(), src.height());
+            if(rect_src_ptr)
+            {
+                rsrc.x1 = rect_src_ptr->x1; 
+                rsrc.y1 = rect_src_ptr->y1;
+                rsrc.x2 = rect_src_ptr->x2 + 1;
+                rsrc.y2 = rect_src_ptr->y2 + 1;
+            }
+
+            // Version with xdst, ydst (absolute positioning)
+            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);
+
+            // Version with dx, dy (relative positioning)
+            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
+
+            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());
+
+            if(rc.x2 > 0)
+            {
+                int incy = 1;
+                if(rdst.y1 > rsrc.y1)
+                {
+                    rsrc.y1 += rc.y2 - 1;
+                    rdst.y1 += rc.y2 - 1;
+                    incy = -1;
+                }
+                while(rc.y2 > 0)
+                {
+                    m_ren->copy_from(src, 
+                                     rdst.x1, rdst.y1,
+                                     rsrc.x1, rsrc.y1,
+                                     rc.x2);
+                    rdst.y1 += incy;
+                    rsrc.y1 += incy;
+                    --rc.y2;
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class SrcPixelFormatRenderer>
+        void blend_from(const SrcPixelFormatRenderer& src, 
+                        const rect_i* rect_src_ptr = 0, 
+                        int dx = 0, 
+                        int dy = 0,
+                        cover_type cover = agg::cover_full)
+        {
+            rect_i rsrc(0, 0, src.width(), src.height());
+            if(rect_src_ptr)
+            {
+                rsrc.x1 = rect_src_ptr->x1; 
+                rsrc.y1 = rect_src_ptr->y1;
+                rsrc.x2 = rect_src_ptr->x2 + 1;
+                rsrc.y2 = rect_src_ptr->y2 + 1;
+            }
+
+            // Version with xdst, ydst (absolute positioning)
+            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);
+
+            // Version with dx, dy (relative positioning)
+            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
+            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());
+
+            if(rc.x2 > 0)
+            {
+                int incy = 1;
+                if(rdst.y1 > rsrc.y1)
+                {
+                    rsrc.y1 += rc.y2 - 1;
+                    rdst.y1 += rc.y2 - 1;
+                    incy = -1;
+                }
+                while(rc.y2 > 0)
+                {
+                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
+                    if(rw.ptr)
+                    {
+                        int x1src = rsrc.x1;
+                        int x1dst = rdst.x1;
+                        int len   = rc.x2;
+                        if(rw.x1 > x1src)
+                        {
+                            x1dst += rw.x1 - x1src;
+                            len   -= rw.x1 - x1src;
+                            x1src  = rw.x1;
+                        }
+                        if(len > 0)
+                        {
+                            if(x1src + len-1 > rw.x2)
+                            {
+                                len -= x1src + len - rw.x2 - 1;
+                            }
+                            if(len > 0)
+                            {
+                                m_ren->blend_from(src,
+                                                  x1dst, rdst.y1,
+                                                  x1src, rsrc.y1,
+                                                  len,
+                                                  cover);
+                            }
+                        }
+                    }
+                    rdst.y1 += incy;
+                    rsrc.y1 += incy;
+                    --rc.y2;
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class SrcPixelFormatRenderer>
+        void blend_from_color(const SrcPixelFormatRenderer& src, 
+                              const color_type& color,
+                              const rect_i* rect_src_ptr = 0, 
+                              int dx = 0, 
+                              int dy = 0,
+                              cover_type cover = agg::cover_full)
+        {
+            rect_i rsrc(0, 0, src.width(), src.height());
+            if(rect_src_ptr)
+            {
+                rsrc.x1 = rect_src_ptr->x1; 
+                rsrc.y1 = rect_src_ptr->y1;
+                rsrc.x2 = rect_src_ptr->x2 + 1;
+                rsrc.y2 = rect_src_ptr->y2 + 1;
+            }
+
+            // Version with xdst, ydst (absolute positioning)
+            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);
+
+            // Version with dx, dy (relative positioning)
+            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
+            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());
+
+            if(rc.x2 > 0)
+            {
+                int incy = 1;
+                if(rdst.y1 > rsrc.y1)
+                {
+                    rsrc.y1 += rc.y2 - 1;
+                    rdst.y1 += rc.y2 - 1;
+                    incy = -1;
+                }
+                while(rc.y2 > 0)
+                {
+                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
+                    if(rw.ptr)
+                    {
+                        int x1src = rsrc.x1;
+                        int x1dst = rdst.x1;
+                        int len   = rc.x2;
+                        if(rw.x1 > x1src)
+                        {
+                            x1dst += rw.x1 - x1src;
+                            len   -= rw.x1 - x1src;
+                            x1src  = rw.x1;
+                        }
+                        if(len > 0)
+                        {
+                            if(x1src + len-1 > rw.x2)
+                            {
+                                len -= x1src + len - rw.x2 - 1;
+                            }
+                            if(len > 0)
+                            {
+                                m_ren->blend_from_color(src,
+                                                        color,
+                                                        x1dst, rdst.y1,
+                                                        x1src, rsrc.y1,
+                                                        len,
+                                                        cover);
+                            }
+                        }
+                    }
+                    rdst.y1 += incy;
+                    rsrc.y1 += incy;
+                    --rc.y2;
+                }
+            }
+        }
+
+        //--------------------------------------------------------------------
+        template<class SrcPixelFormatRenderer>
+        void blend_from_lut(const SrcPixelFormatRenderer& src, 
+                            const color_type* color_lut,
+                            const rect_i* rect_src_ptr = 0, 
+                            int dx = 0, 
+                            int dy = 0,
+                            cover_type cover = agg::cover_full)
+        {
+            rect_i rsrc(0, 0, src.width(), src.height());
+            if(rect_src_ptr)
+            {
+                rsrc.x1 = rect_src_ptr->x1; 
+                rsrc.y1 = rect_src_ptr->y1;
+                rsrc.x2 = rect_src_ptr->x2 + 1;
+                rsrc.y2 = rect_src_ptr->y2 + 1;
+            }
+
+            // Version with xdst, ydst (absolute positioning)
+            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);
+
+            // Version with dx, dy (relative positioning)
+            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
+            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());
+
+            if(rc.x2 > 0)
+            {
+                int incy = 1;
+                if(rdst.y1 > rsrc.y1)
+                {
+                    rsrc.y1 += rc.y2 - 1;
+                    rdst.y1 += rc.y2 - 1;
+                    incy = -1;
+                }
+                while(rc.y2 > 0)
+                {
+                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
+                    if(rw.ptr)
+                    {
+                        int x1src = rsrc.x1;
+                        int x1dst = rdst.x1;
+                        int len   = rc.x2;
+                        if(rw.x1 > x1src)
+                        {
+                            x1dst += rw.x1 - x1src;
+                            len   -= rw.x1 - x1src;
+                            x1src  = rw.x1;
+                        }
+                        if(len > 0)
+                        {
+                            if(x1src + len-1 > rw.x2)
+                            {
+                                len -= x1src + len - rw.x2 - 1;
+                            }
+                            if(len > 0)
+                            {
+                                m_ren->blend_from_lut(src,
+                                                      color_lut,
+                                                      x1dst, rdst.y1,
+                                                      x1src, rsrc.y1,
+                                                      len,
+                                                      cover);
+                            }
+                        }
+                    }
+                    rdst.y1 += incy;
+                    rsrc.y1 += incy;
+                    --rc.y2;
+                }
+            }
+        }
+
+    private:
+        pixfmt_type* m_ren;
+        rect_i       m_clip_box;
+    };
+
+
+}
+
+#endif

xs/src/agg/agg_renderer_scanline.h

@@ -0,0 +1,854 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+
+#ifndef AGG_RENDERER_SCANLINE_INCLUDED
+#define AGG_RENDERER_SCANLINE_INCLUDED
+
+#include <limits>
+#include <cstdlib>
+#include "agg_basics.h"
+#include "agg_renderer_base.h"
+
+namespace agg
+{
+
+    //================================================render_scanline_aa_solid
+    template<class Scanline, class BaseRenderer, class ColorT> 
+    void render_scanline_aa_solid(const Scanline& sl, 
+                                  BaseRenderer& ren, 
+                                  const ColorT& color)
+    {
+        int y = sl.y();
+        unsigned num_spans = sl.num_spans();
+        typename Scanline::const_iterator span = sl.begin();
+
+        for(;;)
+        {
+            int x = span->x;
+            if(span->len > 0)
+            {
+                ren.blend_solid_hspan(x, y, (unsigned)span->len, 
+                                      color, 
+                                      span->covers);
+            }
+            else
+            {
+                ren.blend_hline(x, y, (unsigned)(x - span->len - 1), 
+                                color, 
+                                *(span->covers));
+            }
+            if(--num_spans == 0) break;
+            ++span;
+        }
+    }
+
+    //===============================================render_scanlines_aa_solid
+    template<class Rasterizer, class Scanline, 
+             class BaseRenderer, class ColorT>
+    void render_scanlines_aa_solid(Rasterizer& ras, Scanline& sl, 
+                                   BaseRenderer& ren, const ColorT& color)
+    {
+        if(ras.rewind_scanlines())
+        {
+            // Explicitly convert "color" to the BaseRenderer color type.
+            // For example, it can be called with color type "rgba", while
+            // "rgba8" is needed. Otherwise it will be implicitly 
+            // converted in the loop many times.
+            //----------------------
+            typename BaseRenderer::color_type ren_color = color;
+
+            sl.reset(ras.min_x(), ras.max_x());
+            while(ras.sweep_scanline(sl))
+            {
+                //render_scanline_aa_solid(sl, ren, ren_color);
+
+                // This code is equivalent to the above call (copy/paste). 
+                // It's just a "manual" optimization for old compilers,
+                // like Microsoft Visual C++ v6.0
+                //-------------------------------
+                int y = sl.y();
+                unsigned num_spans = sl.num_spans();
+                typename Scanline::const_iterator span = sl.begin();
+
+                for(;;)
+                {
+                    int x = span->x;
+                    if(span->len > 0)
+                    {
+                        ren.blend_solid_hspan(x, y, (unsigned)span->len, 
+                                              ren_color, 
+                                              span->covers);
+                    }
+                    else
+                    {
+                        ren.blend_hline(x, y, (unsigned)(x - span->len - 1), 
+                                        ren_color, 
+                                        *(span->covers));
+                    }
+                    if(--num_spans == 0) break;
+                    ++span;
+                }
+            }
+        }
+    }
+
+    //==============================================renderer_scanline_aa_solid
+    template<class BaseRenderer> class renderer_scanline_aa_solid
+    {
+    public:
+        typedef BaseRenderer base_ren_type;
+        typedef typename base_ren_type::color_type color_type;
+
+        //--------------------------------------------------------------------
+        renderer_scanline_aa_solid() : m_ren(0) {}
+        explicit renderer_scanline_aa_solid(base_ren_type& ren) : m_ren(&ren) {}
+        void attach(base_ren_type& ren)
+        {
+            m_ren = &ren;
+        }
+        
+        //--------------------------------------------------------------------
+        void color(const color_type& c) { m_color = c; }
+        const color_type& color() const { return m_color; }
+
+        //--------------------------------------------------------------------
+        void prepare() {}
+
+        //--------------------------------------------------------------------
+        template<class Scanline> void render(const Scanline& sl)
+        {
+            render_scanline_aa_solid(sl, *m_ren, m_color);
+        }
+        
+    private:
+        base_ren_type* m_ren;
+        color_type m_color;
+    };
+
+
+
+
+
+
+
+
+
+
+
+
+
+    //======================================================render_scanline_aa
+    template<class Scanline, class BaseRenderer, 
+             class SpanAllocator, class SpanGenerator> 
+    void render_scanline_aa(const Scanline& sl, BaseRenderer& ren, 
+                            SpanAllocator& alloc, SpanGenerator& span_gen)
+    {
+        int y = sl.y();
+
+        unsigned num_spans = sl.num_spans();
+        typename Scanline::const_iterator span = sl.begin();
+        for(;;)
+        {
+            int x = span->x;
+            int len = span->len;
+            const typename Scanline::cover_type* covers = span->covers;
+
+            if(len < 0) len = -len;
+            typename BaseRenderer::color_type* colors = alloc.allocate(len);
+            span_gen.generate(colors, x, y, len);
+            ren.blend_color_hspan(x, y, len, colors, 
+                                  (span->len < 0) ? 0 : covers, *covers);
+
+            if(--num_spans == 0) break;
+            ++span;
+        }
+    }
+
+    //=====================================================render_scanlines_aa
+    template<class Rasterizer, class Scanline, class BaseRenderer, 
+             class SpanAllocator, class SpanGenerator>
+    void render_scanlines_aa(Rasterizer& ras, Scanline& sl, BaseRenderer& ren, 
+                             SpanAllocator& alloc, SpanGenerator& span_gen)
+    {
+        if(ras.rewind_scanlines())
+        {
+            sl.reset(ras.min_x(), ras.max_x());
+            span_gen.prepare();
+            while(ras.sweep_scanline(sl))
+            {
+                render_scanline_aa(sl, ren, alloc, span_gen);
+            }
+        }
+    }
+
+    //====================================================renderer_scanline_aa
+    template<class BaseRenderer, class SpanAllocator, class SpanGenerator> 
+    class renderer_scanline_aa
+    {
+    public:
+        typedef BaseRenderer  base_ren_type;
+        typedef SpanAllocator alloc_type;
+        typedef SpanGenerator span_gen_type;
+
+        //--------------------------------------------------------------------
+        renderer_scanline_aa() : m_ren(0), m_alloc(0), m_span_gen(0) {}
+        renderer_scanline_aa(base_ren_type& ren, 
+                             alloc_type& alloc, 
+                             span_gen_type& span_gen) :
+            m_ren(&ren),
+            m_alloc(&alloc),
+            m_span_gen(&span_gen)
+        {}
+        void attach(base_ren_type& ren, 
+                    alloc_type& alloc, 
+                    span_gen_type& span_gen)
+        {
+            m_ren = &ren;
+            m_alloc = &alloc;
+            m_span_gen = &span_gen;
+        }
+        
+        //--------------------------------------------------------------------
+        void prepare() { m_span_gen->prepare(); }
+
+        //--------------------------------------------------------------------
+        template<class Scanline> void render(const Scanline& sl)
+        {
+            render_scanline_aa(sl, *m_ren, *m_alloc, *m_span_gen);
+        }
+
+    private:
+        base_ren_type* m_ren;
+        alloc_type*    m_alloc;
+        span_gen_type* m_span_gen;
+    };
+
+
+
+
+
+
+    //===============================================render_scanline_bin_solid
+    template<class Scanline, class BaseRenderer, class ColorT> 
+    void render_scanline_bin_solid(const Scanline& sl, 
+                                   BaseRenderer& ren, 
+                                   const ColorT& color)
+    {
+        unsigned num_spans = sl.num_spans();
+        typename Scanline::const_iterator span = sl.begin();
+        for(;;)
+        {
+            ren.blend_hline(span->x, 
+                            sl.y(), 
+                            span->x - 1 + ((span->len < 0) ? 
+                                              -span->len : 
+                                               span->len), 
+                               color, 
+                               cover_full);
+            if(--num_spans == 0) break;
+            ++span;
+        }
+    }
+
+    //==============================================render_scanlines_bin_solid
+    template<class Rasterizer, class Scanline, 
+             class BaseRenderer, class ColorT>
+    void render_scanlines_bin_solid(Rasterizer& ras, Scanline& sl, 
+                                    BaseRenderer& ren, const ColorT& color)
+    {
+        if(ras.rewind_scanlines())
+        {
+            // Explicitly convert "color" to the BaseRenderer color type.
+            // For example, it can be called with color type "rgba", while
+            // "rgba8" is needed. Otherwise it will be implicitly 
+            // converted in the loop many times.
+            //----------------------
+            typename BaseRenderer::color_type ren_color(color);
+
+            sl.reset(ras.min_x(), ras.max_x());
+            while(ras.sweep_scanline(sl))
+            {
+                //render_scanline_bin_solid(sl, ren, ren_color);
+
+                // This code is equivalent to the above call (copy/paste). 
+                // It's just a "manual" optimization for old compilers,
+                // like Microsoft Visual C++ v6.0
+                //-------------------------------
+                unsigned num_spans = sl.num_spans();
+                typename Scanline::const_iterator span = sl.begin();
+                for(;;)
+                {
+                    ren.blend_hline(span->x, 
+                                    sl.y(), 
+                                    span->x - 1 + ((span->len < 0) ? 
+                                                      -span->len : 
+                                                       span->len), 
+                                       ren_color, 
+                                       cover_full);
+                    if(--num_spans == 0) break;
+                    ++span;
+                }
+            }
+        }
+    }
+
+    //=============================================renderer_scanline_bin_solid
+    template<class BaseRenderer> class renderer_scanline_bin_solid
+    {
+    public:
+        typedef BaseRenderer base_ren_type;
+        typedef typename base_ren_type::color_type color_type;
+
+        //--------------------------------------------------------------------
+        renderer_scanline_bin_solid() : m_ren(0) {}
+        explicit renderer_scanline_bin_solid(base_ren_type& ren) : m_ren(&ren) {}
+        void attach(base_ren_type& ren)
+        {
+            m_ren = &ren;
+        }
+        
+        //--------------------------------------------------------------------
+        void color(const color_type& c) { m_color = c; }
+        const color_type& color() const { return m_color; }
+
+        //--------------------------------------------------------------------
+        void prepare() {}
+
+        //--------------------------------------------------------------------
+        template<class Scanline> void render(const Scanline& sl)
+        {
+            render_scanline_bin_solid(sl, *m_ren, m_color);
+        }
+        
+    private:
+        base_ren_type* m_ren;
+        color_type m_color;
+    };
+
+
+
+
+
+
+
+
+    //======================================================render_scanline_bin
+    template<class Scanline, class BaseRenderer, 
+             class SpanAllocator, class SpanGenerator> 
+    void render_scanline_bin(const Scanline& sl, BaseRenderer& ren, 
+                             SpanAllocator& alloc, SpanGenerator& span_gen)
+    {
+        int y = sl.y();
+
+        unsigned num_spans = sl.num_spans();
+        typename Scanline::const_iterator span = sl.begin();
+        for(;;)
+        {
+            int x = span->x;
+            int len = span->len;
+            if(len < 0) len = -len;
+            typename BaseRenderer::color_type* colors = alloc.allocate(len);
+            span_gen.generate(colors, x, y, len);
+            ren.blend_color_hspan(x, y, len, colors, 0, cover_full); 
+            if(--num_spans == 0) break;
+            ++span;
+        }
+    }
+
+    //=====================================================render_scanlines_bin
+    template<class Rasterizer, class Scanline, class BaseRenderer, 
+             class SpanAllocator, class SpanGenerator>
+    void render_scanlines_bin(Rasterizer& ras, Scanline& sl, BaseRenderer& ren, 
+                              SpanAllocator& alloc, SpanGenerator& span_gen)
+    {
+        if(ras.rewind_scanlines())
+        {
+            sl.reset(ras.min_x(), ras.max_x());
+            span_gen.prepare();
+            while(ras.sweep_scanline(sl))
+            {
+                render_scanline_bin(sl, ren, alloc, span_gen);
+            }
+        }
+    }
+
+    //====================================================renderer_scanline_bin
+    template<class BaseRenderer, class SpanAllocator, class SpanGenerator> 
+    class renderer_scanline_bin
+    {
+    public:
+        typedef BaseRenderer  base_ren_type;
+        typedef SpanAllocator alloc_type;
+        typedef SpanGenerator span_gen_type;
+
+        //--------------------------------------------------------------------
+        renderer_scanline_bin() : m_ren(0), m_alloc(0), m_span_gen(0) {}
+        renderer_scanline_bin(base_ren_type& ren, 
+                              alloc_type& alloc, 
+                              span_gen_type& span_gen) :
+            m_ren(&ren),
+            m_alloc(&alloc),
+            m_span_gen(&span_gen)
+        {}
+        void attach(base_ren_type& ren, 
+                    alloc_type& alloc, 
+                    span_gen_type& span_gen)
+        {
+            m_ren = &ren;
+            m_alloc = &alloc;
+            m_span_gen = &span_gen;
+        }
+        
+        //--------------------------------------------------------------------
+        void prepare() { m_span_gen->prepare(); }
+
+        //--------------------------------------------------------------------
+        template<class Scanline> void render(const Scanline& sl)
+        {
+            render_scanline_bin(sl, *m_ren, *m_alloc, *m_span_gen);
+        }
+
+    private:
+        base_ren_type* m_ren;
+        alloc_type*    m_alloc;
+        span_gen_type* m_span_gen;
+    };
+
+
+
+
+
+
+
+
+
+
+    //========================================================render_scanlines
+    template<class Rasterizer, class Scanline, class Renderer>
+    void render_scanlines(Rasterizer& ras, Scanline& sl, Renderer& ren)
+    {
+        if(ras.rewind_scanlines())
+        {
+            sl.reset(ras.min_x(), ras.max_x());
+            ren.prepare();
+            while(ras.sweep_scanline(sl))
+            {
+                ren.render(sl);
+            }
+        }
+    }
+
+    //========================================================render_all_paths
+    template<class Rasterizer, class Scanline, class Renderer, 
+             class VertexSource, class ColorStorage, class PathId>
+    void render_all_paths(Rasterizer& ras, 
+                          Scanline& sl,
+                          Renderer& r, 
+                          VertexSource& vs, 
+                          const ColorStorage& as, 
+                          const PathId& path_id,
+                          unsigned num_paths)
+    {
+        for(unsigned i = 0; i < num_paths; i++)
+        {
+            ras.reset();
+            ras.add_path(vs, path_id[i]);
+            r.color(as[i]);
+            render_scanlines(ras, sl, r);
+        }
+    }
+
+
+
+
+
+
+    //=============================================render_scanlines_compound
+    template<class Rasterizer, 
+             class ScanlineAA, 
+             class ScanlineBin, 
+             class BaseRenderer, 
+             class SpanAllocator,
+             class StyleHandler>
+    void render_scanlines_compound(Rasterizer& ras, 
+                                   ScanlineAA& sl_aa,
+                                   ScanlineBin& sl_bin,
+                                   BaseRenderer& ren,
+                                   SpanAllocator& alloc,
+                                   StyleHandler& sh)
+    {
+        if(ras.rewind_scanlines())
+        {
+            int min_x = ras.min_x();
+            int len = ras.max_x() - min_x + 2;
+            sl_aa.reset(min_x, ras.max_x());
+            sl_bin.reset(min_x, ras.max_x());
+
+            typedef typename BaseRenderer::color_type color_type;
+            color_type* color_span = alloc.allocate(len * 2);
+            color_type* mix_buffer = color_span + len;
+            unsigned num_spans;
+
+            unsigned num_styles;
+            unsigned style;
+            bool     solid;
+            while((num_styles = ras.sweep_styles()) > 0)
+            {
+                typename ScanlineAA::const_iterator span_aa;
+                if(num_styles == 1)
+                {
+                    // Optimization for a single style. Happens often
+                    //-------------------------
+                    if(ras.sweep_scanline(sl_aa, 0))
+                    {
+                        style = ras.style(0);
+                        if(sh.is_solid(style))
+                        {
+                            // Just solid fill
+                            //-----------------------
+                            render_scanline_aa_solid(sl_aa, ren, sh.color(style));
+                        }
+                        else
+                        {
+                            // Arbitrary span generator
+                            //-----------------------
+                            span_aa   = sl_aa.begin();
+                            num_spans = sl_aa.num_spans();
+                            for(;;)
+                            {
+                                len = span_aa->len;
+                                sh.generate_span(color_span, 
+                                                 span_aa->x, 
+                                                 sl_aa.y(), 
+                                                 len, 
+                                                 style);
+
+                                ren.blend_color_hspan(span_aa->x, 
+                                                      sl_aa.y(), 
+                                                      span_aa->len,
+                                                      color_span,
+                                                      span_aa->covers);
+                                if(--num_spans == 0) break;
+                                ++span_aa;
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    if(ras.sweep_scanline(sl_bin, -1))
+                    {
+                        // Clear the spans of the mix_buffer
+                        //--------------------
+                        typename ScanlineBin::const_iterator span_bin = sl_bin.begin();
+                        num_spans = sl_bin.num_spans();
+                        for(;;)
+                        {
+                            memset(mix_buffer + span_bin->x - min_x, 
+                                   0, 
+                                   span_bin->len * sizeof(color_type));
+
+                            if(--num_spans == 0) break;
+                            ++span_bin;
+                        }
+
+                        unsigned i;
+                        for(i = 0; i < num_styles; i++)
+                        {
+                            style = ras.style(i);
+                            solid = sh.is_solid(style);
+
+                            if(ras.sweep_scanline(sl_aa, i))
+                            {
+                                color_type* colors;
+                                color_type* cspan;
+                                typename ScanlineAA::cover_type* covers;
+                                span_aa   = sl_aa.begin();
+                                num_spans = sl_aa.num_spans();
+                                if(solid)
+                                {
+                                    // Just solid fill
+                                    //-----------------------
+                                    for(;;)
+                                    {
+                                        color_type c = sh.color(style);
+                                        len    = span_aa->len;
+                                        colors = mix_buffer + span_aa->x - min_x;
+                                        covers = span_aa->covers;
+                                        do
+                                        {
+                                            if(*covers == cover_full) 
+                                            {
+                                                *colors = c;
+                                            }
+                                            else
+                                            {
+                                                colors->add(c, *covers);
+                                            }
+                                            ++colors;
+                                            ++covers;
+                                        }
+                                        while(--len);
+                                        if(--num_spans == 0) break;
+                                        ++span_aa;
+                                    }
+                                }
+                                else
+                                {
+                                    // Arbitrary span generator
+                                    //-----------------------
+                                    for(;;)
+                                    {
+                                        len = span_aa->len;
+                                        colors = mix_buffer + span_aa->x - min_x;
+                                        cspan  = color_span;
+                                        sh.generate_span(cspan, 
+                                                         span_aa->x, 
+                                                         sl_aa.y(), 
+                                                         len, 
+                                                         style);
+                                        covers = span_aa->covers;
+                                        do
+                                        {
+                                            if(*covers == cover_full) 
+                                            {
+                                                *colors = *cspan;
+                                            }
+                                            else
+                                            {
+                                                colors->add(*cspan, *covers);
+                                            }
+                                            ++cspan;
+                                            ++colors;
+                                            ++covers;
+                                        }
+                                        while(--len);
+                                        if(--num_spans == 0) break;
+                                        ++span_aa;
+                                    }
+                                }
+                            }
+                        }
+
+                        // Emit the blended result as a color hspan
+                        //-------------------------
+                        span_bin = sl_bin.begin();
+                        num_spans = sl_bin.num_spans();
+                        for(;;)
+                        {
+                            ren.blend_color_hspan(span_bin->x, 
+                                                  sl_bin.y(), 
+                                                  span_bin->len,
+                                                  mix_buffer + span_bin->x - min_x,
+                                                  0,
+                                                  cover_full);
+                            if(--num_spans == 0) break;
+                            ++span_bin;
+                        }
+                    } // if(ras.sweep_scanline(sl_bin, -1))
+                } // if(num_styles == 1) ... else
+            } // while((num_styles = ras.sweep_styles()) > 0)
+        } // if(ras.rewind_scanlines())
+    }
+
+    //=======================================render_scanlines_compound_layered
+    template<class Rasterizer, 
+             class ScanlineAA, 
+             class BaseRenderer, 
+             class SpanAllocator,
+             class StyleHandler>
+    void render_scanlines_compound_layered(Rasterizer& ras, 
+                                           ScanlineAA& sl_aa,
+                                           BaseRenderer& ren,
+                                           SpanAllocator& alloc,
+                                           StyleHandler& sh)
+    {
+        if(ras.rewind_scanlines())
+        {
+            int min_x = ras.min_x();
+            int len = ras.max_x() - min_x + 2;
+            sl_aa.reset(min_x, ras.max_x());
+
+            typedef typename BaseRenderer::color_type color_type;
+            color_type* color_span   = alloc.allocate(len * 2);
+            color_type* mix_buffer   = color_span + len;
+            cover_type* cover_buffer = ras.allocate_cover_buffer(len);
+            unsigned num_spans;
+
+            unsigned num_styles;
+            unsigned style;
+            bool     solid;
+            while((num_styles = ras.sweep_styles()) > 0)
+            {
+                typename ScanlineAA::const_iterator span_aa;
+                if(num_styles == 1)
+                {
+                    // Optimization for a single style. Happens often
+                    //-------------------------
+                    if(ras.sweep_scanline(sl_aa, 0))
+                    {
+                        style = ras.style(0);
+                        if(sh.is_solid(style))
+                        {
+                            // Just solid fill
+                            //-----------------------
+                            render_scanline_aa_solid(sl_aa, ren, sh.color(style));
+                        }
+                        else
+                        {
+                            // Arbitrary span generator
+                            //-----------------------
+                            span_aa   = sl_aa.begin();
+                            num_spans = sl_aa.num_spans();
+                            for(;;)
+                            {
+                                len = span_aa->len;
+                                sh.generate_span(color_span, 
+                                                 span_aa->x, 
+                                                 sl_aa.y(), 
+                                                 len, 
+                                                 style);
+
+                                ren.blend_color_hspan(span_aa->x, 
+                                                      sl_aa.y(), 
+                                                      span_aa->len,
+                                                      color_span,
+                                                      span_aa->covers);
+                                if(--num_spans == 0) break;
+                                ++span_aa;
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    int      sl_start = ras.scanline_start();
+                    unsigned sl_len   = ras.scanline_length();
+
+                    if(sl_len)
+                    {
+                        memset(mix_buffer + sl_start - min_x, 
+                               0, 
+                               sl_len * sizeof(color_type));
+
+                        memset(cover_buffer + sl_start - min_x, 
+                               0, 
+                               sl_len * sizeof(cover_type));
+
+                        int sl_y = std::numeric_limits<int>::max();
+                        unsigned i;
+                        for(i = 0; i < num_styles; i++)
+                        {
+                            style = ras.style(i);
+                            solid = sh.is_solid(style);
+
+                            if(ras.sweep_scanline(sl_aa, i))
+                            {
+                                unsigned    cover;
+                                color_type* colors;
+                                color_type* cspan;
+                                cover_type* src_covers;
+                                cover_type* dst_covers;
+                                span_aa   = sl_aa.begin();
+                                num_spans = sl_aa.num_spans();
+                                sl_y      = sl_aa.y();
+                                if(solid)
+                                {
+                                    // Just solid fill
+                                    //-----------------------
+                                    for(;;)
+                                    {
+                                        color_type c = sh.color(style);
+                                        len    = span_aa->len;
+                                        colors = mix_buffer + span_aa->x - min_x;
+                                        src_covers = span_aa->covers;
+                                        dst_covers = cover_buffer + span_aa->x - min_x;
+                                        do
+                                        {
+                                            cover = *src_covers;
+                                            if(*dst_covers + cover > cover_full)
+                                            {
+                                                cover = cover_full - *dst_covers;
+                                            }
+                                            if(cover)
+                                            {
+                                                colors->add(c, cover);
+                                                *dst_covers += cover;
+                                            }
+                                            ++colors;
+                                            ++src_covers;
+                                            ++dst_covers;
+                                        }
+                                        while(--len);
+                                        if(--num_spans == 0) break;
+                                        ++span_aa;
+                                    }
+                                }
+                                else
+                                {
+                                    // Arbitrary span generator
+                                    //-----------------------
+                                    for(;;)
+                                    {
+                                        len = span_aa->len;
+                                        colors = mix_buffer + span_aa->x - min_x;
+                                        cspan  = color_span;
+                                        sh.generate_span(cspan, 
+                                                         span_aa->x, 
+                                                         sl_aa.y(), 
+                                                         len, 
+                                                         style);
+                                        src_covers = span_aa->covers;
+                                        dst_covers = cover_buffer + span_aa->x - min_x;
+                                        do
+                                        {
+                                            cover = *src_covers;
+                                            if(*dst_covers + cover > cover_full)
+                                            {
+                                                cover = cover_full - *dst_covers;
+                                            }
+                                            if(cover)
+                                            {
+                                                colors->add(*cspan, cover);
+                                                *dst_covers += cover;
+                                            }
+                                            ++cspan;
+                                            ++colors;
+                                            ++src_covers;
+                                            ++dst_covers;
+                                        }
+                                        while(--len);
+                                        if(--num_spans == 0) break;
+                                        ++span_aa;
+                                    }
+                                }
+                            }
+                        }
+                        ren.blend_color_hspan(sl_start, 
+                                              sl_y, 
+                                              sl_len,
+                                              mix_buffer + sl_start - min_x,
+                                              0,
+                                              cover_full);
+                    } //if(sl_len)
+                } //if(num_styles == 1) ... else
+            } //while((num_styles = ras.sweep_styles()) > 0)
+        } //if(ras.rewind_scanlines())
+    }
+
+
+}
+
+#endif

xs/src/agg/agg_rendering_buffer.h

@@ -0,0 +1,300 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// class rendering_buffer
+//
+//----------------------------------------------------------------------------
+
+#ifndef AGG_RENDERING_BUFFER_INCLUDED
+#define AGG_RENDERING_BUFFER_INCLUDED
+
+#include "agg_array.h"
+
+namespace agg
+{
+
+    //===========================================================row_accessor
+    template<class T> class row_accessor
+    {
+    public:
+        typedef const_row_info<T> row_data;
+
+        //-------------------------------------------------------------------
+        row_accessor() :
+            m_buf(0),
+            m_start(0),
+            m_width(0),
+            m_height(0),
+            m_stride(0)
+        {
+        }
+
+        //--------------------------------------------------------------------
+        row_accessor(T* buf, unsigned width, unsigned height, int stride) :
+            m_buf(0),
+            m_start(0),
+            m_width(0),
+            m_height(0),
+            m_stride(0)
+        {
+            attach(buf, width, height, stride);
+        }
+
+
+        //--------------------------------------------------------------------
+        void attach(T* buf, unsigned width, unsigned height, int stride)
+        {
+            m_buf = m_start = buf;
+            m_width = width;
+            m_height = height;
+            m_stride = stride;
+            if(stride < 0) 
+            { 
+                m_start = m_buf - int(height - 1) * stride;
+            }
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE       T* buf()          { return m_buf;    }
+        AGG_INLINE const T* buf()    const { return m_buf;    }
+        AGG_INLINE unsigned width()  const { return m_width;  }
+        AGG_INLINE unsigned height() const { return m_height; }
+        AGG_INLINE int      stride() const { return m_stride; }
+        AGG_INLINE unsigned stride_abs() const 
+        {
+            return (m_stride < 0) ? unsigned(-m_stride) : unsigned(m_stride); 
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE       T* row_ptr(int, int y, unsigned) 
+        { 
+            return m_start + y * m_stride; 
+        }
+        AGG_INLINE       T* row_ptr(int y)       { return m_start + y * m_stride; }
+        AGG_INLINE const T* row_ptr(int y) const { return m_start + y * m_stride; }
+        AGG_INLINE row_data row    (int y) const 
+        { 
+            return row_data(0, m_width-1, row_ptr(y)); 
+        }
+
+        //--------------------------------------------------------------------
+        template<class RenBuf>
+        void copy_from(const RenBuf& src)
+        {
+            unsigned h = height();
+            if(src.height() < h) h = src.height();
+        
+            unsigned l = stride_abs();
+            if(src.stride_abs() < l) l = src.stride_abs();
+        
+            l *= sizeof(T);
+
+            unsigned y;
+            unsigned w = width();
+            for (y = 0; y < h; y++)
+            {
+                memcpy(row_ptr(0, y, w), src.row_ptr(y), l);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void clear(T value)
+        {
+            unsigned y;
+            unsigned w = width();
+            unsigned stride = stride_abs();
+            for(y = 0; y < height(); y++)
+            {
+                T* p = row_ptr(0, y, w);
+                unsigned x;
+                for(x = 0; x < stride; x++)
+                {
+                    *p++ = value;
+                }
+            }
+        }
+
+    private:
+        //--------------------------------------------------------------------
+        T*            m_buf;    // Pointer to renrdering buffer
+        T*            m_start;  // Pointer to first pixel depending on stride 
+        unsigned      m_width;  // Width in pixels
+        unsigned      m_height; // Height in pixels
+        int           m_stride; // Number of bytes per row. Can be < 0
+    };
+
+
+
+
+    //==========================================================row_ptr_cache
+    template<class T> class row_ptr_cache
+    {
+    public:
+        typedef const_row_info<T> row_data;
+
+        //-------------------------------------------------------------------
+        row_ptr_cache() :
+            m_buf(0),
+            m_rows(),
+            m_width(0),
+            m_height(0),
+            m_stride(0)
+        {
+        }
+
+        //--------------------------------------------------------------------
+        row_ptr_cache(T* buf, unsigned width, unsigned height, int stride) :
+            m_buf(0),
+            m_rows(),
+            m_width(0),
+            m_height(0),
+            m_stride(0)
+        {
+            attach(buf, width, height, stride);
+        }
+
+        //--------------------------------------------------------------------
+        void attach(T* buf, unsigned width, unsigned height, int stride)
+        {
+            m_buf = buf;
+            m_width = width;
+            m_height = height;
+            m_stride = stride;
+            if(height > m_rows.size())
+            {
+                m_rows.resize(height);
+            }
+
+            T* row_ptr = m_buf;
+
+            if(stride < 0)
+            {
+                row_ptr = m_buf - int(height - 1) * stride;
+            }
+
+            T** rows = &m_rows[0];
+
+            while(height--)
+            {
+                *rows++ = row_ptr;
+                row_ptr += stride;
+            }
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE       T* buf()          { return m_buf;    }
+        AGG_INLINE const T* buf()    const { return m_buf;    }
+        AGG_INLINE unsigned width()  const { return m_width;  }
+        AGG_INLINE unsigned height() const { return m_height; }
+        AGG_INLINE int      stride() const { return m_stride; }
+        AGG_INLINE unsigned stride_abs() const 
+        {
+            return (m_stride < 0) ? unsigned(-m_stride) : unsigned(m_stride); 
+        }
+
+        //--------------------------------------------------------------------
+        AGG_INLINE       T* row_ptr(int, int y, unsigned) 
+        { 
+            return m_rows[y]; 
+        }
+        AGG_INLINE       T* row_ptr(int y)       { return m_rows[y]; }
+        AGG_INLINE const T* row_ptr(int y) const { return m_rows[y]; }
+        AGG_INLINE row_data row    (int y) const 
+        { 
+            return row_data(0, m_width-1, m_rows[y]); 
+        }
+
+        //--------------------------------------------------------------------
+        T const* const* rows() const { return &m_rows[0]; }
+
+        //--------------------------------------------------------------------
+        template<class RenBuf>
+        void copy_from(const RenBuf& src)
+        {
+            unsigned h = height();
+            if(src.height() < h) h = src.height();
+        
+            unsigned l = stride_abs();
+            if(src.stride_abs() < l) l = src.stride_abs();
+        
+            l *= sizeof(T);
+
+            unsigned y;
+            unsigned w = width();
+            for (y = 0; y < h; y++)
+            {
+                memcpy(row_ptr(0, y, w), src.row_ptr(y), l);
+            }
+        }
+
+        //--------------------------------------------------------------------
+        void clear(T value)
+        {
+            unsigned y;
+            unsigned w = width();
+            unsigned stride = stride_abs();
+            for(y = 0; y < height(); y++)
+            {
+                T* p = row_ptr(0, y, w);
+                unsigned x;
+                for(x = 0; x < stride; x++)
+                {
+                    *p++ = value;
+                }
+            }
+        }
+
+    private:
+        //--------------------------------------------------------------------
+        T*            m_buf;        // Pointer to renrdering buffer
+        pod_array<T*> m_rows;       // Pointers to each row of the buffer
+        unsigned      m_width;      // Width in pixels
+        unsigned      m_height;     // Height in pixels
+        int           m_stride;     // Number of bytes per row. Can be < 0
+    };
+
+
+
+
+    //========================================================rendering_buffer
+    // 
+    // The definition of the main type for accessing the rows in the frame 
+    // buffer. It provides functionality to navigate to the rows in a 
+    // rectangular matrix, from top to bottom or from bottom to top depending 
+    // on stride.
+    //
+    // row_accessor is cheap to create/destroy, but performs one multiplication
+    // when calling row_ptr().
+    // 
+    // row_ptr_cache creates an array of pointers to rows, so, the access 
+    // via row_ptr() may be faster. But it requires memory allocation 
+    // when creating. For example, on typical Intel Pentium hardware 
+    // row_ptr_cache speeds span_image_filter_rgb_nn up to 10%
+    //
+    // It's used only in short hand typedefs like pixfmt_rgba32 and can be 
+    // redefined in agg_config.h
+    // In real applications you can use both, depending on your needs
+    //------------------------------------------------------------------------
+#ifdef AGG_RENDERING_BUFFER
+    typedef AGG_RENDERING_BUFFER rendering_buffer;
+#else
+//  typedef row_ptr_cache<int8u> rendering_buffer;
+    typedef row_accessor<int8u> rendering_buffer;
+#endif
+
+}
+
+
+#endif

xs/src/agg/agg_scanline_p.h

@@ -0,0 +1,329 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Class scanline_p - a general purpose scanline container with packed spans.
+//
+//----------------------------------------------------------------------------
+//
+// Adaptation for 32-bit screen coordinates (scanline32_p) has been sponsored by 
+// Liberty Technology Systems, Inc., visit http://lib-sys.com
+//
+// Liberty Technology Systems, Inc. is the provider of
+// PostScript and PDF technology for software developers.
+// 
+//----------------------------------------------------------------------------
+#ifndef AGG_SCANLINE_P_INCLUDED
+#define AGG_SCANLINE_P_INCLUDED
+
+#include "agg_array.h"
+
+namespace agg
+{
+
+    //=============================================================scanline_p8
+    // 
+    // This is a general purpose scaline container which supports the interface 
+    // used in the rasterizer::render(). See description of scanline_u8
+    // for details.
+    // 
+    //------------------------------------------------------------------------
+    class scanline_p8
+    {
+    public:
+        typedef scanline_p8 self_type;
+        typedef int8u       cover_type;
+        typedef int16       coord_type;
+
+        //--------------------------------------------------------------------
+        struct span
+        {
+            coord_type        x;
+            coord_type        len; // If negative, it's a solid span, covers is valid
+            const cover_type* covers;
+        };
+
+        typedef span* iterator;
+        typedef const span* const_iterator;
+
+        scanline_p8() :
+            m_last_x(0x7FFFFFF0),
+            m_covers(),
+            m_cover_ptr(0),
+            m_spans(),
+            m_cur_span(0)
+        {
+        }
+
+        //--------------------------------------------------------------------
+        void reset(int min_x, int max_x)
+        {
+            unsigned max_len = max_x - min_x + 3;
+            if(max_len > m_spans.size())
+            {
+                m_spans.resize(max_len);
+                m_covers.resize(max_len);
+            }
+            m_last_x    = 0x7FFFFFF0;
+            m_cover_ptr = &m_covers[0];
+            m_cur_span  = &m_spans[0];
+            m_cur_span->len = 0;
+        }
+
+        //--------------------------------------------------------------------
+        void add_cell(int x, unsigned cover)
+        {
+            *m_cover_ptr = (cover_type)cover;
+            if(x == m_last_x+1 && m_cur_span->len > 0)
+            {
+                m_cur_span->len++;
+            }
+            else
+            {
+                m_cur_span++;
+                m_cur_span->covers = m_cover_ptr;
+                m_cur_span->x = (int16)x;
+                m_cur_span->len = 1;
+            }
+            m_last_x = x;
+            m_cover_ptr++;
+        }
+
+        //--------------------------------------------------------------------
+        void add_cells(int x, unsigned len, const cover_type* covers)
+        {
+            memcpy(m_cover_ptr, covers, len * sizeof(cover_type));
+            if(x == m_last_x+1 && m_cur_span->len > 0)
+            {
+                m_cur_span->len += (int16)len;
+            }
+            else
+            {
+                m_cur_span++;
+                m_cur_span->covers = m_cover_ptr;
+                m_cur_span->x = (int16)x;
+                m_cur_span->len = (int16)len;
+            }
+            m_cover_ptr += len;
+            m_last_x = x + len - 1;
+        }
+
+        //--------------------------------------------------------------------
+        void add_span(int x, unsigned len, unsigned cover)
+        {
+            if(x == m_last_x+1 && 
+               m_cur_span->len < 0 && 
+               cover == *m_cur_span->covers)
+            {
+                m_cur_span->len -= (int16)len;
+            }
+            else
+            {
+                *m_cover_ptr = (cover_type)cover;
+                m_cur_span++;
+                m_cur_span->covers = m_cover_ptr++;
+                m_cur_span->x      = (int16)x;
+                m_cur_span->len    = (int16)(-int(len));
+            }
+            m_last_x = x + len - 1;
+        }
+
+        //--------------------------------------------------------------------
+        void finalize(int y) 
+        { 
+            m_y = y; 
+        }
+
+        //--------------------------------------------------------------------
+        void reset_spans()
+        {
+            m_last_x    = 0x7FFFFFF0;
+            m_cover_ptr = &m_covers[0];
+            m_cur_span  = &m_spans[0];
+            m_cur_span->len = 0;
+        }
+
+        //--------------------------------------------------------------------
+        int            y()         const { return m_y; }
+        unsigned       num_spans() const { return unsigned(m_cur_span - &m_spans[0]); }
+        const_iterator begin()     const { return &m_spans[1]; }
+
+    private:
+        scanline_p8(const self_type&);
+        const self_type& operator = (const self_type&);
+
+        int                   m_last_x;
+        int                   m_y;
+        pod_array<cover_type> m_covers;
+        cover_type*           m_cover_ptr;
+        pod_array<span>       m_spans;
+        span*                 m_cur_span;
+    };
+
+
+
+
+
+
+
+
+    //==========================================================scanline32_p8
+    class scanline32_p8
+    {
+    public:
+        typedef scanline32_p8 self_type;
+        typedef int8u         cover_type;
+        typedef int32         coord_type;
+
+        struct span
+        {
+            span() {}
+            span(coord_type x_, coord_type len_, const cover_type* covers_) :
+                x(x_), len(len_), covers(covers_) {}
+
+            coord_type x;
+            coord_type len; // If negative, it's a solid span, covers is valid
+            const cover_type* covers;
+        };
+        typedef pod_bvector<span, 4> span_array_type;
+
+
+        //--------------------------------------------------------------------
+        class const_iterator
+        {
+        public:
+            const_iterator(const span_array_type& spans) :
+                m_spans(spans),
+                m_span_idx(0)
+            {}
+
+            const span& operator*()  const { return m_spans[m_span_idx];  }
+            const span* operator->() const { return &m_spans[m_span_idx]; }
+
+            void operator ++ () { ++m_span_idx; }
+
+        private:
+            const span_array_type& m_spans;
+            unsigned               m_span_idx;
+        };
+
+        //--------------------------------------------------------------------
+        scanline32_p8() :
+            m_max_len(0),
+            m_last_x(0x7FFFFFF0),
+            m_covers(),
+            m_cover_ptr(0)
+        {
+        }
+
+        //--------------------------------------------------------------------
+        void reset(int min_x, int max_x)
+        {
+            unsigned max_len = max_x - min_x + 3;
+            if(max_len > m_covers.size())
+            {
+                m_covers.resize(max_len);
+            }
+            m_last_x    = 0x7FFFFFF0;
+            m_cover_ptr = &m_covers[0];
+            m_spans.remove_all();
+        }
+
+        //--------------------------------------------------------------------
+        void add_cell(int x, unsigned cover)
+        {
+            *m_cover_ptr = cover_type(cover);
+            if(x == m_last_x+1 && m_spans.size() && m_spans.last().len > 0)
+            {
+                m_spans.last().len++;
+            }
+            else
+            {
+                m_spans.add(span(coord_type(x), 1, m_cover_ptr));
+            }
+            m_last_x = x;
+            m_cover_ptr++;
+        }
+
+        //--------------------------------------------------------------------
+        void add_cells(int x, unsigned len, const cover_type* covers)
+        {
+            memcpy(m_cover_ptr, covers, len * sizeof(cover_type));
+            if(x == m_last_x+1 && m_spans.size() && m_spans.last().len > 0)
+            {
+                m_spans.last().len += coord_type(len);
+            }
+            else
+            {
+                m_spans.add(span(coord_type(x), coord_type(len), m_cover_ptr));
+            }
+            m_cover_ptr += len;
+            m_last_x = x + len - 1;
+        }
+
+        //--------------------------------------------------------------------
+        void add_span(int x, unsigned len, unsigned cover)
+        {
+            if(x == m_last_x+1 && 
+               m_spans.size() &&
+               m_spans.last().len < 0 && 
+               cover == *m_spans.last().covers)
+            {
+                m_spans.last().len -= coord_type(len);
+            }
+            else
+            {
+                *m_cover_ptr = cover_type(cover);
+                m_spans.add(span(coord_type(x), -coord_type(len), m_cover_ptr++));
+            }
+            m_last_x = x + len - 1;
+        }
+
+        //--------------------------------------------------------------------
+        void finalize(int y) 
+        { 
+            m_y = y; 
+        }
+
+        //--------------------------------------------------------------------
+        void reset_spans()
+        {
+            m_last_x    = 0x7FFFFFF0;
+            m_cover_ptr = &m_covers[0];
+            m_spans.remove_all();
+        }
+
+        //--------------------------------------------------------------------
+        int            y()         const { return m_y; }
+        unsigned       num_spans() const { return m_spans.size(); }
+        const_iterator begin()     const { return const_iterator(m_spans); }
+
+    private:
+        scanline32_p8(const self_type&);
+        const self_type& operator = (const self_type&);
+
+        unsigned              m_max_len;
+        int                   m_last_x;
+        int                   m_y;
+        pod_array<cover_type> m_covers;
+        cover_type*           m_cover_ptr;
+        span_array_type       m_spans;
+    };
+
+
+}
+
+
+#endif
+

xs/src/agg/agg_trans_affine.h

@@ -0,0 +1,518 @@
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.4
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software 
+// is granted provided this copyright notice appears in all copies. 
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+//
+// Affine transformation classes.
+//
+//----------------------------------------------------------------------------
+#ifndef AGG_TRANS_AFFINE_INCLUDED
+#define AGG_TRANS_AFFINE_INCLUDED
+
+#include <math.h>
+#include "agg_basics.h"
+
+namespace agg
+{
+    const double affine_epsilon = 1e-14; 
+
+    //============================================================trans_affine
+    //
+    // See Implementation agg_trans_affine.cpp
+    //
+    // Affine transformation are linear transformations in Cartesian coordinates
+    // (strictly speaking not only in Cartesian, but for the beginning we will 
+    // think so). They are rotation, scaling, translation and skewing.  
+    // After any affine transformation a line segment remains a line segment 
+    // and it will never become a curve. 
+    //
+    // There will be no math about matrix calculations, since it has been 
+    // described many times. Ask yourself a very simple question:
+    // "why do we need to understand and use some matrix stuff instead of just 
+    // rotating, scaling and so on". The answers are:
+    //
+    // 1. Any combination of transformations can be done by only 4 multiplications
+    //    and 4 additions in floating point.
+    // 2. One matrix transformation is equivalent to the number of consecutive
+    //    discrete transformations, i.e. the matrix "accumulates" all transformations 
+    //    in the order of their settings. Suppose we have 4 transformations: 
+    //       * rotate by 30 degrees,
+    //       * scale X to 2.0, 
+    //       * scale Y to 1.5, 
+    //       * move to (100, 100). 
+    //    The result will depend on the order of these transformations, 
+    //    and the advantage of matrix is that the sequence of discret calls:
+    //    rotate(30), scaleX(2.0), scaleY(1.5), move(100,100) 
+    //    will have exactly the same result as the following matrix transformations:
+    //   
+    //    affine_matrix m;
+    //    m *= rotate_matrix(30); 
+    //    m *= scaleX_matrix(2.0);
+    //    m *= scaleY_matrix(1.5);
+    //    m *= move_matrix(100,100);
+    //
+    //    m.transform_my_point_at_last(x, y);
+    //
+    // What is the good of it? In real life we will set-up the matrix only once
+    // and then transform many points, let alone the convenience to set any 
+    // combination of transformations.
+    //
+    // So, how to use it? Very easy - literally as it's shown above. Not quite,
+    // let us write a correct example:
+    //
+    // agg::trans_affine m;
+    // m *= agg::trans_affine_rotation(30.0 * 3.1415926 / 180.0);
+    // m *= agg::trans_affine_scaling(2.0, 1.5);
+    // m *= agg::trans_affine_translation(100.0, 100.0);
+    // m.transform(&x, &y);
+    //
+    // The affine matrix is all you need to perform any linear transformation,
+    // but all transformations have origin point (0,0). It means that we need to 
+    // use 2 translations if we want to rotate someting around (100,100):
+    // 
+    // m *= agg::trans_affine_translation(-100.0, -100.0);         // move to (0,0)
+    // m *= agg::trans_affine_rotation(30.0 * 3.1415926 / 180.0);  // rotate
+    // m *= agg::trans_affine_translation(100.0, 100.0);           // move back to (100,100)
+    //----------------------------------------------------------------------
+    struct trans_affine
+    {
+        double sx, shy, shx, sy, tx, ty;
+
+        //------------------------------------------ Construction
+        // Identity matrix
+        trans_affine() :
+            sx(1.0), shy(0.0), shx(0.0), sy(1.0), tx(0.0), ty(0.0)
+        {}
+
+        // Custom matrix. Usually used in derived classes
+        trans_affine(double v0, double v1, double v2, 
+                     double v3, double v4, double v5) :
+            sx(v0), shy(v1), shx(v2), sy(v3), tx(v4), ty(v5)
+        {}
+
+        // Custom matrix from m[6]
+        explicit trans_affine(const double* m) :
+            sx(m[0]), shy(m[1]), shx(m[2]), sy(m[3]), tx(m[4]), ty(m[5])
+        {}
+
+        // Rectangle to a parallelogram.
+        trans_affine(double x1, double y1, double x2, double y2, 
+                     const double* parl)
+        {
+            rect_to_parl(x1, y1, x2, y2, parl);
+        }
+
+        // Parallelogram to a rectangle.
+        trans_affine(const double* parl, 
+                     double x1, double y1, double x2, double y2)
+        {
+            parl_to_rect(parl, x1, y1, x2, y2);
+        }
+
+        // Arbitrary parallelogram transformation.
+        trans_affine(const double* src, const double* dst)
+        {
+            parl_to_parl(src, dst);
+        }
+
+        //---------------------------------- Parellelogram transformations
+        // transform a parallelogram to another one. Src and dst are 
+        // pointers to arrays of three points (double[6], x1,y1,...) that 
+        // identify three corners of the parallelograms assuming implicit 
+        // fourth point. The arguments are arrays of double[6] mapped 
+        // to x1,y1, x2,y2, x3,y3  where the coordinates are:
+        //        *-----------------*
+        //       /          (x3,y3)/
+        //      /                 /
+        //     /(x1,y1)   (x2,y2)/
+        //    *-----------------*
+        const trans_affine& parl_to_parl(const double* src, 
+                                         const double* dst);
+
+        const trans_affine& rect_to_parl(double x1, double y1, 
+                                         double x2, double y2, 
+                                         const double* parl);
+
+        const trans_affine& parl_to_rect(const double* parl, 
+                                         double x1, double y1, 
+                                         double x2, double y2);
+
+
+        //------------------------------------------ Operations
+        // Reset - load an identity matrix
+        const trans_affine& reset();
+
+        // Direct transformations operations
+        const trans_affine& translate(double x, double y);
+        const trans_affine& rotate(double a);
+        const trans_affine& scale(double s);
+        const trans_affine& scale(double x, double y);
+
+        // Multiply matrix to another one
+        const trans_affine& multiply(const trans_affine& m);
+
+        // Multiply "m" to "this" and assign the result to "this"
+        const trans_affine& premultiply(const trans_affine& m);
+
+        // Multiply matrix to inverse of another one
+        const trans_affine& multiply_inv(const trans_affine& m);
+
+        // Multiply inverse of "m" to "this" and assign the result to "this"
+        const trans_affine& premultiply_inv(const trans_affine& m);
+
+        // Invert matrix. Do not try to invert degenerate matrices, 
+        // there's no check for validity. If you set scale to 0 and 
+        // then try to invert matrix, expect unpredictable result.
+        const trans_affine& invert();
+
+        // Mirroring around X
+        const trans_affine& flip_x();
+
+        // Mirroring around Y
+        const trans_affine& flip_y();
+
+        //------------------------------------------- Load/Store
+        // Store matrix to an array [6] of double
+        void store_to(double* m) const
+        {
+            *m++ = sx; *m++ = shy; *m++ = shx; *m++ = sy; *m++ = tx; *m++ = ty;
+        }
+
+        // Load matrix from an array [6] of double
+        const trans_affine& load_from(const double* m)
+        {
+            sx = *m++; shy = *m++; shx = *m++; sy = *m++; tx = *m++;  ty = *m++;
+            return *this;
+        }
+
+        //------------------------------------------- Operators
+        
+        // Multiply the matrix by another one
+        const trans_affine& operator *= (const trans_affine& m)
+        {
+            return multiply(m);
+        }
+
+        // Multiply the matrix by inverse of another one
+        const trans_affine& operator /= (const trans_affine& m)
+        {
+            return multiply_inv(m);
+        }
+
+        // Multiply the matrix by another one and return
+        // the result in a separete matrix.
+        trans_affine operator * (const trans_affine& m) const
+        {
+            return trans_affine(*this).multiply(m);
+        }
+
+        // Multiply the matrix by inverse of another one 
+        // and return the result in a separete matrix.
+        trans_affine operator / (const trans_affine& m) const
+        {
+            return trans_affine(*this).multiply_inv(m);
+        }
+
+        // Calculate and return the inverse matrix
+        trans_affine operator ~ () const
+        {
+            trans_affine ret = *this;
+            return ret.invert();
+        }
+
+        // Equal operator with default epsilon
+        bool operator == (const trans_affine& m) const
+        {
+            return is_equal(m, affine_epsilon);
+        }
+
+        // Not Equal operator with default epsilon
+        bool operator != (const trans_affine& m) const
+        {
+            return !is_equal(m, affine_epsilon);
+        }
+
+        //-------------------------------------------- Transformations
+        // Direct transformation of x and y
+        void transform(double* x, double* y) const;
+
+        // Direct transformation of x and y, 2x2 matrix only, no translation
+        void transform_2x2(double* x, double* y) const;
+
+        // Inverse transformation of x and y. It works slower than the 
+        // direct transformation. For massive operations it's better to 
+        // invert() the matrix and then use direct transformations. 
+        void inverse_transform(double* x, double* y) const;
+
+        //-------------------------------------------- Auxiliary
+        // Calculate the determinant of matrix
+        double determinant() const
+        {
+            return sx * sy - shy * shx;
+        }
+
+        // Calculate the reciprocal of the determinant
+        double determinant_reciprocal() const
+        {
+            return 1.0 / (sx * sy - shy * shx);
+        }
+
+        // Get the average scale (by X and Y). 
+        // Basically used to calculate the approximation_scale when
+        // decomposinting curves into line segments.
+        double scale() const;
+
+        // Check to see if the matrix is not degenerate
+        bool is_valid(double epsilon = affine_epsilon) const;
+
+        // Check to see if it's an identity matrix
+        bool is_identity(double epsilon = affine_epsilon) const;
+
+        // Check to see if two matrices are equal
+        bool is_equal(const trans_affine& m, double epsilon = affine_epsilon) const;
+
+        // Determine the major parameters. Use with caution considering 
+        // possible degenerate cases.
+        double rotation() const;
+        void   translation(double* dx, double* dy) const;
+        void   scaling(double* x, double* y) const;
+        void   scaling_abs(double* x, double* y) const;
+    };
+
+    //------------------------------------------------------------------------
+    inline void trans_affine::transform(double* x, double* y) const
+    {
+        double tmp = *x;
+        *x = tmp * sx  + *y * shx + tx;
+        *y = tmp * shy + *y * sy  + ty;
+    }
+
+    //------------------------------------------------------------------------
+    inline void trans_affine::transform_2x2(double* x, double* y) const
+    {
+        double tmp = *x;
+        *x = tmp * sx  + *y * shx;
+        *y = tmp * shy + *y * sy;
+    }
+
+    //------------------------------------------------------------------------
+    inline void trans_affine::inverse_transform(double* x, double* y) const
+    {
+        double d = determinant_reciprocal();
+        double a = (*x - tx) * d;
+        double b = (*y - ty) * d;
+        *x = a * sy - b * shx;
+        *y = b * sx - a * shy;
+    }
+
+    //------------------------------------------------------------------------
+    inline double trans_affine::scale() const
+    {
+        double x = 0.707106781 * sx  + 0.707106781 * shx;
+        double y = 0.707106781 * shy + 0.707106781 * sy;
+        return sqrt(x*x + y*y);
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::translate(double x, double y) 
+    { 
+        tx += x;
+        ty += y; 
+        return *this;
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::rotate(double a) 
+    {
+        double ca = cos(a); 
+        double sa = sin(a);
+        double t0 = sx  * ca - shy * sa;
+        double t2 = shx * ca - sy * sa;
+        double t4 = tx  * ca - ty * sa;
+        shy = sx  * sa + shy * ca;
+        sy  = shx * sa + sy * ca; 
+        ty  = tx  * sa + ty * ca;
+        sx  = t0;
+        shx = t2;
+        tx  = t4;
+        return *this;
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::scale(double x, double y) 
+    {
+        double mm0 = x; // Possible hint for the optimizer
+        double mm3 = y; 
+        sx  *= mm0;
+        shx *= mm0;
+        tx  *= mm0;
+        shy *= mm3;
+        sy  *= mm3;
+        ty  *= mm3;
+        return *this;
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::scale(double s) 
+    {
+        double m = s; // Possible hint for the optimizer
+        sx  *= m;
+        shx *= m;
+        tx  *= m;
+        shy *= m;
+        sy  *= m;
+        ty  *= m;
+        return *this;
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::premultiply(const trans_affine& m)
+    {
+        trans_affine t = m;
+        return *this = t.multiply(*this);
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::multiply_inv(const trans_affine& m)
+    {
+        trans_affine t = m;
+        t.invert();
+        return multiply(t);
+    }
+
+    //------------------------------------------------------------------------
+    inline const trans_affine& trans_affine::premultiply_inv(const trans_affine& m)
+    {
+        trans_affine t = m;
+        t.invert();
+        return *this = t.multiply(*this);
+    }
+
+    //------------------------------------------------------------------------
+    inline void trans_affine::scaling_abs(double* x, double* y) const
+    {
+        // Used to calculate scaling coefficients in image resampling. 
+        // When there is considerable shear this method gives us much
+        // better estimation than just sx, sy.
+        *x = sqrt(sx  * sx  + shx * shx);
+        *y = sqrt(shy * shy + sy  * sy);
+    }
+
+    //====================================================trans_affine_rotation
+    // Rotation matrix. sin() and cos() are calculated twice for the same angle.
+    // There's no harm because the performance of sin()/cos() is very good on all
+    // modern processors. Besides, this operation is not going to be invoked too 
+    // often.
+    class trans_affine_rotation : public trans_affine
+    {
+    public:
+        trans_affine_rotation(double a) : 
+          trans_affine(cos(a), sin(a), -sin(a), cos(a), 0.0, 0.0)
+        {}
+    };
+
+    //====================================================trans_affine_scaling
+    // Scaling matrix. x, y - scale coefficients by X and Y respectively
+    class trans_affine_scaling : public trans_affine
+    {
+    public:
+        trans_affine_scaling(double x, double y) : 
+          trans_affine(x, 0.0, 0.0, y, 0.0, 0.0)
+        {}
+
+        trans_affine_scaling(double s) : 
+          trans_affine(s, 0.0, 0.0, s, 0.0, 0.0)
+        {}
+    };
+
+    //================================================trans_affine_translation
+    // Translation matrix
+    class trans_affine_translation : public trans_affine
+    {
+    public:
+        trans_affine_translation(double x, double y) : 
+          trans_affine(1.0, 0.0, 0.0, 1.0, x, y)
+        {}
+    };
+
+    //====================================================trans_affine_skewing
+    // Sckewing (shear) matrix
+    class trans_affine_skewing : public trans_affine
+    {
+    public:
+        trans_affine_skewing(double x, double y) : 
+          trans_affine(1.0, tan(y), tan(x), 1.0, 0.0, 0.0)
+        {}
+    };
+
+
+    //===============================================trans_affine_line_segment
+    // Rotate, Scale and Translate, associating 0...dist with line segment 
+    // x1,y1,x2,y2
+    class trans_affine_line_segment : public trans_affine
+    {
+    public:
+        trans_affine_line_segment(double x1, double y1, double x2, double y2, 
+                                  double dist)
+        {
+            double dx = x2 - x1;
+            double dy = y2 - y1;
+            if(dist > 0.0)
+            {
+                multiply(trans_affine_scaling(sqrt(dx * dx + dy * dy) / dist));
+            }
+            multiply(trans_affine_rotation(atan2(dy, dx)));
+            multiply(trans_affine_translation(x1, y1));
+        }
+    };
+
+
+    //============================================trans_affine_reflection_unit
+    // Reflection matrix. Reflect coordinates across the line through 
+    // the origin containing the unit vector (ux, uy).
+    // Contributed by John Horigan
+    class trans_affine_reflection_unit : public trans_affine
+    {
+    public:
+        trans_affine_reflection_unit(double ux, double uy) :
+          trans_affine(2.0 * ux * ux - 1.0, 
+                       2.0 * ux * uy, 
+                       2.0 * ux * uy, 
+                       2.0 * uy * uy - 1.0, 
+                       0.0, 0.0)
+        {}
+    };
+
+
+    //=================================================trans_affine_reflection
+    // Reflection matrix. Reflect coordinates across the line through 
+    // the origin at the angle a or containing the non-unit vector (x, y).
+    // Contributed by John Horigan
+    class trans_affine_reflection : public trans_affine_reflection_unit
+    {
+    public:
+        trans_affine_reflection(double a) :
+          trans_affine_reflection_unit(cos(a), sin(a))
+        {}
+
+
+        trans_affine_reflection(double x, double y) :
+          trans_affine_reflection_unit(x / sqrt(x * x + y * y), y / sqrt(x * x + y * y))
+        {}
+    };
+
+}
+
+
+#endif
+

xs/src/agg/copying

@@ -0,0 +1,65 @@
+The Anti-Grain Geometry Project
+A high quality rendering engine for C++
+http://antigrain.com
+
+Anti-Grain Geometry has dual licensing model. The Modified BSD 
+License was first added in version v2.4 just for convenience.
+It is a simple, permissive non-copyleft free software license, 
+compatible with the GNU GPL. It's well proven and recognizable.
+See http://www.fsf.org/licensing/licenses/index_html#ModifiedBSD
+for details.
+
+Note that the Modified BSD license DOES NOT restrict your rights 
+if you choose the Anti-Grain Geometry Public License.
+
+
+
+
+Anti-Grain Geometry Public License
+====================================================
+
+Anti-Grain Geometry - Version 2.4 
+Copyright (C) 2002-2005 Maxim Shemanarev (McSeem) 
+
+Permission to copy, use, modify, sell and distribute this software 
+is granted provided this copyright notice appears in all copies. 
+This software is provided "as is" without express or implied
+warranty, and with no claim as to its suitability for any purpose.
+
+
+
+
+
+Modified BSD License
+====================================================
+Anti-Grain Geometry - Version 2.4 
+Copyright (C) 2002-2005 Maxim Shemanarev (McSeem) 
+
+Redistribution and use in source and binary forms, with or without 
+modification, are permitted provided that the following conditions 
+are met:
+
+  1. Redistributions of source code must retain the above copyright 
+     notice, this list of conditions and the following disclaimer. 
+
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in 
+     the documentation and/or other materials provided with the 
+     distribution. 
+
+  3. The name of the author may not be used to endorse or promote 
+     products derived from this software without specific prior 
+     written permission. 
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
+POSSIBILITY OF SUCH DAMAGE.
+

xs/src/libslic3r/Config.cpp

@@ -592,7 +592,7 @@ void StaticConfig::set_defaults()
 t_config_option_keys StaticConfig::keys() const 
 {
     t_config_option_keys keys;
-	assert(this->def != nullptr);
+    assert(this->def() != nullptr);
     for (const auto &opt_def : this->def()->options)
         if (this->option(opt_def.first) != nullptr) 
             keys.push_back(opt_def.first);

xs/src/libslic3r/Config.hpp

@@ -1035,7 +1035,7 @@ public:
     TYPE* option(const t_config_option_key &opt_key, bool create = false)
     { 
         ConfigOption *opt = this->optptr(opt_key, create);
-        assert(opt == nullptr || opt->type() == TYPE::static_type());
+//        assert(opt == nullptr || opt->type() == TYPE::static_type());
         return (opt == nullptr || opt->type() != TYPE::static_type()) ? nullptr : static_cast<TYPE*>(opt);
     }
     template<typename TYPE>

xs/src/libslic3r/Print.cpp

@@ -11,6 +11,10 @@
 #include <unordered_set>
 #include <boost/filesystem.hpp>
 #include <boost/lexical_cast.hpp>
+#include <boost/log/trivial.hpp>
+
+#include "slic3r/IProgressIndicator.hpp"
+#include "PrintExport.hpp"
 
 //! macro used to mark string used at localization, 
 //! return same string
@@ -1230,7 +1234,22 @@ std::string Print::output_filepath(const std::string &path)
 
 void Print::set_status(int percent, const std::string &message)
 {
-    printf("Print::status %d => %s\n", percent, message.c_str());
+    if(progressindicator) progressindicator->update(unsigned(percent), message);
+    else {
+        printf("Print::status %d => %s\n", percent, message.c_str());
+        std::cout.flush();
+    }
+}
+
+void Print::print_to_png(std::string dirpath) {
+    print_to<FilePrinterFormat::PNG>(*this,
+        dirpath,
+        float(this->config.bed_size_x.value),
+        float(this->config.bed_size_y.value),
+        int(this->config.pixel_width.value),
+        int(this->config.pixel_height.value),
+        float(this->config.exp_time.value),
+        float(this->config.exp_time_first.value));
 }
 
 // Returns extruder this eec should be printed with, according to PrintRegion config

xs/src/libslic3r/Print.hpp

@@ -227,6 +227,9 @@ private:
 typedef std::vector<PrintObject*> PrintObjectPtrs;
 typedef std::vector<PrintRegion*> PrintRegionPtrs;
 
+class IProgressIndicator;
+using ProgressIndicatorPtr = std::shared_ptr<IProgressIndicator>;
+
 // The complete print tray with possibly multiple objects.
 class Print
 {
@@ -237,7 +240,10 @@ public:
     PrintObjectPtrs objects;
     PrintRegionPtrs regions;
     PlaceholderParser placeholder_parser;
+
     // TODO: status_cb
+    ProgressIndicatorPtr            progressindicator;
+
     std::string                     estimated_normal_print_time;
     std::string                     estimated_silent_print_time;
     double                          total_used_filament, total_extruded_volume, total_cost, total_weight;
@@ -322,8 +328,10 @@ public:
     // Has the calculation been canceled?
     bool canceled() { return m_canceled; }
 
+    void print_to_png(std::string dirpath);
 
 private:
+
     bool invalidate_state_by_config_options(const std::vector<t_config_option_key> &opt_keys);
     PrintRegionConfig _region_config_from_model_volume(const ModelVolume &volume);
 

xs/src/libslic3r/PrintConfig.cpp

@@ -2122,6 +2122,52 @@ void PrintConfigDef::init_fff_params()
     def->sidetext = L("mm");
     def->cli = "z-offset=f";
     def->default_value = new ConfigOptionFloat(0);
+
+    def = this->add("bed_size_x", coFloat);
+    def->label = L("Bed size X");
+    def->category = L("Dwarf");
+    def->sidetext = L("mm");
+    def->cli = "bed-size-x=f";
+    def->default_value = new ConfigOptionFloat(68.);
+
+    def = this->add("bed_size_y", coFloat);
+    def->label = L("Bed size Y");
+    def->category = L("Dwarf");
+    def->sidetext = L("mm");
+    def->cli = "bed-size-y=f";
+    def->default_value = new ConfigOptionFloat(120.);
+
+    def = this->add("pixel_width", coInt);
+    def->label = L("Picture resolution X");
+    def->category = L("Dwarf");
+    def->sidetext = L("px");
+    def->cli = "pixel-width=i";
+    def->min = 1;
+    def->default_value = new ConfigOptionInt(1440);
+
+    def = this->add("pixel_height", coInt);
+    def->label = L("Picture resolution Y");
+    def->category = L("Dwarf");
+    def->sidetext = L("px");
+    def->cli = "pixel-height=i";
+    def->min = 1;
+    def->default_value = new ConfigOptionInt(2560);
+
+    def = this->add("exp_time", coFloat);
+    def->label = L("Exposure time");
+    def->category = L("Dwarf");
+    def->sidetext = L("s");
+    def->cli = "exp-time=f";
+    def->min = 1;
+    def->default_value = new ConfigOptionFloat(8.);
+
+    def = this->add("exp_time_first", coFloat);
+    def->label = L("Exposure time first layers");
+    def->category = L("Dwarf");
+    def->sidetext = L("s");
+    def->cli = "exp-time-first=f";
+    def->min = 1;
+    def->default_value = new ConfigOptionFloat(35.);
 }
 
 void PrintConfigDef::init_sla_params()

xs/src/libslic3r/PrintConfig.hpp

@@ -750,6 +750,12 @@ public:
     ConfigOptionFloats              wiping_volumes_matrix;
     ConfigOptionFloats              wiping_volumes_extruders;
     ConfigOptionFloat               z_offset;
+    ConfigOptionFloat               bed_size_x;
+    ConfigOptionFloat               bed_size_y;
+    ConfigOptionInt                 pixel_width;
+    ConfigOptionInt                 pixel_height;
+    ConfigOptionFloat               exp_time;
+    ConfigOptionFloat               exp_time_first;
     
 protected:
     PrintConfig(int) : GCodeConfig(1) {}
@@ -821,6 +827,12 @@ protected:
         OPT_PTR(wiping_volumes_matrix);
         OPT_PTR(wiping_volumes_extruders);
         OPT_PTR(z_offset);
+        OPT_PTR(bed_size_x);
+        OPT_PTR(bed_size_y);
+        OPT_PTR(pixel_width);
+        OPT_PTR(pixel_height);
+        OPT_PTR(exp_time);
+        OPT_PTR(exp_time_first);
     }
 };
 

xs/src/libslic3r/PrintExport.hpp

@@ -0,0 +1,389 @@
+#ifndef PRINTEXPORT_HPP
+#define PRINTEXPORT_HPP
+
+#include "Print.hpp"
+
+// For png export of the sliced model
+#include <fstream>
+#include <sstream>
+
+#include <wx/stdstream.h>
+#include <wx/wfstream.h>
+#include <wx/zipstrm.h>
+
+#include <boost/log/trivial.hpp>
+
+#include "Rasterizer/Rasterizer.hpp"
+#include <tbb/parallel_for.h>
+#include <tbb/spin_mutex.h>//#include "tbb/mutex.h"
+
+namespace Slic3r {
+
+enum class FilePrinterFormat {
+    PNG,
+    SVG
+};
+
+/*
+ * Interface for a file printer of the slices. Implementation can be an SVG
+ * or PNG printer or any other format.
+ *
+ * The format argument specifies the output format of the printer and it enables
+ * different implementations of this class template for each supported format.
+ *
+ */
+template<FilePrinterFormat format>
+class FilePrinter {
+public:
+
+    void printConfig(const Print&);
+
+    // Draw an ExPolygon which is a polygon inside a slice on the specified layer.
+    void drawPolygon(const ExPolygon& p, unsigned lyr);
+
+    // Tell the printer how many layers should it consider.
+    void layers(unsigned layernum);
+
+    // Get the number of layers in the print.
+    unsigned layers() const;
+
+    /* Switch to a particular layer. If there where less layers then the
+     * specified layer number than an appropriate number of layers will be
+     * allocated in the printer.
+     */
+    void beginLayer(unsigned layer);
+
+    // Allocate a new layer on top of the last and switch to it.
+    void beginLayer();
+
+    /*
+     * Finish the selected layer. It means that no drawing is allowed on that
+     * layer anymore. This fact can be used to prepare the file system output
+     * data like png comprimation and so on.
+     */
+    void finishLayer(unsigned layer);
+
+    // Finish the top layer.
+    void finishLayer();
+
+    // Save all the layers into the file (or dir) specified in the path argument
+    void save(const std::string& path);
+
+    // Save only the selected layer to the file specified in path argument.
+    void saveLayer(unsigned lyr, const std::string& path);
+};
+
+// Implementation for PNG raster output
+// Be aware that if a large number of layers are allocated, it can very well
+// exhaust the available memory especially on 32 bit platform.
+template<> class FilePrinter<FilePrinterFormat::PNG> {
+
+    struct Layer {
+        Raster first;
+        std::stringstream second;
+
+        Layer() {}
+
+        Layer(const Layer&) = delete;
+        Layer(Layer&& m):
+            first(std::move(m.first))/*, second(std::move(m.second))*/ {}
+    };
+
+    // We will save the compressed PNG data into stringstreams which can be done
+    // in parallel. Later we can write every layer to the disk sequentially.
+    std::vector<Layer> layers_rst_;
+    Raster::Resolution res_;
+    Raster::PixelDim pxdim_;
+    const Print *print_ = nullptr;
+    double exp_time_s_ = .0, exp_time_first_s_ = .0;
+
+    std::string createIniContent(const std::string& projectname) {
+        double layer_height = print_?
+                    print_->default_object_config.layer_height.getFloat() :
+                    0.05;
+
+        using std::string;
+        using std::to_string;
+
+        auto expt_str = to_string(exp_time_s_);
+        auto expt_first_str = to_string(exp_time_first_s_);
+        auto stepnum_str = to_string(static_cast<unsigned>(800*layer_height));
+        auto layerh_str = to_string(layer_height);
+
+        return string(
+        "action = print\n"
+        "jobDir = ") + projectname + "\n" +
+        "expTime = " + expt_str + "\n"
+        "expTimeFirst = " + expt_first_str + "\n"
+        "stepNum = " + stepnum_str + "\n"
+        "wifiOn = 1\n"
+        "tiltSlow = 60\n"
+        "tiltFast = 15\n"
+        "numFade = 10\n"
+        "startdelay = 0\n"
+        "layerHeight = " + layerh_str + "\n"
+        "noteInfo = "
+        "expTime="+expt_str+"+resinType=generic+layerHeight="
+                  +layerh_str+"+printer=DWARF3\n";
+    }
+
+    // Change this to TOP_LEFT if you want correct PNG orientation
+    static const Raster::Origin ORIGIN = Raster::Origin::BOTTOM_LEFT;
+
+public:
+    inline FilePrinter(double width_mm, double height_mm,
+                       unsigned width_px, unsigned height_px,
+                       double exp_time, double exp_time_first):
+        res_(width_px, height_px),
+        pxdim_(width_mm/width_px, height_mm/height_px),
+        exp_time_s_(exp_time),
+        exp_time_first_s_(exp_time_first)
+    {
+    }
+
+    FilePrinter(const FilePrinter& ) = delete;
+    FilePrinter(FilePrinter&& m):
+        layers_rst_(std::move(m.layers_rst_)),
+        res_(m.res_),
+        pxdim_(m.pxdim_) {}
+
+    inline void layers(unsigned cnt) { if(cnt > 0) layers_rst_.resize(cnt); }
+    inline unsigned layers() const { return layers_rst_.size(); }
+
+    void printConfig(const Print& printconf) { print_ = &printconf; }
+
+    inline void drawPolygon(const ExPolygon& p, unsigned lyr) {
+        assert(lyr < layers_rst_.size());
+        layers_rst_[lyr].first.draw(p);
+    }
+
+    inline void beginLayer(unsigned lyr) {
+        if(layers_rst_.size() <= lyr) layers_rst_.resize(lyr+1);
+        layers_rst_[lyr].first.reset(res_, pxdim_, ORIGIN);
+    }
+
+    inline void beginLayer() {
+        layers_rst_.emplace_back();
+        layers_rst_.front().first.reset(res_, pxdim_, ORIGIN);
+    }
+
+    inline void finishLayer(unsigned lyr_id) {
+        assert(lyr_id < layers_rst_.size());
+        layers_rst_[lyr_id].first.save(layers_rst_[lyr_id].second,
+                                       Raster::Compression::PNG);
+        layers_rst_[lyr_id].first.reset();
+    }
+
+    inline void finishLayer() {
+        if(!layers_rst_.empty()) {
+            layers_rst_.back().first.save(layers_rst_.back().second,
+                                          Raster::Compression::PNG);
+            layers_rst_.back().first.reset();
+        }
+    }
+
+    inline void save(const std::string& path) {
+
+        wxFileName filepath(path);
+
+        wxFFileOutputStream zipfile(path);
+
+        std::string project = filepath.GetName().ToStdString();
+
+        if(!zipfile.IsOk()) {
+            BOOST_LOG_TRIVIAL(error) << "Can't create zip file for layers! "
+                                     << path;
+            return;
+        }
+
+        wxZipOutputStream zipstream(zipfile);
+        wxStdOutputStream pngstream(zipstream);
+
+        zipstream.PutNextEntry("config.ini");
+        pngstream << createIniContent(project);
+
+        for(unsigned i = 0; i < layers_rst_.size(); i++) {
+            if(layers_rst_[i].second.rdbuf()->in_avail() > 0) {
+                char lyrnum[6];
+                std::sprintf(lyrnum, "%.5d", i);
+                auto zfilename = project + lyrnum + ".png";
+                zipstream.PutNextEntry(zfilename);
+                pngstream << layers_rst_[i].second.rdbuf();
+                layers_rst_[i].second.str("");
+            }
+        }
+
+        zipstream.Close();
+        zipfile.Close();
+    }
+
+    void saveLayer(unsigned lyr, const std::string& path) {
+        unsigned i = lyr;
+        assert(i < layers_rst_.size());
+
+        char lyrnum[6];
+        std::sprintf(lyrnum, "%.5d", lyr);
+        std::string loc = path + "layer" + lyrnum + ".png";
+
+        std::fstream out(loc, std::fstream::out | std::fstream::binary);
+        if(out.good()) {
+            layers_rst_[i].first.save(out, Raster::Compression::PNG);
+        } else {
+            BOOST_LOG_TRIVIAL(error) << "Can't create file for layer";
+        }
+
+        out.close();
+        layers_rst_[i].first.reset();
+    }
+};
+
+// Let's shadow this eigen interface
+inline coord_t px(const Point& p) { return p(0); }
+inline coord_t py(const Point& p) { return p(1); }
+inline coordf_t px(const Vec2d& p) { return p(0); }
+inline coordf_t py(const Vec2d& p) { return p(1); }
+
+template<FilePrinterFormat format, class...Args>
+void print_to(Print& print,
+              std::string dirpath,
+              double width_mm,
+              double height_mm,
+              Args&&...args)
+{
+
+    std::string& dir = dirpath;
+
+    // This map will hold the layers sorted by z coordinate. Layers on the
+    // same height (from different objects) will be mapped to the same key and
+    // rasterized to the same image.
+    std::map<long long, LayerPtrs> layers;
+
+    auto& objects = print.objects;
+
+    // Merge the sliced layers with the support layers
+    std::for_each(objects.begin(), objects.end(), [&layers](PrintObject *o) {
+        for(auto l : o->layers) {
+            auto& lyrs = layers[static_cast<long long>(scale_(l->print_z))];
+            lyrs.push_back(l);
+        }
+
+        for(auto l : o->support_layers) {
+            auto& lyrs = layers[static_cast<long long>(scale_(l->print_z))];
+            lyrs.push_back(l);
+        }
+    });
+
+    auto print_bb = print.bounding_box();
+    Vec2d punsc = unscale(print_bb.size());
+
+    // If the print does not fit into the print area we should cry about it.
+    if(px(punsc) > width_mm || py(punsc) > height_mm) {
+        BOOST_LOG_TRIVIAL(warning) << "Warning: Print will not fit!" << "\n"
+            << "Width needed: " << px(punsc) << "\n"
+            << "Height needed: " << py(punsc) << "\n";
+    }
+
+    // Offset for centering the print onto the print area
+    auto cx = scale_(width_mm)/2 - (px(print_bb.center()) - px(print_bb.min));
+    auto cy = scale_(height_mm)/2 - (py(print_bb.center()) - py(print_bb.min));
+
+    // Create the actual printer, forward any additional arguments to it.
+    FilePrinter<format> printer(width_mm, height_mm,
+                                std::forward<Args>(args)...);
+
+    printer.printConfig(print);
+
+    printer.layers(layers.size());  // Allocate space for all the layers
+
+    int st_prev = 0;
+    const std::string jobdesc = "Rasterizing and compressing sliced layers";
+    tbb::spin_mutex m;
+
+    std::vector<long long> keys;
+    keys.reserve(layers.size());
+    for(auto& e : layers) keys.push_back(e.first);
+
+    int initstatus = print.progressindicator? print.progressindicator->state()
+                                            : 0;
+    print.set_status(initstatus, jobdesc);
+
+    // Method that prints one layer
+    auto process_layer = [&layers, &keys, &printer, &st_prev, &m,
+            &jobdesc, print_bb, dir, cx, cy, &print, initstatus]
+            (unsigned layer_id)
+    {
+        LayerPtrs lrange = layers[keys[layer_id]];
+
+        printer.beginLayer(layer_id);   // Switch to the appropriate layer
+
+        for(Layer *lp : lrange) {
+            Layer& l = *lp;
+
+            ExPolygonCollection slices = l.slices;  // Copy the layer slices
+
+            // Sort the polygons in the layer
+            std::stable_sort(slices.expolygons.begin(), slices.expolygons.end(),
+                             [](const ExPolygon& a, const ExPolygon& b) {
+                return a.contour.contains(b.contour.first_point()) ? false :
+                                                                     true;
+            });
+
+            // Draw all the polygons in the slice to the actual layer.
+            std::for_each(l.object()->_shifted_copies.begin(),
+                          l.object()->_shifted_copies.end(),
+                          [&] (Point d)
+            {
+                std::for_each(slices.expolygons.begin(),
+                              slices.expolygons.end(),
+                              [&] (ExPolygon slice)
+                {
+                    slice.translate(px(d), py(d));
+                    slice.translate(-px(print_bb.min) + cx,
+                                    -py(print_bb.min) + cy);
+
+                    printer.drawPolygon(slice, layer_id);
+                });
+            });
+
+            /*if(print.has_support_material() && layer_id > 0) {
+                BOOST_LOG_TRIVIAL(warning) << "support material for layer "
+                                           << layer_id
+                                           << " defined but export is "
+                                              "not yet implemented.";
+
+            }*/
+
+        }
+
+        printer.finishLayer(layer_id);  // Finish the layer for later saving it.
+
+        auto st = static_cast<int>(layer_id*80.0/layers.size());
+        m.lock();
+        if( st - st_prev > 10) {
+            print.set_status(initstatus + st, jobdesc);
+            st_prev = st;
+        }
+        m.unlock();
+
+        // printer.saveLayer(layer_id, dir); We could save the layer immediately
+    };
+
+    // Print all the layers in parallel
+    tbb::parallel_for<size_t, decltype(process_layer)>(0,
+                                                       layers.size(),
+                                                       process_layer);
+
+    // Sequential version (for testing)
+    // for(unsigned l = 0; l < layers.size(); ++l) process_layer(l);
+
+//    print.set_status(100, jobdesc);
+
+    // Save the print into the file system.
+    print.set_status(initstatus + 90, "Writing layers to disk");
+    printer.save(dir);
+    print.set_status(initstatus + 100, "Writing layers completed");
+}
+
+}
+
+#endif // PRINTEXPORT_HPP

xs/src/libslic3r/Rasterizer/Rasterizer.cpp

@@ -0,0 +1,214 @@
+#include "Rasterizer.hpp"
+#include <ExPolygon.hpp>
+
+#include <cstdint>
+
+// For rasterizing
+#include <agg/agg_basics.h>
+#include <agg/agg_rendering_buffer.h>
+#include <agg/agg_pixfmt_gray.h>
+#include <agg/agg_pixfmt_rgb.h>
+#include <agg/agg_renderer_base.h>
+#include <agg/agg_renderer_scanline.h>
+
+#include <agg/agg_scanline_p.h>
+#include <agg/agg_rasterizer_scanline_aa.h>
+#include <agg/agg_path_storage.h>
+
+// For png compression
+#include <png/writer.hpp>
+
+namespace Slic3r {
+
+class Raster::Impl {
+public:
+    using TPixelRenderer = agg::pixfmt_gray8; // agg::pixfmt_rgb24;
+    using TRawRenderer = agg::renderer_base<TPixelRenderer>;
+    using TPixel = TPixelRenderer::color_type;
+    using TRawBuffer = agg::rendering_buffer;
+
+    using TBuffer = std::vector<TPixelRenderer::pixel_type>;
+
+    using TRendererAA = agg::renderer_scanline_aa_solid<TRawRenderer>;
+
+    static const TPixel ColorWhite;
+    static const TPixel ColorBlack;
+
+    using Origin = Raster::Origin;
+
+private:
+    Raster::Resolution resolution_;
+    Raster::PixelDim pxdim_;
+    TBuffer buf_;
+    TRawBuffer rbuf_;
+    TPixelRenderer pixfmt_;
+    TRawRenderer raw_renderer_;
+    TRendererAA renderer_;
+    Origin o_;
+    std::function<void(agg::path_storage&)> flipy_ = [](agg::path_storage&) {};
+public:
+    inline Impl(const Raster::Resolution& res, const Raster::PixelDim &pd,
+                Origin o):
+        resolution_(res), pxdim_(pd),
+        buf_(res.pixels()),
+        rbuf_(reinterpret_cast<TPixelRenderer::value_type*>(buf_.data()),
+              res.width_px, res.height_px,
+              res.width_px*TPixelRenderer::num_components),
+        pixfmt_(rbuf_),
+        raw_renderer_(pixfmt_),
+        renderer_(raw_renderer_),
+        o_(o)
+    {
+        renderer_.color(ColorWhite);
+
+        // If we would like to play around with gamma
+        // ras.gamma(agg::gamma_power(1.0));
+
+        clear();
+
+        if(o_ == Origin::TOP_LEFT) flipy_ = [this](agg::path_storage& path) {
+            path.flip_y(0, resolution_.height_px);
+        };
+    }
+
+    void draw(const ExPolygon &poly) {
+        agg::rasterizer_scanline_aa<> ras;
+        agg::scanline_p8 scanlines;
+
+        auto&& path = to_path(poly.contour);
+        flipy_(path);
+        ras.add_path(path);
+
+        for(auto h : poly.holes) {
+            auto&& holepath = to_path(h);
+            flipy_(holepath);
+            ras.add_path(holepath);
+        }
+
+        agg::render_scanlines(ras, scanlines, renderer_);
+    }
+
+    inline void clear() {
+        raw_renderer_.clear(ColorBlack);
+    }
+
+    inline TBuffer& buffer()  { return buf_; }
+
+    inline const Raster::Resolution resolution() { return resolution_; }
+
+    inline Origin origin() const /*noexcept*/ { return o_; }
+
+private:
+    double getPx(const Point& p) {
+        return p(0) * SCALING_FACTOR/pxdim_.w_mm;
+    }
+
+    double getPy(const Point& p) {
+        return p(1) * SCALING_FACTOR/pxdim_.h_mm;
+    }
+
+    agg::path_storage to_path(const Polygon& poly) {
+        agg::path_storage path;
+        auto it = poly.points.begin();
+        path.move_to(getPx(*it), getPy(*it));
+        while(++it != poly.points.end())
+            path.line_to(getPx(*it), getPy(*it));
+
+        path.line_to(getPx(poly.points.front()), getPy(poly.points.front()));
+        return path;
+    }
+
+};
+
+const Raster::Impl::TPixel Raster::Impl::ColorWhite = Raster::Impl::TPixel(255);
+const Raster::Impl::TPixel Raster::Impl::ColorBlack = Raster::Impl::TPixel(0);
+
+Raster::Raster(const Resolution &r, const PixelDim &pd, Origin o):
+    impl_(new Impl(r, pd, o)) {}
+
+Raster::Raster() {}
+
+Raster::~Raster() {}
+
+Raster::Raster(Raster &&m):
+    impl_(std::move(m.impl_)) {}
+
+void Raster::reset(const Raster::Resolution &r, const Raster::PixelDim &pd)
+{
+    // Free up the unnecessary memory and make sure it stays clear after
+    // an exception
+    auto o = impl_? impl_->origin() : Origin::TOP_LEFT;
+    reset(r, pd, o);
+}
+
+void Raster::reset(const Raster::Resolution &r, const Raster::PixelDim &pd,
+                   Raster::Origin o)
+{
+    impl_.reset();
+    impl_.reset(new Impl(r, pd, o));
+}
+
+void Raster::reset()
+{
+    impl_.reset();
+}
+
+Raster::Resolution Raster::resolution() const
+{
+    if(impl_) return impl_->resolution();
+
+    return Resolution(0, 0);
+}
+
+void Raster::clear()
+{
+    assert(impl_);
+    impl_->clear();
+}
+
+void Raster::draw(const ExPolygon &poly)
+{
+    assert(impl_);
+    impl_->draw(poly);
+}
+
+void Raster::save(std::ostream& stream, Compression comp)
+{
+    assert(impl_);
+    switch(comp) {
+    case Compression::PNG: {
+
+        png::writer<std::ostream> wr(stream);
+
+        wr.set_bit_depth(8);
+        wr.set_color_type(png::color_type_gray);
+        wr.set_width(resolution().width_px);
+        wr.set_height(resolution().height_px);
+        wr.set_compression_type(png::compression_type_default);
+
+        wr.write_info();
+
+        auto& b = impl_->buffer();
+        auto ptr = reinterpret_cast<png::byte*>( b.data() );
+        unsigned stride =
+                sizeof(Impl::TBuffer::value_type) *  resolution().width_px;
+
+        for(unsigned r = 0; r < resolution().height_px; r++, ptr+=stride) {
+            wr.write_row(ptr);
+        }
+
+        break;
+    }
+    case Compression::RAW: {
+        stream << "P5 "
+               << impl_->resolution().width_px << " "
+               << impl_->resolution().height_px << " "
+               << "255 ";
+
+        stream.write(reinterpret_cast<const char*>(impl_->buffer().data()),
+                     impl_->buffer().size()*sizeof(Impl::TBuffer::value_type));
+    }
+    }
+}
+
+}

xs/src/libslic3r/Rasterizer/Rasterizer.hpp

@@ -0,0 +1,86 @@
+#ifndef RASTERIZER_HPP
+#define RASTERIZER_HPP
+
+#include <ostream>
+#include <memory>
+
+namespace Slic3r {
+
+class ExPolygon;
+
+/**
+ * @brief Raster captures an anti-aliased monochrome canvas where vectorial
+ * polygons can be rasterized. Fill color is always white and the background is
+ * black. Contours are anti-aliased.
+ *
+ * It also supports saving the raster data into a standard output stream in raw
+ * or PNG format.
+ */
+class Raster {
+    class Impl;
+    std::unique_ptr<Impl> impl_;
+public:
+
+    /// Supported compression types
+    enum class Compression {
+        RAW,    //!> Uncompressed pixel data
+        PNG     //!> PNG compression
+    };
+
+    enum class Origin {
+        TOP_LEFT,
+        BOTTOM_LEFT
+    };
+
+    /// Type that represents a resolution in pixels.
+    struct Resolution {
+        unsigned width_px;
+        unsigned height_px;
+        inline Resolution(unsigned w, unsigned h): width_px(w), height_px(h) {}
+        inline unsigned pixels() const /*noexcept*/ {
+            return width_px * height_px;
+        }
+    };
+
+    /// Types that represents the dimension of a pixel in millimeters.
+    struct PixelDim {
+        double w_mm;
+        double h_mm;
+        inline PixelDim(double px_width_mm, double px_height_mm ):
+            w_mm(px_width_mm), h_mm(px_height_mm) {}
+    };
+
+    /// Constructor taking the resolution and the pixel dimension.
+    explicit Raster(const Resolution& r, const PixelDim& pd,
+                    Origin o = Origin::BOTTOM_LEFT );
+    Raster();
+    Raster(const Raster& cpy) = delete;
+    Raster& operator=(const Raster& cpy) = delete;
+    Raster(Raster&& m);
+    ~Raster();
+
+    /// Reallocated everything for the given resolution and pixel dimension.
+    void reset(const Resolution& r, const PixelDim& pd);
+    void reset(const Resolution& r, const PixelDim& pd, Origin o);
+
+    /**
+     * Release the allocated resources. Drawing in this state ends in
+     * unspecified behaviour.
+     */
+    void reset();
+
+    /// Get the resolution of the raster.
+    Resolution resolution() const;
+
+    /// Clear the raster with black color.
+    void clear();
+
+    /// Draw a polygon with holes.
+    void draw(const ExPolygon& poly);
+
+    /// Save the raster on the specified stream.
+    void save(std::ostream& stream, Compression comp = Compression::RAW);
+};
+
+}
+#endif // RASTERIZER_HPP

xs/src/libslic3r/SLABasePool.cpp

@@ -0,0 +1,526 @@
+#include <functional>
+#include <numeric>
+
+#include "SLABasePool.hpp"
+#include "ExPolygon.hpp"
+#include "TriangleMesh.hpp"
+#include "ClipperUtils.hpp"
+#include "boost/log/trivial.hpp"
+
+//#include "SVG.hpp"
+
+namespace Slic3r { namespace sla {
+
+namespace {
+
+using coord_t = Point::coord_type;
+
+/// get the scaled clipper units for a millimeter value
+inline coord_t mm(double v) { return coord_t(v/SCALING_FACTOR); }
+
+/// Get x and y coordinates (because we are eigenizing...)
+inline coord_t x(const Point& p) { return p(0); }
+inline coord_t y(const Point& p) { return p(1); }
+inline coord_t& x(Point& p) { return p(0); }
+inline coord_t& y(Point& p) { return p(1); }
+
+inline coordf_t x(const Vec3d& p) { return p(0); }
+inline coordf_t y(const Vec3d& p) { return p(1); }
+inline coordf_t z(const Vec3d& p) { return p(2); }
+inline coordf_t& x(Vec3d& p) { return p(0); }
+inline coordf_t& y(Vec3d& p) { return p(1); }
+inline coordf_t& z(Vec3d& p) { return p(2); }
+
+inline coord_t& x(Vec3crd& p) { return p(0); }
+inline coord_t& y(Vec3crd& p) { return p(1); }
+inline coord_t& z(Vec3crd& p) { return p(2); }
+inline coord_t x(const Vec3crd& p) { return p(0); }
+inline coord_t y(const Vec3crd& p) { return p(1); }
+inline coord_t z(const Vec3crd& p) { return p(2); }
+
+inline void triangulate(const ExPolygon& expoly, Polygons& triangles) {
+    expoly.triangulate_p2t(&triangles);
+}
+
+inline Polygons triangulate(const ExPolygon& expoly) {
+    Polygons tri; triangulate(expoly, tri); return tri;
+}
+
+using Indices = std::vector<Vec3crd>;
+
+/// Intermediate struct for a 3D mesh
+struct Contour3D {
+    Pointf3s points;
+    Indices indices;
+
+    void merge(const Contour3D& ctr) {
+        auto s3 = coord_t(points.size());
+        auto s = coord_t(indices.size());
+
+        points.insert(points.end(), ctr.points.begin(), ctr.points.end());
+        indices.insert(indices.end(), ctr.indices.begin(), ctr.indices.end());
+
+        for(auto n = s; n < indices.size(); n++) {
+            auto& idx = indices[n]; x(idx) += s3; y(idx) += s3; z(idx) += s3;
+        }
+    }
+};
+
+/// Convert the triangulation output to an intermediate mesh.
+inline Contour3D convert(const Polygons& triangles, coord_t z, bool dir) {
+
+    Pointf3s points;
+    points.reserve(3*triangles.size());
+    Indices indices;
+    indices.reserve(points.size());
+
+    for(auto& tr : triangles) {
+        auto c = coord_t(points.size()), b = c++, a = c++;
+        if(dir) indices.emplace_back(a, b, c);
+        else indices.emplace_back(c, b, a);
+        for(auto& p : tr.points) {
+            points.emplace_back(unscale(x(p), y(p), z));
+        }
+    }
+
+    return {points, indices};
+}
+
+/// Only a debug function to generate top and bottom plates from a 2D shape.
+/// It is not used in the algorithm directly.
+inline Contour3D roofs(const ExPolygon& poly, coord_t z_distance) {
+    Polygons triangles = triangulate(poly);
+
+    auto lower = convert(triangles, 0, false);
+    auto upper = convert(triangles, z_distance, true);
+    lower.merge(upper);
+    return lower;
+}
+
+inline Contour3D walls(const ExPolygon& floor_plate, const ExPolygon& ceiling,
+                       double floor_z_mm, double ceiling_z_mm) {
+    using std::transform; using std::back_inserter;
+
+    ExPolygon poly;
+    poly.contour.points = floor_plate.contour.points;
+    poly.holes.emplace_back(ceiling.contour);
+    auto& h = poly.holes.front();
+    std::reverse(h.points.begin(), h.points.end());
+    Polygons tri = triangulate(poly);
+
+    Contour3D ret;
+    ret.points.reserve(tri.size() * 3);
+
+    double fz = floor_z_mm;
+    double cz = ceiling_z_mm;
+    auto& rp = ret.points;
+    auto& rpi = ret.indices;
+    ret.indices.reserve(tri.size() * 3);
+
+    coord_t idx = 0;
+
+    auto hlines = h.lines();
+    auto is_upper = [&hlines](const Point& p) {
+        return std::any_of(hlines.begin(), hlines.end(),
+                               [&p](const Line& l) {
+            return l.distance_to(p) < mm(0.01);
+        });
+    };
+
+    std::for_each(tri.begin(), tri.end(),
+                  [&rp, &rpi, &poly, &idx, is_upper, fz, cz](const Polygon& pp)
+    {
+        for(auto& p : pp.points)
+            if(is_upper(p))
+                rp.emplace_back(unscale(x(p), y(p), mm(cz)));
+            else rp.emplace_back(unscale(x(p), y(p), mm(fz)));
+
+        coord_t a = idx++, b = idx++, c = idx++;
+        if(fz > cz) rpi.emplace_back(c, b, a);
+        else rpi.emplace_back(a, b, c);
+    });
+
+    return ret;
+}
+
+/// Mesh from an existing contour.
+inline TriangleMesh mesh(const Contour3D& ctour) {
+    return {ctour.points, ctour.indices};
+}
+
+/// Mesh from an evaporating 3D contour
+inline TriangleMesh mesh(Contour3D&& ctour) {
+    return {std::move(ctour.points), std::move(ctour.indices)};
+}
+
+/// Offsetting with clipper and smoothing the edges into a curvature.
+inline void offset(ExPolygon& sh, coord_t distance) {
+    using ClipperLib::ClipperOffset;
+    using ClipperLib::jtRound;
+    using ClipperLib::etClosedPolygon;
+    using ClipperLib::Paths;
+    using ClipperLib::Path;
+
+    auto&& ctour = Slic3rMultiPoint_to_ClipperPath(sh.contour);
+    auto&& holes = Slic3rMultiPoints_to_ClipperPaths(sh.holes);
+
+    // If the input is not at least a triangle, we can not do this algorithm
+    if(ctour.size() < 3 ||
+       std::any_of(holes.begin(), holes.end(),
+                   [](const Path& p) { return p.size() < 3; })
+            ) {
+        BOOST_LOG_TRIVIAL(error) << "Invalid geometry for offsetting!";
+        return;
+    }
+
+    ClipperOffset offs;
+    offs.ArcTolerance = 0.01*mm(1);
+    Paths result;
+    offs.AddPath(ctour, jtRound, etClosedPolygon);
+    offs.AddPaths(holes, jtRound, etClosedPolygon);
+    offs.Execute(result, static_cast<double>(distance));
+
+    // Offsetting reverts the orientation and also removes the last vertex
+    // so boost will not have a closed polygon.
+
+    bool found_the_contour = false;
+    sh.holes.clear();
+    for(auto& r : result) {
+        if(ClipperLib::Orientation(r)) {
+            // We don't like if the offsetting generates more than one contour
+            // but throwing would be an overkill. Instead, we should warn the
+            // caller about the inability to create correct geometries
+            if(!found_the_contour) {
+                auto rr = ClipperPath_to_Slic3rPolygon(r);
+                sh.contour.points.swap(rr.points);
+                found_the_contour = true;
+            } else {
+                BOOST_LOG_TRIVIAL(warning)
+                        << "Warning: offsetting result is invalid!";
+            }
+        } else {
+            // TODO If there are multiple contours we can't be sure which hole
+            // belongs to the first contour. (But in this case the situation is
+            // bad enough to let it go...)
+            sh.holes.emplace_back(ClipperPath_to_Slic3rPolygon(r));
+        }
+    }
+}
+
+template<class ExP, class D>
+inline Contour3D round_edges(const ExPolygon& base_plate,
+                            double radius_mm,
+                            double degrees,
+                            double ceilheight_mm,
+                            bool dir,
+                            ExP&& last_offset = ExP(), D&& last_height = D())
+{
+    auto ob = base_plate;
+    auto ob_prev = ob;
+    double wh = ceilheight_mm, wh_prev = wh;
+    Contour3D curvedwalls;
+
+    const size_t steps = 6;     // steps for 180 degrees
+    degrees = std::fmod(degrees, 180);
+    const int portion = int(steps*degrees / 90);
+    const double ystep_mm = radius_mm/steps;
+    coord_t s = dir? 1 : -1;
+    double xxprev = 0;
+    for(int i = 0; i < portion; i++) {
+        ob = base_plate;
+
+        // The offset is given by the equation: x = sqrt(r^2 - y^2)
+        // which can be derived from the circle equation. y is the current
+        // height for which the offset is calculated and x is the offset itself
+        // r is the radius of the circle that is used to smooth the edges
+
+        double r2 = radius_mm * radius_mm;
+        double y2 = steps*ystep_mm - i*ystep_mm;
+        y2 *= y2;
+
+        double xx = sqrt(r2 - y2);
+
+        offset(ob, s*mm(xx));
+        wh = ceilheight_mm - i*ystep_mm;
+
+        Contour3D pwalls;
+        if(xxprev < xx) pwalls = walls(ob, ob_prev, wh, wh_prev);
+        else pwalls = walls(ob_prev, ob, wh_prev, wh);
+
+        curvedwalls.merge(pwalls);
+        ob_prev = ob;
+        wh_prev = wh;
+        xxprev = xx;
+    }
+
+    last_offset = std::move(ob);
+    last_height = wh;
+
+    return curvedwalls;
+}
+
+/// Generating the concave part of the 3D pool with the bottom plate and the
+/// side walls.
+inline Contour3D inner_bed(const ExPolygon& poly, double depth_mm,
+                           double begin_h_mm = 0) {
+
+    Polygons triangles = triangulate(poly);
+
+    coord_t depth = mm(depth_mm);
+    coord_t begin_h = mm(begin_h_mm);
+
+    auto bottom = convert(triangles, -depth + begin_h, false);
+    auto lines = poly.lines();
+
+    // Generate outer walls
+    auto fp = [](const Point& p, Point::coord_type z) {
+        return unscale(x(p), y(p), z);
+    };
+
+    for(auto& l : lines) {
+        auto s = coord_t(bottom.points.size());
+
+        bottom.points.emplace_back(fp(l.a, -depth + begin_h));
+        bottom.points.emplace_back(fp(l.b, -depth + begin_h));
+        bottom.points.emplace_back(fp(l.a, begin_h));
+        bottom.points.emplace_back(fp(l.b, begin_h));
+
+        bottom.indices.emplace_back(s + 3, s + 1, s);
+        bottom.indices.emplace_back(s + 2, s + 3, s);
+    }
+
+    return bottom;
+}
+
+/// Unification of polygons (with clipper) preserving holes as well.
+inline ExPolygons unify(const ExPolygons& shapes) {
+    ExPolygons retv;
+
+    bool closed = true;
+    bool valid = true;
+
+    ClipperLib::Clipper clipper;
+
+    for(auto& path : shapes) {
+        auto clipperpath = Slic3rMultiPoint_to_ClipperPath(path.contour);
+        valid &= clipper.AddPath(clipperpath, ClipperLib::ptSubject, closed);
+
+        auto clipperholes = Slic3rMultiPoints_to_ClipperPaths(path.holes);
+        for(auto& hole : clipperholes) {
+            valid &= clipper.AddPath(hole, ClipperLib::ptSubject, closed);
+        }
+    }
+
+    if(!valid) BOOST_LOG_TRIVIAL(warning) << "Unification of invalid shapes!";
+
+    ClipperLib::PolyTree result;
+    clipper.Execute(ClipperLib::ctUnion, result, ClipperLib::pftNonZero);
+
+    retv.reserve(static_cast<size_t>(result.Total()));
+
+    // Now we will recursively traverse the polygon tree and serialize it
+    // into an ExPolygon with holes. The polygon tree has the clipper-ish
+    // PolyTree structure which alternates its nodes as contours and holes
+
+    // A "declaration" of function for traversing leafs which are holes
+    std::function<void(ClipperLib::PolyNode*, ExPolygon&)> processHole;
+
+    // Process polygon which calls processHoles which than calls processPoly
+    // again until no leafs are left.
+    auto processPoly = [&retv, &processHole](ClipperLib::PolyNode *pptr) {
+        ExPolygon poly;
+        poly.contour.points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
+        for(auto h : pptr->Childs) { processHole(h, poly); }
+        retv.push_back(poly);
+    };
+
+    // Body of the processHole function
+    processHole = [&processPoly](ClipperLib::PolyNode *pptr, ExPolygon& poly)
+    {
+        poly.holes.emplace_back();
+        poly.holes.back().points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
+        for(auto c : pptr->Childs) processPoly(c);
+    };
+
+    // Wrapper for traversing.
+    auto traverse = [&processPoly] (ClipperLib::PolyNode *node)
+    {
+        for(auto ch : node->Childs) {
+            processPoly(ch);
+        }
+    };
+
+    // Here is the actual traverse
+    traverse(&result);
+
+    return retv;
+}
+
+inline Point centroid(Points& pp) {
+    Point c;
+    switch(pp.size()) {
+    case 0: break;
+    case 1: c = pp.front(); break;
+    case 2: c = (pp[0] + pp[1]) / 2; break;
+    default: {
+        Polygon p;
+        p.points.swap(pp);
+        c = p.centroid();
+        pp.swap(p.points);
+        break;
+    }
+    }
+
+    return c;
+}
+
+inline Point centroid(const ExPolygon& poly) {
+    return poly.contour.centroid();
+}
+
+/// A fake concave hull that is constructed by connecting separate shapes
+/// with explicit bridges. Bridges are generated from each shape's centroid
+/// to the center of the "scene" which is the centroid calculated from the shape
+/// centroids (a star is created...)
+inline ExPolygons concave_hull(const ExPolygons& polys, double max_dist_mm = 0)
+{
+    if(polys.empty()) return ExPolygons();
+
+    ExPolygons punion = unify(polys);   // could be redundant
+
+    if(punion.size() == 1) return punion;
+
+    // We get the centroids of all the islands in the 2D slice
+    Points centroids; centroids.reserve(punion.size());
+    std::transform(punion.begin(), punion.end(), std::back_inserter(centroids),
+                   [](const ExPolygon& poly) { return centroid(poly); });
+
+    // Centroid of the centroids of islands. This is where the additional
+    // connector sticks are routed.
+    Point cc = centroid(centroids);
+
+    punion.reserve(punion.size() + centroids.size());
+
+    std::transform(centroids.begin(), centroids.end(),
+                   std::back_inserter(punion),
+                   [cc, max_dist_mm](const Point& c) {
+
+        double dx = x(c) - x(cc), dy = y(c) - y(cc);
+        double l = std::sqrt(dx * dx + dy * dy);
+        double nx = dx / l, ny = dy / l;
+
+        if(l < max_dist_mm) return ExPolygon();
+
+        ExPolygon r;
+        auto& ctour = r.contour.points;
+
+        ctour.reserve(3);
+        ctour.emplace_back(cc);
+
+        Point d(coord_t(mm(1)*nx), coord_t(mm(1)*ny));
+        ctour.emplace_back(c + Point( -y(d),  x(d) ));
+        ctour.emplace_back(c + Point(  y(d), -x(d) ));
+        offset(r, mm(1));
+
+        return r;
+    });
+
+    punion = unify(punion);
+
+    if(punion.size() != 1)
+        BOOST_LOG_TRIVIAL(error) << "Cannot generate correct SLA base pool!";
+
+    return punion;
+}
+
+}
+
+void ground_layer(const TriangleMesh &mesh, ExPolygons &output, float h)
+{
+    TriangleMesh m = mesh;
+    TriangleMeshSlicer slicer(&m);
+
+    std::vector<ExPolygons> tmp;
+
+    slicer.slice({h}, &tmp);
+
+    output = tmp.front();
+}
+
+void create_base_pool(const ExPolygons &ground_layer, TriangleMesh& out,
+                      double min_wall_thickness_mm,
+                      double min_wall_height_mm)
+{
+    auto concavehs = concave_hull(ground_layer);
+    for(ExPolygon& concaveh : concavehs) {
+        if(concaveh.contour.points.empty()) return;
+        concaveh.holes.clear();
+
+        BoundingBox bb(concaveh);
+        coord_t w = x(bb.max) - x(bb.min);
+        coord_t h = y(bb.max) - y(bb.min);
+
+        auto wall_thickness = coord_t(std::pow((w+h)*0.1, 0.8));
+
+        const coord_t WALL_THICKNESS = mm(min_wall_thickness_mm) +
+                                       wall_thickness;
+
+        const coord_t WALL_DISTANCE = coord_t(0.3*WALL_THICKNESS);
+        const coord_t HEIGHT = mm(min_wall_height_mm);
+
+        auto outer_base = concaveh;
+        offset(outer_base, WALL_THICKNESS+WALL_DISTANCE);
+        auto inner_base = outer_base;
+        offset(inner_base, -WALL_THICKNESS);
+        inner_base.holes.clear(); outer_base.holes.clear();
+
+        ExPolygon top_poly;
+        top_poly.contour = outer_base.contour;
+        top_poly.holes.emplace_back(inner_base.contour);
+        auto& tph = top_poly.holes.back().points;
+        std::reverse(tph.begin(), tph.end());
+
+        Contour3D pool;
+
+        ExPolygon ob = outer_base; double wh = 0;
+        auto curvedwalls = round_edges(ob,
+                                       1,    // radius 1 mm
+                                       170,  // 170 degrees
+                                       0,    // z position of the input plane
+                                       true,
+                                       ob, wh);
+        pool.merge(curvedwalls);
+
+        ExPolygon ob_contr = ob;
+        ob_contr.holes.clear();
+
+        auto pwalls = walls(ob_contr, inner_base, wh, -min_wall_height_mm);
+        pool.merge(pwalls);
+
+        Polygons top_triangles, bottom_triangles;
+        triangulate(top_poly, top_triangles);
+        triangulate(inner_base, bottom_triangles);
+        auto top_plate = convert(top_triangles, 0, false);
+        auto bottom_plate = convert(bottom_triangles, -HEIGHT, true);
+
+        ob = inner_base; wh = 0;
+        curvedwalls = round_edges(ob,
+                                  1,    // radius 1 mm
+                                  90,  // 170 degrees
+                                  0,    // z position of the input plane
+                                  false,
+                                  ob, wh);
+        pool.merge(curvedwalls);
+
+        auto innerbed = inner_bed(ob, min_wall_height_mm/2 + wh, wh);
+
+        pool.merge(top_plate);
+        pool.merge(bottom_plate);
+        pool.merge(innerbed);
+
+        out.merge(mesh(pool));
+    }
+}
+
+}
+}

xs/src/libslic3r/SLABasePool.hpp

@@ -0,0 +1,31 @@
+#ifndef SLASUPPORTPOOL_HPP
+#define SLASUPPORTPOOL_HPP
+
+#include <vector>
+
+namespace Slic3r {
+
+class ExPolygon;
+class TriangleMesh;
+
+namespace sla {
+
+using ExPolygons = std::vector<ExPolygon>;
+
+/// Calculate the polygon representing the slice of the lowest layer of mesh
+void ground_layer(const TriangleMesh& mesh,
+                  ExPolygons& output,
+                  float height = 0.1f);
+
+/// Calculate the pool for the mesh for SLA printing
+void create_base_pool(const ExPolygons& ground_layer,
+                      TriangleMesh& output_mesh,
+                      double min_wall_thickness_mm = 4,
+                      double min_wall_height_mm = 5
+                      );
+
+}
+
+}
+
+#endif // SLASUPPORTPOOL_HPP

xs/src/libslic3r/TriangleMesh.cpp

@@ -858,7 +858,7 @@ TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<ExPolygons>*
 #ifdef SLIC3R_TRIANGLEMESH_DEBUG
     			printf("Layer " PRINTF_ZU " (slice_z = %.2f):\n", layer_id, z[layer_id]);
 #endif
-    			this->make_expolygons(layers_p[layer_id], &(*layers)[layer_id]);
+                this->make_expolygons(layers_p[layer_id], &(*layers)[layer_id]);
     		}
     	});
 	BOOST_LOG_TRIVIAL(debug) << "TriangleMeshSlicer::make_expolygons in parallel - end";
@@ -1205,8 +1205,8 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
                 if ((ip1.edge_id  != -1 && ip1.edge_id  == ip2.edge_id) ||
                     (ip1.point_id != -1 && ip1.point_id == ip2.point_id)) {
                     // The current loop is complete. Add it to the output.
-                    assert(opl.points.front().point_id == opl.points.back().point_id);
-                    assert(opl.points.front().edge_id  == opl.points.back().edge_id);
+                    /*assert(opl.points.front().point_id == opl.points.back().point_id);
+                    assert(opl.points.front().edge_id  == opl.points.back().edge_id);*/
                     // Remove the duplicate last point.
                     opl.points.pop_back();
                     if (opl.points.size() >= 3) {

xs/src/png/AUTHORS

@@ -0,0 +1,4 @@
+png++ is written by Alexander Shulgin  (alex dot shulgin at gmail dot com)
+Copyright (C) 2007,2008
+
+When writing to me be sure to put png++: in the subject :-)

xs/src/png/COPYING

@@ -0,0 +1,25 @@
+Copying png++ is subject to the following license:
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+   1. Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+
+   2. Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+   3. The name of the author may not be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.

xs/src/png/NEWS

@@ -0,0 +1,60 @@
+Version 0.2.7:
+
+  - Added solid_pixel_buffer (patch by Andrey Potapov).
+
+  - Fixed some compilation problems on Win32.
+
+Version 0.2.5:
+
+  - Fixed compatibility with newer libpng versions (>= 1.4)
+
+  - Fixed compilation on FreeBSD.
+
+  - Fixed tRNS handling with transformations.
+
+  - Added IO transformation debugging facility.
+
+  - Better organized test suite.
+
+Version 0.2.3:
+
+  - Fixed numerous `already defined' errors due to require_color_space
+    implementation.
+
+  - Added `config.hpp'.
+
+  - Fixed `strerror' usage.
+
+  - Minor docs fixes.
+
+
+Version 0.2.1:
+
+  - Added support for tRNS chunk.
+
+  - Added non-std IO streams support.
+
+  - Fixed 16-bit endianness problems.
+
+  - Improved test script.
+
+
+Version 0.2.0:
+
+  - Added support for 16-bit data (RGB, RGBA, Grayscale and Gray+Alpha
+    color types)
+
+  - Added support for packed 1-, 2- or 4-bit pixels (Grayscale and
+    Indexed colors)
+
+  - Fixed interlace handling code which was severely broken
+
+  - Added possibility to process images without reading the entire
+    image into memory
+
+  - Internals are refactored while the client interface is mostly
+    unchanged
+
+  - Added intensive test suite
+
+  - Added documentation

xs/src/png/color.hpp

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_COLOR_HPP_INCLUDED
+#define PNGPP_COLOR_HPP_INCLUDED
+
+#include "types.hpp"
+
+namespace png
+{
+
+    /**
+     * \brief PNG color struct extension.  Adds constructors. 
+     */
+    struct color
+        : png_color
+    {
+        explicit color(byte r = 0, byte g = 0, byte b = 0)
+        {
+            this->red = r;
+            this->green = g;
+            this->blue = b;
+        }
+
+        /**
+         * \brief Initializes color with a copy of png_color object.
+         */
+        color(png_color const& other)
+        {
+            this->red = other.red;
+            this->green = other.green;
+            this->blue = other.blue;
+        }
+    };
+
+} // namespace png
+
+#endif // PNGPP_COLOR_HPP_INCLUDED

xs/src/png/end_info.hpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_END_INFO_HPP_INCLUDED
+#define PNGPP_END_INFO_HPP_INCLUDED
+
+#include "info_base.hpp"
+
+namespace png
+{
+
+    /**
+     * \brief Internal class to hold PNG ending %info.
+     *
+     * \see info, info_base
+     */
+    class end_info
+        : public info_base
+    {
+    public:
+        end_info(io_base& io, png_struct* png)
+            : info_base(io, png)
+        {
+        }
+
+        void destroy()
+        {
+            assert(m_info);
+            png_destroy_info_struct(m_png, & m_info);
+        }
+
+        void read()
+        {
+            png_read_end(m_png, m_info);
+        }
+        
+        void write() const
+        {
+            png_write_end(m_png, m_info);
+        }
+
+        // TODO: add methods to read/write text comments etc.
+    };
+
+} // namespace png
+
+#endif // PNGPP_END_INFO_HPP_INCLUDED

xs/src/png/error.hpp

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_ERROR_HPP_INCLUDED
+#define PNGPP_ERROR_HPP_INCLUDED
+
+/* check if we have strerror_s or strerror_r, prefer the former which is C11 std */
+#ifdef __STDC_LIB_EXT1__
+#define __STDC_WANT_LIB_EXT1__ 1
+#include <string.h>
+
+#define HAVE_STRERROR_S 1
+#else
+#undef  HAVE_STRERROR_S
+#endif
+
+#include <string>
+#include <stdexcept>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+
+namespace png
+{
+
+    /**
+     * \brief Exception class to represent runtime errors related to
+     * png++ operation.
+     */
+    class error
+        : public std::runtime_error
+    {
+    public:
+        /**
+         * \param  message  error description
+         */
+        explicit error(std::string const& message)
+            : std::runtime_error(message)
+        {
+        }
+    };
+
+    /**
+     * \brief Exception class to represent standard library errors
+     * (generally IO).
+     *
+     * \see  reader, writer
+     */
+    class std_error
+        : public std::runtime_error
+    {
+    public:
+        /**
+         * Constructs an std_error object.  The \a message string is
+         * appended with <tt>": "</tt> and the error description as
+         * returned by \c strerror(\a error).
+         *
+         * \param  message  error description
+         * \param  error    error number
+         */
+        explicit std_error(std::string const& message, int errnum = errno)
+            : std::runtime_error((message + ": ") + thread_safe_strerror(errnum))
+        {
+        }
+
+    protected:
+        static std::string thread_safe_strerror(int errnum)
+        {
+#define ERRBUF_SIZE 512
+
+#ifdef HAVE_STRERROR_S
+            char buf[ERRBUF_SIZE] = { 0 };
+            strerror_s(buf, ERRBUF_SIZE, errnum);
+            return std::string(buf);
+#else
+#if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE
+            char buf[ERRBUF_SIZE] = { 0 };
+            strerror_r(errnum, buf, ERRBUF_SIZE);
+            return std::string(buf);
+#elif _GNU_SOURCE
+            /* GNU variant can return a pointer to static buffer instead of buf */
+            char buf[ERRBUF_SIZE] = { 0 };
+            return std::string(strerror_r(errnum, buf, ERRBUF_SIZE));
+#else
+            return std::string("An error occured with errnum ") +
+                    std::to_string(errnum) +
+                    ". Converting to the appropriate error message is disabled"
+                    "in this instance of the png++ library.";
+#endif
+#endif
+
+#undef ERRBUF_SIZE
+        }
+    };
+
+} // namespace png
+
+#endif // PNGPP_ERROR_HPP_INCLUDED

xs/src/png/image_info.hpp

@@ -0,0 +1,215 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_IMAGE_INFO_HPP_INCLUDED
+#define PNGPP_IMAGE_INFO_HPP_INCLUDED
+
+#include "types.hpp"
+#include "palette.hpp"
+#include "tRNS.hpp"
+#include "pixel_traits.hpp"
+
+namespace png
+{
+
+    /**
+     * \brief Holds information about PNG image.
+     *
+     * \see image, generator, consumer
+     */
+    class image_info
+    {
+    public:
+        /**
+         * \brief Constructs the image_info object with default values
+         * for color_type, interlace_type, compression_method and
+         * filter_type.
+         */
+        image_info()
+            : m_width(0),
+              m_height(0),
+              m_bit_depth(0),
+              m_color_type(color_type_none),
+              m_interlace_type(interlace_none),
+              m_compression_type(compression_type_default),
+              m_filter_type(filter_type_default),
+              m_gamma(0.0)
+        {
+        }
+
+        uint_32 get_width() const
+        {
+            return m_width;
+        }
+
+        void set_width(uint_32 width)
+        {
+            m_width = width;
+        }
+
+        uint_32 get_height() const
+        {
+            return m_height;
+        }
+
+        void set_height(uint_32 height)
+        {
+            m_height = height;
+        }
+
+        color_type get_color_type() const
+        {
+            return m_color_type;
+        }
+
+        void set_color_type(color_type color_space)
+        {
+            m_color_type = color_space;
+        }
+
+        int get_bit_depth() const
+        {
+            return m_bit_depth;
+        }
+
+        void set_bit_depth(int bit_depth)
+        {
+            m_bit_depth = bit_depth;
+        }
+
+        interlace_type get_interlace_type() const
+        {
+            return m_interlace_type;
+        }
+
+        void set_interlace_type(interlace_type interlace)
+        {
+            m_interlace_type = interlace;
+        }
+
+        compression_type get_compression_type() const
+        {
+            return m_compression_type;
+        }
+
+        void set_compression_type(compression_type compression)
+        {
+            m_compression_type = compression;
+        }
+
+        filter_type get_filter_type() const
+        {
+            return m_filter_type;
+        }
+
+        void set_filter_type(filter_type filter)
+        {
+            m_filter_type = filter;
+        }
+
+        palette const& get_palette() const
+        {
+            return m_palette;
+        }
+
+        palette& get_palette()
+        {
+            return m_palette;
+        }
+
+        void set_palette(palette const& plte)
+        {
+            m_palette = plte;
+        }
+
+        /**
+         * \brief Removes all entries from the palette.
+         */
+        void drop_palette()
+        {
+            m_palette.clear();
+        }
+
+        tRNS const& get_tRNS() const
+        {
+            return m_tRNS;
+        }
+
+        tRNS& get_tRNS()
+        {
+            return m_tRNS;
+        }
+
+        void set_tRNS(tRNS const& trns)
+        {
+            m_tRNS = trns;
+        }
+
+        double get_gamma() const
+        {
+            return m_gamma;
+        }
+
+        void set_gamma(double gamma)
+        {
+            m_gamma = gamma;
+        }
+
+    protected:
+        uint_32 m_width;
+        uint_32 m_height;
+        int m_bit_depth;
+        color_type m_color_type;
+        interlace_type m_interlace_type;
+        compression_type m_compression_type;
+        filter_type m_filter_type;
+        palette m_palette;
+        tRNS m_tRNS;
+        double m_gamma;
+    };
+
+    /**
+     * \brief Returns an image_info object with color_type and
+     * bit_depth fields setup appropriate for the \c pixel type.
+     */
+    template< typename pixel >
+    image_info
+    make_image_info()
+    {
+        typedef pixel_traits< pixel > traits;
+        image_info info;
+        info.set_color_type(traits::get_color_type());
+        info.set_bit_depth(traits::get_bit_depth());
+        return info;
+    }
+
+} // namespace png
+
+#endif // PNGPP_IMAGE_INFO_HPP_INCLUDED

xs/src/png/info.hpp

@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_INFO_HPP_INCLUDED
+#define PNGPP_INFO_HPP_INCLUDED
+
+#include <cassert>
+#include "info_base.hpp"
+#include "image_info.hpp"
+
+namespace png
+{
+
+    /**
+     * \brief Holds information about PNG image.  Adapter class for IO
+     * image operations.
+     */
+    class info
+        : public info_base,
+          public image_info
+    {
+    public:
+        info(io_base& io, png_struct* png)
+            : info_base(io, png)
+        {
+        }
+
+        void read()
+        {
+            assert(m_png);
+            assert(m_info);
+
+            png_read_info(m_png, m_info);
+            png_get_IHDR(m_png,
+                         m_info,
+                         & m_width,
+                         & m_height,
+                         reinterpret_cast< int* >(& m_bit_depth),
+                         reinterpret_cast< int* >(& m_color_type),
+                         reinterpret_cast< int* >(& m_interlace_type),
+                         reinterpret_cast< int* >(& m_compression_type),
+                         reinterpret_cast< int* >(& m_filter_type));
+
+            if (png_get_valid(m_png, m_info, chunk_PLTE) == chunk_PLTE)
+            {
+                png_color* colors = 0;
+                int count = 0;
+                png_get_PLTE(m_png, m_info, & colors, & count);
+                m_palette.assign(colors, colors + count);
+            }
+
+#ifdef PNG_tRNS_SUPPORTED
+            if (png_get_valid(m_png, m_info, chunk_tRNS) == chunk_tRNS)
+            {
+                if (m_color_type == color_type_palette)
+                {
+                    int count;
+                    byte* values;
+                    if (png_get_tRNS(m_png, m_info, & values, & count, NULL)
+                        != PNG_INFO_tRNS)
+                    {
+                        throw error("png_get_tRNS() failed");
+                    }
+                    m_tRNS.assign(values, values + count);
+                }
+            }
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+            if (png_get_valid(m_png, m_info, chunk_gAMA) == chunk_gAMA)
+            {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+                if (png_get_gAMA(m_png, m_info, &m_gamma) != PNG_INFO_gAMA)
+                {
+                    throw error("png_get_gAMA() failed");
+                }
+#else
+                png_fixed_point gamma = 0;
+                if (png_get_gAMA_fixed(m_png, m_info, &gamma) != PNG_INFO_gAMA)
+                {
+                    throw error("png_get_gAMA_fixed() failed");
+                }
+                m_gamma = gamma / 100000.0;
+#endif
+            }
+#endif
+        }
+
+        void write() const
+        {
+            assert(m_png);
+            assert(m_info);
+
+            sync_ihdr();
+            if (m_color_type == color_type_palette)
+            {
+                if (! m_palette.empty())
+                {
+                    png_set_PLTE(m_png, m_info,
+                                 const_cast< color* >(& m_palette[0]),
+                                 (int) m_palette.size());
+                }
+                if (! m_tRNS.empty())
+                {
+#ifdef PNG_tRNS_SUPPORTED
+                    png_set_tRNS(m_png, m_info,
+                                 const_cast< byte* >(& m_tRNS[0]),
+                                 m_tRNS.size(),
+                                 NULL);
+#else
+                    throw error("attempted to write tRNS chunk; recompile with PNG_tRNS_SUPPORTED");
+#endif
+                }
+            }
+
+            if (m_gamma > 0)
+            {
+#ifdef PNG_gAMA_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+                png_set_gAMA(m_png, m_info, m_gamma);
+#else
+                png_set_gAMA_fixed(m_png, m_info,
+                                   (png_fixed_point)(m_gamma * 100000));
+#endif
+#else
+                throw error("attempted to write gAMA chunk; recompile with PNG_gAMA_SUPPORTED");
+#endif
+            }
+
+            png_write_info(m_png, m_info);
+        }
+
+        void update()
+        {
+            assert(m_png);
+            assert(m_info);
+
+            sync_ihdr();
+            png_read_update_info(m_png, m_info);
+        }
+
+    protected:
+        void sync_ihdr(void) const
+        {
+            png_set_IHDR(m_png,
+                         m_info,
+                         m_width,
+                         m_height,
+                         m_bit_depth,
+                         m_color_type,
+                         m_interlace_type,
+                         m_compression_type,
+                         m_filter_type);
+        }
+    };
+
+} // namespace png
+
+#endif // PNGPP_INFO_HPP_INCLUDED

xs/src/png/info_base.hpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_INFO_BASE_HPP_INCLUDED
+#define PNGPP_INFO_BASE_HPP_INCLUDED
+
+#include <cassert>
+#include "error.hpp"
+#include "types.hpp"
+
+namespace png
+{
+
+    class io_base;
+
+    /**
+     * \brief Internal class to hold PNG info or end_info.
+     */
+    class info_base
+    {
+        info_base(info_base const&);
+        info_base& operator=(info_base const&);
+
+    public:
+        info_base(io_base& io, png_struct* png)
+            : m_io(io),
+              m_png(png),
+              m_info(png_create_info_struct(m_png))
+        {
+        }
+
+        png_info* get_png_info() const
+        {
+            return m_info;
+        }
+
+        png_info** get_png_info_ptr()
+        {
+            return & m_info;
+        }
+
+    protected:
+        io_base& m_io;
+        png_struct* m_png;
+        png_info* m_info;
+    };
+
+} // namespace png
+
+#endif // PNGPP_INFO_BASE_HPP_INCLUDED

xs/src/png/io_base.hpp

@@ -0,0 +1,467 @@
+/*
+ * Copyright (C) 2007,2008   Alex Shulgin
+ *
+ * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
+ * software; the exact copying conditions are as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef PNGPP_IO_BASE_HPP_INCLUDED
+#define PNGPP_IO_BASE_HPP_INCLUDED
+
+#include <cassert>
+#include <cstdio>
+#include <cstdarg>
+#include "error.hpp"
+#include "info.hpp"
+#include "end_info.hpp"
+
+static void
+trace_io_transform(char const* fmt, ...)
+{
+#ifdef DEBUG_IO_TRANSFORM
+    va_list va;
+    va_start(va, fmt);
+    fprintf(stderr, "TRANSFORM_IO: ");
+    vfprintf(stderr, fmt, va);
+    va_end(va);
+#endif
+}
+#define TRACE_IO_TRANSFORM trace_io_transform
+
+namespace png
+{
+
+    /**
+     * \brief Base class for PNG reader/writer classes.
+     *
+     * \see  reader, writer
+     */
+    class io_base
+    {
+        io_base(io_base const&);
+        io_base& operator=(io_base const&);
+
+    public:
+        explicit io_base(png_struct* png)
+            : m_png(png),
+              m_info(*this, m_png),
+              m_end_info(*this, m_png)
+        {
+        }
+
+        ~io_base()
+        {
+            assert(! m_png);
+            assert(! m_info.get_png_info());
+            assert(! m_end_info.get_png_info());
+        }
+
+        png_struct* get_png_struct() const
+        {
+            return m_png;
+        }
+
+        info& get_info()
+        {
+            return m_info;
+        }
+
+        info const& get_info() const
+        {
+            return m_info;
+        }
+
+        image_info const& get_image_info() const
+        {
+            return m_info;
+        }
+
+        void set_image_info(image_info const& info)
+        {
+            static_cast< image_info& >(m_info) = info; // slice it
+        }
+
+        end_info& get_end_info()
+        {
+            return m_end_info;
+        }
+
+        end_info const& get_end_info() const
+        {
+            return m_end_info;
+        }
+
+        //////////////////////////////////////////////////////////////////////
+        // info accessors
+        //
+        uint_32 get_width() const
+        {
+            return m_info.get_width();
+        }
+
+        void set_width(uint_32 width)
+        {
+            m_info.set_width(width);
+        }
+
+        uint_32 get_height() const
+        {
+            return m_info.get_height();
+        }
+
+        void set_height(uint_32 height)
+        {
+            m_info.set_height(height);
+        }
+
+        color_type get_color_type() const
+        {
+            return m_info.get_color_type();
+        }
+
+        void set_color_type(color_type color_space)
+        {
+            m_info.set_color_type(color_space);
+        }
+
+        int get_bit_depth() const
+        {
+            return m_info.get_bit_depth();
+        }
+
+        void set_bit_depth(int bit_depth)
+        {
+            m_info.set_bit_depth(bit_depth);
+        }
+
+        interlace_type get_interlace_type() const
+        {
+            return m_info.get_interlace_type();
+        }
+
+        void set_interlace_type(interlace_type interlace)
+        {
+            m_info.set_interlace_type(interlace);
+        }
+
+        compression_type get_compression_type() const
+        {
+            return m_info.get_compression_type();
+        }
+
+        void set_compression_type(compression_type compression)
+        {
+            m_info.set_compression_type(compression);
+        }
+
+        filter_type get_filter_type() const
+        {
+            return m_info.get_filter_type();
+        }
+
+        void set_filter_type(filter_type filter)
+        {
+            m_info.set_filter_type(filter);
+        }
+
+        //////////////////////////////////////////////////////////////////////
+
+        bool has_chunk(chunk id)
+        {
+            return png_get_valid(m_png,
+                                 m_info.get_png_info(),
+                                 uint_32(id)) == uint_32(id);
+        }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+        void set_gray_1_2_4_to_8() const
+        {
+            TRACE_IO_TRANSFORM("png_set_expand_gray_1_2_4_to_8\n");
+            png_set_expand_gray_1_2_4_to_8(m_png);
+        }
+
+        void set_palette_to_rgb() const
+        {
+            TRACE_IO_TRANSFORM("png_set_palette_to_rgb\n");
+            png_set_palette_to_rgb(m_png);
+        }
+
+        void set_tRNS_to_alpha() const
+        {
+            TRACE_IO_TRANSFORM("png_set_tRNS_to_alpha\n");
+            png_set_tRNS_to_alpha(m_png);
+        }
+#endif // defined(PNG_READ_EXPAND_SUPPORTED)
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+        void set_bgr() const
+        {
+            TRACE_IO_TRANSFORM("png_set_bgr\n");
+            png_set_bgr(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+        void set_gray_to_rgb() const
+        {
+            TRACE_IO_TRANSFORM("png_set_gray_to_rgb\n");
+            png_set_gray_to_rgb(m_png);
+        }
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+        void set_rgb_to_gray(rgb_to_gray_error_action error_action
+                             = rgb_to_gray_silent,
+                             double red_weight   = -1.0,
+                             double green_weight = -1.0) const
+        {
+            TRACE_IO_TRANSFORM("png_set_rgb_to_gray: error_action=%d,"
+                               " red_weight=%lf, green_weight=%lf\n",
+                               error_action, red_weight, green_weight);
+
+            png_set_rgb_to_gray(m_png, error_action, red_weight, green_weight);
+        }
+#else
+        void set_rgb_to_gray(rgb_to_gray_error_action error_action
+                             = rgb_to_gray_silent,
+                             fixed_point red_weight   = -1,
+                             fixed_point green_weight = -1) const
+        {
+            TRACE_IO_TRANSFORM("png_set_rgb_to_gray_fixed: error_action=%d,"
+                               " red_weight=%d, green_weight=%d\n",
+                               error_action, red_weight, green_weight);
+
+            png_set_rgb_to_gray_fixed(m_png, error_action,
+                                      red_weight, green_weight);
+        }
+#endif // PNG_FLOATING_POINT_SUPPORTED
+
+        //////////////////////////////////////////////////////////////////////
+        // alpha channel transformations
+        //
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+        void set_strip_alpha() const
+        {
+            TRACE_IO_TRANSFORM("png_set_strip_alpha\n");
+            png_set_strip_alpha(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) \
+    || defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+        void set_swap_alpha() const
+        {
+            TRACE_IO_TRANSFORM("png_set_swap_alpha\n");
+            png_set_swap_alpha(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) \
+    || defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+        void set_invert_alpha() const
+        {
+            TRACE_IO_TRANSFORM("png_set_invert_alpha\n");
+            png_set_invert_alpha(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+        void set_filler(uint_32 filler, filler_type type) const
+        {
+            TRACE_IO_TRANSFORM("png_set_filler: filler=%08x, type=%d\n",
+                               filler, type);
+
+            png_set_filler(m_png, filler, type);
+        }
+
+#if !defined(PNG_1_0_X)
+        void set_add_alpha(uint_32 filler, filler_type type) const
+        {
+            TRACE_IO_TRANSFORM("png_set_add_alpha: filler=%08x, type=%d\n",
+                               filler, type);
+
+            png_set_add_alpha(m_png, filler, type);
+        }
+#endif
+#endif // PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+        void set_swap() const
+        {
+            TRACE_IO_TRANSFORM("png_set_swap\n");
+            png_set_swap(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+        void set_packing() const
+        {
+            TRACE_IO_TRANSFORM("png_set_packing\n");
+            png_set_packing(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) \
+    || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+        void set_packswap() const
+        {
+            TRACE_IO_TRANSFORM("png_set_packswap\n");
+            png_set_packswap(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+        void set_shift(byte red_bits, byte green_bits, byte blue_bits,
+                       byte alpha_bits = 0) const
+        {
+            TRACE_IO_TRANSFORM("png_set_shift: red_bits=%d, green_bits=%d,"
+                               " blue_bits=%d, alpha_bits=%d\n",
+                               red_bits, green_bits, blue_bits, alpha_bits);
+
+            if (get_color_type() != color_type_rgb
+                || get_color_type() != color_type_rgb_alpha)
+            {
+                throw error("set_shift: expected RGB or RGBA color type");
+            }
+            color_info bits;
+            bits.red = red_bits;
+            bits.green = green_bits;
+            bits.blue = blue_bits;
+            bits.alpha = alpha_bits;
+            png_set_shift(m_png, & bits);
+        }
+
+        void set_shift(byte gray_bits, byte alpha_bits = 0) const
+        {
+            TRACE_IO_TRANSFORM("png_set_shift: gray_bits=%d, alpha_bits=%d\n",
+                               gray_bits, alpha_bits);
+
+            if (get_color_type() != color_type_gray
+                || get_color_type() != color_type_gray_alpha)
+            {
+                throw error("set_shift: expected Gray or Gray+Alpha color type");
+            }
+            color_info bits;
+            bits.gray = gray_bits;
+            bits.alpha = alpha_bits;
+            png_set_shift(m_png, & bits);
+        }
+#endif // PNG_READ_SHIFT_SUPPORTED || PNG_WRITE_SHIFT_SUPPORTED
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) \
+    || defined(PNG_WRITE_INTERLACING_SUPPORTED)
+        int set_interlace_handling() const
+        {
+            TRACE_IO_TRANSFORM("png_set_interlace_handling\n");
+            return png_set_interlace_handling(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+        void set_invert_mono() const
+        {
+            TRACE_IO_TRANSFORM("png_set_invert_mono\n");
+            png_set_invert_mono(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+        void set_strip_16() const
+        {
+            TRACE_IO_TRANSFORM("png_set_strip_16\n");
+            png_set_strip_16(m_png);
+        }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+        void set_read_user_transform(png_user_transform_ptr transform_fn)
+        {
+            TRACE_IO_TRANSFORM("png_set_read_user_transform_fn\n");
+            png_set_read_user_transform_fn(m_png, transform_fn);
+        }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \
+    || defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+        void set_user_transform_info(void* info, int bit_depth, int channels)
+        {
+            TRACE_IO_TRANSFORM("png_set_user_transform_info: bit_depth=%d,"
+                               " channels=%d\n", bit_depth, channels);
+
+            png_set_user_transform_info(m_png, info, bit_depth, channels);
+        }
+#endif
+
+    protected:
+        void* get_io_ptr() const
+        {
+            return png_get_io_ptr(m_png);
+        }
+
+        void set_error(char const* message)
+        {
+            assert(message);
+            m_error = message;
+        }
+
+        void reset_error()
+        {
+            m_error.clear();
+        }
+
+/*
+        std::string const& get_error() const
+        {
+            return m_error;
+        }
+*/
+
+        bool is_error() const
+        {
+            return !m_error.empty();
+        }
+
+        void raise_error()
+        {
+            longjmp(png_jmpbuf(m_png), -1);
+        }
+
+        static void raise_error(png_struct* png, char const* message)
+        {
+            io_base* io = static_cast< io_base* >(png_get_error_ptr(png));
+            io->set_error(message);
+            io->raise_error();
+        }
+
+        png_struct* m_png;
+        info m_info;
+        end_info m_end_info;
+        std::string m_error;
+    };
+
+} // namespace png
+
+#endif // PNGPP_IO_BASE_HPP_INCLUDED

xs/src/png/libpng/ANNOUNCE

@@ -0,0 +1,35 @@
+Libpng 1.6.34 - September 29, 2017
+
+This is a public release of libpng, intended for use in production codes.
+
+Files available for download:
+
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
+
+   libpng-1.6.34.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.34.tar.gz
+
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+   lpng1634.7z  (LZMA-compressed, recommended)
+   lpng1634.zip
+
+Other information:
+
+   libpng-1.6.34-README.txt
+   libpng-1.6.34-LICENSE.txt
+   libpng-1.6.34-*.asc (armored detached GPG signatures)
+
+Changes since the last public release (1.6.33):
+  Removed contrib/pngsuite/i*.png; some of these were incorrect and caused
+    test failures.
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe)
+or to glennrp at users.sourceforge.net
+
+Glenn R-P

xs/src/png/libpng/CMakeLists.txt

@@ -0,0 +1,937 @@
+# CMakeLists.txt
+
+# Copyright (C) 2007,2009-2017 Glenn Randers-Pehrson
+# Written by Christian Ehrlicher, 2007
+# Revised by Roger Lowman, 2009-2010
+# Revised by Clifford Yapp, 2011-2012
+# Revised by Roger Leigh, 2016
+# Revised by Andreas Franek, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+cmake_minimum_required(VERSION 3.0.2)
+cmake_policy(VERSION 3.0.2)
+
+# Set MacOSX @rpath usage globally.
+if (POLICY CMP0020)
+  cmake_policy(SET CMP0020 NEW)
+endif(POLICY CMP0020)
+if (POLICY CMP0042)
+  cmake_policy(SET CMP0042 NEW)
+endif(POLICY CMP0042)
+# Use new variable expansion policy.
+if (POLICY CMP0053)
+  cmake_policy(SET CMP0053 NEW)
+endif(POLICY CMP0053)
+if (POLICY CMP0054)
+  cmake_policy(SET CMP0054 NEW)
+endif(POLICY CMP0054)
+
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
+
+project(libpng ASM C)
+
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_RELEASE 34)
+set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
+
+# needed packages
+
+#Allow users to specify location of Zlib,
+# Useful if zlib is being built alongside this as a sub-project
+
+set(PNG_BUILD_ZLIB ${CMAKE_CURRENT_SOURCE_DIR}/zlib)
+
+if(NOT WIN32)
+  find_library(M_LIBRARY
+    NAMES m
+    PATHS /usr/lib /usr/local/lib
+  )
+  if(NOT M_LIBRARY)
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
+  endif()
+else()
+  # not needed on windows
+  set(M_LIBRARY "")
+endif()
+
+# COMMAND LINE OPTIONS
+option(PNG_SHARED "Build shared lib" OFF)
+option(PNG_STATIC "Build static lib" ON)
+option(PNG_TESTS  "Build libpng tests" OFF)
+
+# Many more configuration options could be added here
+option(PNG_FRAMEWORK "Build OS X framework" OFF)
+option(PNG_DEBUG     "Build with debug output" OFF)
+option(PNGARG        "Disable ANSI-C prototypes" OFF)
+
+option(PNG_HARDWARE_OPTIMIZATIONS "Enable Hardware Optimizations" ON)
+
+set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
+set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
+
+if(PNG_HARDWARE_OPTIMIZATIONS)
+# set definitions and sources for arm
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
+  CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64")
+  set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
+  set(PNG_ARM_NEON "check" CACHE STRING "Enable ARM NEON optimizations:
+     check: (default) use internal checking code;
+     off: disable the optimizations;
+     on: turn on unconditionally.")
+  set_property(CACHE PNG_ARM_NEON PROPERTY STRINGS
+     ${PNG_ARM_NEON_POSSIBLE_VALUES})
+  list(FIND PNG_ARM_NEON_POSSIBLE_VALUES ${PNG_ARM_NEON} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_ARM_NEON must be one of [${PNG_ARM_NEON_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_ARM_NEON} STREQUAL "no")
+    set(libpng_arm_sources
+      arm/arm_init.c
+      arm/filter_neon.S
+      arm/filter_neon_intrinsics.c)
+
+    if(${PNG_ARM_NEON} STREQUAL "on")
+      add_definitions(-DPNG_ARM_NEON_OPT=2)
+    elseif(${PNG_ARM_NEON} STREQUAL "check")
+      add_definitions(-DPNG_ARM_NEON_CHECK_SUPPORTED)
+    endif()
+  else()
+    add_definitions(-DPNG_ARM_NEON_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for powerpc
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^powerpc*" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "^ppc64*" )
+  set(PNG_POWERPC_VSX_POSSIBLE_VALUES on off)
+  set(PNG_POWERPC_VSX "on" CACHE STRING "Enable POWERPC VSX optimizations:
+     off: disable the optimizations.")
+  set_property(CACHE PNG_POWERPC_VSX PROPERTY STRINGS
+     ${PNG_POWERPC_VSX_POSSIBLE_VALUES})
+  list(FIND PNG_POWERPC_VSX_POSSIBLE_VALUES ${PNG_POWERPC_VSX} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_POWERPC_VSX must be one of [${PNG_POWERPC_VSX_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_POWERPC_VSX} STREQUAL "no")
+    set(libpng_powerpc_sources
+      powerpc/powerpc_init.c
+      powerpc/filter_vsx_intrinsics.c)
+    if(${PNG_POWERPC_VSX} STREQUAL "on")
+      add_definitions(-DPNG_POWERPC_VSX_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for intel
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^i?86" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "^x86_64*" )
+  set(PNG_INTEL_SSE_POSSIBLE_VALUES on off)
+  set(PNG_INTEL_SSE "on" CACHE STRING "Enable INTEL_SSE optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_INTEL_SSE PROPERTY STRINGS
+     ${PNG_INTEL_SSE_POSSIBLE_VALUES})
+  list(FIND PNG_INTEL_SSE_POSSIBLE_VALUES ${PNG_INTEL_SSE} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_INTEL_SSE must be one of [${PNG_INTEL_SSE_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_INTEL_SSE} STREQUAL "no")
+    set(libpng_intel_sources
+      intel/intel_init.c
+      intel/filter_sse2_intrinsics.c)
+    if(${PNG_INTEL_SSE} STREQUAL "on")
+      add_definitions(-DPNG_INTEL_SSE_OPT=1)
+    endif()
+  else()
+    add_definitions(-DPNG_INTEL_SSE_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for MIPS
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "mipsel*" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "mips64el*" )
+  set(PNG_MIPS_MSA_POSSIBLE_VALUES on off)
+  set(PNG_MIPS_MSA "on" CACHE STRING "Enable MIPS_MSA optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_MIPS_MSA PROPERTY STRINGS
+     ${PNG_MIPS_MSA_POSSIBLE_VALUES})
+  list(FIND PNG_MIPS_MSA_POSSIBLE_VALUES ${PNG_MIPS_MSA} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_MIPS_MSA must be one of [${PNG_MIPS_MSA_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_MIPS_MSA} STREQUAL "no")
+    set(libpng_mips_sources
+      mips/mips_init.c
+      mips/filter_msa_intrinsics.c)
+    if(${PNG_MIPS_MSA} STREQUAL "on")
+      add_definitions(-DPNG_MIPS_MSA_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_MIPS_MSA_OPT=0)
+  endif()
+endif()
+endif(PNG_HARDWARE_OPTIMIZATIONS)
+
+# SET LIBNAME
+set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
+
+# to distinguish between debug and release lib
+set(CMAKE_DEBUG_POSTFIX "d")
+
+include(CheckCSourceCompiles)
+option(ld-version-script "Enable linker version script" ON)
+if(ld-version-script AND NOT APPLE)
+  # Check if LD supports linker scripts.
+  file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "VERS_1 {
+        global: sym;
+        local: *;
+};
+
+VERS_2 {
+        global: sym2;
+                main;
+} VERS_1;
+")
+  set(CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/conftest.map'")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_LD_VERSION_SCRIPT)
+  if(NOT HAVE_LD_VERSION_SCRIPT)
+    set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE} "-Wl,-M -Wl,${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_SOLARIS_LD_VERSION_SCRIPT)
+  endif()
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
+  file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+endif()
+
+# Find symbol prefix.  Likely obsolete and unnecessary with recent
+# toolchains (it's not done in many other projects).
+function(symbol_prefix)
+  set(SYMBOL_PREFIX)
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E" "-"
+                  INPUT_FILE /dev/null
+                  OUTPUT_VARIABLE OUT
+                  RESULT_VARIABLE STATUS)
+
+  if(CPP_FAIL)
+    message(WARNING "Failed to run the C preprocessor")
+  endif()
+
+  string(REPLACE "\n" ";" OUT "${OUT}")
+  foreach(line ${OUT})
+    string(REGEX MATCH "^PREFIX=" found_match "${line}")
+    if(found_match)
+      STRING(REGEX REPLACE "^PREFIX=(.*\)" "\\1" prefix "${line}")
+      string(REGEX MATCH "__USER_LABEL_PREFIX__" found_match "${prefix}")
+      if(found_match)
+        STRING(REGEX REPLACE "(.*)__USER_LABEL_PREFIX__(.*)" "\\1\\2" prefix "${prefix}")
+      endif()
+      set(SYMBOL_PREFIX "${prefix}")
+    endif()
+  endforeach()
+
+    message(STATUS "Symbol prefix: ${SYMBOL_PREFIX}")
+    set(SYMBOL_PREFIX "${SYMBOL_PREFIX}" PARENT_SCOPE)
+endfunction()
+
+if(UNIX)
+  symbol_prefix()
+endif()
+
+find_program(AWK NAMES gawk awk)
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+if(NOT AWK OR ANDROID)
+  # No awk available to generate sources; use pre-built pnglibconf.h
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
+                 ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
+  add_custom_target(genfiles) # Dummy
+else()
+  include(CMakeParseArguments)
+  # Generate .chk from .out with awk
+  # generate_chk(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_chk)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GC "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GC_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GC_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GC_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GC_INPUT}"
+                               "-DOUTPUT=${_GC_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake"
+                       DEPENDS "${_GC_INPUT}" ${_GC_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate .out from .c with awk
+  # generate_out(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_out)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GO_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GO_INPUT}"
+                               "-DOUTPUT=${_GO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake"
+                       DEPENDS "${_GO_INPUT}" ${_GO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate specific source file with awk
+  # generate_source(OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_source)
+    set(options)
+    set(oneValueArgs OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GSO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GSO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_source requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_GSO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DOUTPUT=${_GSO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                       DEPENDS ${_GSO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Copy file
+  function(generate_copy source destination)
+    add_custom_command(OUTPUT "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E remove "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E copy "${source}"
+                                                          "${destination}"
+                       DEPENDS "${source}")
+  endfunction()
+
+  # Generate scripts/pnglibconf.h
+  generate_source(OUTPUT "scripts/pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  # Generate pnglibconf.c
+  generate_source(OUTPUT "pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  if(PNG_PREFIX)
+    set(PNGLIBCONF_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+        "${CMAKE_CURRENT_SOURCE_DIR}/scripts/macro.lst")
+    set(PNGPREFIX_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out")
+  endif()
+
+  generate_out(INPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pnglibconf.h
+  generate_source(OUTPUT "pnglibconf.h"
+                  DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+                          ${PNGLIBCONF_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/intprefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/prefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pngprefix.h
+  generate_source(OUTPUT "pngprefix.h"
+                  DEPENDS ${PNGPREFIX_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/sym.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/vers.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_chk(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/checksym.awk"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.def")
+
+  add_custom_target(symbol-check DEPENDS
+                    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk")
+
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+
+  add_custom_target(genvers DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+  add_custom_target(gensym DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+
+  add_custom_target("genprebuilt"
+                    COMMAND "${CMAKE_COMMAND}"
+                            "-DOUTPUT=scripts/pnglibconf.h.prebuilt"
+                            -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                    WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+
+  # A single target handles generation of all generated files.  If
+  # they are dependend upon separately by multiple targets, this
+  # confuses parallel make (it would require a separate top-level
+  # target for each file to track the dependencies properly).
+  add_custom_target(genfiles DEPENDS
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym"
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
+endif(NOT AWK OR ANDROID)
+
+# OUR SOURCES
+set(libpng_public_hdrs
+  png.h
+  pngconf.h
+  "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+)
+set(libpng_private_hdrs
+  pngpriv.h
+  pngdebug.h
+  pnginfo.h
+  pngstruct.h
+)
+if(AWK AND NOT ANDROID)
+  list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
+endif()
+set(libpng_sources
+  ${libpng_public_hdrs}
+  ${libpng_private_hdrs}
+  png.c
+  pngerror.c
+  pngget.c
+  pngmem.c
+  pngpread.c
+  pngread.c
+  pngrio.c
+  pngrtran.c
+  pngrutil.c
+  pngset.c
+  pngtrans.c
+  pngwio.c
+  pngwrite.c
+  pngwtran.c
+  pngwutil.c
+  ${libpng_arm_sources}
+  ${libpng_intel_sources}
+  ${libpng_mips_sources}
+  ${libpng_powerpc_sources}
+)
+set(pngtest_sources
+  pngtest.c
+)
+set(pngvalid_sources
+  contrib/libtests/pngvalid.c
+)
+set(pngstest_sources
+  contrib/libtests/pngstest.c
+)
+set(pngunknown_sources
+  contrib/libtests/pngunknown.c
+)
+set(pngimage_sources
+  contrib/libtests/pngimage.c
+)
+set(pngfix_sources
+  contrib/tools/pngfix.c
+)
+set(png_fix_itxt_sources
+  contrib/tools/png-fix-itxt.c
+)
+
+if(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif(MSVC)
+
+if(PNG_DEBUG)
+  add_definitions(-DPNG_DEBUG)
+endif()
+
+# NOW BUILD OUR TARGET
+include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
+
+unset(PNG_LIB_TARGETS)
+
+if(PNG_SHARED)
+  add_library(png SHARED ${libpng_sources})
+  set(PNG_LIB_TARGETS png)
+  set_target_properties(png PROPERTIES OUTPUT_NAME ${PNG_LIB_NAME})
+  add_dependencies(png genfiles)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png PROPERTIES PREFIX "lib")
+    set_target_properties(png PROPERTIES IMPORT_PREFIX "lib")
+  endif()
+  target_link_libraries(png ${ZLIB_LIBRARY} ${M_LIBRARY})
+
+  if(UNIX AND AWK)
+    if(HAVE_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    elseif(HAVE_SOLARIS_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,-M -Wl,'${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    endif()
+  endif()
+endif()
+
+if(PNG_STATIC)
+  # does not work without changing name
+  set(PNG_LIB_NAME_STATIC png_static)
+  add_library(png_static STATIC ${libpng_sources})
+  add_dependencies(png_static genfiles)
+  # MSVC doesn't use a different file extension for shared vs. static
+  # libs.  We are able to change OUTPUT_NAME to remove the _static
+  # for all other platforms.
+  if(NOT MSVC)
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}"
+      CLEAN_DIRECT_OUTPUT 1)
+  else()
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}_static"
+      CLEAN_DIRECT_OUTPUT 1)
+  endif()
+  list(APPEND PNG_LIB_TARGETS png_static)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png_static PROPERTIES PREFIX "lib")
+  endif()
+  target_link_libraries(png_static ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(PNG_FRAMEWORK)
+  set(PNG_LIB_NAME_FRAMEWORK png_framework)
+  add_library(png_framework SHARED ${libpng_sources})
+  add_dependencies(png_framework genfiles)
+  list(APPEND PNG_LIB_TARGETS png_framework)
+  set_target_properties(png_framework PROPERTIES
+    FRAMEWORK TRUE
+    FRAMEWORK_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${PNGLIB_MAJOR}.${PNGLIB_MINOR}
+    MACOSX_FRAMEWORK_BUNDLE_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_IDENTIFIER org.libpng.libpng
+    XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+    PUBLIC_HEADER "${libpng_public_hdrs}"
+    OUTPUT_NAME png)
+  target_link_libraries(png_framework ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(NOT PNG_LIB_TARGETS)
+  message(SEND_ERROR
+    "No library variant selected to build. "
+    "Please enable at least one of the following options: "
+    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
+endif()
+
+if(PNG_SHARED AND WIN32)
+  set_target_properties(png PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
+endif()
+
+function(png_add_test)
+  set(options)
+  set(oneValueArgs NAME COMMAND)
+  set(multiValueArgs OPTIONS FILES)
+  cmake_parse_arguments(_PAT "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+  if (NOT _PAT_NAME)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires name.")
+  endif()
+  if (NOT _PAT_COMMAND)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires command.")
+  endif()
+
+  set(TEST_OPTIONS "${_PAT_OPTIONS}")
+  set(TEST_FILES "${_PAT_FILES}")
+
+  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/scripts/test.cmake.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake" @ONLY)
+  if(CMAKE_MAJOR_VERSION GREATER 2) # have generator expressions
+    add_test(NAME "${_PAT_NAME}"
+             COMMAND "${CMAKE_COMMAND}"
+             "-DLIBPNG=$<TARGET_FILE:png>"
+             "-DTEST_COMMAND=$<TARGET_FILE:${_PAT_COMMAND}>"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  else() # old 2.x add_test; limited and won't work well on Windows
+    # Note LIBPNG is a dummy value as there are no generator expressions
+    add_test("${_PAT_NAME}" "${CMAKE_COMMAND}"
+             "-DLIBPNG=${CMAKE_CURRENT_BINARY_DIR}/libpng.so"
+             "-DTEST_COMMAND=./${_PAT_COMMAND}"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  endif()
+endfunction()
+
+if(PNG_TESTS AND PNG_SHARED)
+  # Find test PNG files by globbing, but sort lists to ensure
+  # consistency between different filesystems.
+  file(GLOB PNGSUITE_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/*.png")
+  list(SORT PNGSUITE_PNGS)
+  file(GLOB TEST_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/testpngs/*.png")
+  list(SORT TEST_PNGS)
+
+  set(PNGTEST_PNG "${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png")
+
+  add_executable(pngtest ${pngtest_sources})
+  target_link_libraries(pngtest png)
+
+  png_add_test(NAME pngtest COMMAND pngtest FILES "${PNGTEST_PNG}")
+
+  add_executable(pngvalid ${pngvalid_sources})
+  target_link_libraries(pngvalid png)
+
+  png_add_test(NAME pngvalid-gamma-16-to-8
+               COMMAND pngvalid OPTIONS --gamma-16-to-8)
+  png_add_test(NAME pngvalid-gamma-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode)
+  png_add_test(NAME pngvalid-gamma-background
+               COMMAND pngvalid OPTIONS --gamma-background)
+  png_add_test(NAME pngvalid-gamma-expand16-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-background
+               COMMAND pngvalid OPTIONS --gamma-background --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-transform
+               COMMAND pngvalid OPTIONS --gamma-transform --expand16)
+  png_add_test(NAME pngvalid-gamma-sbit
+               COMMAND pngvalid OPTIONS --gamma-sbit)
+  png_add_test(NAME pngvalid-gamma-threshold
+               COMMAND pngvalid OPTIONS --gamma-threshold)
+  png_add_test(NAME pngvalid-gamma-transform
+               COMMAND pngvalid OPTIONS --gamma-transform)
+  png_add_test(NAME pngvalid-progressive-interlace-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read --interlace)
+  png_add_test(NAME pngvalid-progressive-size
+               COMMAND pngvalid OPTIONS --size --progressive-read)
+  png_add_test(NAME pngvalid-progressive-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read)
+  png_add_test(NAME pngvalid-standard
+               COMMAND pngvalid OPTIONS --standard)
+  png_add_test(NAME pngvalid-transform
+               COMMAND pngvalid OPTIONS --transform)
+
+  add_executable(pngstest ${pngstest_sources})
+  target_link_libraries(pngstest png)
+
+  foreach(gamma_type 1.8 linear none sRGB)
+    foreach(alpha_type none alpha)
+      set(PNGSTEST_FILES)
+      foreach(test_png ${TEST_PNGS})
+        string(REGEX MATCH ".*-linear[-.].*" TEST_PNG_LINEAR "${test_png}")
+        string(REGEX MATCH ".*-sRGB[-.].*" TEST_PNG_SRGB "${test_png}")
+        string(REGEX MATCH ".*-1.8[-.].*" TEST_PNG_G18 "${test_png}")
+        string(REGEX MATCH ".*-alpha-.*" TEST_PNG_ALPHA "${test_png}")
+
+        set(TEST_PNG_VALID TRUE)
+
+        if(TEST_PNG_ALPHA)
+          if (NOT "${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if ("${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_LINEAR)
+          if(NOT "${gamma_type}" STREQUAL "linear")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_SRGB)
+          if(NOT "${gamma_type}" STREQUAL "sRGB")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_G18)
+          if(NOT "${gamma_type}" STREQUAL "1.8")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if(NOT "${gamma_type}" STREQUAL "none")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_VALID)
+          list(APPEND PNGSTEST_FILES "${test_png}")
+        endif()
+      endforeach()
+      # Should already be sorted, but sort anyway to be certain.
+      list(SORT PNGSTEST_FILES)
+      png_add_test(NAME pngstest-${gamma_type}-${alpha_type}
+                   COMMAND pngstest
+                   OPTIONS --tmpfile "${gamma_type}-${alpha_type}-" --log
+                   FILES ${PNGSTEST_FILES})
+    endforeach()
+  endforeach()
+
+  add_executable(pngunknown ${pngunknown_sources})
+  target_link_libraries(pngunknown png)
+
+  png_add_test(NAME pngunknown-discard COMMAND pngunknown OPTIONS --strict default=discard FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-IDAT COMMAND pngunknown OPTIONS --strict default=discard IDAT=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-if-safe COMMAND pngunknown OPTIONS --strict default=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sAPI COMMAND pngunknown OPTIONS --strict bKGD=save cHRM=save gAMA=save all=discard iCCP=save sBIT=save sRGB=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-save COMMAND pngunknown OPTIONS --strict default=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sTER COMMAND pngunknown OPTIONS --strict sTER=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-vpAg COMMAND pngunknown OPTIONS --strict vpAg=if-safe FILES "${PNGTEST_PNG}")
+
+  add_executable(pngimage ${pngimage_sources})
+  target_link_libraries(pngimage png)
+
+  png_add_test(NAME pngimage-quick COMMAND pngimage OPTIONS --list-combos --log FILES ${PNGSUITE_PNGS})
+  png_add_test(NAME pngimage-full COMMAND pngimage OPTIONS --exhaustive --list-combos --log FILES ${PNGSUITE_PNGS})
+endif()
+
+if(PNG_SHARED)
+  add_executable(pngfix ${pngfix_sources})
+  target_link_libraries(pngfix png)
+  set(PNG_BIN_TARGETS pngfix)
+
+  add_executable(png-fix-itxt ${png_fix_itxt_sources})
+  target_link_libraries(png-fix-itxt ${ZLIB_LIBRARY} ${M_LIBRARY})
+  list(APPEND PNG_BIN_TARGETS png-fix-itxt)
+endif()
+
+# Set a variable with CMake code which:
+# Creates a symlink from src to dest (if possible) or alternatively
+# copies if different.
+include(CMakeParseArguments)
+
+function(CREATE_SYMLINK DEST_FILE)
+
+  cmake_parse_arguments(S "" "FILE;TARGET" "" ${ARGN})
+
+  if(NOT S_TARGET AND NOT S_FILE)
+    message(FATAL_ERROR "Specify either a TARGET or a FILE for CREATE_SYMLINK to link to.")
+  endif(NOT S_TARGET AND NOT S_FILE)
+
+  if(S_TARGET AND S_FILE)
+    message(FATAL_ERROR "CREATE_SYMLINK called with both source file ${S_FILE} and build target ${S_TARGET} arguments - can only handle 1 type per call.")
+  endif(S_TARGET AND S_FILE)
+
+  if(S_FILE)
+    # If we don't need to symlink something that's coming from a build target,
+    # we can go ahead and symlink/copy at configure time.
+
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      execute_process(
+	COMMAND "${CMAKE_COMMAND}" -E copy_if_different ${S_FILE} ${DEST_FILE}
+	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+	)
+    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      execute_process(
+	COMMAND ${CMAKE_COMMAND} -E create_symlink ${S_FILE} ${DEST_FILE}
+	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+	)
+    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+  endif(S_FILE)
+
+  if(S_TARGET)
+    # We need to use generator expressions, which can be a bit tricky, so for
+    # simplicity make the symlink a POST_BUILD step and use the TARGET
+    # signature of add_custom_command.
+
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+	COMMAND "${CMAKE_COMMAND}" -E copy_if_different $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
+	)
+    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+	COMMAND "${CMAKE_COMMAND}" -E create_symlink $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
+	)
+    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+
+  endif(S_TARGET)
+
+endfunction()
+
+# Create source generation scripts.
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genchk.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genout.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/gensrc.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake @ONLY)
+
+
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+  set(CMAKE_INSTALL_LIBDIR lib)
+endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+
+# CREATE PKGCONFIG FILES
+# we use the same files like ./configure, so we have to set its vars
+# Only do this on Windows for Cygwin - the files don't make much sense outside
+# a UNIX look alike
+if(NOT WIN32 OR CYGWIN OR MINGW)
+  set(prefix      ${CMAKE_INSTALL_PREFIX})
+  set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(LIBS        "-lz -lm")
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
+  CREATE_SYMLINK(libpng.pc FILE ${PNGLIB_NAME}.pc)
+
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
+  CREATE_SYMLINK(libpng-config FILE ${PNGLIB_NAME}-config)
+endif(NOT WIN32 OR CYGWIN OR MINGW)
+
+# SET UP LINKS
+if(PNG_SHARED)
+  set_target_properties(png PROPERTIES
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.34
+    VERSION 16.${PNGLIB_RELEASE}.0
+    SOVERSION 16
+    CLEAN_DIRECT_OUTPUT 1)
+endif()
+
+# If CMake > 2.4.x, we set a variable used below to export
+# targets to an export file.
+# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
+if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
+  set(PNG_EXPORT_RULE EXPORT libpng)
+elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
+  set(PNG_EXPORT_RULE EXPORT libpng)
+endif()
+
+# INSTALL
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_LIB_TARGETS}
+      ${PNG_EXPORT_RULE}
+      RUNTIME DESTINATION bin
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+  if(PNG_SHARED)
+    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+    if(CYGWIN OR MINGW)
+      CREATE_SYMLINK(libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(CYGWIN OR MINGW)
+
+    if(NOT WIN32)
+      CREATE_SYMLINK(libpng${CMAKE_SHARED_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32)
+  endif(PNG_SHARED)
+
+  if(PNG_STATIC)
+    if(NOT WIN32 OR CYGWIN OR MINGW)
+      CREATE_SYMLINK( libpng${CMAKE_STATIC_LIBRARY_SUFFIX} TARGET png_static)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png_static>/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN OR MINGW)
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+  install(FILES ${libpng_public_hdrs}   DESTINATION include)
+  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+
+if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_BIN_TARGETS}
+      RUNTIME DESTINATION bin)
+endif()
+
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+  # Install man pages
+  if(NOT PNG_MAN_DIR)
+    set(PNG_MAN_DIR "share/man")
+  endif()
+  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  # Install pkg-config files
+  if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+            DESTINATION bin)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+endif()
+
+# On versions of CMake that support it, create an export file CMake
+# users can include() to import our targets
+if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
+  install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
+endif()
+
+# what's with libpng-manual.txt and all the extra files?
+
+# UNINSTALL
+# do we need this?
+
+# DIST
+# do we need this?
+
+# to create msvc import lib for mingw compiled shared lib
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86

xs/src/png/libpng/LICENSE

@@ -0,0 +1,133 @@
+
+This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+This code is released under the libpng license.
+
+libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are
+Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
+derived from libpng-1.0.6, and are distributed according to the same
+disclaimer and license as libpng-1.0.6 with the following individuals
+added to the list of Contributing Authors:
+
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Mans Rullgard
+   Cosmin Truta
+   Gilles Vollant
+   James Yu
+   Mandar Sahastrabuddhe
+   Google Inc.
+   Vadim Barkov
+
+and with the following additions to the disclaimer:
+
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.
+
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners and
+are released under other open source licenses.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+libpng-0.96, and are distributed according to the same disclaimer and
+license as libpng-0.96, with the following individuals added to the list
+of Contributing Authors:
+
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+and are distributed according to the same disclaimer and license as
+libpng-0.88, with the following individuals added to the list of
+Contributing Authors:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+
+Some files in the "scripts" directory have other copyright owners
+but are released under this license.
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+  1. The origin of this source code must not be misrepresented.
+
+  2. Altered versions must be plainly marked as such and must not
+     be misrepresented as being the original source.
+
+  3. This Copyright notice may not be removed or altered from any
+     source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
+
+TRADEMARK:
+
+The name "libpng" has not been registered by the Copyright owner
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owner claims "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
+
+OSI CERTIFICATION:
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.
+
+EXPORT CONTROL:
+
+The Copyright owner believes that the Export Control Classification
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because
+it is open source, publicly available software, that does not contain
+any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+734.7(b).
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+September 29, 2017

xs/src/png/libpng/arm/arm_init.c

@@ -0,0 +1,135 @@
+
+/* arm_init.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.6.22 [May 26, 2016]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
+ * called.
+ */
+#define _POSIX_SOURCE 1
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_ARM_NEON_OPT > 0
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible.  In the case of the ARM
+ * NEON instructions there is no processor-specific way of detecting the
+ * presence of the required support, therefore run-time detection is extremely
+ * OS specific.
+ *
+ * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_neon function.  There
+ * are a number of implementations in contrib/arm-neon, but the only one that
+ * has partial support is contrib/arm-neon/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
+ */
+#ifndef PNG_ARM_NEON_FILE
+#  ifdef __linux__
+#     define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+#  endif
+#endif
+
+#ifdef PNG_ARM_NEON_FILE
+
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_neon(png_structp png_ptr);
+#include PNG_ARM_NEON_FILE
+
+#else  /* PNG_ARM_NEON_FILE */
+#  error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
+#endif /* PNG_ARM_NEON_FILE */
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
+#  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
+#endif
+
+void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+   /* The switch statement is compiled in for ARM_NEON_API, the call to
+    * png_have_neon is compiled in for ARM_NEON_CHECK.  If both are defined
+    * the check is only performed if the API has not set the NEON option on
+    * or off explicitly.  In this case the check controls what happens.
+    *
+    * If the CHECK is not compiled in and the option is UNSET the behavior prior
+    * to 1.6.7 was to use the NEON code - this was a bug caused by having the
+    * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
+    * as documented in png.h
+    */
+   png_debug(1, "in png_init_filter_functions_neon");
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+   switch ((pp->options >> PNG_ARM_NEON) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_ARM_NEON_API_SUPPORTED */
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
+         {
+            static volatile sig_atomic_t no_neon = -1; /* not checked */
+
+            if (no_neon < 0)
+               no_neon = !png_have_neon(pp);
+
+            if (no_neon)
+               return;
+         }
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+         break;
+#endif
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+   }
+#endif
+
+   /* IMPORTANT: any new external functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth3_neon;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_neon;
+   }
+}
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* READ */

xs/src/png/libpng/arm/filter_neon.S

@@ -0,0 +1,253 @@
+
+/* filter_neon.S - NEON optimised filter functions
+ *
+ * Copyright (c) 2014,2017 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* This is required to get the symbol renames, which are #defines, and the
+ * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
+ */
+#define PNG_VERSION_INFO_ONLY
+#include "../pngpriv.h"
+
+#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__ELF__)
+.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
+ * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
+ * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
+ * for the logic which sets PNG_USE_ARM_NEON_ASM:
+ */
+#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
+
+#if PNG_ARM_NEON_OPT > 0
+
+#ifdef __ELF__
+#   define ELF
+#else
+#   define ELF @
+#endif
+
+        .arch armv7-a
+        .fpu  neon
+
+.macro  func    name, export=0
+    .macro endfunc
+ELF     .size   \name, . - \name
+        .endfunc
+        .purgem endfunc
+    .endm
+        .text
+
+        /* Explicitly specifying alignment here because some versions of
+         * GAS don't align code correctly.  This is harmless in correctly
+         * written versions of GAS.
+         */
+        .align 2
+
+    .if \export
+        .global \name
+    .endif
+ELF     .type   \name, STT_FUNC
+        .func   \name
+\name:
+.endm
+
+func    png_read_filter_row_sub4_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vadd.u8         d0,  d3,  d4
+        vadd.u8         d1,  d0,  d5
+        vadd.u8         d2,  d1,  d6
+        vadd.u8         d3,  d2,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r3,  r3,  #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_sub3_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        mov             r0,  r1
+        mov             r2,  #3
+        mov             r12, #12
+        vld1.8          {q11},    [r0], r12
+1:
+        vext.8          d5,  d22, d23, #3
+        vadd.u8         d0,  d3,  d22
+        vext.8          d6,  d22, d23, #6
+        vadd.u8         d1,  d0,  d5
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], r12
+        vst1.32         {d0[0]},  [r1,:32], r2
+        vadd.u8         d2,  d1,  d6
+        vst1.32         {d1[0]},  [r1], r2
+        vadd.u8         d3,  d2,  d7
+        vst1.32         {d2[0]},  [r1], r2
+        vst1.32         {d3[0]},  [r1], r2
+        subs            r3,  r3,  #12
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_up_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+1:
+        vld1.8          {q0}, [r1,:128]
+        vld1.8          {q1}, [r2,:128]!
+        vadd.u8         q0,  q0,  q1
+        vst1.8          {q0}, [r1,:128]!
+        subs            r3,  r3,  #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_avg4_neon, export=1
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
+        vhadd.u8        d0,  d3,  d16
+        vadd.u8         d0,  d0,  d4
+        vhadd.u8        d1,  d0,  d17
+        vadd.u8         d1,  d1,  d5
+        vhadd.u8        d2,  d1,  d18
+        vadd.u8         d2,  d2,  d6
+        vhadd.u8        d3,  d2,  d19
+        vadd.u8         d3,  d3,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r12, r12, #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_avg3_neon, export=1
+        push            {r4,lr}
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        mov             r0,  r1
+        mov             r4,  #3
+        mov             lr,  #12
+        vld1.8          {q11},    [r0], lr
+1:
+        vld1.8          {q10},    [r2], lr
+        vext.8          d5,  d22, d23, #3
+        vhadd.u8        d0,  d3,  d20
+        vext.8          d17, d20, d21, #3
+        vadd.u8         d0,  d0,  d22
+        vext.8          d6,  d22, d23, #6
+        vhadd.u8        d1,  d0,  d17
+        vext.8          d18, d20, d21, #6
+        vadd.u8         d1,  d1,  d5
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], lr
+        vst1.32         {d0[0]},  [r1,:32], r4
+        vhadd.u8        d2,  d1,  d18
+        vst1.32         {d1[0]},  [r1], r4
+        vext.8          d19, d21, d21, #1
+        vadd.u8         d2,  d2,  d6
+        vhadd.u8        d3,  d2,  d19
+        vst1.32         {d2[0]},  [r1], r4
+        vadd.u8         d3,  d3,  d7
+        vst1.32         {d3[0]},  [r1], r4
+        subs            r12, r12, #12
+        bgt             1b
+
+        pop             {r4,pc}
+endfunc
+
+.macro  paeth           rx,  ra,  rb,  rc
+        vaddl.u8        q12, \ra, \rb           @ a + b
+        vaddl.u8        q15, \rc, \rc           @ 2*c
+        vabdl.u8        q13, \rb, \rc           @ pa
+        vabdl.u8        q14, \ra, \rc           @ pb
+        vabd.u16        q15, q12, q15           @ pc
+        vcle.u16        q12, q13, q14           @ pa <= pb
+        vcle.u16        q13, q13, q15           @ pa <= pc
+        vcle.u16        q14, q14, q15           @ pb <= pc
+        vand            q12, q12, q13           @ pa <= pb && pa <= pc
+        vmovn.u16       d28, q14
+        vmovn.u16       \rx, q12
+        vbsl            d28, \rb, \rc
+        vbsl            \rx, \ra, d28
+.endm
+
+func    png_read_filter_row_paeth4_neon, export=1
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        vmov.i8         d20, #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
+        paeth           d0,  d3,  d16, d20
+        vadd.u8         d0,  d0,  d4
+        paeth           d1,  d0,  d17, d16
+        vadd.u8         d1,  d1,  d5
+        paeth           d2,  d1,  d18, d17
+        vadd.u8         d2,  d2,  d6
+        paeth           d3,  d2,  d19, d18
+        vmov            d20, d19
+        vadd.u8         d3,  d3,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r12, r12, #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_paeth3_neon, export=1
+        push            {r4,lr}
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        vmov.i8         d4,  #0
+        mov             r0,  r1
+        mov             r4,  #3
+        mov             lr,  #12
+        vld1.8          {q11},    [r0], lr
+1:
+        vld1.8          {q10},    [r2], lr
+        paeth           d0,  d3,  d20, d4
+        vext.8          d5,  d22, d23, #3
+        vadd.u8         d0,  d0,  d22
+        vext.8          d17, d20, d21, #3
+        paeth           d1,  d0,  d17, d20
+        vst1.32         {d0[0]},  [r1,:32], r4
+        vext.8          d6,  d22, d23, #6
+        vadd.u8         d1,  d1,  d5
+        vext.8          d18, d20, d21, #6
+        paeth           d2,  d1,  d18, d17
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], lr
+        vst1.32         {d1[0]},  [r1], r4
+        vadd.u8         d2,  d2,  d6
+        vext.8          d19, d21, d21, #1
+        paeth           d3,  d2,  d19, d18
+        vst1.32         {d2[0]},  [r1], r4
+        vmov            d4,  d19
+        vadd.u8         d3,  d3,  d7
+        vst1.32         {d3[0]},  [r1], r4
+        subs            r12, r12, #12
+        bgt             1b
+
+        pop             {r4,pc}
+endfunc
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* READ */

xs/src/png/libpng/arm/filter_neon_intrinsics.c

@@ -0,0 +1,387 @@
+
+/* filter_neon_intrinsics.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Written by James Yu <james.yu at linaro.org>, October 2013.
+ * Based on filter_neon.S, written by Mans Rullgard, 2011.
+ *
+ * Last changed in libpng 1.6.22 [May 26, 2016]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* This code requires -mfpu=neon on the command line: */
+#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <arm_neon.h>
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment.  arm/arm_init.c
+ * checks for this (and will not compile unless it is done). This code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'.  This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ */
+#define png_ldr(type,pointer)\
+   (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#if PNG_ARM_NEON_OPT > 0
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   png_debug(1, "in png_read_filter_row_up_neon");
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint8x16_t qrp, qpp;
+
+      qrp = vld1q_u8(rp);
+      qpp = vld1q_u8(pp);
+      qrp = vaddq_u8(qrp, qpp);
+      vst1q_u8(rp, qrp);
+   }
+}
+
+void
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp = vld1q_u8(rp);
+   uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
+   uint8x8x2_t vrp = *vrpt;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   png_debug(1, "in png_read_filter_row_sub3_neon");
+
+   for (; rp < rp_stop;)
+   {
+      uint8x8_t vtmp1, vtmp2;
+      uint32x2_t *temp_pointer;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t, &vtmp);
+      vrp = *vrpt;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   png_debug(1, "in png_read_filter_row_sub4_neon");
+
+   for (; rp < rp_stop; rp += 16)
+   {
+      uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      uint8x8x4_t vrp = *vrpt;
+      uint32x2x4_t *temp_pointer;
+
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   png_debug(1, "in png_read_filter_row_avg3_neon");
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   png_debug(1, "in png_read_filter_row_avg4_neon");
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+static uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+   uint8x8_t d, e;
+   uint16x8_t p1, pa, pb, pc;
+
+   p1 = vaddl_u8(a, b); /* a + b */
+   pc = vaddl_u8(c, c); /* c * 2 */
+   pa = vabdl_u8(b, c); /* pa */
+   pb = vabdl_u8(a, c); /* pb */
+   pc = vabdq_u16(p1, pc); /* pc */
+
+   p1 = vcleq_u16(pa, pb); /* pa <= pb */
+   pa = vcleq_u16(pa, pc); /* pa <= pc */
+   pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+   p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+   d = vmovn_u16(pb);
+   e = vmovn_u16(p1);
+
+   d = vbsl_u8(d, b, c);
+   e = vbsl_u8(e, a, d);
+
+   return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   png_debug(1, "in png_read_filter_row_paeth3_neon");
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vlast = vtmp2;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   png_debug(1, "in png_read_filter_row_paeth4_neon");
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vlast = vpp.val[3];
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */

xs/src/png/libpng/intel/filter_sse2_intrinsics.c

@@ -0,0 +1,406 @@
+
+/* filter_sse2_intrinsics.c - SSE2 optimized filter functions
+ *
+ * Copyright (c) 2016-2017 Glenn Randers-Pehrson
+ * Written by Mike Klein and Matt Sarett
+ * Derived from arm/filter_neon_intrinsics.c
+ *
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+
+#include <immintrin.h>
+
+/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d).
+ * They're positioned like this:
+ *    prev:  c b
+ *    row:   a d
+ * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be
+ * whichever of a, b, or c is closest to p=a+b-c.
+ */
+
+static __m128i load4(const void* p) {
+   return _mm_cvtsi32_si128(*(const int*)p);
+}
+
+static void store4(void* p, __m128i v) {
+   *(int*)p = _mm_cvtsi128_si32(v);
+}
+
+static __m128i load3(const void* p) {
+   /* We'll load 2 bytes, then 1 byte,
+    * then mask them together, and finally load into SSE.
+    */
+   const png_uint_16* p01 = (png_const_uint_16p)p;
+   const png_byte*    p2  = (const png_byte*)(p01+1);
+
+   png_uint_32 v012 = (png_uint_32)(*p01)
+                    | (png_uint_32)(*p2) << 16;
+   return load4(&v012);
+}
+
+static void store3(void* p, __m128i v) {
+   /* We'll pull from SSE as a 32-bit int, then write
+    * its bottom two bytes, then its third byte.
+    */
+   png_uint_32 v012;
+   png_uint_16* p01;
+   png_byte*    p2;
+
+   store4(&v012, v);
+
+   p01 = (png_uint_16p)p;
+   p2  = (png_byte*)(p01+1);
+   *p01 = (png_uint_16)v012;
+   *p2  = (png_byte)(v012 >> 16);
+}
+
+void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* The Sub filter predicts each pixel as the previous pixel, a.
+    * There is no pixel to the left of the first pixel.  It's encoded directly.
+    * That works with our main loop if we just say that left pixel was zero.
+    */
+   png_size_t rb;
+
+   __m128i a, d = _mm_setzero_si128();
+
+   png_debug(1, "in png_read_filter_row_sub3_sse2");
+
+   rb = row_info->rowbytes;
+   while (rb >= 4) {
+      a = d; d = load4(row);
+      d = _mm_add_epi8(d, a);
+      store3(row, d);
+
+      row += 3;
+      rb  -= 3;
+   }
+   if (rb > 0) {
+      a = d; d = load3(row);
+      d = _mm_add_epi8(d, a);
+      store3(row, d);
+
+      row += 3;
+      rb  -= 3;
+   }
+   PNG_UNUSED(prev)
+}
+
+void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* The Sub filter predicts each pixel as the previous pixel, a.
+    * There is no pixel to the left of the first pixel.  It's encoded directly.
+    * That works with our main loop if we just say that left pixel was zero.
+    */
+   png_size_t rb;
+
+   __m128i a, d = _mm_setzero_si128();
+
+   png_debug(1, "in png_read_filter_row_sub4_sse2");
+
+   rb = row_info->rowbytes+4;
+   while (rb > 4) {
+      a = d; d = load4(row);
+      d = _mm_add_epi8(d, a);
+      store4(row, d);
+
+      row += 4;
+      rb  -= 4;
+   }
+   PNG_UNUSED(prev)
+}
+
+void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* The Avg filter predicts each pixel as the (truncated) average of a and b.
+    * There's no pixel to the left of the first pixel.  Luckily, it's
+    * predicted to be half of the pixel above it.  So again, this works
+    * perfectly with our loop if we make sure a starts at zero.
+    */
+
+   png_size_t rb;
+
+   const __m128i zero = _mm_setzero_si128();
+
+   __m128i    b;
+   __m128i a, d = zero;
+
+   png_debug(1, "in png_read_filter_row_avg3_sse2");
+   rb = row_info->rowbytes;
+   while (rb >= 4) {
+      __m128i avg;
+             b = load4(prev);
+      a = d; d = load4(row );
+
+      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+      avg = _mm_avg_epu8(a,b);
+      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+                                            _mm_set1_epi8(1)));
+      d = _mm_add_epi8(d, avg);
+      store3(row, d);
+
+      prev += 3;
+      row  += 3;
+      rb   -= 3;
+   }
+   if (rb > 0) {
+      __m128i avg;
+             b = load3(prev);
+      a = d; d = load3(row );
+
+      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+      avg = _mm_avg_epu8(a,b);
+      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+                                            _mm_set1_epi8(1)));
+
+      d = _mm_add_epi8(d, avg);
+      store3(row, d);
+
+      prev += 3;
+      row  += 3;
+      rb   -= 3;
+   }
+}
+
+void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* The Avg filter predicts each pixel as the (truncated) average of a and b.
+    * There's no pixel to the left of the first pixel.  Luckily, it's
+    * predicted to be half of the pixel above it.  So again, this works
+    * perfectly with our loop if we make sure a starts at zero.
+    */
+   png_size_t rb;
+   const __m128i zero = _mm_setzero_si128();
+   __m128i    b;
+   __m128i a, d = zero;
+
+   png_debug(1, "in png_read_filter_row_avg4_sse2");
+
+   rb = row_info->rowbytes+4;
+   while (rb > 4) {
+      __m128i avg;
+             b = load4(prev);
+      a = d; d = load4(row );
+
+      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+      avg = _mm_avg_epu8(a,b);
+      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+                                            _mm_set1_epi8(1)));
+
+      d = _mm_add_epi8(d, avg);
+      store4(row, d);
+
+      prev += 4;
+      row  += 4;
+      rb   -= 4;
+   }
+}
+
+/* Returns |x| for 16-bit lanes. */
+static __m128i abs_i16(__m128i x) {
+#if PNG_INTEL_SSE_IMPLEMENTATION >= 2
+   return _mm_abs_epi16(x);
+#else
+   /* Read this all as, return x<0 ? -x : x.
+   * To negate two's complement, you flip all the bits then add 1.
+    */
+   __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128());
+
+   /* Flip negative lanes. */
+   x = _mm_xor_si128(x, is_negative);
+
+   /* +1 to negative lanes, else +0. */
+   x = _mm_sub_epi16(x, is_negative);
+   return x;
+#endif
+}
+
+/* Bytewise c ? t : e. */
+static __m128i if_then_else(__m128i c, __m128i t, __m128i e) {
+#if PNG_INTEL_SSE_IMPLEMENTATION >= 3
+   return _mm_blendv_epi8(e,t,c);
+#else
+   return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e));
+#endif
+}
+
+void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* Paeth tries to predict pixel d using the pixel to the left of it, a,
+    * and two pixels from the previous row, b and c:
+    *   prev: c b
+    *   row:  a d
+    * The Paeth function predicts d to be whichever of a, b, or c is nearest to
+    * p=a+b-c.
+    *
+    * The first pixel has no left context, and so uses an Up filter, p = b.
+    * This works naturally with our main loop's p = a+b-c if we force a and c
+    * to zero.
+    * Here we zero b and d, which become c and a respectively at the start of
+    * the loop.
+    */
+   png_size_t rb;
+   const __m128i zero = _mm_setzero_si128();
+   __m128i c, b = zero,
+           a, d = zero;
+
+   png_debug(1, "in png_read_filter_row_paeth3_sse2");
+
+   rb = row_info->rowbytes;
+   while (rb >= 4) {
+      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+       * intermediates.
+       */
+      __m128i pa,pb,pc,smallest,nearest;
+      c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
+      a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
+
+      /* (p-a) == (a+b-c - a) == (b-c) */
+   
+      pa = _mm_sub_epi16(b,c);
+
+      /* (p-b) == (a+b-c - b) == (a-c) */
+      pb = _mm_sub_epi16(a,c);
+
+      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+      pc = _mm_add_epi16(pa,pb);
+
+      pa = abs_i16(pa);  /* |p-a| */
+      pb = abs_i16(pb);  /* |p-b| */
+      pc = abs_i16(pc);  /* |p-c| */
+
+      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+      /* Paeth breaks ties favoring a over b over c. */
+      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+                 if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+                                                             c));
+
+      /* Note `_epi8`: we need addition to wrap modulo 255. */
+      d = _mm_add_epi8(d, nearest);
+      store3(row, _mm_packus_epi16(d,d));
+
+      prev += 3;
+      row  += 3;
+      rb   -= 3;
+   }
+   if (rb > 0) {
+      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+       * intermediates.
+       */
+      __m128i pa,pb,pc,smallest,nearest;
+      c = b; b = _mm_unpacklo_epi8(load3(prev), zero);
+      a = d; d = _mm_unpacklo_epi8(load3(row ), zero);
+
+      /* (p-a) == (a+b-c - a) == (b-c) */
+      pa = _mm_sub_epi16(b,c);
+
+      /* (p-b) == (a+b-c - b) == (a-c) */
+      pb = _mm_sub_epi16(a,c);
+
+      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+      pc = _mm_add_epi16(pa,pb);
+
+      pa = abs_i16(pa);  /* |p-a| */
+      pb = abs_i16(pb);  /* |p-b| */
+      pc = abs_i16(pc);  /* |p-c| */
+
+      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+      /* Paeth breaks ties favoring a over b over c. */
+      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+                         if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+                                                                     c));
+
+      /* Note `_epi8`: we need addition to wrap modulo 255. */
+      d = _mm_add_epi8(d, nearest);
+      store3(row, _mm_packus_epi16(d,d));
+
+      prev += 3;
+      row  += 3;
+      rb   -= 3;
+   }
+}
+
+void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev)
+{
+   /* Paeth tries to predict pixel d using the pixel to the left of it, a,
+    * and two pixels from the previous row, b and c:
+    *   prev: c b
+    *   row:  a d
+    * The Paeth function predicts d to be whichever of a, b, or c is nearest to
+    * p=a+b-c.
+    *
+    * The first pixel has no left context, and so uses an Up filter, p = b.
+    * This works naturally with our main loop's p = a+b-c if we force a and c
+    * to zero.
+    * Here we zero b and d, which become c and a respectively at the start of
+    * the loop.
+    */
+   png_size_t rb;
+   const __m128i zero = _mm_setzero_si128();
+   __m128i pa,pb,pc,smallest,nearest;
+   __m128i c, b = zero,
+           a, d = zero;
+
+   png_debug(1, "in png_read_filter_row_paeth4_sse2");
+
+   rb = row_info->rowbytes+4;
+   while (rb > 4) {
+      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+       * intermediates.
+       */
+      c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
+      a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
+
+      /* (p-a) == (a+b-c - a) == (b-c) */
+      pa = _mm_sub_epi16(b,c);
+
+      /* (p-b) == (a+b-c - b) == (a-c) */
+      pb = _mm_sub_epi16(a,c);
+
+      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+      pc = _mm_add_epi16(pa,pb);
+
+      pa = abs_i16(pa);  /* |p-a| */
+      pb = abs_i16(pb);  /* |p-b| */
+      pc = abs_i16(pc);  /* |p-c| */
+
+      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+      /* Paeth breaks ties favoring a over b over c. */
+      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+                         if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+                                                                     c));
+
+      /* Note `_epi8`: we need addition to wrap modulo 255. */
+      d = _mm_add_epi8(d, nearest);
+      store4(row, _mm_packus_epi16(d,d));
+
+      prev += 4;
+      row  += 4;
+      rb   -= 4;
+   }
+}
+
+#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
+#endif /* READ */

xs/src/png/libpng/intel/intel_init.c

@@ -0,0 +1,53 @@
+
+/* intel_init.c - SSE2 optimized filter functions
+ *
+ * Copyright (c) 2016-2017 Glenn Randers-Pehrson
+ * Written by Mike Klein and Matt Sarett, Google, Inc.
+ * Derived from arm/arm_init.c
+ *
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+
+void
+png_init_filter_functions_sse2(png_structp pp, unsigned int bpp)
+{
+   /* The techniques used to implement each of these filters in SSE operate on
+    * one pixel at a time.
+    * So they generally speed up 3bpp images about 3x, 4bpp images about 4x.
+    * They can scale up to 6 and 8 bpp images and down to 2 bpp images,
+    * but they'd not likely have any benefit for 1bpp images.
+    * Most of these can be implemented using only MMX and 64-bit registers,
+    * but they end up a bit slower than using the equally-ubiquitous SSE2.
+   */
+   png_debug(1, "in png_init_filter_functions_sse2");
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth3_sse2;
+   }
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_sse2;
+   }
+
+   /* No need optimize PNG_FILTER_VALUE_UP.  The compiler should
+    * autovectorize.
+    */
+}
+
+#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
+#endif /* PNG_READ_SUPPORTED */

xs/src/png/libpng/libpng-config.in

@@ -0,0 +1,127 @@
+#! /bin/sh
+
+# libpng-config
+# provides configuration info for libpng.
+
+# Copyright (C) 2002, 2004, 2006, 2007 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Modeled after libxml-config.
+
+version="@PNGLIB_VERSION@"
+prefix="@prefix@"
+exec_prefix="@exec_prefix@"
+libdir="@libdir@"
+includedir="@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+all_libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ @LIBS@"
+I_opts="-I${includedir}"
+L_opts="-L${libdir}"
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+
+usage()
+{
+    cat <<EOF
+Usage: $0 [OPTION] ...
+
+Known values for OPTION are:
+
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+
+    exit $1
+}
+
+if test $# -eq 0; then
+    usage 1
+fi
+
+while test $# -gt 0; do
+    case "$1" in
+
+    --prefix)
+        echo ${prefix}
+        ;;
+
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+
+    --help)
+        usage 0
+        ;;
+
+    --ccopts)
+        echo ${ccopts}
+        ;;
+
+    --cppflags)
+        echo ${cppflags}
+        ;;
+
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+
+    --libdir)
+        echo ${libdir}
+        ;;
+
+    --libs)
+        echo ${libs}
+        ;;
+
+    --I_opts)
+        echo ${I_opts}
+        ;;
+
+    --L_opts)
+        echo ${L_opts}
+        ;;
+
+    --R_opts)
+        echo ${R_opts}
+        ;;
+
+    --ldopts)
+        echo ${ldopts}
+        ;;
+
+    --ldflags)
+        echo ${ldopts} ${L_opts} ${R_opts} ${libs}
+        ;;
+
+    --static)
+        R_opts=""
+        libs=${all_libs}
+        ;;
+
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+
+exit 0

xs/src/png/libpng/libpng.pc.in

@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+
+Name: libpng
+Description: Loads and saves PNG files
+Version: @PNGLIB_VERSION@
+Requires: zlib
+Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+Libs.private: @LIBS@
+Cflags: -I${includedir}

xs/src/png/libpng/mips/filter_msa_intrinsics.c

@@ -0,0 +1,807 @@
+
+/* filter_msa_intrinsics.c - MSA optimised filter functions
+ *
+ * Copyright (c) 2016 Glenn Randers-Pehrson
+ * Written by Mandar Sahastrabuddhe, August 2016.
+ * Last changed in libpng 1.6.25 [September 1, 2016]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* This code requires -mfpu=msa on the command line: */
+#if PNG_MIPS_MSA_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <msa.h>
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment. mips/mips_init.c
+ * checks for this (and will not compile unless it is done). This code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'.  This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ */
+#define png_ldr(type,pointer)\
+   (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#if PNG_MIPS_MSA_OPT > 0
+
+#ifdef CLANG_BUILD
+   #define MSA_SRLI_B(a, b)   __msa_srli_b((v16i8) a, b)
+
+   #define LW(psrc)                              \
+   ( {                                           \
+       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
+       uint32_t val_m;                           \
+                                                 \
+       asm volatile (                            \
+           "lw  %[val_m],  %[psrc_lw_m]  \n\t"   \
+                                                 \
+           : [val_m] "=r" (val_m)                \
+           : [psrc_lw_m] "m" (*psrc_lw_m)        \
+       );                                        \
+                                                 \
+       val_m;                                    \
+   } )
+
+   #define SH(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
+       uint16_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "sh  %[val_m],  %[pdst_sh_m]  \n\t"   \
+                                                 \
+           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+   #define SW(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
+       uint32_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "sw  %[val_m],  %[pdst_sw_m]  \n\t"   \
+                                                 \
+           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+       #if (__mips == 64)
+        #define SD(val, pdst)                         \
+        {                                             \
+            uint8_t *pdst_sd_m = (uint8_t *) (pdst);  \
+            uint64_t val_m = (val);                   \
+                                                      \
+            asm volatile (                            \
+                "sd  %[val_m],  %[pdst_sd_m]  \n\t"   \
+                                                      \
+                : [pdst_sd_m] "=m" (*pdst_sd_m)       \
+                : [val_m] "r" (val_m)                 \
+            );                                        \
+        }
+    #else
+        #define SD(val, pdst)                                          \
+        {                                                              \
+            uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
+            uint32_t val0_m, val1_m;                                   \
+                                                                       \
+            val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF);          \
+            val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF);  \
+                                                                       \
+            SW(val0_m, pdst_sd_m);                                     \
+            SW(val1_m, pdst_sd_m + 4);                                 \
+        }
+    #endif
+#else
+   #define MSA_SRLI_B(a, b)   (a >> b)
+
+#if (__mips_isa_rev >= 6)
+   #define LW(psrc)                              \
+   ( {                                           \
+       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
+       uint32_t val_m;                           \
+                                                 \
+       asm volatile (                            \
+           "lw  %[val_m],  %[psrc_lw_m]  \n\t"   \
+                                                 \
+           : [val_m] "=r" (val_m)                \
+           : [psrc_lw_m] "m" (*psrc_lw_m)        \
+       );                                        \
+                                                 \
+       val_m;                                    \
+   } )
+
+   #define SH(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
+       uint16_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "sh  %[val_m],  %[pdst_sh_m]  \n\t"   \
+                                                 \
+           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+   #define SW(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
+       uint32_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "sw  %[val_m],  %[pdst_sw_m]  \n\t"   \
+                                                 \
+           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+   #if (__mips == 64)
+        #define SD(val, pdst)                         \
+        {                                             \
+            uint8_t *pdst_sd_m = (uint8_t *) (pdst);  \
+            uint64_t val_m = (val);                   \
+                                                      \
+            asm volatile (                            \
+                "sd  %[val_m],  %[pdst_sd_m]  \n\t"   \
+                                                      \
+                : [pdst_sd_m] "=m" (*pdst_sd_m)       \
+                : [val_m] "r" (val_m)                 \
+            );                                        \
+        }
+    #else
+        #define SD(val, pdst)                                          \
+        {                                                              \
+            uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
+            uint32_t val0_m, val1_m;                                   \
+                                                                       \
+            val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF);          \
+            val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF);  \
+                                                                       \
+            SW(val0_m, pdst_sd_m);                                     \
+            SW(val1_m, pdst_sd_m + 4);                                 \
+        }
+    #endif
+#else  // !(__mips_isa_rev >= 6)
+   #define LW(psrc)                              \
+   ( {                                           \
+       uint8_t *psrc_lw_m = (uint8_t *) (psrc);  \
+       uint32_t val_m;                           \
+                                                 \
+       asm volatile (                            \
+           "ulw  %[val_m],  %[psrc_lw_m]  \n\t"  \
+                                                 \
+           : [val_m] "=r" (val_m)                \
+           : [psrc_lw_m] "m" (*psrc_lw_m)        \
+       );                                        \
+                                                 \
+       val_m;                                    \
+   } )
+
+   #define SH(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sh_m = (uint8_t *) (pdst);  \
+       uint16_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "ush  %[val_m],  %[pdst_sh_m]  \n\t"  \
+                                                 \
+           : [pdst_sh_m] "=m" (*pdst_sh_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+   #define SW(val, pdst)                         \
+   {                                             \
+       uint8_t *pdst_sw_m = (uint8_t *) (pdst);  \
+       uint32_t val_m = (val);                   \
+                                                 \
+       asm volatile (                            \
+           "usw  %[val_m],  %[pdst_sw_m]  \n\t"  \
+                                                 \
+           : [pdst_sw_m] "=m" (*pdst_sw_m)       \
+           : [val_m] "r" (val_m)                 \
+       );                                        \
+   }
+
+   #define SD(val, pdst)                                          \
+    {                                                              \
+        uint8_t *pdst_sd_m = (uint8_t *) (pdst);                   \
+        uint32_t val0_m, val1_m;                                   \
+                                                                   \
+        val0_m = (uint32_t) ((val) & 0x00000000FFFFFFFF);          \
+        val1_m = (uint32_t) (((val) >> 32) & 0x00000000FFFFFFFF);  \
+                                                                   \
+        SW(val0_m, pdst_sd_m);                                     \
+        SW(val1_m, pdst_sd_m + 4);                                 \
+    }
+
+    #define SW_ZERO(pdst)                      \
+    {                                          \
+        uint8_t *pdst_m = (uint8_t *) (pdst);  \
+                                               \
+        asm volatile (                         \
+            "usw  $0,  %[pdst_m]  \n\t"        \
+                                               \
+            : [pdst_m] "=m" (*pdst_m)          \
+            :                                  \
+        );                                     \
+    }
+#endif  // (__mips_isa_rev >= 6)
+#endif
+
+#define LD_B(RTYPE, psrc) *((RTYPE *) (psrc))
+#define LD_UB(...) LD_B(v16u8, __VA_ARGS__)
+#define LD_B2(RTYPE, psrc, stride, out0, out1)  \
+{                                               \
+    out0 = LD_B(RTYPE, (psrc));                 \
+    out1 = LD_B(RTYPE, (psrc) + stride);        \
+}
+#define LD_UB2(...) LD_B2(v16u8, __VA_ARGS__)
+#define LD_B4(RTYPE, psrc, stride, out0, out1, out2, out3)   \
+{                                                            \
+    LD_B2(RTYPE, (psrc), stride, out0, out1);                \
+    LD_B2(RTYPE, (psrc) + 2 * stride , stride, out2, out3);  \
+}
+#define LD_UB4(...) LD_B4(v16u8, __VA_ARGS__)
+
+#define ST_B(RTYPE, in, pdst) *((RTYPE *) (pdst)) = (in)
+#define ST_UB(...) ST_B(v16u8, __VA_ARGS__)
+#define ST_B2(RTYPE, in0, in1, pdst, stride)  \
+{                                             \
+    ST_B(RTYPE, in0, (pdst));                 \
+    ST_B(RTYPE, in1, (pdst) + stride);        \
+}
+#define ST_UB2(...) ST_B2(v16u8, __VA_ARGS__)
+#define ST_B4(RTYPE, in0, in1, in2, in3, pdst, stride)    \
+{                                                         \
+    ST_B2(RTYPE, in0, in1, (pdst), stride);               \
+    ST_B2(RTYPE, in2, in3, (pdst) + 2 * stride, stride);  \
+}
+#define ST_UB4(...) ST_B4(v16u8, __VA_ARGS__)
+
+#define ADD2(in0, in1, in2, in3, out0, out1)  \
+{                                             \
+    out0 = in0 + in1;                         \
+    out1 = in2 + in3;                         \
+}
+#define ADD3(in0, in1, in2, in3, in4, in5,  \
+             out0, out1, out2)              \
+{                                           \
+    ADD2(in0, in1, in2, in3, out0, out1);   \
+    out2 = in4 + in5;                       \
+}
+#define ADD4(in0, in1, in2, in3, in4, in5, in6, in7,  \
+             out0, out1, out2, out3)                  \
+{                                                     \
+    ADD2(in0, in1, in2, in3, out0, out1);             \
+    ADD2(in4, in5, in6, in7, out2, out3);             \
+}
+
+#define ILVR_B2(RTYPE, in0, in1, in2, in3, out0, out1)      \
+{                                                           \
+    out0 = (RTYPE) __msa_ilvr_b((v16i8) in0, (v16i8) in1);  \
+    out1 = (RTYPE) __msa_ilvr_b((v16i8) in2, (v16i8) in3);  \
+}
+#define ILVR_B2_SH(...) ILVR_B2(v8i16, __VA_ARGS__)
+
+#define HSUB_UB2(RTYPE, in0, in1, out0, out1)                 \
+{                                                             \
+    out0 = (RTYPE) __msa_hsub_u_h((v16u8) in0, (v16u8) in0);  \
+    out1 = (RTYPE) __msa_hsub_u_h((v16u8) in1, (v16u8) in1);  \
+}
+#define HSUB_UB2_SH(...) HSUB_UB2(v8i16, __VA_ARGS__)
+
+#define SLDI_B2_0(RTYPE, in0, in1, out0, out1, slide_val)                 \
+{                                                                         \
+    v16i8 zero_m = { 0 };                                                 \
+    out0 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in0, slide_val);  \
+    out1 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in1, slide_val);  \
+}
+#define SLDI_B2_0_UB(...) SLDI_B2_0(v16u8, __VA_ARGS__)
+
+#define SLDI_B3_0(RTYPE, in0, in1, in2, out0, out1, out2,  slide_val)     \
+{                                                                         \
+    v16i8 zero_m = { 0 };                                                 \
+    SLDI_B2_0(RTYPE, in0, in1, out0, out1, slide_val);                    \
+    out2 = (RTYPE) __msa_sldi_b((v16i8) zero_m, (v16i8) in2, slide_val);  \
+}
+#define SLDI_B3_0_UB(...) SLDI_B3_0(v16u8, __VA_ARGS__)
+
+#define ILVEV_W2(RTYPE, in0, in1, in2, in3, out0, out1)      \
+{                                                            \
+    out0 = (RTYPE) __msa_ilvev_w((v4i32) in1, (v4i32) in0);  \
+    out1 = (RTYPE) __msa_ilvev_w((v4i32) in3, (v4i32) in2);  \
+}
+#define ILVEV_W2_UB(...) ILVEV_W2(v16u8, __VA_ARGS__)
+
+#define ADD_ABS_H3(RTYPE, in0, in1, in2, out0, out1, out2)  \
+{                                                           \
+    RTYPE zero = {0};                                       \
+                                                            \
+    out0 = __msa_add_a_h((v8i16) zero, in0);                \
+    out1 = __msa_add_a_h((v8i16) zero, in1);                \
+    out2 = __msa_add_a_h((v8i16) zero, in2);                \
+}
+#define ADD_ABS_H3_SH(...) ADD_ABS_H3(v8i16, __VA_ARGS__)
+
+#define VSHF_B2(RTYPE, in0, in1, in2, in3, mask0, mask1, out0, out1)       \
+{                                                                          \
+    out0 = (RTYPE) __msa_vshf_b((v16i8) mask0, (v16i8) in1, (v16i8) in0);  \
+    out1 = (RTYPE) __msa_vshf_b((v16i8) mask1, (v16i8) in3, (v16i8) in2);  \
+}
+#define VSHF_B2_UB(...) VSHF_B2(v16u8, __VA_ARGS__)
+
+#define CMP_AND_SELECT(inp0, inp1, inp2, inp3, inp4, inp5, out0)              \
+{                                                                             \
+   v8i16 _sel_h0, _sel_h1;                                                    \
+   v16u8 _sel_b0, _sel_b1;                                                    \
+   _sel_h0 = (v8i16) __msa_clt_u_h((v8u16) inp1, (v8u16) inp0);               \
+   _sel_b0 = (v16u8) __msa_pckev_b((v16i8) _sel_h0, (v16i8) _sel_h0);         \
+   inp0 = (v8i16) __msa_bmnz_v((v16u8) inp0, (v16u8) inp1, (v16u8) _sel_h0);  \
+   inp4 = (v16u8) __msa_bmnz_v(inp3, inp4, _sel_b0);                          \
+   _sel_h1 = (v8i16) __msa_clt_u_h((v8u16) inp2, (v8u16) inp0);               \
+   _sel_b1 = (v16u8) __msa_pckev_b((v16i8) _sel_h1, (v16i8) _sel_h1);         \
+   inp4 = (v16u8) __msa_bmnz_v(inp4, inp5, _sel_b1);                          \
+   out0 += inp4;                                                              \
+}
+
+void png_read_filter_row_up_msa(png_row_infop row_info, png_bytep row,
+                                png_const_bytep prev_row)
+{
+   png_size_t i, cnt, cnt16, cnt32;
+   png_size_t istop = row_info->rowbytes;
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   v16u8 src0, src1, src2, src3, src4, src5, src6, src7;
+
+   for (i = 0; i < (istop >> 6); i++)
+   {
+      LD_UB4(rp, 16, src0, src1, src2, src3);
+      LD_UB4(pp, 16, src4, src5, src6, src7);
+      pp += 64;
+
+	  ADD4(src0, src4, src1, src5, src2, src6, src3, src7,
+	       src0, src1, src2, src3);
+
+      ST_UB4(src0, src1, src2, src3, rp, 16);
+      rp += 64;
+   }
+
+   if (istop & 0x3F)
+   {
+      cnt32 = istop & 0x20;
+      cnt16 = istop & 0x10;
+      cnt = istop & 0xF;
+
+      if(cnt32)
+      {
+         if (cnt16 && cnt)
+         {
+            LD_UB4(rp, 16, src0, src1, src2, src3);
+            LD_UB4(pp, 16, src4, src5, src6, src7);
+
+            ADD4(src0, src4, src1, src5, src2, src6, src3, src7,
+	             src0, src1, src2, src3);
+
+            ST_UB4(src0, src1, src2, src3, rp, 16);
+            rp += 64;
+         }
+         else if (cnt16 || cnt)
+         {
+            LD_UB2(rp, 16, src0, src1);
+            LD_UB2(pp, 16, src4, src5);
+            pp += 32;
+            src2 = LD_UB(rp + 32);
+            src6 = LD_UB(pp);
+
+            ADD3(src0, src4, src1, src5, src2, src6, src0, src1, src2);
+
+            ST_UB2(src0, src1, rp, 16);
+            rp += 32;
+            ST_UB(src2, rp);
+            rp += 16;
+         }
+         else
+         {
+            LD_UB2(rp, 16, src0, src1);
+            LD_UB2(pp, 16, src4, src5);
+
+			ADD2(src0, src4, src1, src5, src0, src1);
+
+            ST_UB2(src0, src1, rp, 16);
+            rp += 32;
+         }
+      }
+      else if (cnt16 && cnt)
+      {
+         LD_UB2(rp, 16, src0, src1);
+         LD_UB2(pp, 16, src4, src5);
+
+         ADD2(src0, src4, src1, src5, src0, src1);
+
+         ST_UB2(src0, src1, rp, 16);
+         rp += 32;
+      }
+      else if (cnt16 || cnt)
+      {
+         src0 = LD_UB(rp);
+         src4 = LD_UB(pp);
+         pp += 16;
+
+         src0 += src4;
+
+         ST_UB(src0, rp);
+         rp += 16;
+      }
+   }
+}
+
+void png_read_filter_row_sub4_msa(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   png_size_t count;
+   png_size_t istop = row_info->rowbytes;
+   png_bytep src = row;
+   png_bytep nxt = row + 4;
+   int32_t inp0;
+   v16u8 src0, src1, src2, src3, src4;
+   v16u8 dst0, dst1;
+   v16u8 zero = { 0 };
+
+   istop -= 4;
+
+   inp0 = LW(src);
+   src += 4;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+
+   for (count = 0; count < istop; count += 16)
+   {
+      src1 = LD_UB(src);
+      src += 16;
+
+      src2 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 4);
+      src3 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 8);
+      src4 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 12);
+      src1 += src0;
+      src2 += src1;
+      src3 += src2;
+      src4 += src3;
+      src0 = src4;
+      ILVEV_W2_UB(src1, src2, src3, src4, dst0, dst1);
+      dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0);
+
+      ST_UB(dst0, nxt);
+      nxt += 16;
+   }
+}
+
+void png_read_filter_row_sub3_msa(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   png_size_t count;
+   png_size_t istop = row_info->rowbytes;
+   png_bytep src = row;
+   png_bytep nxt = row + 3;
+   int64_t out0;
+   int32_t inp0, out1;
+   v16u8 src0, src1, src2, src3, src4, dst0, dst1;
+   v16u8 zero = { 0 };
+   v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+   v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 };
+
+   istop -= 3;
+
+   inp0 = LW(src);
+   src += 3;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+
+   for (count = 0; count < istop; count += 12)
+   {
+      src1 = LD_UB(src);
+      src += 12;
+
+      src2 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 3);
+      src3 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 6);
+      src4 = (v16u8) __msa_sldi_b((v16i8) zero, (v16i8) src1, 9);
+      src1 += src0;
+      src2 += src1;
+      src3 += src2;
+      src4 += src3;
+      src0 = src4;
+      VSHF_B2_UB(src1, src2, src3, src4, mask0, mask0, dst0, dst1);
+      dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0);
+      out0 = __msa_copy_s_d((v2i64) dst0, 0);
+      out1 = __msa_copy_s_w((v4i32) dst0, 2);
+
+      SD(out0, nxt);
+      nxt += 8;
+      SW(out1, nxt);
+      nxt += 4;
+   }
+}
+
+void png_read_filter_row_avg4_msa(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_bytep src = row;
+   png_bytep nxt = row;
+   png_const_bytep pp = prev_row;
+   png_size_t istop = row_info->rowbytes - 4;
+   int32_t inp0, inp1, out0;
+   v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1;
+   v16u8 zero = { 0 };
+
+   inp0 = LW(pp);
+   pp += 4;
+   inp1 = LW(src);
+   src += 4;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+   src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1);
+   src0 = (v16u8) MSA_SRLI_B(src0, 1);
+   src1 += src0;
+   out0 = __msa_copy_s_w((v4i32) src1, 0);
+   SW(out0, nxt);
+   nxt += 4;
+
+   for (i = 0; i < istop; i += 16)
+   {
+      src2 = LD_UB(pp);
+      pp += 16;
+      src6 = LD_UB(src);
+      src += 16;
+
+      SLDI_B2_0_UB(src2, src6, src3, src7, 4);
+      SLDI_B2_0_UB(src2, src6, src4, src8, 8);
+      SLDI_B2_0_UB(src2, src6, src5, src9, 12);
+      src2 = __msa_ave_u_b(src2, src1);
+      src6 += src2;
+      src3 = __msa_ave_u_b(src3, src6);
+      src7 += src3;
+      src4 = __msa_ave_u_b(src4, src7);
+      src8 += src4;
+      src5 = __msa_ave_u_b(src5, src8);
+      src9 += src5;
+      src1 = src9;
+      ILVEV_W2_UB(src6, src7, src8, src9, dst0, dst1);
+      dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0);
+
+      ST_UB(dst0, nxt);
+      nxt += 16;
+   }
+}
+
+void png_read_filter_row_avg3_msa(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_bytep src = row;
+   png_bytep nxt = row;
+   png_const_bytep pp = prev_row;
+   png_size_t istop = row_info->rowbytes - 3;
+   int64_t out0;
+   int32_t inp0, inp1, out1;
+   int16_t out2;
+   v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1;
+   v16u8 zero = { 0 };
+   v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+   v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 };
+
+   inp0 = LW(pp);
+   pp += 3;
+   inp1 = LW(src);
+   src += 3;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+   src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1);
+   src0 = (v16u8) MSA_SRLI_B(src0, 1);
+   src1 += src0;
+   out2 = __msa_copy_s_h((v8i16) src1, 0);
+   SH(out2, nxt);
+   nxt += 2;
+   nxt[0] = src1[2];
+   nxt++;
+
+   for (i = 0; i < istop; i += 12)
+   {
+      src2 = LD_UB(pp);
+      pp += 12;
+      src6 = LD_UB(src);
+      src += 12;
+
+      SLDI_B2_0_UB(src2, src6, src3, src7, 3);
+      SLDI_B2_0_UB(src2, src6, src4, src8, 6);
+      SLDI_B2_0_UB(src2, src6, src5, src9, 9);
+      src2 = __msa_ave_u_b(src2, src1);
+      src6 += src2;
+      src3 = __msa_ave_u_b(src3, src6);
+      src7 += src3;
+      src4 = __msa_ave_u_b(src4, src7);
+      src8 += src4;
+      src5 = __msa_ave_u_b(src5, src8);
+      src9 += src5;
+      src1 = src9;
+      VSHF_B2_UB(src6, src7, src8, src9, mask0, mask0, dst0, dst1);
+      dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0);
+      out0 = __msa_copy_s_d((v2i64) dst0, 0);
+      out1 = __msa_copy_s_w((v4i32) dst0, 2);
+
+      SD(out0, nxt);
+      nxt += 8;
+      SW(out1, nxt);
+      nxt += 4;
+   }
+}
+
+void png_read_filter_row_paeth4_msa(png_row_infop row_info,
+                                    png_bytep row,
+                                    png_const_bytep prev_row)
+{
+   int32_t count, rp_end;
+   png_bytep nxt;
+   png_const_bytep prev_nxt;
+   int32_t inp0, inp1, res0;
+   v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9;
+   v16u8 src10, src11, src12, src13, dst0, dst1;
+   v8i16 vec0, vec1, vec2;
+   v16u8 zero = { 0 };
+
+   nxt = row;
+   prev_nxt = prev_row;
+
+   inp0 = LW(nxt);
+   inp1 = LW(prev_nxt);
+   prev_nxt += 4;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+   src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1);
+
+   src1 += src0;
+   res0 = __msa_copy_s_w((v4i32) src1, 0);
+
+   SW(res0, nxt);
+   nxt += 4;
+
+   /* Remainder */
+   rp_end = row_info->rowbytes - 4;
+
+   for (count = 0; count < rp_end; count += 16)
+   {
+      src2 = LD_UB(prev_nxt);
+      prev_nxt += 16;
+      src6 = LD_UB(prev_row);
+      prev_row += 16;
+      src10 = LD_UB(nxt);
+
+      SLDI_B3_0_UB(src2, src6, src10, src3, src7, src11, 4);
+      SLDI_B3_0_UB(src2, src6, src10, src4, src8, src12, 8);
+      SLDI_B3_0_UB(src2, src6, src10, src5, src9, src13, 12);
+      ILVR_B2_SH(src2, src6, src1, src6, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src1, src2, src6, src10);
+      ILVR_B2_SH(src3, src7, src10, src7, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src10, src3, src7, src11);
+      ILVR_B2_SH(src4, src8, src11, src8, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src11, src4, src8, src12);
+      ILVR_B2_SH(src5, src9, src12, src9, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src12, src5, src9, src13);
+      src1 = src13;
+      ILVEV_W2_UB(src10, src11, src12, src1, dst0, dst1);
+      dst0 = (v16u8) __msa_pckev_d((v2i64) dst1, (v2i64) dst0);
+
+      ST_UB(dst0, nxt);
+      nxt += 16;
+   }
+}
+
+void png_read_filter_row_paeth3_msa(png_row_infop row_info,
+                                    png_bytep row,
+                                    png_const_bytep prev_row)
+{
+   int32_t count, rp_end;
+   png_bytep nxt;
+   png_const_bytep prev_nxt;
+   int64_t out0;
+   int32_t inp0, inp1, out1;
+   int16_t out2;
+   v16u8 src0, src1, src2, src3, src4, src5, src6, src7, src8, src9, dst0, dst1;
+   v16u8 src10, src11, src12, src13;
+   v8i16 vec0, vec1, vec2;
+   v16u8 zero = { 0 };
+   v16i8 mask0 = { 0, 1, 2, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+   v16i8 mask1 = { 0, 1, 2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 0, 0, 0, 0 };
+
+   nxt = row;
+   prev_nxt = prev_row;
+
+   inp0 = LW(nxt);
+   inp1 = LW(prev_nxt);
+   prev_nxt += 3;
+   src0 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp0);
+   src1 = (v16u8) __msa_insert_w((v4i32) zero, 0, inp1);
+
+   src1 += src0;
+   out2 = __msa_copy_s_h((v8i16) src1, 0);
+
+   SH(out2, nxt);
+   nxt += 2;
+   nxt[0] = src1[2];
+   nxt++;
+
+   /* Remainder */
+   rp_end = row_info->rowbytes - 3;
+
+   for (count = 0; count < rp_end; count += 12)
+   {
+      src2 = LD_UB(prev_nxt);
+      prev_nxt += 12;
+      src6 = LD_UB(prev_row);
+      prev_row += 12;
+      src10 = LD_UB(nxt);
+
+      SLDI_B3_0_UB(src2, src6, src10, src3, src7, src11, 3);
+      SLDI_B3_0_UB(src2, src6, src10, src4, src8, src12, 6);
+      SLDI_B3_0_UB(src2, src6, src10, src5, src9, src13, 9);
+      ILVR_B2_SH(src2, src6, src1, src6, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src1, src2, src6, src10);
+      ILVR_B2_SH(src3, src7, src10, src7, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src10, src3, src7, src11);
+      ILVR_B2_SH(src4, src8, src11, src8, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src11, src4, src8, src12);
+      ILVR_B2_SH(src5, src9, src12, src9, vec0, vec1);
+      HSUB_UB2_SH(vec0, vec1, vec0, vec1);
+      vec2 = vec0 + vec1;
+      ADD_ABS_H3_SH(vec0, vec1, vec2, vec0, vec1, vec2);
+      CMP_AND_SELECT(vec0, vec1, vec2, src12, src5, src9, src13);
+      src1 = src13;
+      VSHF_B2_UB(src10, src11, src12, src13, mask0, mask0, dst0, dst1);
+      dst0 = (v16u8) __msa_vshf_b(mask1, (v16i8) dst1, (v16i8) dst0);
+      out0 = __msa_copy_s_d((v2i64) dst0, 0);
+      out1 = __msa_copy_s_w((v4i32) dst0, 2);
+
+      SD(out0, nxt);
+      nxt += 8;
+      SW(out1, nxt);
+      nxt += 4;
+   }
+}
+
+#endif /* PNG_MIPS_MSA_OPT > 0 */
+#endif /* PNG_MIPS_MSA_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */

xs/src/png/libpng/mips/mips_init.c

@@ -0,0 +1,129 @@
+
+/* mips_init.c - MSA optimised filter functions
+ *
+ * Copyright (c) 2016 Glenn Randers-Pehrson
+ * Written by Mandar Sahastrabuddhe, 2016.
+ * Last changed in libpng 1.6.25 [September 1, 2016]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
+ * called.
+ */
+#define _POSIX_SOURCE 1
+
+#include <stdio.h>
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_MIPS_MSA_OPT > 0
+#ifdef PNG_MIPS_MSA_CHECK_SUPPORTED /* Do run-time checks */
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible.  In the case of the MIPS
+ * MSA instructions there is no processor-specific way of detecting the
+ * presence of the required support, therefore run-time detection is extremely
+ * OS specific.
+ *
+ * You may set the macro PNG_MIPS_MSA_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_msa function.  There
+ * are a number of implementations in contrib/mips-msa, but the only one that
+ * has partial support is contrib/mips-msa/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
+ */
+#ifndef PNG_MIPS_MSA_FILE
+#  ifdef __linux__
+#     define PNG_MIPS_MSA_FILE "contrib/mips-msa/linux.c"
+#  endif
+#endif
+
+#ifdef PNG_MIPS_MSA_FILE
+
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_msa(png_structp png_ptr);
+#include PNG_MIPS_MSA_FILE
+
+#else  /* PNG_MIPS_MSA_FILE */
+#  error "PNG_MIPS_MSA_FILE undefined: no support for run-time MIPS MSA checks"
+#endif /* PNG_MIPS_MSA_FILE */
+#endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */
+
+#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
+#  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
+#endif
+
+void
+png_init_filter_functions_msa(png_structp pp, unsigned int bpp)
+{
+   /* The switch statement is compiled in for MIPS_MSA_API, the call to
+    * png_have_msa is compiled in for MIPS_MSA_CHECK. If both are defined
+    * the check is only performed if the API has not set the MSA option on
+    * or off explicitly. In this case the check controls what happens.
+    */
+
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+   switch ((pp->options >> PNG_MIPS_MSA) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_MIPS_MSA_API_SUPPORTED */
+#ifdef PNG_MIPS_MSA_CHECK_SUPPORTED
+         {
+            static volatile sig_atomic_t no_msa = -1; /* not checked */
+
+            if (no_msa < 0)
+               no_msa = !png_have_msa(pp);
+
+            if (no_msa)
+               return;
+         }
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+         break;
+#endif
+#endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */
+
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+   }
+#endif
+
+   /* IMPORTANT: any new external functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_msa;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_msa;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_msa;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_msa;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_msa;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_msa;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_msa;
+   }
+}
+#endif /* PNG_MIPS_MSA_OPT > 0 */
+#endif /* READ */

xs/src/png/libpng/pngconf.h

@@ -0,0 +1,622 @@
+
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.6.34, September 29, 2017
+ *
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
+
+/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
+ * compiler for correct compilation.  The following header files are required by
+ * the standard.  If your compiler doesn't provide these header files, or they
+ * do not match the standard, you will need to provide/improve them.
+ */
+#include <limits.h>
+#include <stddef.h>
+
+/* Library header files.  These header files are all defined by ISOC90; libpng
+ * expects conformant implementations, however, an ISOC90 conformant system need
+ * not provide these header files if the functionality cannot be implemented.
+ * In this case it will be necessary to disable the relevant parts of libpng in
+ * the build of pnglibconf.h.
+ *
+ * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
+ * include this unnecessary header file.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+   /* Required for the definition of FILE: */
+#  include <stdio.h>
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+   /* Required for the definition of jmp_buf and the declaration of longjmp: */
+#  include <setjmp.h>
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+   /* Required for struct tm: */
+#  include <time.h>
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using
+ * PNG_NO_CONST; this is no longer supported except for data declarations which
+ * apparently still cause problems in 2011 on some compilers.
+ */
+#define PNG_CONST const /* backward compatibility only */
+
+/* This controls optimization of the reading of 16-bit and 32-bit values
+ * from PNG files.  It can be set on a per-app-file basis - it
+ * just changes whether a macro is used when the function is called.
+ * The library builder sets the default; if read functions are not
+ * built into the library the macro implementation is forced on.
+ */
+#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
+#  define PNG_USE_READ_MACROS
+#endif
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+#  if PNG_DEFAULT_READ_MACROS
+#    define PNG_USE_READ_MACROS
+#  endif
+#endif
+
+/* COMPILER SPECIFIC OPTIONS.
+ *
+ * These options are provided so that a variety of difficult compilers
+ * can be used.  Some are fixed at build time (e.g. PNG_API_RULE
+ * below) but still have compiler specific implementations, others
+ * may be changed on a per-file basis when compiling against libpng.
+ */
+
+/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
+ * against legacy (pre ISOC90) compilers that did not understand function
+ * prototypes.  It is not required for modern C compilers.
+ */
+#ifndef PNGARG
+#  define PNGARG(arglist) arglist
+#endif
+
+/* Function calling conventions.
+ * =============================
+ * Normally it is not necessary to specify to the compiler how to call
+ * a function - it just does it - however on x86 systems derived from
+ * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
+ * and some others) there are multiple ways to call a function and the
+ * default can be changed on the compiler command line.  For this reason
+ * libpng specifies the calling convention of every exported function and
+ * every function called via a user supplied function pointer.  This is
+ * done in this file by defining the following macros:
+ *
+ * PNGAPI    Calling convention for exported functions.
+ * PNGCBAPI  Calling convention for user provided (callback) functions.
+ * PNGCAPI   Calling convention used by the ANSI-C library (required
+ *           for longjmp callbacks and sometimes used internally to
+ *           specify the calling convention for zlib).
+ *
+ * These macros should never be overridden.  If it is necessary to
+ * change calling convention in a private build this can be done
+ * by setting PNG_API_RULE (which defaults to 0) to one of the values
+ * below to select the correct 'API' variants.
+ *
+ * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
+ *                This is correct in every known environment.
+ * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
+ *                the 'C' calling convention (from PNGCAPI) for
+ *                callbacks (PNGCBAPI).  This is no longer required
+ *                in any known environment - if it has to be used
+ *                please post an explanation of the problem to the
+ *                libpng mailing list.
+ *
+ * These cases only differ if the operating system does not use the C
+ * calling convention, at present this just means the above cases
+ * (x86 DOS/Windows sytems) and, even then, this does not apply to
+ * Cygwin running on those systems.
+ *
+ * Note that the value must be defined in pnglibconf.h so that what
+ * the application uses to call the library matches the conventions
+ * set when building the library.
+ */
+
+/* Symbol export
+ * =============
+ * When building a shared library it is almost always necessary to tell
+ * the compiler which symbols to export.  The png.h macro 'PNG_EXPORT'
+ * is used to mark the symbols.  On some systems these symbols can be
+ * extracted at link time and need no special processing by the compiler,
+ * on other systems the symbols are flagged by the compiler and just
+ * the declaration requires a special tag applied (unfortunately) in a
+ * compiler dependent way.  Some systems can do either.
+ *
+ * A small number of older systems also require a symbol from a DLL to
+ * be flagged to the program that calls it.  This is a problem because
+ * we do not know in the header file included by application code that
+ * the symbol will come from a shared library, as opposed to a statically
+ * linked one.  For this reason the application must tell us by setting
+ * the magic flag PNG_USE_DLL to turn on the special processing before
+ * it includes png.h.
+ *
+ * Four additional macros are used to make this happen:
+ *
+ * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
+ *            the build or imported if PNG_USE_DLL is set - compiler
+ *            and system specific.
+ *
+ * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
+ *                       'type', compiler specific.
+ *
+ * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
+ *                make a symbol exported from the DLL.  Not used in the
+ *                public header files; see pngpriv.h for how it is used
+ *                in the libpng build.
+ *
+ * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
+ *                from a DLL - used to define PNG_IMPEXP when
+ *                PNG_USE_DLL is set.
+ */
+
+/* System specific discovery.
+ * ==========================
+ * This code is used at build time to find PNG_IMPEXP, the API settings
+ * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
+ * import processing is possible.  On Windows systems it also sets
+ * compiler-specific macros to the values required to change the calling
+ * conventions of the various functions.
+ */
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+  /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
+   * MinGW on any architecture currently supported by Windows.  Also includes
+   * Watcom builds but these need special treatment because they are not
+   * compatible with GCC or Visual C because of different calling conventions.
+   */
+#  if PNG_API_RULE == 2
+   /* If this line results in an error, either because __watcall is not
+    * understood or because of a redefine just below you cannot use *this*
+    * build of the library with the compiler you are using.  *This* build was
+    * build using Watcom and applications must also be built using Watcom!
+    */
+#    define PNGCAPI __watcall
+#  endif
+
+#  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
+#    define PNGCAPI __cdecl
+#    if PNG_API_RULE == 1
+   /* If this line results in an error __stdcall is not understood and
+    * PNG_API_RULE should not have been set to '1'.
+    */
+#      define PNGAPI __stdcall
+#    endif
+#  else
+   /* An older compiler, or one not detected (erroneously) above,
+    * if necessary override on the command line to get the correct
+    * variants for the compiler.
+    */
+#    ifndef PNGCAPI
+#      define PNGCAPI _cdecl
+#    endif
+#    if PNG_API_RULE == 1 && !defined(PNGAPI)
+#      define PNGAPI _stdcall
+#    endif
+#  endif /* compiler/api */
+
+  /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
+
+#  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
+#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+#  endif
+
+#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
+      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
+   /* older Borland and MSC
+    * compilers used '__export' and required this to be after
+    * the type.
+    */
+#    ifndef PNG_EXPORT_TYPE
+#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
+#    endif
+#    define PNG_DLL_EXPORT __export
+#  else /* newer compiler */
+#    define PNG_DLL_EXPORT __declspec(dllexport)
+#    ifndef PNG_DLL_IMPORT
+#      define PNG_DLL_IMPORT __declspec(dllimport)
+#    endif
+#  endif /* compiler */
+
+#else /* !Windows */
+#  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+#    define PNGAPI _System
+#  else /* !Windows/x86 && !OS/2 */
+   /* Use the defaults, or define PNG*API on the command line (but
+    * this will have to be done for every compile!)
+    */
+#  endif /* other system, !OS/2 */
+#endif /* !Windows/x86 */
+
+/* Now do all the defaulting . */
+#ifndef PNGCAPI
+#  define PNGCAPI
+#endif
+#ifndef PNGCBAPI
+#  define PNGCBAPI PNGCAPI
+#endif
+#ifndef PNGAPI
+#  define PNGAPI PNGCAPI
+#endif
+
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
+ */
+#ifndef PNG_IMPEXP
+#  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+   /* This forces use of a DLL, disallowing static linking */
+#    define PNG_IMPEXP PNG_DLL_IMPORT
+#  endif
+
+#  ifndef PNG_IMPEXP
+#    define PNG_IMPEXP
+#  endif
+#endif
+
+/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
+ * 'attributes' as a storage class - the attributes go at the start of the
+ * function definition, and attributes are always appended regardless of the
+ * compiler.  This considerably simplifies these macros but may cause problems
+ * if any compilers both need function attributes and fail to handle them as
+ * a storage class (this is unlikely.)
+ */
+#ifndef PNG_FUNCTION
+#  define PNG_FUNCTION(type, name, args, attributes) attributes type name args
+#endif
+
+#ifndef PNG_EXPORT_TYPE
+#  define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
+#endif
+
+   /* The ordinal value is only relevant when preprocessing png.h for symbol
+    * table entries, so we discard it here.  See the .dfn files in the
+    * scripts directory.
+    */
+
+#ifndef PNG_EXPORTA
+#  define PNG_EXPORTA(ordinal, type, name, args, attributes) \
+      PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \
+      PNG_LINKAGE_API attributes)
+#endif
+
+/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
+ * so make something non-empty to satisfy the requirement:
+ */
+#define PNG_EMPTY /*empty list*/
+
+#define PNG_EXPORT(ordinal, type, name, args) \
+   PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
+
+/* Use PNG_REMOVED to comment out a removed interface. */
+#ifndef PNG_REMOVED
+#  define PNG_REMOVED(ordinal, type, name, args, attributes)
+#endif
+
+#ifndef PNG_CALLBACK
+#  define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
+#endif
+
+/* Support for compiler specific function attributes.  These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+#  ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+#    define PNG_PEDANTIC_WARNINGS_SUPPORTED
+#  endif
+#endif
+
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+  /* Support for compiler specific function attributes.  These are used
+   * so that where compiler support is available, incorrect use of API
+   * functions in png.h will generate compiler warnings.  Added at libpng
+   * version 1.2.41.  Disabling these removes the warnings but may also produce
+   * less efficient code.
+   */
+#  if defined(__clang__) && defined(__has_attribute)
+   /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+#    if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
+#      define PNG_NORETURN __attribute__((__noreturn__))
+#    endif
+#    if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
+#      define PNG_ALLOCATED __attribute__((__malloc__))
+#    endif
+#    if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
+#      define PNG_DEPRECATED __attribute__((__deprecated__))
+#    endif
+#    if !defined(PNG_PRIVATE)
+#      ifdef __has_extension
+#        if __has_extension(attribute_unavailable_with_message)
+#          define PNG_PRIVATE __attribute__((__unavailable__(\
+             "This function is not exported by libpng.")))
+#        endif
+#      endif
+#    endif
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
+
+#  elif defined(__GNUC__)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __attribute__((__noreturn__))
+#    endif
+#    if __GNUC__ >= 3
+#      ifndef PNG_ALLOCATED
+#        define PNG_ALLOCATED  __attribute__((__malloc__))
+#      endif
+#      ifndef PNG_DEPRECATED
+#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#      endif
+#      ifndef PNG_PRIVATE
+#        if 0 /* Doesn't work so we use deprecated instead*/
+#          define PNG_PRIVATE \
+            __attribute__((warning("This function is not exported by libpng.")))
+#        else
+#          define PNG_PRIVATE \
+            __attribute__((__deprecated__))
+#        endif
+#      endif
+#      if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
+#    endif /* __GNUC__ >= 3 */
+
+#  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT /* not supported */
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __declspec(noreturn)
+#    endif
+#    ifndef PNG_ALLOCATED
+#      if (_MSC_VER >= 1400)
+#        define PNG_ALLOCATED __declspec(restrict)
+#      endif
+#    endif
+#    ifndef PNG_DEPRECATED
+#      define PNG_DEPRECATED __declspec(deprecated)
+#    endif
+#    ifndef PNG_PRIVATE
+#      define PNG_PRIVATE __declspec(deprecated)
+#    endif
+#    ifndef PNG_RESTRICT
+#      if (_MSC_VER >= 1400)
+#        define PNG_RESTRICT __restrict
+#      endif
+#    endif
+
+#  elif defined(__WATCOMC__)
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
+#  endif
+#endif /* PNG_PEDANTIC_WARNINGS */
+
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED  /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+#  define PNG_USE_RESULT  /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+#  define PNG_NORETURN    /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+#  define PNG_ALLOCATED   /* The result of the function is new memory */
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE     /* This is a private libpng function */
+#endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
+
+#ifndef PNG_FP_EXPORT     /* A floating point API. */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+#     define PNG_FP_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args);
+#  else                   /* No floating point APIs */
+#     define PNG_FP_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+#ifndef PNG_FIXED_EXPORT  /* A fixed point API. */
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args);
+#  else                   /* No fixed point APIs */
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* Some typedefs to get us started.  These should be safe on most of the common
+ * platforms.
+ *
+ * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
+ * 32-bit value however this is not normally advisable.
+ *
+ * png_uint_16 and png_int_16 should always be two bytes in size - this is
+ * verified at library build time.
+ *
+ * png_byte must always be one byte in size.
+ *
+ * The checks below use constants from limits.h, as defined by the ISOC90
+ * standard.
+ */
+#if CHAR_BIT == 8 && UCHAR_MAX == 255
+   typedef unsigned char png_byte;
+#else
+#  error "libpng requires 8-bit bytes"
+#endif
+
+#if INT_MIN == -32768 && INT_MAX == 32767
+   typedef int png_int_16;
+#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
+   typedef short png_int_16;
+#else
+#  error "libpng requires a signed 16-bit type"
+#endif
+
+#if UINT_MAX == 65535
+   typedef unsigned int png_uint_16;
+#elif USHRT_MAX == 65535
+   typedef unsigned short png_uint_16;
+#else
+#  error "libpng requires an unsigned 16-bit type"
+#endif
+
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
+   typedef int png_int_32;
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
+   typedef long int png_int_32;
+#else
+#  error "libpng requires a signed 32-bit (or more) type"
+#endif
+
+#if UINT_MAX > 4294967294U
+   typedef unsigned int png_uint_32;
+#elif ULONG_MAX > 4294967294U
+   typedef unsigned long int png_uint_32;
+#else
+#  error "libpng requires an unsigned 32-bit (or more) type"
+#endif
+
+/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
+ * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
+ */
+typedef size_t png_size_t;
+typedef ptrdiff_t png_ptrdiff_t;
+
+/* libpng needs to know the maximum value of 'size_t' and this controls the
+ * definition of png_alloc_size_t, below.  This maximum value of size_t limits
+ * but does not control the maximum allocations the library makes - there is
+ * direct application control of this through png_set_user_limits().
+ */
+#ifndef PNG_SMALL_SIZE_T
+   /* Compiler specific tests for systems where size_t is known to be less than
+    * 32 bits (some of these systems may no longer work because of the lack of
+    * 'far' support; see above.)
+    */
+#  if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
+   (defined(_MSC_VER) && defined(MAXSEG_64K))
+#     define PNG_SMALL_SIZE_T
+#  endif
+#endif
+
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
+ * smaller than png_uint_32.  Casts from png_size_t or png_uint_32 to
+ * png_alloc_size_t are not necessary; in fact, it is recommended not to use
+ * them at all so that the compiler can complain when something turns out to be
+ * problematic.
+ *
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect to
+ * encounter practical situations that require such conversions.
+ *
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
+ * 4294967295 - i.e. less than the maximum value of png_uint_32.
+ */
+#ifdef PNG_SMALL_SIZE_T
+   typedef png_uint_32 png_alloc_size_t;
+#else
+   typedef png_size_t png_alloc_size_t;
+#endif
+
+/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
+ * implementations of Intel CPU specific support of user-mode segmented address
+ * spaces, where 16-bit pointers address more than 65536 bytes of memory using
+ * separate 'segment' registers.  The implementation requires two different
+ * types of pointer (only one of which includes the segment value.)
+ *
+ * If required this support is available in version 1.2 of libpng and may be
+ * available in versions through 1.5, although the correctness of the code has
+ * not been verified recently.
+ */
+
+/* Typedef for floating-point numbers that are converted to fixed-point with a
+ * multiple of 100,000, e.g., gamma
+ */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void                  * png_voidp;
+typedef const void            * png_const_voidp;
+typedef png_byte              * png_bytep;
+typedef const png_byte        * png_const_bytep;
+typedef png_uint_32           * png_uint_32p;
+typedef const png_uint_32     * png_const_uint_32p;
+typedef png_int_32            * png_int_32p;
+typedef const png_int_32      * png_const_int_32p;
+typedef png_uint_16           * png_uint_16p;
+typedef const png_uint_16     * png_const_uint_16p;
+typedef png_int_16            * png_int_16p;
+typedef const png_int_16      * png_const_int_16p;
+typedef char                  * png_charp;
+typedef const char            * png_const_charp;
+typedef png_fixed_point       * png_fixed_point_p;
+typedef const png_fixed_point * png_const_fixed_point_p;
+typedef png_size_t            * png_size_tp;
+typedef const png_size_t      * png_const_size_tp;
+
+#ifdef PNG_STDIO_SUPPORTED
+typedef FILE            * png_FILE_p;
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double       * png_doublep;
+typedef const double * png_const_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte        * * png_bytepp;
+typedef png_uint_32     * * png_uint_32pp;
+typedef png_int_32      * * png_int_32pp;
+typedef png_uint_16     * * png_uint_16pp;
+typedef png_int_16      * * png_int_16pp;
+typedef const char      * * png_const_charpp;
+typedef char            * * png_charpp;
+typedef png_fixed_point * * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double          * * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char            * * * png_charppp;
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+#endif /* PNGCONF_H */

xs/src/png/libpng/pngdebug.h

@@ -0,0 +1,153 @@
+
+/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+ *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* Define PNG_DEBUG at compile time for debugging information.  Higher
+ * numbers for PNG_DEBUG mean more debugging information.  This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ *
+ * png_debug[1-2]?(level, message ,arg{0-2})
+ *   Expands to a statement (either a simple expression or a compound
+ *   do..while(0) statement) that outputs a message with parameter
+ *   substitution if PNG_DEBUG is defined to 2 or more.  If PNG_DEBUG
+ *   is undefined, 0 or 1 every png_debug expands to a simple expression
+ *   (actually ((void)0)).
+ *
+ *   level: level of detail of message, starting at 0.  A level 'n'
+ *          message is preceded by 'n' 3-space indentations (not implemented
+ *          on Microsoft compilers unless PNG_DEBUG_FILE is also
+ *          defined, to allow debug DLL compilation with no standard IO).
+ *   message: a printf(3) style text string.  A trailing '\n' is added
+ *            to the message.
+ *   arg: 0 to 2 arguments for printf(3) style substitution in message.
+ */
+#ifndef PNGDEBUG_H
+#define PNGDEBUG_H
+/* These settings control the formatting of messages in png.c and pngerror.c */
+/* Moved to pngdebug.h at 1.5.0 */
+#  ifndef PNG_LITERAL_SHARP
+#    define PNG_LITERAL_SHARP 0x23
+#  endif
+#  ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+#    define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+#  endif
+#  ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+#    define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+#  endif
+#  ifndef PNG_STRING_NEWLINE
+#    define PNG_STRING_NEWLINE "\n"
+#  endif
+
+#ifdef PNG_DEBUG
+#  if (PNG_DEBUG > 0)
+#    if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+#      include <crtdbg.h>
+#      if (PNG_DEBUG > 1)
+#        ifndef _DEBUG
+#          define _DEBUG
+#        endif
+#        ifndef png_debug
+#          define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+#        endif
+#        ifndef png_debug1
+#          define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+#        endif
+#        ifndef png_debug2
+#          define png_debug2(l,m,p1,p2) \
+             _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+#        endif
+#      endif
+#    else /* PNG_DEBUG_FILE || !_MSC_VER */
+#      ifndef PNG_STDIO_SUPPORTED
+#        include <stdio.h> /* not included yet */
+#      endif
+#      ifndef PNG_DEBUG_FILE
+#        define PNG_DEBUG_FILE stderr
+#      endif /* PNG_DEBUG_FILE */
+
+#      if (PNG_DEBUG > 1)
+#        ifdef __STDC__
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : "")))); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1,p2);\
+       } while (0)
+#          endif
+#        else /* __STDC __ */
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+       } while (0)
+#          endif
+#        endif /* __STDC __ */
+#      endif /* (PNG_DEBUG > 1) */
+
+#    endif /* _MSC_VER */
+#  endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#  define png_debug(l, m) ((void)0)
+#endif
+#ifndef png_debug1
+#  define png_debug1(l, m, p1) ((void)0)
+#endif
+#ifndef png_debug2
+#  define png_debug2(l, m, p1, p2) ((void)0)
+#endif
+#endif /* PNGDEBUG_H */

xs/src/png/libpng/pngerror.c

@@ -0,0 +1,963 @@
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling.  Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions.  See the instructions
+ * at each function.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
+    png_const_charp error_message)),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning PNGARG((png_const_structrp png_ptr,
+    png_const_charp warning_message));
+#endif /* WARNINGS */
+
+/* This function is called whenever there is a fatal error.  This function
+ * should not be changed.  If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+PNG_FUNCTION(void,PNGAPI
+png_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   char msg[16];
+   if (png_ptr != NULL)
+   {
+      if ((png_ptr->flags &
+         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+      {
+         if (*error_message == PNG_LITERAL_SHARP)
+         {
+            /* Strip "#nnnn " from beginning of error message. */
+            int offset;
+            for (offset = 1; offset<15; offset++)
+               if (error_message[offset] == ' ')
+                  break;
+
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+            {
+               int i;
+               for (i = 0; i < offset - 1; i++)
+                  msg[i] = error_message[i + 1];
+               msg[i - 1] = '\0';
+               error_message = msg;
+            }
+
+            else
+               error_message += offset;
+         }
+
+         else
+         {
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+            {
+               msg[0] = '0';
+               msg[1] = '\0';
+               error_message = msg;
+            }
+         }
+      }
+   }
+#endif
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
+
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, error_message);
+}
+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_const_structrp png_ptr),PNG_NORETURN)
+{
+   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
+
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, "");
+}
+#endif /* ERROR_TEXT */
+
+/* Utility to safely appends strings to a buffer.  This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string)
+{
+   if (buffer != NULL && pos < bufsize)
+   {
+      if (string != NULL)
+         while (*string != '\0' && pos < bufsize-1)
+           buffer[pos++] = *string++;
+
+      buffer[pos] = '\0';
+   }
+
+   return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+    png_alloc_size_t number)
+{
+   int count = 0;    /* number of digits output */
+   int mincount = 1; /* minimum number required */
+   int output = 0;   /* digit output (for the fixed point format) */
+
+   *--end = '\0';
+
+   /* This is written so that the loop always runs at least once, even with
+    * number zero.
+    */
+   while (end > start && (number != 0 || count < mincount))
+   {
+
+      static const char digits[] = "0123456789ABCDEF";
+
+      switch (format)
+      {
+         case PNG_NUMBER_FORMAT_fixed:
+            /* Needs five digits (the fraction) */
+            mincount = 5;
+            if (output != 0 || number % 10 != 0)
+            {
+               *--end = digits[number % 10];
+               output = 1;
+            }
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02u:
+            /* Expects at least 2 digits. */
+            mincount = 2;
+            /* FALLTHROUGH */
+
+         case PNG_NUMBER_FORMAT_u:
+            *--end = digits[number % 10];
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02x:
+            /* This format expects at least two digits */
+            mincount = 2;
+            /* FALLTHROUGH */
+
+         case PNG_NUMBER_FORMAT_x:
+            *--end = digits[number & 0xf];
+            number >>= 4;
+            break;
+
+         default: /* an error */
+            number = 0;
+            break;
+      }
+
+      /* Keep track of the number of digits added */
+      ++count;
+
+      /* Float a fixed number here: */
+      if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
+      {
+         /* End of the fraction, but maybe nothing was output?  In that case
+          * drop the decimal point.  If the number is a true zero handle that
+          * here.
+          */
+         if (output != 0)
+            *--end = '.';
+         else if (number == 0) /* and !output */
+            *--end = '0';
+      }
+   }
+
+   return end;
+}
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error.  This function
+ * should not be changed.  If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+   int offset = 0;
+   if (png_ptr != NULL)
+   {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if ((png_ptr->flags &
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+#endif
+      {
+         if (*warning_message == PNG_LITERAL_SHARP)
+         {
+            for (offset = 1; offset < 15; offset++)
+               if (warning_message[offset] == ' ')
+                  break;
+         }
+      }
+   }
+   if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+      (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
+          warning_message + offset);
+   else
+      png_default_warning(png_ptr, warning_message + offset);
+}
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1.  This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string)
+{
+   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+    png_alloc_size_t value)
+{
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+    png_int_32 value)
+{
+   png_alloc_size_t u;
+   png_charp str;
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+
+   /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+   u = (png_alloc_size_t)value;
+   if (value < 0)
+      u = ~u + 1;
+
+   str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+   if (value < 0 && str > buffer)
+      *--str = '-';
+
+   png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
+    png_const_charp message)
+{
+   /* The internal buffer is just 192 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!  If someone figures
+    * out how to send us a message longer than 192 bytes, all that will
+    * happen is that the message will be truncated appropriately.
+    */
+   size_t i = 0; /* Index in the msg[] buffer: */
+   char msg[192];
+
+   /* Each iteration through the following loop writes at most one character
+    * to msg[i++] then returns here to validate that there is still space for
+    * the trailing '\0'.  It may (in the case of a parameter) read more than
+    * one character from message[]; it must check for '\0' and continue to the
+    * test if it finds the end of string.
+    */
+   while (i<(sizeof msg)-1 && *message != '\0')
+   {
+      /* '@' at end of string is now just printed (previously it was skipped);
+       * it is an error in the calling code to terminate the string with @.
+       */
+      if (p != NULL && *message == '@' && message[1] != '\0')
+      {
+         int parameter_char = *++message; /* Consume the '@' */
+         static const char valid_parameters[] = "123456789";
+         int parameter = 0;
+
+         /* Search for the parameter digit, the index in the string is the
+          * parameter to use.
+          */
+         while (valid_parameters[parameter] != parameter_char &&
+            valid_parameters[parameter] != '\0')
+            ++parameter;
+
+         /* If the parameter digit is out of range it will just get printed. */
+         if (parameter < PNG_WARNING_PARAMETER_COUNT)
+         {
+            /* Append this parameter */
+            png_const_charp parm = p[parameter];
+            png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+            /* No need to copy the trailing '\0' here, but there is no guarantee
+             * that parm[] has been initialized, so there is no guarantee of a
+             * trailing '\0':
+             */
+            while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+               msg[i++] = *parm++;
+
+            /* Consume the parameter digit too: */
+            ++message;
+            continue;
+         }
+
+         /* else not a parameter and there is a character after the @ sign; just
+          * copy that.  This is known not to be '\0' because of the test above.
+          */
+      }
+
+      /* At this point *message can't be '\0', even in the bad parameter case
+       * above where there is a lone '@' at the end of the message string.
+       */
+      msg[i++] = *message++;
+   }
+
+   /* i is always less than (sizeof msg), so: */
+   msg[i] = '\0';
+
+   /* And this is the formatted message. It may be larger than
+    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+    * are not (currently) formatted.
+    */
+   png_warning(png_ptr, msg);
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_warning(png_ptr, error_message);
+         else
+#     endif
+      png_warning(png_ptr, error_message);
+   }
+
+   else
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_error(png_ptr, error_message);
+         else
+#     endif
+      png_error(png_ptr, error_message);
+   }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
+      png_warning(png_ptr, error_message);
+   else
+      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
+      png_warning(png_ptr, error_message);
+   else
+      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+#endif /* BENIGN_ERRORS */
+
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
+ * which is used to prefix the message.  The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+   'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+static void /* PRIVATE */
+png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
+    error_message)
+{
+   png_uint_32 chunk_name = png_ptr->chunk_name;
+   int iout = 0, ishift = 24;
+
+   while (ishift >= 0)
+   {
+      int c = (int)(chunk_name >> ishift) & 0xff;
+
+      ishift -= 8;
+      if (isnonalpha(c) != 0)
+      {
+         buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+         buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+         buffer[iout++] = png_digit[c & 0x0f];
+         buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+      }
+
+      else
+      {
+         buffer[iout++] = (char)c;
+      }
+   }
+
+   if (error_message == NULL)
+      buffer[iout] = '\0';
+
+   else
+   {
+      int iin = 0;
+
+      buffer[iout++] = ':';
+      buffer[iout++] = ' ';
+
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
+   }
+}
+#endif /* WARNINGS || ERROR_TEXT */
+
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_FUNCTION(void,PNGAPI
+png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_error(png_ptr, error_message);
+
+   else
+   {
+      png_format_buffer(png_ptr, msg, error_message);
+      png_error(png_ptr, msg);
+   }
+}
+#endif /* READ && ERROR_TEXT */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_warning(png_ptr, warning_message);
+
+   else
+   {
+      png_format_buffer(png_ptr, msg, warning_message);
+      png_warning(png_ptr, msg);
+   }
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+      png_chunk_warning(png_ptr, error_message);
+
+   else
+      png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+#endif
+#endif /* READ */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+#  ifndef PNG_WARNINGS_SUPPORTED
+      PNG_UNUSED(message)
+#  endif
+
+   /* This is always supported, but for just read or just write it
+    * unconditionally does the right thing.
+    */
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+#  define fixed_message "fixed point overflow in "
+#  define fixed_message_ln ((sizeof fixed_message)-1)
+   unsigned int  iin;
+   char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+   memcpy(msg, fixed_message, fixed_message_ln);
+   iin = 0;
+   if (name != NULL)
+      while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+      {
+         msg[fixed_message_ln + iin] = name[iin];
+         ++iin;
+      }
+   msg[fixed_message_ln + iin] = 0;
+   png_error(png_ptr, msg);
+}
+#endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
+    size_t jmp_buf_size)
+{
+   /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+    * and it must not change after that.  Libpng doesn't care how big the
+    * buffer is, just that it doesn't change.
+    *
+    * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+    * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+    * semantics that this call will not fail.  If the size is larger, however,
+    * the buffer is allocated and this may fail, causing the function to return
+    * NULL.
+    */
+   if (png_ptr == NULL)
+      return NULL;
+
+   if (png_ptr->jmp_buf_ptr == NULL)
+   {
+      png_ptr->jmp_buf_size = 0; /* not allocated */
+
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+         png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+      else
+      {
+         png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+             png_malloc_warn(png_ptr, jmp_buf_size));
+
+         if (png_ptr->jmp_buf_ptr == NULL)
+            return NULL; /* new NULL return on OOM */
+
+         png_ptr->jmp_buf_size = jmp_buf_size;
+      }
+   }
+
+   else /* Already allocated: check the size */
+   {
+      size_t size = png_ptr->jmp_buf_size;
+
+      if (size == 0)
+      {
+         size = (sizeof png_ptr->jmp_buf_local);
+         if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+         {
+            /* This is an internal error in libpng: somehow we have been left
+             * with a stack allocated jmp_buf when the application regained
+             * control.  It's always possible to fix this up, but for the moment
+             * this is a png_error because that makes it easy to detect.
+             */
+            png_error(png_ptr, "Libpng jmp_buf still allocated");
+            /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+         }
+      }
+
+      if (size != jmp_buf_size)
+      {
+         png_warning(png_ptr, "Application jmp_buf size changed");
+         return NULL; /* caller will probably crash: no choice here */
+      }
+   }
+
+   /* Finally fill in the function, now we have a satisfactory buffer. It is
+    * valid to change the function on every call.
+    */
+   png_ptr->longjmp_fn = longjmp_fn;
+   return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+   {
+      jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+      /* A size of 0 is used to indicate a local, stack, allocation of the
+       * pointer; used here and in png.c
+       */
+      if (jb != NULL && png_ptr->jmp_buf_size > 0)
+      {
+
+         /* This stuff is so that a failure to free the error control structure
+          * does not leave libpng in a state with no valid error handling: the
+          * free always succeeds, if there is an error it gets ignored.
+          */
+         if (jb != &png_ptr->jmp_buf_local)
+         {
+            /* Make an internal, libpng, jmp_buf to return here */
+            jmp_buf free_jmp_buf;
+
+            if (!setjmp(free_jmp_buf))
+            {
+               png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+               png_ptr->jmp_buf_size = 0; /* stack allocation */
+               png_ptr->longjmp_fn = longjmp;
+               png_free(png_ptr, jb); /* Return to setjmp on error */
+            }
+         }
+      }
+
+      /* *Always* cancel everything out: */
+      png_ptr->jmp_buf_size = 0;
+      png_ptr->jmp_buf_ptr = NULL;
+      png_ptr->longjmp_fn = 0;
+   }
+}
+#endif
+
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   /* Check on NULL only added in 1.5.4 */
+   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
+   {
+      /* Strip "#nnnn " from beginning of error message. */
+      int offset;
+      char error_number[16];
+      for (offset = 0; offset<15; offset++)
+      {
+         error_number[offset] = error_message[offset + 1];
+         if (error_message[offset] == ' ')
+            break;
+      }
+
+      if ((offset > 1) && (offset < 15))
+      {
+         error_number[offset - 1] = '\0';
+         fprintf(stderr, "libpng error no. %s: %s",
+             error_number, error_message + offset + 1);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+
+      else
+      {
+         fprintf(stderr, "libpng error: %s, offset=%d",
+             error_message, offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#endif
+   {
+      fprintf(stderr, "libpng error: %s", error_message ? error_message :
+         "undefined");
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(error_message) /* Make compiler happy */
+#endif
+   png_longjmp(png_ptr, 1);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+       png_ptr->jmp_buf_ptr != NULL)
+      png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(val)
+#endif
+
+   /* If control reaches this point, png_longjmp() must not return. The only
+    * choice is to terminate the whole process (or maybe the thread); to do
+    * this the ANSI-C abort() function is used unless a different method is
+    * implemented by overriding the default configuration setting for
+    * PNG_ABORT().
+    */
+   PNG_ABORT();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want them to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (*warning_message == PNG_LITERAL_SHARP)
+   {
+      int offset;
+      char warning_number[16];
+      for (offset = 0; offset < 15; offset++)
+      {
+         warning_number[offset] = warning_message[offset + 1];
+         if (warning_message[offset] == ' ')
+            break;
+      }
+
+      if ((offset > 1) && (offset < 15))
+      {
+         warning_number[offset + 1] = '\0';
+         fprintf(stderr, "libpng warning no. %s: %s",
+             warning_number, warning_message + offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+
+      else
+      {
+         fprintf(stderr, "libpng warning: %s",
+             warning_message);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#  endif
+
+   {
+      fprintf(stderr, "libpng warning: %s", warning_message);
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(warning_message) /* Make compiler happy */
+#endif
+   PNG_UNUSED(png_ptr) /* Make compiler happy */
+}
+#endif /* WARNINGS */
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings.  Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur.  The return
+ * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->error_ptr = error_ptr;
+   png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_ptr->warning_fn = warning_fn;
+#else
+   PNG_UNUSED(warning_fn)
+#endif
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return NULL;
+
+   return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->flags &=
+         ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
+         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+   }
+}
+#endif
+
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+   /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+    * possible to implement without setjmp support just so long as there is some
+    * way to handle the error return here:
+    */
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* An error is always logged here, overwriting anything (typically a warning)
+    * that is already there:
+    */
+   if (image != NULL)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
+      image->warning_or_error |= PNG_IMAGE_ERROR;
+
+      /* Retrieve the jmp_buf from within the png_control, making this work for
+       * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+       * element of a jmp_buf, but C doesn't tell us the type of that.
+       */
+      if (image->opaque != NULL && image->opaque->error_buf != NULL)
+         longjmp(png_control_jmp_buf(image->opaque), 1);
+
+      /* Missing longjmp buffer, the following is to help debugging: */
+      {
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+             "bad longjmp: ");
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
+      }
+   }
+
+   /* Here on an internal programming error. */
+   abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */ PNGCBAPI
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* A warning is only logged if there is no prior warning or error. */
+   if (image->warning_or_error == 0)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
+      image->warning_or_error |= PNG_IMAGE_WARNING;
+   }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
+{
+   volatile png_imagep image = image_in;
+   volatile int result;
+   volatile png_voidp saved_error_buf;
+   jmp_buf safe_jmpbuf;
+
+   /* Safely execute function(arg) with png_error returning to this function. */
+   saved_error_buf = image->opaque->error_buf;
+   result = setjmp(safe_jmpbuf) == 0;
+
+   if (result != 0)
+   {
+
+      image->opaque->error_buf = safe_jmpbuf;
+      result = function(arg);
+   }
+
+   image->opaque->error_buf = saved_error_buf;
+
+   /* And do the cleanup prior to any failure return. */
+   if (result == 0)
+      png_image_free(image);
+
+   return result;
+}
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */

xs/src/png/libpng/pnginfo.h

@@ -0,0 +1,267 @@
+
+/* pnginfo.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+ /* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file.  If you are writing the file, fill in the information
+ * you want to put into the PNG file, using png_set_*() functions, then
+ * call png_write_info().
+ *
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed.  With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality.  In libpng-1.5.0 this was moved into a separate private
+ * file that is not visible to applications.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng.  This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions.  A function to clear these members is available: see
+ * png_free_data().  The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+#ifndef PNGINFO_H
+#define PNGINFO_H
+
+struct png_info_def
+{
+   /* The following are necessary for every PNG file */
+   png_uint_32 width;  /* width of image in pixels (from IHDR) */
+   png_uint_32 height; /* height of image in pixels (from IHDR) */
+   png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
+   png_size_t rowbytes; /* bytes needed to hold an untransformed row */
+   png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
+   png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+   png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
+   png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+   png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
+   /* The following three should have been named *_method not *_type */
+   png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+   png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+   png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
+   png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
+   png_byte pixel_depth;    /* number of bits per pixel */
+   png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
+   png_byte signature[8];   /* magic bytes read by libpng from start of file */
+#endif
+
+   /* The rest of the data is optional.  If you are reading, check the
+    * valid field to see if the information in these are valid.  If you
+    * are writing, set the valid field to those chunks you want written,
+    * and initialize the appropriate fields below.
+    */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
+    * defined.  When COLORSPACE is switched on all the colorspace-defining
+    * chunks should be enabled, when GAMMA is switched on all the gamma-defining
+    * chunks should be enabled.  If this is not done it becomes possible to read
+    * inconsistent PNG files and assign a probably incorrect interpretation to
+    * the information.  (In other words, by carefully choosing which chunks to
+    * recognize the system configuration can select an interpretation for PNG
+    * files containing ambiguous data and this will result in inconsistent
+    * behavior between different libpng builds!)
+    */
+   png_colorspace colorspace;
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+   /* iCCP chunk data. */
+   png_charp iccp_name;     /* profile name */
+   png_bytep iccp_profile;  /* International Color Consortium profile data */
+   png_uint_32 iccp_proflen;  /* ICC profile data length */
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+   /* The tEXt, and zTXt chunks contain human-readable textual data in
+    * uncompressed, compressed, and optionally compressed forms, respectively.
+    * The data in "text" is an array of pointers to uncompressed,
+    * null-terminated C strings. Each chunk has a keyword that describes the
+    * textual data contained in that chunk.  Keywords are not required to be
+    * unique, and the text string may be empty.  Any number of text chunks may
+    * be in an image.
+    */
+   int num_text; /* number of comments read or comments to write */
+   int max_text; /* current size of text array */
+   png_textp text; /* array of comments read or comments to write */
+#endif /* TEXT */
+
+#ifdef PNG_tIME_SUPPORTED
+   /* The tIME chunk holds the last time the displayed image data was
+    * modified.  See the png_time struct for the contents of this struct.
+    */
+   png_time mod_time;
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+   /* The sBIT chunk specifies the number of significant high-order bits
+    * in the pixel data.  Values are in the range [1, bit_depth], and are
+    * only specified for the channels in the pixel data.  The contents of
+    * the low-order bits is not specified.  Data is valid if
+    * (valid & PNG_INFO_sBIT) is non-zero.
+    */
+   png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The tRNS chunk supplies transparency data for paletted images and
+    * other image types that don't need a full alpha channel.  There are
+    * "num_trans" transparency values for a paletted image, stored in the
+    * same order as the palette colors, starting from index 0.  Values
+    * for the data are in the range [0, 255], ranging from fully transparent
+    * to fully opaque, respectively.  For non-paletted images, there is a
+    * single color specified that should be treated as fully transparent.
+    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+    */
+   png_bytep trans_alpha;    /* alpha values for paletted image */
+   png_color_16 trans_color; /* transparent color for non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The bKGD chunk gives the suggested image background color if the
+    * display program does not have its own background color and the image
+    * is needs to composited onto a background before display.  The colors
+    * in "background" are normally in the same color space/depth as the
+    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+    */
+   png_color_16 background;
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+    * and downwards from the top-left corner of the display, page, or other
+    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
+    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
+    */
+   png_int_32 x_offset; /* x offset on page */
+   png_int_32 y_offset; /* y offset on page */
+   png_byte offset_unit_type; /* offset units type */
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+   /* The pHYs chunk gives the physical pixel density of the image for
+    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+    */
+   png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+   png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+   png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+   int num_exif;  /* Added at libpng-1.6.31 */
+   png_bytep exif;
+# ifdef PNG_READ_eXIf_SUPPORTED
+   png_bytep eXIf_buf;  /* Added at libpng-1.6.32 */
+# endif
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+   /* The hIST chunk contains the relative frequency or importance of the
+    * various palette entries, so that a viewer can intelligently select a
+    * reduced-color palette, if required.  Data is an array of "num_palette"
+    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+    * is non-zero.
+    */
+   png_uint_16p hist;
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+   /* The pCAL chunk describes a transformation between the stored pixel
+    * values and original physical data values used to create the image.
+    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+    * range given by [pcal_X0, pcal_X1], and are further transformed by a
+    * (possibly non-linear) transformation function given by "pcal_type"
+    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
+    * defines below, and the PNG-Group's PNG extensions document for a
+    * complete description of the transformations and how they should be
+    * implemented, and for a description of the ASCII parameter strings.
+    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+    */
+   png_charp pcal_purpose;  /* pCAL chunk description string */
+   png_int_32 pcal_X0;      /* minimum value */
+   png_int_32 pcal_X1;      /* maximum value */
+   png_charp pcal_units;    /* Latin-1 string giving physical units */
+   png_charpp pcal_params;  /* ASCII strings containing parameter values */
+   png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
+   png_byte pcal_nparams;   /* number of parameters given in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+   png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+   /* Storage for unknown chunks that the library doesn't recognize. */
+   png_unknown_chunkp unknown_chunks;
+
+   /* The type of this field is limited by the type of
+    * png_struct::user_chunk_cache_max, else overflow can occur.
+    */
+   int                unknown_chunks_num;
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+   /* Data on sPLT chunks (there may be more than one). */
+   png_sPLT_tp splt_palettes;
+   int         splt_palettes_num; /* Match type returned by png_get API */
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+   /* The sCAL chunk describes the actual physical dimensions of the
+    * subject matter of the graphic.  The chunk contains a unit specification
+    * a byte value, and two ASCII strings representing floating-point
+    * values.  The values are width and height corresponsing to one pixel
+    * in the image.  Data values are valid if (valid & PNG_INFO_sCAL) is
+    * non-zero.
+    */
+   png_byte scal_unit;         /* unit of physical scale */
+   png_charp scal_s_width;     /* string containing height */
+   png_charp scal_s_height;    /* string containing width */
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+      non-zero */
+   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+   png_bytepp row_pointers;        /* the image bits */
+#endif
+
+};
+#endif /* PNGINFO_H */

xs/src/png/libpng/pngmem.c

@@ -0,0 +1,284 @@
+
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation.  Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Free a png_struct */
+void /* PRIVATE */
+png_destroy_png_struct(png_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+   {
+      /* png_free might call png_error and may certainly call
+       * png_get_mem_ptr, so fake a temporary png_struct to support this.
+       */
+      png_struct dummy_struct = *png_ptr;
+      memset(png_ptr, 0, (sizeof *png_ptr));
+      png_free(&dummy_struct, png_ptr);
+
+#     ifdef PNG_SETJMP_SUPPORTED
+         /* We may have a jmp_buf left to deallocate. */
+         png_free_jmpbuf(&dummy_struct);
+#     endif
+   }
+}
+
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   ret = png_malloc(png_ptr, size);
+
+   if (ret != NULL)
+      memset(ret, 0, size);
+
+   return ret;
+}
+
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED)
+{
+   /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+    * allocators have also been removed in 1.6.0, so any 16-bit system now has
+    * to implement a user memory handler.  This checks to be sure it isn't
+    * called with big numbers.
+    */
+#ifndef PNG_USER_MEM_SUPPORTED
+   PNG_UNUSED(png_ptr)
+#endif
+
+   /* Some compilers complain that this is always true.  However, it
+    * can be false when integer overflow happens.
+    */
+   if (size > 0 && size <= PNG_SIZE_MAX
+#     ifdef PNG_MAX_MALLOC_64K
+         && size <= 65536U
+#     endif
+      )
+   {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+         return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
+
+      else
+#endif
+         return malloc((size_t)size); /* checked for truncation above */
+   }
+
+   else
+      return NULL;
+}
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+    size_t element_size)
+{
+   png_alloc_size_t req = (png_alloc_size_t)nelements; /* known to be > 0 */
+
+   if (req <= PNG_SIZE_MAX/element_size)
+      return png_malloc_base(png_ptr, req * element_size);
+
+   /* The failure case when the request is too large */
+   return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+    size_t element_size),PNG_ALLOCATED)
+{
+   if (nelements <= 0 || element_size == 0)
+      png_error(png_ptr, "internal error: array alloc");
+
+   return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+    int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+   /* These are internal errors: */
+   if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+      (old_array == NULL && old_elements > 0))
+      png_error(png_ptr, "internal error: array realloc");
+
+   /* Check for overflow on the elements count (so the caller does not have to
+    * check.)
+    */
+   if (add_elements <= INT_MAX - old_elements)
+   {
+      png_voidp new_array = png_malloc_array_checked(png_ptr,
+          old_elements+add_elements, element_size);
+
+      if (new_array != NULL)
+      {
+         /* Because png_malloc_array worked the size calculations below cannot
+          * overflow.
+          */
+         if (old_elements > 0)
+            memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+         memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+             element_size*(unsigned)add_elements);
+
+         return new_array;
+      }
+   }
+
+   return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
+/* Various functions that have different error handling are derived from this.
+ * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   ret = png_malloc_base(png_ptr, size);
+
+   if (ret == NULL)
+       png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+
+   return ret;
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED PNG_DEPRECATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   /* Passing 'NULL' here bypasses the application provided memory handler. */
+   ret = png_malloc_base(NULL/*use malloc*/, size);
+
+   if (ret == NULL)
+      png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+
+   return ret;
+}
+#endif /* USER_MEM */
+
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED)
+{
+   if (png_ptr != NULL)
+   {
+      png_voidp ret = png_malloc_base(png_ptr, size);
+
+      if (ret != NULL)
+         return ret;
+
+      png_warning(png_ptr, "Out of memory");
+   }
+
+   return NULL;
+}
+
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_const_structrp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+      png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
+
+   else
+      png_free_default(png_ptr, ptr);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+#endif /* USER_MEM */
+
+   free(ptr);
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
+   }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return NULL;
+
+   return png_ptr->mem_ptr;
+}
+#endif /* USER_MEM */
+#endif /* READ || WRITE */

xs/src/png/libpng/pngrio.c

@@ -0,0 +1,120 @@
+
+/* pngrio.c - functions for data input
+ *
+ * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input.  Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method.  Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Read the data from whatever input you are using.  The default routine
+ * reads from a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads.  This should never be asked
+ * to read more than 64K on a 16-bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
+{
+   png_debug1(4, "reading %d bytes", (int)length);
+
+   if (png_ptr->read_data_fn != NULL)
+      (*(png_ptr->read_data_fn))(png_ptr, data, length);
+
+   else
+      png_error(png_ptr, "Call to NULL read function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   if (png_ptr == NULL)
+      return;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
+
+   if (check != length)
+      png_error(png_ptr, "Read Error");
+}
+#endif
+
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ *
+ * png_ptr      - pointer to a png input data structure
+ *
+ * io_ptr       - pointer to user supplied structure containing info about
+ *                the input functions.  May be NULL.
+ *
+ * read_data_fn - pointer to a new input function that takes as its
+ *                arguments a pointer to a png_struct, a pointer to
+ *                a location where input data can be stored, and a 32-bit
+ *                unsigned int that is the number of bytes to be read.
+ *                To exit and output any fatal error messages the new write
+ *                function should call png_error(png_ptr, "Error msg").
+ *                May be NULL, in which case libpng's default function will
+ *                be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr read_data_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+   if (read_data_fn != NULL)
+      png_ptr->read_data_fn = read_data_fn;
+
+   else
+      png_ptr->read_data_fn = png_default_read_data;
+#else
+   png_ptr->read_data_fn = read_data_fn;
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   /* It is an error to write to a read device */
+   if (png_ptr->write_data_fn != NULL)
+   {
+      png_ptr->write_data_fn = NULL;
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* READ */

xs/src/png/libpng/pngstruct.h

@@ -0,0 +1,483 @@
+
+/* pngstruct.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application.
+ */
+
+#ifndef PNGSTRUCT_H
+#define PNGSTRUCT_H
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#ifndef ZLIB_CONST
+   /* We must ensure that zlib uses 'const' in declarations. */
+#  define ZLIB_CONST
+#endif
+#include "zlib.h"
+#ifdef const
+   /* zlib.h sometimes #defines const to nothing, undo this. */
+#  undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+#  define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+#  define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+#  define PNGZ_MSG_CAST(s) (s)
+#  define PNGZ_INPUT_CAST(b) (b)
+#endif
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once.  This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t.  The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+#  define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+   struct png_compression_buffer *next;
+   png_byte                       output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+   (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ *
+ * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
+ * colorspace corrections, otherwise all the colorspace information can be
+ * skipped and the size of libpng can be reduced (significantly) by compiling
+ * out the colorspace support.
+ */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values.  When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+   png_fixed_point red_X, red_Y, red_Z;
+   png_fixed_point green_X, green_Y, green_Z;
+   png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+#endif /* COLORSPACE */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+/* A colorspace is all the above plus, potentially, profile information;
+ * however at present libpng does not use the profile internally so it is only
+ * stored in the png_info struct (if iCCP is supported.)  The rendering intent
+ * is retained here and is checked.
+ *
+ * The file gamma encoding information is also stored here and gamma correction
+ * is done by libpng, whereas color correction must currently be done by the
+ * application.
+ */
+typedef struct png_colorspace
+{
+#ifdef PNG_GAMMA_SUPPORTED
+   png_fixed_point gamma;        /* File gamma */
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+   png_xy      end_points_xy;    /* End points as chromaticities */
+   png_XYZ     end_points_XYZ;   /* End points as CIE XYZ colorant values */
+   png_uint_16 rendering_intent; /* Rendering intent of a profile */
+#endif
+
+   /* Flags are always defined to simplify the code. */
+   png_uint_16 flags;            /* As defined below */
+} png_colorspace, * PNG_RESTRICT png_colorspacerp;
+
+typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
+
+/* General flags for the 'flags' field */
+#define PNG_COLORSPACE_HAVE_GAMMA           0x0001
+#define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
+#define PNG_COLORSPACE_HAVE_INTENT          0x0004
+#define PNG_COLORSPACE_FROM_gAMA            0x0008
+#define PNG_COLORSPACE_FROM_cHRM            0x0010
+#define PNG_COLORSPACE_FROM_sRGB            0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_INVALID              0x8000
+#define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
+#endif /* COLORSPACE || GAMMA */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf jmp_buf_local;     /* New name in 1.6.0 for jmp_buf in png_struct */
+   png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+   jmp_buf *jmp_buf_ptr;      /* passed to longjmp_fn */
+   size_t jmp_buf_size;       /* size of the above, if allocated */
+#endif
+   png_error_ptr error_fn;    /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;  /* function for printing warnings */
+#endif
+   png_voidp error_ptr;       /* user supplied struct for error functions */
+   png_rw_ptr write_data_fn;  /* function for writing output data */
+   png_rw_ptr read_data_fn;   /* function for reading input data */
+   png_voidp io_ptr;          /* ptr to application struct for I/O functions */
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   png_voidp user_transform_ptr; /* user supplied struct for user transform */
+   png_byte user_transform_depth;    /* bit depth of user transformed pixels */
+   png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+
+   png_uint_32 mode;          /* tells us where we are in the PNG file */
+   png_uint_32 flags;         /* flags indicating various things to libpng */
+   png_uint_32 transformations; /* which transformations to perform */
+
+   png_uint_32 zowner;        /* ID (chunk type) of zstream owner, 0 if none */
+   z_stream    zstream;       /* decompression structure */
+
+#ifdef PNG_WRITE_SUPPORTED
+   png_compression_bufferp zbuffer_list; /* Created on demand during write */
+   uInt                    zbuffer_size; /* size of the actual buffer */
+
+   int zlib_level;            /* holds zlib compression level */
+   int zlib_method;           /* holds zlib compression method */
+   int zlib_window_bits;      /* holds zlib compression window bits */
+   int zlib_mem_level;        /* holds zlib compression memory level */
+   int zlib_strategy;         /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   int zlib_text_level;            /* holds zlib compression level */
+   int zlib_text_method;           /* holds zlib compression method */
+   int zlib_text_window_bits;      /* holds zlib compression window bits */
+   int zlib_text_mem_level;        /* holds zlib compression memory level */
+   int zlib_text_strategy;         /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
+/* Added at libpng 1.6.0 */
+#ifdef PNG_WRITE_SUPPORTED
+   int zlib_set_level;        /* Actual values set into the zstream on write */
+   int zlib_set_method;
+   int zlib_set_window_bits;
+   int zlib_set_mem_level;
+   int zlib_set_strategy;
+#endif
+
+   png_uint_32 width;         /* width of image in pixels */
+   png_uint_32 height;        /* height of image in pixels */
+   png_uint_32 num_rows;      /* number of rows in current pass */
+   png_uint_32 usr_width;     /* width of row at start of write */
+   png_size_t rowbytes;       /* size of row in bytes */
+   png_uint_32 iwidth;        /* width of current interlaced row in pixels */
+   png_uint_32 row_number;    /* current row in interlace pass */
+   png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
+   png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
+                               * While reading this is a pointer into
+                               * big_prev_row; while writing it is separately
+                               * allocated if needed.
+                               */
+   png_bytep row_buf;         /* buffer to save current (unfiltered) row.
+                               * While reading, this is a pointer into
+                               * big_row_buf; while writing it is separately
+                               * allocated.
+                               */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_bytep try_row;    /* buffer to save trial row when filtering */
+   png_bytep tst_row;    /* buffer to save best trial row when filtering */
+#endif
+   png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
+
+   png_uint_32 idat_size;     /* current IDAT size for read */
+   png_uint_32 crc;           /* current chunk CRC value */
+   png_colorp palette;        /* palette from the input file */
+   png_uint_16 num_palette;   /* number of color entries in palette */
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   int num_palette_max;       /* maximum palette index found in IDAT */
+#endif
+
+   png_uint_16 num_trans;     /* number of transparency values */
+   png_byte compression;      /* file compression type (always 0) */
+   png_byte filter;           /* file filter type (always 0) */
+   png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+   png_byte pass;             /* current interlace pass (0 - 6) */
+   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ in png.h ) */
+   png_byte color_type;       /* color type of file */
+   png_byte bit_depth;        /* bit depth of file */
+   png_byte usr_bit_depth;    /* bit depth of users row: write only */
+   png_byte pixel_depth;      /* number of bits per pixel */
+   png_byte channels;         /* number of channels in file */
+#ifdef PNG_WRITE_SUPPORTED
+   png_byte usr_channels;     /* channels at start of write: write only */
+#endif
+   png_byte sig_bytes;        /* magic bytes read/written from start of file */
+   png_byte maximum_pixel_depth;
+                              /* pixel depth used for the row buffers */
+   png_byte transformed_pixel_depth;
+                              /* pixel depth after read/write transforms */
+#if ZLIB_VERNUM >= 0x1240
+   png_byte zstream_start;    /* at start of an input zlib stream */
+#endif /* Zlib >= 1.2.4 */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+   png_uint_16 filler;           /* filler bytes for pixel expansion */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_byte background_gamma_type;
+   png_fixed_point background_gamma;
+   png_color_16 background;   /* background color in screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* bKGD */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_flush_ptr output_flush_fn; /* Function for flushing output */
+   png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
+   png_uint_32 flush_rows;    /* number of rows written since last flush */
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
+   png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
+
+   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
+   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_bytep gamma_from_1;    /* converts from 1.0 to screen */
+   png_bytep gamma_to_1;      /* converts from file to 1.0 */
+   png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+   png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+   png_color_8 sig_bit;       /* significant bits in each available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+   png_color_8 shift;         /* shift for significant bit tranformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   png_bytep trans_alpha;           /* alpha values for paletted files */
+   png_color_16 trans_color;  /* transparent color for non-paletted files */
+#endif
+
+   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
+   png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_progressive_info_ptr info_fn; /* called after header data fully read */
+   png_progressive_row_ptr row_fn;   /* called after a prog. row is decoded */
+   png_progressive_end_ptr end_fn;   /* called after image is complete */
+   png_bytep save_buffer_ptr;        /* current location in save_buffer */
+   png_bytep save_buffer;            /* buffer for previously read data */
+   png_bytep current_buffer_ptr;     /* current location in current_buffer */
+   png_bytep current_buffer;         /* buffer for recently used data */
+   png_uint_32 push_length;          /* size of current input chunk */
+   png_uint_32 skip_length;          /* bytes to skip in input data */
+   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
+   png_size_t save_buffer_max;       /* total size of save_buffer */
+   png_size_t buffer_size;           /* total amount of available input data */
+   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
+   int process_mode;                 /* what push library is currently doing */
+   int cur_palette;                  /* current push library palette index */
+
+#endif /* PROGRESSIVE_READ */
+
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* For the Borland special 64K segment handler */
+   png_bytepp offset_table_ptr;
+   png_bytep offset_table;
+   png_uint_16 offset_table_number;
+   png_uint_16 offset_table_count;
+   png_uint_16 offset_table_count_free;
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_bytep palette_lookup; /* lookup table for quantizing */
+   png_bytep quantize_index; /* index translation for palette files */
+#endif
+
+/* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+   png_uint_32 options;           /* On/off state (up to 16 options) */
+#endif
+
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng-1.7 */
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   char time_buffer[29]; /* String to hold RFC 1123 time text */
+#endif
+#endif
+
+/* New members added in libpng-1.0.6 */
+
+   png_uint_32 free_me;    /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+   png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   int          unknown_default; /* As PNG_HANDLE_* */
+   unsigned int num_chunk_list;  /* Number of entries in the list */
+   png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
+                                  * followed by a PNG_HANDLE_* byte */
+#endif
+
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   png_byte rgb_to_gray_status;
+   /* Added in libpng 1.5.5 to record setting of coefficients: */
+   png_byte rgb_to_gray_coefficients_set;
+   /* These were changed from png_byte in libpng-1.0.6 */
+   png_uint_16 rgb_to_gray_red_coeff;
+   png_uint_16 rgb_to_gray_green_coeff;
+   /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+   png_uint_32 mng_features_permitted;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_byte filter_type;
+#endif
+
+/* New members added in libpng-1.2.0 */
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_voidp mem_ptr;             /* user supplied struct for mem functions */
+   png_malloc_ptr malloc_fn;      /* function for allocating memory */
+   png_free_ptr free_fn;          /* function for freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+   png_bytep quantize_sort;          /* working sort array */
+   png_bytep index_to_palette;       /* where the original index currently is
+                                        in the palette */
+   png_bytep palette_to_index;       /* which original index points to this
+                                         palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+   png_byte compression_type;
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   png_uint_32 user_width_max;
+   png_uint_32 user_height_max;
+
+   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+    * chunks that can be stored (0 means unlimited).
+    */
+   png_uint_32 user_chunk_cache_max;
+
+   /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+    * can occupy when decompressed.  0 means unlimited.
+    */
+   png_alloc_size_t user_chunk_malloc_max;
+#endif
+
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* Temporary storage for unknown chunk that the library doesn't recognize,
+    * used while reading the chunk.
+    */
+   png_unknown_chunk unknown_chunk;
+#endif
+
+/* New member added in libpng-1.2.26 */
+  png_size_t old_big_row_buf_size;
+
+#ifdef PNG_READ_SUPPORTED
+/* New member added in libpng-1.2.30 */
+  png_bytep        read_buffer;      /* buffer for reading chunk data */
+  png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+  uInt             IDAT_read_size;   /* limit on read buffer size for IDAT */
+#endif
+
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+   png_uint_32 io_state;
+#endif
+
+/* New member added in libpng-1.5.6 */
+   png_bytep big_prev_row;
+
+/* New member added in libpng-1.5.7 */
+   void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+      png_bytep row, png_const_bytep prev_row);
+
+#ifdef PNG_READ_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   png_colorspace   colorspace;
+#endif
+#endif
+};
+#endif /* PNGSTRUCT_H */

xs/src/png/libpng/pngtrans.c

@@ -0,0 +1,864 @@
+
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_bgr");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_BGR;
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16-bit byte swapping */
+void PNGAPI
+png_set_swap(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_swap");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth == 16)
+      png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_packing");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth < 8)
+   {
+      png_ptr->transformations |= PNG_PACK;
+#     ifdef PNG_WRITE_SUPPORTED
+         png_ptr->usr_bit_depth = 8;
+#     endif
+   }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_packswap");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth < 8)
+      png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
+{
+   png_debug(1, "in png_set_shift");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_SHIFT;
+   png_ptr->shift = *true_bits;
+}
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_interlace handling");
+
+   if (png_ptr != 0 && png_ptr->interlaced != 0)
+   {
+      png_ptr->transformations |= PNG_INTERLACE;
+      return (7);
+   }
+
+   return (1);
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_filler");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                      "png_set_filler is invalid for"
+                      " low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                   "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
+   png_ptr->transformations |= PNG_FILLER;
+
+   if (filler_loc == PNG_FILLER_AFTER)
+      png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+
+   else
+      png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+}
+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_add_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_set_filler(png_ptr, filler, filler_loc);
+   /* The above may fail to do anything. */
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_swap_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_invert_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_invert_mono");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_INVERT_MONO;
+}
+
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_invert");
+
+  /* This test removed from libpng version 1.0.13 and 1.2.0:
+   *   if (row_info->bit_depth == 1 &&
+   */
+   if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i++)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp++;
+      }
+   }
+
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 8)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i += 2)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp += 2;
+      }
+   }
+
+#ifdef PNG_16BIT_SUPPORTED
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i += 4)
+      {
+         *rp = (png_byte)(~(*rp));
+         *(rp + 1) = (png_byte)(~(*(rp + 1)));
+         rp += 4;
+      }
+   }
+#endif
+}
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16-bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_swap");
+
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_uint_32 i;
+      png_uint_32 istop= row_info->width * row_info->channels;
+
+      for (i = 0; i < istop; i++, rp += 2)
+      {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+         /* Feature added to libpng-1.6.11 for testing purposes, not
+          * enabled by default.
+          */
+         *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
+         png_byte t = *rp;
+         *rp = *(rp + 1);
+         *(rp + 1) = t;
+#endif
+      }
+   }
+}
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static PNG_CONST png_byte onebppswaptable[256] = {
+   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+   0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+   0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+   0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+   0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+   0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+   0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+   0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+   0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+   0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+   0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+   0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+   0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+   0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+   0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+   0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+   0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+   0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+   0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+   0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+   0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+   0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+   0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+   0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+   0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+   0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+   0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+   0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+   0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static PNG_CONST png_byte twobppswaptable[256] = {
+   0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+   0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+   0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+   0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+   0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+   0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+   0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+   0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+   0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+   0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+   0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+   0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+   0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+   0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+   0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+   0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+   0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+   0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+   0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+   0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+   0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+   0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+   0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+   0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+   0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+   0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+   0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+   0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+   0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+   0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+   0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+   0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static PNG_CONST png_byte fourbppswaptable[256] = {
+   0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+   0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+   0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+   0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+   0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+   0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+   0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+   0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+   0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+   0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+   0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+   0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+   0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+   0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+   0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+   0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+   0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+   0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+   0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+   0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+   0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+   0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+   0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+   0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+   0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+   0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+   0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+   0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+   0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+   0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+   0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+   0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_packswap");
+
+   if (row_info->bit_depth < 8)
+   {
+      png_bytep rp;
+      png_const_bytep end, table;
+
+      end = row + row_info->rowbytes;
+
+      if (row_info->bit_depth == 1)
+         table = onebppswaptable;
+
+      else if (row_info->bit_depth == 2)
+         table = twobppswaptable;
+
+      else if (row_info->bit_depth == 4)
+         table = fourbppswaptable;
+
+      else
+         return;
+
+      for (rp = row; rp < end; rp++)
+         *rp = table[*rp];
+   }
+}
+#endif /* PACKSWAP || WRITE_PACKSWAP */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do.  All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
+void /* PRIVATE */
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
+{
+   png_bytep sp = row; /* source pointer */
+   png_bytep dp = row; /* destination pointer */
+   png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+   /* At the start sp will point to the first byte to copy and dp to where
+    * it is copied to.  ep always points just beyond the end of the row, so
+    * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+    */
+
+   /* GA, GX, XG cases */
+   if (row_info->channels == 2)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channel and, for sp, the filler */
+         {
+            sp += 2; ++dp;
+         }
+
+         /* For a 1 pixel wide image there is nothing to do */
+         while (sp < ep)
+         {
+            *dp++ = *sp; sp += 2;
+         }
+
+         row_info->pixel_depth = 8;
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channel and, for sp, the filler */
+         {
+            sp += 4; dp += 2;
+         }
+
+         while (sp < ep)
+         {
+            *dp++ = *sp++; *dp++ = *sp; sp += 3;
+         }
+
+         row_info->pixel_depth = 16;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 1;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_GRAY;
+   }
+
+   /* RGBA, RGBX, XRGB cases */
+   else if (row_info->channels == 4)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channels and, for sp, the filler */
+         {
+            sp += 4; dp += 3;
+         }
+
+         /* Note that the loop adds 3 to dp and 4 to sp each time. */
+         while (sp < ep)
+         {
+            *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp; sp += 2;
+         }
+
+         row_info->pixel_depth = 24;
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channels and, for sp, the filler */
+         {
+            sp += 8; dp += 6;
+         }
+
+         while (sp < ep)
+         {
+            /* Copy 6 bytes, skip 2 */
+            *dp++ = *sp++; *dp++ = *sp++;
+            *dp++ = *sp++; *dp++ = *sp++;
+            *dp++ = *sp++; *dp++ = *sp; sp += 3;
+         }
+
+         row_info->pixel_depth = 48;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 3;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_RGB;
+   }
+
+   else
+      return; /* The filler channel has gone already */
+
+   /* Fix the rowbytes value. */
+   row_info->rowbytes = (png_size_t)(dp-row);
+}
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_bgr");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 3)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 4)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+      }
+
+#ifdef PNG_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 6)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 8)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+      }
+#endif
+   }
+}
+#endif /* READ_BGR || WRITE_BGR */
+
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+/* Added at libpng-1.5.10 */
+void /* PRIVATE */
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
+{
+   if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
+      png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
+   {
+      /* Calculations moved outside switch in an attempt to stop different
+       * compiler warnings.  'padding' is in *bits* within the last byte, it is
+       * an 'int' because pixel_depth becomes an 'int' in the expression below,
+       * and this calculation is used because it avoids warnings that other
+       * forms produced on either GCC or MSVC.
+       */
+      int padding = PNG_PADBITS(row_info->pixel_depth, row_info->width);
+      png_bytep rp = png_ptr->row_buf + row_info->rowbytes - 1;
+
+      switch (row_info->bit_depth)
+      {
+         case 1:
+         {
+            /* in this case, all bytes must be 0 so we don't need
+             * to unpack the pixels except for the rightmost one.
+             */
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              if ((*rp >> padding) != 0)
+                 png_ptr->num_palette_max = 1;
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 2:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int i = ((*rp >> padding) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 2) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 4) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 6) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 4:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int i = ((*rp >> padding) & 0x0f);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 4) & 0x0f);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 8:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+               if (*rp > png_ptr->num_palette_max)
+                  png_ptr->num_palette_max = (int) *rp;
+            }
+
+            break;
+         }
+
+         default:
+            break;
+      }
+   }
+}
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+void PNGAPI
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
+   user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+   png_debug(1, "in png_set_user_transform_info");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+   {
+      png_app_error(png_ptr,
+          "info change after png_start_read_image or png_read_update_info");
+      return;
+   }
+#endif
+
+   png_ptr->user_transform_ptr = user_transform_ptr;
+   png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+   png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+}
+#endif
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions.  The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+
+   return png_ptr->user_transform_ptr;
+}
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structrp png_ptr)
+{
+   /* See the comments in png.h - this is the sub-image row when reading an
+    * interlaced image.
+    */
+   if (png_ptr != NULL)
+      return png_ptr->row_number;
+
+   return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+      return png_ptr->pass;
+   return 8; /* invalid */
+}
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */

xs/src/png/libpng/pngusr.dfa

@@ -0,0 +1,14 @@
+# pngusr.dfa
+#
+# Build time configuration of libpng
+#
+# Enter build configuration options in this file
+#
+# Security settings: by default these limits are unset, you can change them
+# here by entering the appropriate values as #defines preceded by '@' (to cause,
+# them to be passed through to the build of pnglibconf.h), for example:
+#
+# @# define PNG_USER_WIDTH_MAX 65535
+# @# define PNG_USER_HEIGHT_MAX 65535
+# @# define PNG_USER_CHUNK_CACHE_MAX 256
+# @# define PNG_USER_CHUNK_MALLOC_MAX 640000

xs/src/png/libpng/pngwio.c

@@ -0,0 +1,168 @@
+
+/* pngwio.c - functions for data output
+ *
+ * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output.  Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods.  Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Write the data to whatever output you are using.  The default routine
+ * writes to a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes.  This should never be asked
+ * to write more than 64K on a 16-bit machine.
+ */
+
+void /* PRIVATE */
+png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
+{
+   /* NOTE: write_data_fn must not change the buffer! */
+   if (png_ptr->write_data_fn != NULL )
+      (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+          length);
+
+   else
+      png_error(png_ptr, "Call to NULL write function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   if (png_ptr == NULL)
+      return;
+
+   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+
+   if (check != length)
+      png_error(png_ptr, "Write Error");
+}
+#endif
+
+/* This function is called to output any data pending writing (normally
+ * to disk).  After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structrp png_ptr)
+{
+   if (png_ptr->output_flush_fn != NULL)
+      (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+#  ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
+png_default_flush(png_structp png_ptr)
+{
+   png_FILE_p io_ptr;
+
+   if (png_ptr == NULL)
+      return;
+
+   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
+   fflush(io_ptr);
+}
+#  endif
+#endif
+
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr       - pointer to a png output data structure
+ * io_ptr        - pointer to user supplied structure containing info about
+ *                 the output functions.  May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ *                 arguments a pointer to a png_struct, a pointer to
+ *                 data to be written, and a 32-bit unsigned int that is
+ *                 the number of bytes to be written.  The new write
+ *                 function should call png_error(png_ptr, "Error msg")
+ *                 to exit and output any fatal error messages.  May be
+ *                 NULL, in which case libpng's default function will
+ *                 be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ *                 arguments a pointer to a png_struct.  After a call to
+ *                 the flush function, there should be no data in any buffers
+ *                 or pending transmission.  If the output method doesn't do
+ *                 any buffering of output, a function prototype must still be
+ *                 supplied although it doesn't have to do anything.  If
+ *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ *                 time, output_flush_fn will be ignored, although it must be
+ *                 supplied for compatibility.  May be NULL, in which case
+ *                 libpng's default function will be used, if
+ *                 PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
+ *                 a good idea if io_ptr does not point to a standard
+ *                 *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+   if (write_data_fn != NULL)
+      png_ptr->write_data_fn = write_data_fn;
+
+   else
+      png_ptr->write_data_fn = png_default_write_data;
+#else
+   png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_STDIO_SUPPORTED
+
+   if (output_flush_fn != NULL)
+      png_ptr->output_flush_fn = output_flush_fn;
+
+   else
+      png_ptr->output_flush_fn = png_default_flush;
+
+#  else
+   png_ptr->output_flush_fn = output_flush_fn;
+#  endif
+#else
+   PNG_UNUSED(output_flush_fn)
+#endif /* WRITE_FLUSH */
+
+#ifdef PNG_READ_SUPPORTED
+   /* It is an error to read while writing a png file */
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+#endif
+}
+#endif /* WRITE */

xs/src/png/libpng/pngwtran.c

@@ -0,0 +1,576 @@
+
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
+ * row_info bit depth should be 8 (one pixel per byte).  The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+static void
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+   png_debug(1, "in png_do_pack");
+
+   if (row_info->bit_depth == 8 &&
+      row_info->channels == 1)
+   {
+      switch ((int)bit_depth)
+      {
+         case 1:
+         {
+            png_bytep sp, dp;
+            int mask, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            mask = 0x80;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               if (*sp != 0)
+                  v |= mask;
+
+               sp++;
+
+               if (mask > 1)
+                  mask >>= 1;
+
+               else
+               {
+                  mask = 0x80;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+            }
+
+            if (mask != 0x80)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp, dp;
+            unsigned int shift;
+            int v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            shift = 6;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+
+               value = (png_byte)(*sp & 0x03);
+               v |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 6;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+
+               else
+                  shift -= 2;
+
+               sp++;
+            }
+
+            if (shift != 6)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp, dp;
+            unsigned int shift;
+            int v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            shift = 4;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+
+               value = (png_byte)(*sp & 0x0f);
+               v |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 4;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+
+               else
+                  shift -= 4;
+
+               sp++;
+            }
+
+            if (shift != 4)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         default:
+            break;
+      }
+
+      row_info->bit_depth = (png_byte)bit_depth;
+      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range.  Pass the
+ * true number of bits in bit_depth.  The row should be packed
+ * according to row_info->bit_depth.  Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+static void
+png_do_shift(png_row_infop row_info, png_bytep row,
+    png_const_color_8p bit_depth)
+{
+   png_debug(1, "in png_do_shift");
+
+   if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      int shift_start[4], shift_dec[4];
+      unsigned int channels = 0;
+
+      if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->red;
+         shift_dec[channels] = bit_depth->red;
+         channels++;
+
+         shift_start[channels] = row_info->bit_depth - bit_depth->green;
+         shift_dec[channels] = bit_depth->green;
+         channels++;
+
+         shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+         shift_dec[channels] = bit_depth->blue;
+         channels++;
+      }
+
+      else
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+         shift_dec[channels] = bit_depth->gray;
+         channels++;
+      }
+
+      if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+         shift_dec[channels] = bit_depth->alpha;
+         channels++;
+      }
+
+      /* With low row depths, could only be grayscale, so one channel */
+      if (row_info->bit_depth < 8)
+      {
+         png_bytep bp = row;
+         png_size_t i;
+         unsigned int mask;
+         png_size_t row_bytes = row_info->rowbytes;
+
+         if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+            mask = 0x55;
+
+         else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+            mask = 0x11;
+
+         else
+            mask = 0xff;
+
+         for (i = 0; i < row_bytes; i++, bp++)
+         {
+            int j;
+            unsigned int v, out;
+
+            v = *bp;
+            out = 0;
+
+            for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+            {
+               if (j > 0)
+                  out |= v << j;
+
+               else
+                  out |= (v >> (-j)) & mask;
+            }
+
+            *bp = (png_byte)(out & 0xff);
+         }
+      }
+
+      else if (row_info->bit_depth == 8)
+      {
+         png_bytep bp = row;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+
+         for (i = 0; i < istop; i++, bp++)
+         {
+
+            const unsigned int c = i%channels;
+            int j;
+            unsigned int v, out;
+
+            v = *bp;
+            out = 0;
+
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  out |= v << j;
+
+               else
+                  out |= v >> (-j);
+            }
+
+            *bp = (png_byte)(out & 0xff);
+         }
+      }
+
+      else
+      {
+         png_bytep bp;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+
+         for (bp = row, i = 0; i < istop; i++)
+         {
+            const unsigned int c = i%channels;
+            int j;
+            unsigned int value, v;
+
+            v = png_get_uint_16(bp);
+            value = 0;
+
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  value |= v << j;
+
+               else
+                  value |= v >> (-j);
+            }
+            *bp++ = (png_byte)((value >> 8) & 0xff);
+            *bp++ = (png_byte)(value & 0xff);
+         }
+      }
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+static void
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_swap_alpha");
+
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from ARGB to RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AARRGGBB to RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from AG to GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AAGG to GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+static void
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_invert_alpha");
+
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=3; dp = sp;
+               *dp = (png_byte)(255 - *(sp++));
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=6; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=2; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+   }
+}
+#endif
+
+/* Transform the data according to the user's wishes.  The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+   png_debug(1, "in png_do_write_transformations");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+      if (png_ptr->write_user_transform_fn != NULL)
+         (*(png_ptr->write_user_transform_fn)) /* User write transform
+                                                 function */
+             (png_ptr,  /* png_ptr */
+             row_info,  /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);      /* start of pixel data for row */
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+          !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) != 0)
+      png_do_pack(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->bit_depth);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+#  ifdef PNG_16BIT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#  endif
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
+      png_do_shift(row_info, png_ptr->row_buf + 1,
+           &(png_ptr->shift));
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+   if ((png_ptr->transformations & PNG_BGR) != 0)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+}
+#endif /* WRITE_TRANSFORMS */
+#endif /* WRITE */

xs/src/png/libpng/powerpc/filter_vsx_intrinsics.c

@@ -0,0 +1,767 @@
+/* filter_vsx_intrinsics.c - PowerPC optimised filter functions
+ *
+ * Copyright (c) 2017 Glenn Randers-Pehrson
+ * Written by Vadim Barkov, 2017.
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* This code requires -maltivec and -mvsx on the command line: */
+#if PNG_POWERPC_VSX_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <altivec.h>
+
+#if PNG_POWERPC_VSX_OPT > 0
+
+#ifndef __VSX__
+#  error "This code requires VSX support (POWER7 and later). Please provide -mvsx compiler flag."
+#endif
+
+#define vec_ld_unaligned(vec,data) vec = vec_vsx_ld(0,data)
+#define vec_st_unaligned(vec,data) vec_vsx_st(vec,0,data)
+
+
+/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d).
+ * They're positioned like this:
+ *    prev:  c b
+ *    row:   a d
+ * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be
+ * whichever of a, b, or c is closest to p=a+b-c.
+ * ( this is taken from ../intel/filter_sse2_intrinsics.c )
+ */
+
+#define vsx_declare_common_vars(row_info,row,prev_row,offset) \
+   png_byte i;\
+   png_bytep rp = row + offset;\
+   png_const_bytep pp = prev_row;\
+   png_size_t unaligned_top = 16 - (((png_size_t)rp % 16));\
+   png_size_t istop;\
+   if(unaligned_top == 16)\
+      unaligned_top = 0;\
+   istop = row_info->rowbytes;\
+   if((unaligned_top < istop))\
+      istop -= unaligned_top;\
+   else{\
+      unaligned_top = istop;\
+      istop = 0;\
+   }
+
+void png_read_filter_row_up_vsx(png_row_infop row_info, png_bytep row,
+                                png_const_bytep prev_row)
+{
+   vector unsigned char rp_vec;
+   vector unsigned char pp_vec;
+   vsx_declare_common_vars(row_info,row,prev_row,0)
+
+   /* Altivec operations require 16-byte aligned data
+    * but input can be unaligned. So we calculate
+    * unaligned part as usual.
+    */
+   for (i = 0; i < unaligned_top; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+      rp++;
+   }
+
+   /* Using SIMD while we can */
+   while( istop >= 16 )
+   {
+      rp_vec = vec_ld(0,rp);
+      vec_ld_unaligned(pp_vec,pp);
+
+      rp_vec = vec_add(rp_vec,pp_vec);
+
+      vec_st(rp_vec,0,rp);
+
+      pp += 16;
+      rp += 16;
+      istop -= 16;
+   }
+
+   if(istop > 0)
+   {
+      /* If byte count of row is not divisible by 16
+       * we will process remaining part as usual
+       */
+      for (i = 0; i < istop; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+         rp++;
+      }
+}
+
+}
+
+static const vector unsigned char VSX_LEFTSHIFTED1_4 = {16,16,16,16, 0, 1, 2, 3,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_LEFTSHIFTED2_4 = {16,16,16,16,16,16,16,16, 4, 5, 6, 7,16,16,16,16};
+static const vector unsigned char VSX_LEFTSHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 8, 9,10,11};
+
+static const vector unsigned char VSX_LEFTSHIFTED1_3 = {16,16,16, 0, 1, 2,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_LEFTSHIFTED2_3 = {16,16,16,16,16,16, 3, 4, 5,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_LEFTSHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 6, 7, 8,16,16,16,16};
+static const vector unsigned char VSX_LEFTSHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 9,10,11,16};
+
+static const vector unsigned char VSX_NOT_SHIFTED1_4 = {16,16,16,16, 4, 5, 6, 7,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_NOT_SHIFTED2_4 = {16,16,16,16,16,16,16,16, 8, 9,10,11,16,16,16,16};
+static const vector unsigned char VSX_NOT_SHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,15};
+
+static const vector unsigned char VSX_NOT_SHIFTED1_3 = {16,16,16, 3, 4, 5,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_NOT_SHIFTED2_3 = {16,16,16,16,16,16, 6, 7, 8,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_NOT_SHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 9,10,11,16,16,16,16};
+static const vector unsigned char VSX_NOT_SHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,16};
+
+static const vector unsigned char VSX_CHAR_ZERO = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+#ifdef __LITTLE_ENDIAN__
+
+static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = { 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = { 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {12,16,13,16,14,16,15,16,16,16,16,16,16,16,16,16};
+
+static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 0, 2, 4, 6,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 0, 2, 4, 6,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4, 6};
+
+static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = { 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = { 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = { 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {12,16,13,16,14,16,16,16,16,16,16,16,16,16,16,16};
+
+static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 0, 2, 4,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 0, 2, 4,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 0, 2, 4,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4,16};
+
+#elif defined(__BIG_ENDIAN__)
+
+static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = {16, 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = {16, 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {16,12,16,13,16,14,16,15,16,16,16,16,16,16,16,16};
+
+static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 1, 3, 5, 7,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 1, 3, 5, 7,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5, 7};
+
+static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = {16, 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = {16, 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = {16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {16,12,16,13,16,14,16,16,16,16,16,16,16,16,16,16};
+
+static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 1, 3, 5,16,16,16,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 1, 3, 5,16,16,16,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 1, 3, 5,16,16,16,16};
+static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5,16};
+
+#endif
+
+#define vsx_char_to_short(vec,offset,bpp) (vector unsigned short)vec_perm((vec),VSX_CHAR_ZERO,VSX_CHAR_TO_SHORT##offset##_##bpp)
+#define vsx_short_to_char(vec,offset,bpp) vec_perm(((vector unsigned char)(vec)),VSX_CHAR_ZERO,VSX_SHORT_TO_CHAR##offset##_##bpp)
+
+#ifdef PNG_USE_ABS
+#  define vsx_abs(number) abs(number)
+#else
+#  define vsx_abs(number) (number > 0) ? (number) : -(number)
+#endif
+
+void png_read_filter_row_sub4_vsx(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   const png_byte bpp = 4;
+
+   vector unsigned char rp_vec;
+   vector unsigned char part_vec;
+
+   vsx_declare_common_vars(row_info,row,prev_row,bpp)
+
+   PNG_UNUSED(pp)
+
+   /* Altivec operations require 16-byte aligned data
+    * but input can be unaligned. So we calculate
+    * unaligned part as usual.
+    */
+   for (i = 0; i < unaligned_top; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+      rp++;
+   }
+
+   /* Using SIMD while we can */
+   while( istop >= 16 )
+   {
+      for(i=0;i < bpp ; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+         rp++;
+      }
+      rp -= bpp;
+
+      rp_vec = vec_ld(0,rp);
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      vec_st(rp_vec,0,rp);
+
+      rp += 16;
+      istop -= 16;
+   }
+
+   if(istop > 0)
+      for (i = 0; i < istop % 16; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) + (int)(*(rp - bpp))) & 0xff);
+         rp++;
+      }
+
+}
+
+void png_read_filter_row_sub3_vsx(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   const png_byte bpp = 3;
+
+   vector unsigned char rp_vec;
+   vector unsigned char part_vec;
+
+   vsx_declare_common_vars(row_info,row,prev_row,bpp)
+
+   PNG_UNUSED(pp)
+
+   /* Altivec operations require 16-byte aligned data
+    * but input can be unaligned. So we calculate
+    * unaligned part as usual.
+    */
+   for (i = 0; i < unaligned_top; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+      rp++;
+   }
+
+   /* Using SIMD while we can */
+   while( istop >= 16 )
+   {
+      for(i=0;i < bpp ; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+         rp++;
+      }
+      rp -= bpp;
+
+      rp_vec = vec_ld(0,rp);
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3);
+      rp_vec = vec_add(rp_vec,part_vec);
+
+      vec_st(rp_vec,0,rp);
+      rp += 15;
+      istop -= 16;
+
+      /* Since 16 % bpp = 16 % 3 = 1, last element of array must
+       * be proceeded manually
+       */
+      *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+      rp++;
+   }
+
+   if(istop > 0)
+      for (i = 0; i < istop % 16; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+         rp++;
+      }
+}
+
+void png_read_filter_row_avg4_vsx(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+   const png_byte bpp = 4;
+
+   vector unsigned char rp_vec;
+   vector unsigned char pp_vec;
+   vector unsigned char pp_part_vec;
+   vector unsigned char rp_part_vec;
+   vector unsigned char avg_vec;
+
+   vsx_declare_common_vars(row_info,row,prev_row,bpp)
+   rp -= bpp;
+   if(istop >= bpp)
+      istop -= bpp;
+
+   for (i = 0; i < bpp; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         ((int)(*pp++) / 2 )) & 0xff);
+
+      rp++;
+   }
+
+   /* Altivec operations require 16-byte aligned data
+    * but input can be unaligned. So we calculate
+    * unaligned part as usual.
+    */
+   for (i = 0; i < unaligned_top; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+      rp++;
+   }
+
+   /* Using SIMD while we can */
+   while( istop >= 16 )
+   {
+      for(i=0;i < bpp ; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) +
+            (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+         rp++;
+      }
+      rp -= bpp;
+      pp -= bpp;
+
+      vec_ld_unaligned(pp_vec,pp);
+      rp_vec = vec_ld(0,rp);
+
+      rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4);
+      pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_4);
+      avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+      avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+      rp_vec = vec_add(rp_vec,avg_vec);
+
+      rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4);
+      pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_4);
+      avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+      avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+      rp_vec = vec_add(rp_vec,avg_vec);
+
+      rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4);
+      pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_4);
+      avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+      avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+      rp_vec = vec_add(rp_vec,avg_vec);
+
+      vec_st(rp_vec,0,rp);
+
+      rp += 16;
+      pp += 16;
+      istop -= 16;
+   }
+
+   if(istop  > 0)
+      for (i = 0; i < istop % 16; i++)
+      {
+         *rp = (png_byte)(((int)(*rp) +
+            (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+         rp++;
+      }
+}
+
+void png_read_filter_row_avg3_vsx(png_row_infop row_info, png_bytep row,
+                                  png_const_bytep prev_row)
+{
+  const png_byte bpp = 3;
+
+  vector unsigned char rp_vec;
+  vector unsigned char pp_vec;
+  vector unsigned char pp_part_vec;
+  vector unsigned char rp_part_vec;
+  vector unsigned char avg_vec;
+
+  vsx_declare_common_vars(row_info,row,prev_row,bpp)
+  rp -= bpp;
+  if(istop >= bpp)
+     istop -= bpp;
+
+  for (i = 0; i < bpp; i++)
+  {
+     *rp = (png_byte)(((int)(*rp) +
+        ((int)(*pp++) / 2 )) & 0xff);
+
+     rp++;
+  }
+
+  /* Altivec operations require 16-byte aligned data
+   * but input can be unaligned. So we calculate
+   * unaligned part as usual.
+   */
+  for (i = 0; i < unaligned_top; i++)
+  {
+     *rp = (png_byte)(((int)(*rp) +
+        (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+     rp++;
+  }
+
+  /* Using SIMD while we can */
+  while( istop >= 16 )
+  {
+     for(i=0;i < bpp ; i++)
+     {
+        *rp = (png_byte)(((int)(*rp) +
+           (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+        rp++;
+     }
+     rp -= bpp;
+     pp -= bpp;
+
+     vec_ld_unaligned(pp_vec,pp);
+     rp_vec = vec_ld(0,rp);
+
+     rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3);
+     pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_3);
+     avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+     avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+     rp_vec = vec_add(rp_vec,avg_vec);
+
+     rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3);
+     pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_3);
+     avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+     avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+     rp_vec = vec_add(rp_vec,avg_vec);
+
+     rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3);
+     pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_3);
+     avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+     avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+     rp_vec = vec_add(rp_vec,avg_vec);
+
+     rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3);
+     pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED4_3);
+     avg_vec = vec_avg(rp_part_vec,pp_part_vec);
+     avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
+     rp_vec = vec_add(rp_vec,avg_vec);
+
+     vec_st(rp_vec,0,rp);
+
+     rp += 15;
+     pp += 15;
+     istop -= 16;
+
+     /* Since 16 % bpp = 16 % 3 = 1, last element of array must
+      * be proceeded manually
+      */
+     *rp = (png_byte)(((int)(*rp) +
+        (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+     rp++;
+  }
+
+  if(istop  > 0)
+     for (i = 0; i < istop % 16; i++)
+     {
+        *rp = (png_byte)(((int)(*rp) +
+           (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+        rp++;
+     }
+}
+
+/* Bytewise c ? t : e. */
+#define if_then_else(c,t,e) vec_sel(e,t,c)
+
+#define vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) {\
+      c = *(pp - bpp);\
+      a = *(rp - bpp);\
+      b = *pp++;\
+      p = b - c;\
+      pc = a - c;\
+      pa = vsx_abs(p);\
+      pb = vsx_abs(pc);\
+      pc = vsx_abs(p + pc);\
+      if (pb < pa) pa = pb, a = b;\
+      if (pc < pa) a = c;\
+      a += *rp;\
+      *rp++ = (png_byte)a;\
+      }
+
+void png_read_filter_row_paeth4_vsx(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   const png_byte bpp = 4;
+
+   int a, b, c, pa, pb, pc, p;
+   vector unsigned char rp_vec;
+   vector unsigned char pp_vec;
+   vector unsigned short a_vec,b_vec,c_vec,nearest_vec;
+   vector signed short pa_vec,pb_vec,pc_vec,smallest_vec;
+
+   vsx_declare_common_vars(row_info,row,prev_row,bpp)
+   rp -= bpp;
+   if(istop >= bpp)
+      istop -= bpp;
+
+   /* Process the first pixel in the row completely (this is the same as 'up'
+    * because there is only one candidate predictor for the first row).
+    */
+   for(i = 0; i < bpp ; i++)
+   {
+      *rp = (png_byte)( *rp + *pp);
+      rp++;
+      pp++;
+   }
+
+   for(i = 0; i < unaligned_top ; i++)
+   {
+      vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+   }
+
+   while( istop >= 16)
+   {
+      for(i = 0; i < bpp ; i++)
+      {
+         vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+      }
+
+      rp -= bpp;
+      pp -= bpp;
+      rp_vec = vec_ld(0,rp);
+      vec_ld_unaligned(pp_vec,pp);
+
+      a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4);
+      b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_4),1,4);
+      c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4);
+      pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+      pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+      pc_vec = vec_add(pa_vec,pb_vec);
+      pa_vec = vec_abs(pa_vec);
+      pb_vec = vec_abs(pb_vec);
+      pc_vec = vec_abs(pc_vec);
+      smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+      nearest_vec =  if_then_else(
+            vec_cmpeq(pa_vec,smallest_vec),
+            a_vec,
+            if_then_else(
+              vec_cmpeq(pb_vec,smallest_vec),
+              b_vec,
+              c_vec
+              )
+            );
+      rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,4)));
+
+      a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4);
+      b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_4),2,4);
+      c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4);
+      pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+      pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+      pc_vec = vec_add(pa_vec,pb_vec);
+      pa_vec = vec_abs(pa_vec);
+      pb_vec = vec_abs(pb_vec);
+      pc_vec = vec_abs(pc_vec);
+      smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+      nearest_vec =  if_then_else(
+            vec_cmpeq(pa_vec,smallest_vec),
+            a_vec,
+            if_then_else(
+              vec_cmpeq(pb_vec,smallest_vec),
+              b_vec,
+              c_vec
+              )
+            );
+      rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,4)));
+
+      a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4);
+      b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_4),3,4);
+      c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4);
+      pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+      pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+      pc_vec = vec_add(pa_vec,pb_vec);
+      pa_vec = vec_abs(pa_vec);
+      pb_vec = vec_abs(pb_vec);
+      pc_vec = vec_abs(pc_vec);
+      smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+      nearest_vec =  if_then_else(
+            vec_cmpeq(pa_vec,smallest_vec),
+            a_vec,
+            if_then_else(
+              vec_cmpeq(pb_vec,smallest_vec),
+              b_vec,
+              c_vec
+              )
+            );
+      rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,4)));
+
+      vec_st(rp_vec,0,rp);
+
+      rp += 16;
+      pp += 16;
+      istop -= 16;
+   }
+
+   if(istop > 0)
+      for (i = 0; i < istop % 16; i++)
+      {
+         vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+      }
+}
+
+void png_read_filter_row_paeth3_vsx(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+  const png_byte bpp = 3;
+
+  int a, b, c, pa, pb, pc, p;
+  vector unsigned char rp_vec;
+  vector unsigned char pp_vec;
+  vector unsigned short a_vec,b_vec,c_vec,nearest_vec;
+  vector signed short pa_vec,pb_vec,pc_vec,smallest_vec;
+
+  vsx_declare_common_vars(row_info,row,prev_row,bpp)
+  rp -= bpp;
+  if(istop >= bpp)
+     istop -= bpp;
+
+  /* Process the first pixel in the row completely (this is the same as 'up'
+   * because there is only one candidate predictor for the first row).
+   */
+  for(i = 0; i < bpp ; i++)
+  {
+     *rp = (png_byte)( *rp + *pp);
+     rp++;
+     pp++;
+  }
+
+  for(i = 0; i < unaligned_top ; i++)
+  {
+     vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+  }
+
+  while( istop >= 16)
+  {
+     for(i = 0; i < bpp ; i++)
+     {
+        vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+     }
+
+     rp -= bpp;
+     pp -= bpp;
+     rp_vec = vec_ld(0,rp);
+     vec_ld_unaligned(pp_vec,pp);
+
+     a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3);
+     b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_3),1,3);
+     c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3);
+     pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+     pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+     pc_vec = vec_add(pa_vec,pb_vec);
+     pa_vec = vec_abs(pa_vec);
+     pb_vec = vec_abs(pb_vec);
+     pc_vec = vec_abs(pc_vec);
+     smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+     nearest_vec =  if_then_else(
+           vec_cmpeq(pa_vec,smallest_vec),
+           a_vec,
+           if_then_else(
+             vec_cmpeq(pb_vec,smallest_vec),
+             b_vec,
+             c_vec
+             )
+           );
+     rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,3)));
+
+     a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3);
+     b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_3),2,3);
+     c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3);
+     pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+     pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+     pc_vec = vec_add(pa_vec,pb_vec);
+     pa_vec = vec_abs(pa_vec);
+     pb_vec = vec_abs(pb_vec);
+     pc_vec = vec_abs(pc_vec);
+     smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+     nearest_vec =  if_then_else(
+           vec_cmpeq(pa_vec,smallest_vec),
+           a_vec,
+           if_then_else(
+             vec_cmpeq(pb_vec,smallest_vec),
+             b_vec,
+             c_vec
+             )
+           );
+     rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,3)));
+
+     a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3);
+     b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_3),3,3);
+     c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3);
+     pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+     pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+     pc_vec = vec_add(pa_vec,pb_vec);
+     pa_vec = vec_abs(pa_vec);
+     pb_vec = vec_abs(pb_vec);
+     pc_vec = vec_abs(pc_vec);
+     smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+     nearest_vec =  if_then_else(
+           vec_cmpeq(pa_vec,smallest_vec),
+           a_vec,
+           if_then_else(
+             vec_cmpeq(pb_vec,smallest_vec),
+             b_vec,
+             c_vec
+             )
+           );
+     rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,3)));
+
+     a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3);
+     b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED4_3),4,3);
+     c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3);
+     pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
+     pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
+     pc_vec = vec_add(pa_vec,pb_vec);
+     pa_vec = vec_abs(pa_vec);
+     pb_vec = vec_abs(pb_vec);
+     pc_vec = vec_abs(pc_vec);
+     smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
+     nearest_vec =  if_then_else(
+           vec_cmpeq(pa_vec,smallest_vec),
+           a_vec,
+           if_then_else(
+             vec_cmpeq(pb_vec,smallest_vec),
+             b_vec,
+             c_vec
+             )
+           );
+     rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,4,3)));
+
+     vec_st(rp_vec,0,rp);
+
+     rp += 15;
+     pp += 15;
+     istop -= 16;
+
+     /* Since 16 % bpp = 16 % 3 = 1, last element of array must
+      * be proceeded manually
+      */
+     vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+  }
+
+  if(istop > 0)
+     for (i = 0; i < istop % 16; i++)
+     {
+        vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
+     }
+}
+
+#endif /* PNG_POWERPC_VSX_OPT > 0 */
+#endif /* PNG_POWERPC_VSX_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */

xs/src/png/libpng/powerpc/powerpc_init.c

@@ -0,0 +1,125 @@
+
+/* powerpc_init.c - POWERPC optimised filter functions
+ *
+ * Copyright (c) 2017 Glenn Randers-Pehrson
+ * Written by Vadim Barkov, 2017.
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
+ * called.
+ */
+#define _POSIX_SOURCE 1
+
+#include <stdio.h>
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_POWERPC_VSX_OPT > 0
+#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED /* Do run-time checks */
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible.  In the case of the PowerPC
+ * VSX instructions there is no processor-specific way of detecting the
+ * presence of the required support, therefore run-time detection is extremely
+ * OS specific.
+ *
+ * You may set the macro PNG_POWERPC_VSX_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_vsx function.  There
+ * are a number of implementations in contrib/powerpc-vsx, but the only one that
+ * has partial support is contrib/powerpc-vsx/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
+ */
+#ifndef PNG_POWERPC_VSX_FILE
+#  ifdef __linux__
+#     define  PNG_POWERPC_VSX_FILE "contrib/powerpc-vsx/linux_aux.c"
+#  endif
+#endif
+
+#ifdef PNG_POWERPC_VSX_FILE
+
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_vsx(png_structp png_ptr);
+#include PNG_POWERPC_VSX_FILE
+
+#else  /* PNG_POWERPC_VSX_FILE */
+#  error "PNG_POWERPC_VSX_FILE undefined: no support for run-time POWERPC VSX checks"
+#endif /* PNG_POWERPC_VSX_FILE */
+#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */
+
+void
+png_init_filter_functions_vsx(png_structp pp, unsigned int bpp)
+{
+   /* The switch statement is compiled in for POWERPC_VSX_API, the call to
+    * png_have_vsx is compiled in for POWERPC_VSX_CHECK. If both are defined
+    * the check is only performed if the API has not set the PowerPC option on
+    * or off explicitly. In this case the check controls what happens.
+    */
+
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+   switch ((pp->options >> PNG_POWERPC_VSX) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_POWERPC_VSX_API_SUPPORTED */
+#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED
+         {
+            static volatile sig_atomic_t no_vsx = -1; /* not checked */
+
+            if (no_vsx < 0)
+               no_vsx = !png_have_vsx(pp);
+
+            if (no_vsx)
+               return;
+         }
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+         break;
+#endif
+#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */
+
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+   }
+#endif
+
+   /* IMPORTANT: any new internal functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_vsx;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_vsx;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_vsx;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_vsx;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_vsx;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_vsx;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_vsx;
+   }
+}
+#endif /* PNG_POWERPC_VSX_OPT > 0 */
+#endif /* READ */

xs/src/png/libpng/scripts/checksym.awk

@@ -0,0 +1,173 @@
+#!/bin/awk -f
+# Check a list of symbols against the master definition
+# (official) list.  Arguments:
+#
+# awk -f checksym.awk official-def list-to-check
+#
+# Output is a file in the current directory called 'symbols.new',
+# the value of the awk variable "of" (which can be changed on the
+# command line if required.)  stdout holds error messages.  Error
+# code indicates success or failure.
+#
+# NOTE: this is a pure, old fashioned, awk script.  It will
+# work with any awk
+
+BEGIN{
+   err=0
+   master=""        # master file
+   official[1] = "" # defined symbols from master file
+   symbol[1] = ""   # defined symbols from png.h
+   removed[1] = ""  # removed symbols from png.h
+   lasto = 0        # last ordinal value from png.h
+   mastero = 0      # highest ordinal in master file
+   symbolo = 0      # highest ordinal in png.h
+   missing = "error"# log an error on missing symbols
+   of="symbols.new" # default to a fixed name
+}
+
+# Read existing definitions from the master file (the first
+# file on the command line.)  This must be a def file and it
+# has definition lines (others are ignored) of the form:
+#
+#   symbol @ordinal
+#
+master == "" {
+   master = FILENAME
+}
+FILENAME==master && NF==2 && $2~/^@/ && $1!~/^;/ {
+   o=0+substr($2,2)
+   if (o > 0) {
+      if (official[o] == "") {
+         official[o] = $1
+         if (o > mastero) mastero = o
+         next
+      } else
+         print master ": duplicated symbol:", official[o] ":", $0
+   } else
+      print master ": bad export line format:", $0
+   err = 1
+}
+FILENAME==master && $1==";missing" && NF==2{
+   # This allows the master file to control how missing symbols
+   # are handled; symbols that aren't in either the master or
+   # the new file.  Valid values are 'ignore', 'warning' and
+   # 'error'
+   missing = $2
+}
+FILENAME==master {
+   next
+}
+
+# Read new definitions, these are free form but the lines must
+# just be symbol definitions.  Lines will be commented out for
+# 'removed' symbols, introduced in png.h using PNG_REMOVED rather
+# than PNG_EXPORT.  Use symbols.dfn or pngwin.dfn to generate the
+# input file.
+#
+#  symbol @ordinal   # two fields, exported symbol
+#  ; symbol @ordinal # three fields, removed symbol
+#  ; @ordinal        # two fields, the last ordinal
+NF==2 && $1 == ";" && $2 ~ /^@[1-9][0-9]*$/ { # last ordinal
+   o=0+substr($2,2)
+   if (lasto == 0 || lasto == o)
+      lasto=o
+   else {
+      print "png.h: duplicated last ordinal:", lasto, o
+      err = 1
+   }
+   next
+}
+NF==3 && $1 == ";" && $3 ~ /^@[1-9][0-9]*$/ { # removed symbol
+   o=0+substr($3,2)
+   if (removed[o] == "" || removed[o] == $2) {
+      removed[o] = $2
+      if (o > symbolo) symbolo = o
+   } else {
+      print "png.h: duplicated removed symbol", o ": '" removed[o] "' != '" $2 "'"
+      err = 1
+   }
+   next
+}
+NF==2 && $2 ~ /^@[1-9][0-9]*$/ { # exported symbol
+   o=0+substr($2,2)
+   if (symbol[o] == "" || symbol[o] == $1) {
+      symbol[o] = $1
+      if (o > symbolo) symbolo = o
+   } else {
+      print "png.h: duplicated symbol", o ": '" symbol[o] "' != '" $1 "'"
+      err = 1
+   }
+}
+{
+   next # skip all other lines
+}
+
+# At the end check for symbols marked as both duplicated and removed
+END{
+   if (symbolo > lasto) {
+      print "highest symbol ordinal in png.h,", symbolo ", exceeds last ordinal from png.h", lasto
+      err = 1
+   }
+   if (mastero > lasto) {
+      print "highest symbol ordinal in", master ",", mastero ", exceeds last ordinal from png.h", lasto
+      err = 1
+   }
+   unexported=0
+   # Add a standard header to symbols.new:
+   print ";Version INSERT-VERSION-HERE" >of
+   print ";--------------------------------------------------------------" >of
+   print "; LIBPNG symbol list as a Win32 DEF file" >of
+   print "; Contains all the symbols that can be exported from libpng" >of
+   print ";--------------------------------------------------------------" >of
+   print "LIBRARY" >of
+   print "" >of
+   print "EXPORTS" >of
+
+   for (o=1; o<=lasto; ++o) {
+      if (symbol[o] == "" && removed[o] == "") {
+         if (unexported == 0) unexported = o
+         if (official[o] == "") {
+            # missing in export list too, so ok
+            if (o < lasto) continue
+         }
+      }
+      if (unexported != 0) {
+         # Symbols in the .def but not in the new file are errors, but
+         # the 'unexported' symbols aren't in either.  By default this
+         # is an error too (see the setting of 'missing' at the start),
+         # but this can be reset on the command line or by stuff in the
+         # file - see the comments above.
+         if (missing != "ignore") {
+            if (o-1 > unexported)
+               print "png.h:", missing ": missing symbols:", unexported "-" o-1
+            else
+               print "png.h:", missing ": missing symbol:", unexported
+            if (missing != "warning")
+               err = 1
+         }
+         unexported = 0
+      }
+      if (symbol[o] != "" && removed[o] != "") {
+         print "png.h: symbol", o, "both exported as '" symbol[o] "' and removed as '" removed[o] "'"
+         err = 1
+      } else if (symbol[o] != official[o]) {
+         # either the symbol is missing somewhere or it changed
+         err = 1
+         if (symbol[o] == "")
+            print "png.h: symbol", o, "is exported as '" official[o] "' in", master
+         else if (official[o] == "")
+            print "png.h: exported symbol", o, "'" symbol[o] "' not present in", master
+         else
+            print "png.h: exported symbol", o, "'" symbol[o] "' exists as '" official[o] "' in", master
+      }
+
+      # Finally generate symbols.new
+      if (symbol[o] != "")
+         print " " symbol[o], "@" o > of
+   }
+
+   if (err != 0) {
+      print "*** A new list is in", of, "***"
+      exit 1
+   }
+}

xs/src/png/libpng/scripts/def.c

@@ -0,0 +1,29 @@
+/* def.c - define format of libpng.def
+ *
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2011-2014 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* Write the export file header: */
+PNG_DFN ";--------------------------------------------------------------"
+PNG_DFN "; LIBPNG module definition file for OS/2"
+PNG_DFN ";--------------------------------------------------------------"
+PNG_DFN ""
+PNG_DFN "; If you give the library an explicit name one or other files"
+PNG_DFN "; may need modifying to support the new name on one or more"
+PNG_DFN "; systems."
+PNG_DFN "LIBRARY"
+PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
+PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
+PNG_DFN ""
+PNG_DFN "EXPORTS"
+PNG_DFN ";Version 1.6.35beta02"
+
+#define PNG_EXPORTA(ordinal, type, name, args, attributes)\
+        PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"
+
+#include "../png.h"

xs/src/png/libpng/scripts/dfn.awk

@@ -0,0 +1,203 @@
+#!/bin/awk -f
+# scripts/dfn.awk - process a .dfn file
+#
+# last changed in libpng version 1.5.19 - August 21, 2014
+#
+# Copyright (c) 2013-2014 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# The output of this script is written to the file given by
+# the variable 'out', which should be set on the command line.
+# Error messages are printed to stdout and if any are printed
+# the script will exit with error code 1.
+
+BEGIN{
+   out="/dev/null"       # as a flag
+   out_count=0           # count of output lines
+   err=0                 # set if an error occurred
+   sort=0                # sort the output
+   array[""]=""
+}
+
+# The output file must be specified before any input:
+NR==1 && out == "/dev/null" {
+   print "out=output.file must be given on the command line"
+   # but continue without setting the error code; this allows the
+   # script to be checked easily
+}
+
+# Output can be sorted; two lines are recognized
+$1 == "PNG_DFN_START_SORT"{
+   sort=0+$2
+   next
+}
+
+$1 ~ /^PNG_DFN_END_SORT/{
+   # Do a very simple, slow, sort; notice that blank lines won't be
+   # output by this
+   for (entry in array) {
+      while (array[entry] != "") {
+         key = entry
+         value = array[key]
+         array[key] = ""
+
+         for (alt in array) {
+            if (array[alt] != "" && alt < key) {
+               array[key] = value
+               value = array[alt]
+               key = alt
+               array[alt] = ""
+            }
+         }
+
+         print value >out
+      }
+   }
+   sort=0
+   next
+}
+
+/^[^"]*PNG_DFN *".*"[^"]*$/{
+   # A definition line, apparently correctly formatted; extract the
+   # definition then replace any doubled "" that remain with a single
+   # double quote.  Notice that the original doubled double quotes
+   # may have been split by tokenization
+   #
+   # Sometimes GCC splits the PNG_DFN lines; we know this has happened
+   # if the quotes aren't closed and must read another line.  In this
+   # case it is essential to reject lines that start with '#' because those
+   # are introduced #line directives.
+   orig=$0
+   line=$0
+   lineno=FNR
+   if (lineno == "") lineno=NR
+
+   if (sub(/^[^"]*PNG_DFN *"/,"",line) != 1) {
+	print "line", lineno ": processing failed:"
+	print orig
+	err=1
+       next
+   } else {
+	++out_count
+   }
+
+   # Now examine quotes within the value:
+   #
+   #   @" - delete this and any following spaces
+   #   "@ - delete this and any preceding spaces
+   #   @' - replace this by a double quote
+   #
+   # This allows macro substitution by the C compiler thus:
+   #
+   #   #define first_name John
+   #   #define last_name Smith
+   #
+   #	PNG_DFN"#define name @'@" first_name "@ @" last_name "@@'"
+   #
+   # Might get C preprocessed to:
+   #
+   #   PNG_DFN "#define foo @'@" John "@ @" Smith "@@'"
+   #
+   # Which this script reduces to:
+   #
+   #	#define name "John Smith"
+   #
+   while (1) {
+      # While there is an @" remove it and the next "@
+      if (line ~ /@"/) {
+         if (line ~ /@".*"@/) {
+            # Do this special case first to avoid swallowing extra spaces
+            # before or after the @ stuff:
+            if (!sub(/@" *"@/, "", line)) {
+               # Ok, do it in pieces - there has to be a non-space between the
+               # two.  NOTE: really weird things happen if a leading @" is
+               # lost - the code will error out below (I believe).
+               if (!sub(/@" */, "", line) || !sub(/ *"@/, "", line)) {
+                  print "line", lineno, ": internal error:", orig
+                  exit 1
+               }
+            }
+         }
+
+         # There is no matching "@.  Assume a split line
+         else while (1) {
+            if (getline nextline) {
+               # If the line starts with '#' it is a preprocesor line directive
+               # from cc -E; skip it:
+               if (nextline !~ /^#/) {
+                  line = line " " nextline
+                  break
+               }
+            } else {
+               # This is end-of-input - probably a missing "@ on the first line:
+               print "line", lineno ": unbalanced @\" ... \"@ pair"
+               err=1
+               next
+            }
+         }
+
+         # Keep going until all the @" have gone
+         continue
+      }
+
+      # Attempt to remove a trailing " (not preceded by '@') - if this can
+      # be done, stop now; if not assume a split line again
+      if (sub(/"[^"]*$/, "", line))
+         break
+
+      # Read another line
+      while (1) {
+         if (getline nextline) {
+            if (nextline !~ /^#/) {
+               line = line " " nextline
+               # Go back to stripping @" "@ pairs
+               break
+            }
+         } else {
+            print "line", lineno ": unterminated PNG_DFN string"
+            err=1
+            next
+         }
+      }
+   }
+
+   # Put any needed double quotes in (at the end, because these would otherwise
+   # interfere with the processing above.)
+   gsub(/@'/,"\"", line)
+
+   # Remove any trailing spaces (not really required, but for
+   # editorial consistency
+   sub(/ *$/, "", line)
+
+   # Remove trailing CR
+   sub(/
$/, "", line)
+
+   if (sort) {
+      if (split(line, parts) < sort) {
+         print "line", lineno ": missing sort field:", line
+         err=1
+      } else
+         array[parts[sort]] = line
+   }
+
+   else
+      print line >out
+   next
+}
+
+/PNG_DFN/{
+   print "line", NR, "incorrectly formatted PNG_DFN line:"
+   print $0
+   err = 1
+}
+
+END{
+   if (out_count > 0 || err > 0)
+	exit err
+
+   print "no definition lines found"
+   exit 1
+}

xs/src/png/libpng/scripts/genchk.cmake.in

@@ -0,0 +1,37 @@
+# genchk.cmake.in
+# Generate .chk from .out with awk (generic), based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+
+set(AWK "@AWK@")
+
+get_filename_component(INPUTEXT "${INPUT}" EXT)
+get_filename_component(OUTPUTEXT "${OUTPUT}" EXT)
+get_filename_component(INPUTBASE "${INPUT}" NAME_WE)
+get_filename_component(OUTPUTBASE "${OUTPUT}" NAME_WE)
+get_filename_component(INPUTDIR "${INPUT}" PATH)
+get_filename_component(OUTPUTDIR "${OUTPUT}" PATH)
+
+if("${INPUTEXT}" STREQUAL ".out" AND "${OUTPUTEXT}" STREQUAL ".chk")
+  # Generate .chk from .out with awk (generic)
+  file(REMOVE "${OUTPUT}" "${OUTPUTDIR}/${OUTPUTBASE}.new")
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/checksym.awk"
+                          "${SRCDIR}/scripts/${INPUTBASE}.def"
+                          "of=${OUTPUTDIR}/${OUTPUTBASE}.new"
+                          "${INPUT}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUTDIR}/${OUTPUTBASE}.new")
+  endif()
+  file(RENAME "${OUTPUTDIR}/${OUTPUTBASE}.new" "${OUTPUT}")
+else()
+  message(FATAL_ERROR "Unsupported conversion: ${INPUTEXT} to ${OUTPUTEXT}")
+endif()

xs/src/png/libpng/scripts/genout.cmake.in

@@ -0,0 +1,93 @@
+# genout.cmake.in
+# Generate .out from .c with awk (generic), based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+set(BINDIR "@CMAKE_CURRENT_BINARY_DIR@")
+
+set(AWK "@AWK@")
+set(CMAKE_C_COMPILER "@CMAKE_C_COMPILER@")
+set(CMAKE_C_FLAGS @CMAKE_C_FLAGS@)
+set(INCDIR "@CMAKE_CURRENT_BINARY_DIR@")
+set(PNG_PREFIX "@PNG_PREFIX@")
+set(PNGLIB_MAJOR "@PNGLIB_MAJOR@")
+set(PNGLIB_MINOR "@PNGLIB_MINOR@")
+set(PNGLIB_VERSION "@PNGLIB_VERSION@")
+set(ZLIBINCDIR "@ZLIB_INCLUDE_DIR@")
+
+set(PLATFORM_C_FLAGS)
+if(APPLE)
+  set(CMAKE_OSX_ARCHITECTURES "@CMAKE_OSX_ARCHITECTURES@")
+  set(CMAKE_OSX_SYSROOT "@CMAKE_OSX_SYSROOT@")
+  if(CMAKE_OSX_ARCHITECTURES)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -arch ${CMAKE_OSX_ARCHITECTURES})
+  endif()
+  if(CMAKE_OSX_SYSROOT)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT})
+  endif()
+endif()
+
+get_filename_component(INPUTEXT "${INPUT}" EXT)
+get_filename_component(OUTPUTEXT "${OUTPUT}" EXT)
+get_filename_component(INPUTBASE "${INPUT}" NAME_WE)
+get_filename_component(OUTPUTBASE "${OUTPUT}" NAME_WE)
+get_filename_component(INPUTDIR "${INPUT}" PATH)
+get_filename_component(OUTPUTDIR "${OUTPUT}" PATH)
+
+if ("${INPUTEXT}" STREQUAL ".c" AND "${OUTPUTEXT}" STREQUAL ".out")
+  get_filename_component(GENDIR "${OUTPUT}" PATH)
+  file(MAKE_DIRECTORY "${GENDIR}")
+
+  file(REMOVE "${OUTPUT}.tf1" "${OUTPUT}.tf2")
+
+  set(INCLUDES "-I${INCDIR}")
+  if(ZLIBINCDIR)
+    foreach(dir ${ZLIBINCDIR})
+      list(APPEND INCLUDES "-I${dir}")
+    endforeach()
+  endif()
+
+  if(PNG_PREFIX)
+    set(PNG_PREFIX_DEF "-DPNG_PREFIX=${PNG_PREFIX}")
+  endif()
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E"
+                          ${CMAKE_C_FLAGS}
+                          ${PLATFORM_C_FLAGS}
+                          "-I${SRCDIR}"
+                          "-I${BINDIR}"
+                          ${INCLUDES}
+                          "-DPNGLIB_LIBNAME=PNG${PNGLIB_MAJOR}${PNGLIB_MINOR}_0"
+                          "-DPNGLIB_VERSION=${PNGLIB_VERSION}"
+                          "-DSYMBOL_PREFIX=${SYMBOL_PREFIX}"
+                          "-DPNG_NO_USE_READ_MACROS"
+                          "-DPNG_BUILDING_SYMBOL_TABLE"
+                          ${PNG_PREFIX_DEF}
+                          "${INPUT}"
+                  OUTPUT_FILE "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE CPP_FAIL)
+  if(CPP_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf1")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/dfn.awk"
+                          "out=${OUTPUT}.tf2" "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf2")
+  endif()
+
+  file(REMOVE "${OUTPUT}.tf1")
+  file(RENAME "${OUTPUT}.tf2" "${OUTPUT}")
+else()
+  message(FATAL_ERROR "Unsupported conversion: ${INPUTEXT} to ${OUTPUTEXT}")
+endif()

xs/src/png/libpng/scripts/gensrc.cmake.in

@@ -0,0 +1,138 @@
+# gensrc.cmake.in
+# Generate source files with awk, based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+set(BINDIR "@CMAKE_CURRENT_BINARY_DIR@")
+
+set(AWK "@AWK@")
+set(DFA_XTRA "@DFA_XTRA@")
+set(PNG_PREFIX "@PNG_PREFIX@")
+set(PNGLIB_VERSION "@PNGLIB_VERSION@")
+
+if("${OUTPUT}" STREQUAL "scripts/pnglibconf.c")
+  # Generate scripts/pnglibconf.c
+
+  file(REMOVE "${BINDIR}/pnglibconf.tf6" "${BINDIR}/pnglibconf.tf7")
+
+  execute_process(COMMAND "${CMAKE_COMMAND}" -E echo "com ${PNGLIB_VERSION} STANDARD API DEFINITION"
+                  COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                          "out=pnglibconf.tf6" "logunsupported=1" "version=search"
+                          "${SRCDIR}/pngconf.h" "-"
+                          "${SRCDIR}/scripts/pnglibconf.dfa"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf6")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  "out=pnglibconf.tf7" "pnglibconf.tf6"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf7")
+  endif()
+
+  file(REMOVE "pnglibconf.tf6")
+  file(MAKE_DIRECTORY "${BINDIR}/scripts")
+  file(RENAME "pnglibconf.tf7" "${BINDIR}/scripts/pnglibconf.c")
+
+elseif ("${OUTPUT}" STREQUAL "pnglibconf.c")
+  # Generate pnglibconf.c
+
+  file(REMOVE "${BINDIR}/pnglibconf.tf4" "${BINDIR}/pnglibconf.tf5")
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  out=pnglibconf.tf4 version=search
+                  ${SRCDIR}/pngconf.h ${SRCDIR}/scripts/pnglibconf.dfa
+                  ${SRCDIR}/pngusr.dfa ${DFA_XTRA}
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf4")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  out=pnglibconf.tf5 pnglibconf.tf4
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf5")
+  endif()
+
+  file(REMOVE "pnglibconf.tf4")
+  file(MAKE_DIRECTORY "${BINDIR}/scripts")
+  file(RENAME "pnglibconf.tf5" "${BINDIR}/pnglibconf.c")
+
+elseif ("${OUTPUT}" STREQUAL "pnglibconf.h")
+  # Generate pnglibconf.h
+
+  file(REMOVE "${BINDIR}/${OUTPUT}")
+  if(PNG_PREFIX)
+    file(REMOVE "pnglibconf.tf8")
+
+    execute_process(COMMAND "${AWK}" "s==0 && NR>1{print prev}
+                             s==0{prev=\$0}
+                             s==1{print \"#define\", \$1, \"${PNG_PREFIX}\" \$1}
+                             s==2{print \"#define ${PNG_PREFIX}png_\" \$1, \"PNG_\" \$1}
+                             END{print prev}" s=0 pnglibconf.out s=1 "${BINDIR}/scripts/prefix.out"
+                             s=2 "${SRCDIR}/scripts/macro.lst"
+                    OUTPUT_FILE pnglibconf.tf8
+                    RESULT_VARIABLE AWK_FAIL)
+    if(AWK_FAIL)
+      message(FATAL_ERROR "Failed to generate pnglibconf.tf8")
+    endif()
+
+    file(RENAME "pnglibconf.tf8" "${BINDIR}/${OUTPUT}")
+  else()
+    execute_process(COMMAND "${CMAKE_COMMAND}" -E copy "${BINDIR}/pnglibconf.out"
+                                                       "${BINDIR}/${OUTPUT}"
+                    RESULT_VARIABLE COPY_FAIL)
+    if(COPY_FAIL)
+      message(FATAL_ERROR "Failed to create pnglibconf.h")
+    endif()
+  endif()
+
+elseif ("${OUTPUT}" STREQUAL "pngprefix.h")
+  # Generate pngprefix.h
+
+  file(REMOVE "${BINDIR}/${OUTPUT}")
+
+  if(PNG_PREFIX)
+    file(REMOVE "pngprefix.tf1")
+
+    execute_process(COMMAND "${AWK}"
+                            "{print \"#define\", \$1, \"${PNG_PREFIX}\" \$1}"
+                            "${BINDIR}/scripts/intprefix.out"
+                    OUTPUT_FILE "pngprefix.tf1"
+                    RESULT_VARIABLE AWK_FAIL)
+    if(AWK_FAIL)
+      message(FATAL_ERROR "Failed to generate pngprefix.tf1")
+    endif()
+
+    file(RENAME "pngprefix.tf1" "${BINDIR}/${OUTPUT}")
+  else()
+    file(WRITE "${BINDIR}/${OUTPUT}" "/* No libpng symbol prefix configured. */")
+  endif()
+
+elseif("${OUTPUT}" STREQUAL "scripts/pnglibconf.h.prebuilt")
+  # Generate scripts/pnglibconf.h.prebuilt (fails build)
+
+  message(STATUS "Attempting to build scripts/pnglibconf.h.prebuilt")
+  message(STATUS "This is a machine generated file, but if you want to make")
+  message(STATUS "a new one simply build the 'genfiles' target, and copy")
+  message(STATUS "scripts/pnglibconf.out to scripts/pnglibconf.h.prebuilt")
+  message(STATUS "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)")
+  message(FATAL_ERROR "Stopping build")
+
+else()
+  message(FATAL_ERROR "Unsupported output: ${OUTPUT}")
+endif()

xs/src/png/libpng/scripts/intprefix.c

@@ -0,0 +1,22 @@
+
+/* intprefix.c - generate an unprefixed internal symbol list
+ *
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2013-2014 Glenn Randers-Pehrson
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#define PNG_INTERNAL_DATA(type, name, array)\
+        PNG_DFN "@" name "@"
+
+#define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
+        PNG_DFN "@" name "@"
+
+#define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
+        PNG_DFN "@" name "@"
+
+#define PNGPREFIX_H /* self generation */
+#include "../pngpriv.h"

xs/src/png/libpng/scripts/libpng-config-body.in

@@ -0,0 +1,96 @@
+
+usage()
+{
+    cat <<EOF
+Usage: libpng-config [OPTION] ...
+
+Known values for OPTION are:
+
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+
+    exit $1
+}
+
+if test $# -eq 0; then
+    usage 1
+fi
+
+while test $# -gt 0; do
+    case "$1" in
+
+    --prefix)
+        echo ${prefix}
+        ;;
+
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+
+    --help)
+        usage 0
+        ;;
+
+    --ccopts)
+        echo ${ccopts}
+        ;;
+
+    --cppflags)
+        echo ${cppflags}
+        ;;
+
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+
+    --libdir)
+        echo ${libdir}
+        ;;
+
+    --libs)
+        echo ${libs}
+        ;;
+
+    --I_opts)
+        echo ${I_opts}
+        ;;
+
+    --L_opts)
+        echo ${L_opts}
+        ;;
+
+    --R_opts)
+        echo ${R_opts}
+        ;;
+
+    --ldflags)
+        echo ${ldflags} ${L_opts} ${R_opts} ${libs}
+        ;;
+
+    --static)
+        R_opts=""
+        ;;
+
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+
+exit 0

xs/src/png/libpng/scripts/libpng-config-head.in

@@ -0,0 +1,24 @@
+#! /bin/sh
+
+# libpng-config
+# provides configuration info for libpng.
+
+# Copyright (C) 2002 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Modeled after libxml-config.
+
+version=1.6.34
+prefix=""
+libdir=""
+libs=""
+I_opts=""
+L_opts=""
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+

xs/src/png/libpng/scripts/libpng.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng16
+
+Name: libpng
+Description: Loads and saves PNG files
+Version: 1.6.34
+Libs: -L${libdir} -lpng16
+Cflags: -I${includedir}

xs/src/png/libpng/scripts/options.awk

@@ -0,0 +1,898 @@
+#!/bin/awk -f
+# scripts/options.awk - library build configuration control
+#
+# last changed in libpng version 1.6.11 - June 5, 2014
+#
+# Copyright (c) 1998-2014 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# The output of this script is written to the file given by
+# the variable 'out'.  The script is run twice, once with
+# an intermediate output file, 'options.tmp' then again on
+# that file to produce the final output:
+#
+#  awk -f scripts/options.awk out=options.tmp scripts/options.dfa 1>&2
+#  awk -f scripts/options.awk out=options.dfn options.tmp 1>&2
+#
+# Some options may be specified on the command line:
+#
+#  deb=1            Causes debugging to be output
+#  logunsupported=1 Causes all options to be recorded in the output
+#  everything=off   Causes all options to be disabled by default
+#  everything=on    Causes all options to be enabled by default
+#
+# If awk fails on your platform, try nawk instead.
+#
+# These options may also be specified in the original input file (and
+# are copied to the preprocessed file).
+
+BEGIN{
+   out=""                       # intermediate, preprocessed, file
+   pre=-1                       # preprocess (first line)
+   version="libpng version unknown" # version information
+   version_file=""              # where to find the version
+   err=0                        # in-line exit sets this
+   # The following definitions prevent the C preprocessor noticing the lines
+   # that will be in the final output file.  Some C preprocessors tokenise
+   # the lines, for example by inserting spaces around operators, and all
+   # C preprocessors notice lines that start with '#', most remove comments.
+   # The technique adopted here is to make the final output lines into
+   # C strings (enclosed in double quotes), preceded by PNG_DFN.  As a
+   # consequence the output cannot contain a 'raw' double quote - instead put
+   # @' in, this will be replaced by a single " afterward.  See the parser
+   # script dfn.awk for more capabilities (not required here).  Note that if
+   # you need a " in a 'setting' in pnglibconf.dfa it must also be @'!
+   dq="@'"                      # For a single double quote
+   start=" PNG_DFN \""          # Start stuff to output (can't contain a "!)
+   end="\" "                    # End stuff to output
+   subs="@\" "                  # Substitute start (substitute a C macro)
+   sube=" \"@"                  # Substitute end
+   comment=start "/*"           # Comment start
+   cend="*/" end                # Comment end
+   def=start "#define PNG_"     # Arbitrary define
+   sup="_SUPPORTED" end         # end supported option
+   und=comment "#undef PNG_"    # Unsupported option
+   une="_SUPPORTED" cend        # end unsupported option
+   error=start "ERROR:"         # error message, terminate with 'end'
+
+   # Variables
+   deb=0                        # debug - set on command line
+   everything=""                # do not override defaults
+   logunsupported=0             # write unsupported options too
+
+   # Precreate arrays
+   # for each option:
+   option[""] = ""    # list of all options: default enabled/disabled
+   done[""] = 1       # marks option as having been output
+   requires[""] = ""  # requires by option
+   iffs[""] = ""      # if by option
+   enabledby[""] = "" # options that enable it by option
+   sets[""] = ""      # settings set by each option
+   setval[""] = ""    # value to set (indexed: 'option sets[option]')
+   # for each setting:
+   setting[""] = ""   # requires by setting
+   defaults[""] = ""  # used for a defaulted value
+   doneset[""] = 1    # marks setting as having been output
+   r[""] = ""         # Temporary array
+
+   # For decorating the output file
+   protect = ""
+}
+
+# The output file must be specified before any input:
+out == "" {
+   print "out=output.file must be given on the command line"
+   err = 1
+   exit 1
+}
+
+# The very first line indicates whether we are reading pre-processed
+# input or not, this must come *first* because 'PREPROCESSED' needs
+# to be the very first line in the temporary file.
+pre == -1{
+   if ($0 == "PREPROCESSED") {
+      pre = 0
+      next
+   } else {
+      pre = 1
+      print "PREPROCESSED" >out
+      # And fall through to continue processing
+   }
+}
+
+# While pre-processing if version is set to "search" look for a version string
+# in the following file.
+pre && version == "search" && version_file == ""{
+   version_file = FILENAME
+}
+
+pre && version == "search" && version_file != FILENAME{
+   print "version string not found in", version_file
+   err = 1
+   exit 1
+}
+
+pre && version == "search" && $0 ~ /^ \* libpng version/{
+   version = substr($0, 4)
+   print "version =", version >out
+   next
+}
+
+pre && FILENAME == version_file{
+   next
+}
+
+# variable=value
+#   Sets the given variable to the given value (the syntax is fairly
+#   free form, except for deb (you are expected to understand how to
+#   set the debug variable...)
+#
+#   This happens before the check on 'pre' below skips most of the
+#   rest of the actions, so the variable settings happen during
+#   preprocessing but are recorded in the END action too.  This
+#   allows them to be set on the command line too.
+$0 ~ /^[ 	]*version[ 	]*=/{
+   sub(/^[  ]*version[  ]*=[  ]*/, "")
+   version = $0
+   next
+}
+$0 ~ /^[ 	]*everything[ 	=]*off[ 	]*$/{
+   everything = "off"
+   next
+}
+$0 ~ /^[ 	]*everything[ 	=]*on[ 	]*$/{
+   everything = "on"
+   next
+}
+$0 ~ /^[ 	]*logunsupported[ 	=]*0[ 	]*$/{
+   logunsupported = 0
+   next
+}
+$0 ~ /^[ 	]*logunsupported[ 	=]*1[ 	]*$/{
+   logunsupported = 1
+   next
+}
+$1 == "deb" && $2 == "=" && NF == 3{
+   deb = $3
+   next
+}
+
+# Preprocessing - this just copies the input file with lines
+# that need preprocessing (just chunk at present) expanded
+# The bare "pre" instead of "pre != 0" crashes under Sunos awk
+pre && $1 != "chunk"{
+   print >out
+   next
+}
+
+# The first characters of the line determine how it is processed,
+# leading spaces are ignored.  In general tokens that are not
+# keywords are the names of options.  An option 'name' is
+# controlled by the definition of the corresponding macros:
+#
+#   PNG_name_SUPPORTED    The option is turned on
+#   PNG_NO_name
+#   PNG_NO_name_SUPPORTED If the first macro is not defined
+#                         either of these will turn the option off
+#
+# If none of these macros are defined the option is turned on, unless
+# the keyword 'off' is given in a line relating to the option.  The
+# keyword 'on' can also be given, but it will be ignored (since it is
+# the default.)
+#
+# In the syntax below a 'name' is indicated by "NAME", other macro
+# values are indicated by "MACRO", as with "NAME" the leading "PNG_"
+# is omitted, but in this case the "NO_" prefix and the "_SUPPORTED"
+# suffix are never used.
+#
+# Each line is introduced by a keyword - the first non-space characters
+# on the line.  A line starting with a '#' is a comment - it is totally
+# ignored.  Keywords are as follows, a NAME, is simply a macro name
+# without the leading PNG_, PNG_NO_ or the trailing _SUPPORTED.
+
+$1 ~ /^#/ || $0 ~ /^[ 	]*$/{
+   next
+}
+
+# com <comment>
+#   The whole line is placed in the output file as a comment with
+#   the preceding 'com' removed
+$1 == "com"{
+   if (NF > 1) {
+      # sub(/^[ 	]*com[ 	]*/, "")
+      $1 = ""
+      print comment $0, cend >out
+   } else
+      print start end >out
+   next
+}
+
+# version
+#   Inserts a version comment
+$1 == "version" && NF == 1{
+   if (version == "") {
+      print "ERROR: no version string set"
+      err = 1 # prevent END{} running
+      exit 1
+   }
+
+   print comment, version, cend >out
+   next
+}
+
+# file output input protect
+#   Informational: the official name of the input file (without
+#   make generated local directories), the official name of the
+#   output file and, if required, a name to use in a protection
+#   macro for the contents.
+$1 == "file" && NF >= 2{
+   print comment, $2, cend >out
+   print comment, "Machine generated file: DO NOT EDIT", cend >out
+   if (NF >= 3)
+      print comment, "Derived from:", $3, cend >out
+   protect = $4
+   if (protect != "") {
+      print start "#ifndef", protect end >out
+      print start "#define", protect end >out
+   }
+   next
+}
+
+# option NAME ( (requires|enables|if) NAME* | on | off | disabled |
+#                sets SETTING VALUE+ )*
+#     
+#   Declares an option 'NAME' and describes its default setting (disabled)
+#   and its relationship to other options.  The option is disabled
+#   unless *all* the options listed after 'requires' are set and at
+#   least one of the options listed after 'if' is set.  If the
+#   option is set then it turns on all the options listed after 'enables'.
+#
+#   Note that "enables" takes priority over the required/if/disabled/off
+#   setting of the target option.
+#
+#   The definition file may list an option as 'disabled': off by default,
+#   otherwise the option is enabled: on by default.  A later (and it must
+#   be later) entry may turn an option on or off explicitly.
+
+$1 == "option" && NF >= 2{
+   opt = $2
+   sub(/,$/,"",opt)
+   onoff = option[opt]  # records current (and the default is "", enabled)
+   key = ""
+   istart = 3
+   do {
+      if (istart == 1) {     # continuation line
+         val = getline
+
+         if (val != 1) { # error reading it
+            if (val == 0)
+               print "option", opt ": ERROR: missing continuation line"
+            else
+               print "option", opt ": ERROR: error reading continuation line"
+
+            # This is a hard error
+            err = 1 # prevent END{} running
+            exit 1
+         }
+      }
+
+      for (i=istart; i<=NF; ++i) {
+         val=$(i)
+         sub(/,$/,"",val)
+         if (val == "on" || val == "off" || val == "disabled" || val =="enabled") {
+            key = ""
+            if (onoff != val) {
+               # on or off can zap disabled or enabled:
+               if (onoff == "" || (onoff == "disabled" || onoff == "enabled") &&
+                   (val == "on" || val == "off")) {
+                  # It's easy to mis-spell the option when turning it
+                  # on or off, so warn about it here:
+                  if (onoff == "" && (val == "on" || val == "off")) {
+                     print "option", opt ": ERROR: turning unrecognized option", val
+                     # For the moment error out - it is safer
+                     err = 1 # prevent END{} running
+                     exit 1
+                  }
+                  onoff = val
+               } else {
+                  # Print a message, otherwise the error
+                  # below is incomprehensible
+                  print "option", opt ": currently", onoff ": attempt to turn", val
+                  break
+               }
+            }
+         } else if (val == "requires" || val == "if" || val == "enables" || val =="sets") {
+            key = val
+         } else if (key == "requires") {
+            requires[opt] = requires[opt] " " val
+         } else if (key == "if") {
+            iffs[opt] = iffs[opt] " " val
+         } else if (key == "enables") {
+            enabledby[val] = enabledby[val] " " opt
+         } else if (key == "sets") {
+            sets[opt] = sets[opt] " " val
+            key = "setval"
+            set = val
+         } else if (key == "setval") {
+            setval[opt " " set] = setval[opt " " set] " " val
+         } else
+            break # bad line format
+      }
+
+      istart = 1
+   } while (i > NF && $0 ~ /,$/)
+
+   if (i > NF) {
+      # Set the option, defaulting to 'enabled'
+      if (onoff == "") onoff = "enabled"
+      option[opt] = onoff
+      next
+   }
+   # Else fall through to the error handler
+}
+
+# chunk NAME [requires OPT] [enables LIST] [on|off|disabled]
+#   Expands to the 'option' settings appropriate to the reading and
+#   writing of an ancillary PNG chunk 'NAME':
+#
+#   option READ_NAME requires READ_ANCILLARY_CHUNKS [READ_OPT]
+#   option READ_NAME enables NAME LIST
+#   [option READ_NAME off]
+#   option WRITE_NAME requires WRITE_ANCILLARY_CHUNKS [WRITE_OPT]
+#   option WRITE_NAME enables NAME LIST
+#   [option WRITE_NAME off]
+
+pre != 0 && $1 == "chunk" && NF >= 2{
+   # 'chunk' is handled on the first pass by writing appropriate
+   # 'option' lines into the intermediate file.
+   opt = $2
+   sub(/,$/,"",opt)
+   onoff = ""
+   reqread = ""
+   reqwrite = ""
+   enables = ""
+   req = 0
+   istart = 3
+   do {
+      if (istart == 1) {     # continuation line
+         val = getline
+
+         if (val != 1) { # error reading it
+            if (val == 0)
+               print "chunk", opt ": ERROR: missing continuation line"
+            else
+               print "chunk", opt ": ERROR: error reading continuation line"
+
+            # This is a hard error
+            err = 1 # prevent END{} running
+            exit 1
+         }
+      }
+
+      # read the keywords/additional OPTS
+      for (i=istart; i<=NF; ++i) {
+         val = $(i)
+         sub(/,$/,"",val)
+         if (val == "on" || val == "off" || val == "disabled") {
+            if (onoff != val) {
+               if (onoff == "")
+                  onoff = val
+               else
+                  break # on/off conflict
+            }
+            req = 0
+         } else if (val == "requires")
+            req = 1
+         else if (val == "enables")
+            req = 2
+         else if (req == 1){
+            reqread = reqread " READ_" val
+            reqwrite = reqwrite " WRITE_" val
+         } else if (req == 2)
+            enables = enables " " val
+         else
+            break # bad line: handled below
+      }
+
+      istart = 1
+   } while (i > NF && $0 ~ /,$/)
+
+   if (i > NF) {
+      # Output new 'option' lines to the intermediate file (out)
+      print "option READ_" opt, "requires READ_ANCILLARY_CHUNKS" reqread, "enables", opt enables , onoff >out
+      print "option WRITE_" opt, "requires WRITE_ANCILLARY_CHUNKS" reqwrite, "enables", opt enables, onoff >out
+      next
+   }
+   # Else hit the error handler below - bad line format!
+}
+
+# setting MACRO ( requires MACRO* )* [ default VALUE ]
+#   Behaves in a similar way to 'option' without looking for NO_ or
+#   _SUPPORTED; the macro is enabled if it is defined so long as all
+#   the 'requires' macros are also defined.  The definitions may be
+#   empty, an error will be issued if the 'requires' macros are
+#   *not* defined.  If given the 'default' value is used if the
+#   macro is not defined.  The default value will be re-tokenised.
+#   (BTW: this is somewhat restrictive, it mainly exists for the
+#   support of non-standard configurations and numeric parameters,
+#   see the uses in scripts/options.dat
+
+$1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){
+   reqs = ""
+   deflt = ""
+   isdef = 0
+   key = ""
+   for (i=3; i<=NF; ++i)
+      if ($(i) == "requires" || $(i) == "default") {
+         key = $(i)
+         if (key == "default") isdef = 1
+      } else if (key == "requires")
+         reqs = reqs " " $(i)
+      else if (key == "default")
+         deflt = deflt " " $(i)
+      else
+         break # Format error, handled below
+
+   setting[$2] = reqs
+   # NOTE: this overwrites a previous value silently
+   if (isdef && deflt == "")
+      deflt = " " # as a flag to force output
+   defaults[$2] = deflt
+   next
+}
+
+# The order of the dependency lines (option, chunk, setting) is irrelevant
+# - the 'enables', 'requires' and 'if' settings will be used to determine
+# the correct order in the output and the final values in pnglibconf.h are
+# not order dependent.  'requires' and 'if' entries take precedence over
+# 'enables' from other options; if an option requires another option it
+# won't be set regardless of any options that enable it unless the other
+# option is also enabled.
+#
+# Similarly 'enables' trumps a NO_ definition in CFLAGS or pngusr.h
+#
+# For simplicity cycles in the definitions are regarded as errors,
+# even if they are not ambiguous.
+# A given NAME can be specified in as many 'option' lines as required, the
+# definitions are additive.
+
+# For backwards compatibility equivalent macros may be listed thus:
+#
+# = [NO_]NAME MACRO
+#   Makes -DMACRO equivalent to -DPNG_NO_NAME or -DPNG_NAME_SUPPORTED
+#   as appropriate.
+#
+# The definition is injected into the C compiler input when encountered
+# in the second pass (so all these definitions appear *after* the @
+# lines!)
+#
+# 'NAME' is as above, but 'MACRO' is the full text of the equivalent
+# old, deprecated, macro.
+
+$1 == "=" && NF == 3{
+   print "#ifdef PNG_" $3 >out
+   if ($2 ~ /^NO_/)
+      print "#   define PNG_" $2 >out
+   else
+      print "#   define PNG_" $2 "_SUPPORTED" >out
+   print "#endif" >out
+   next
+}
+
+# Lines may be injected into the C compiler input by preceding them
+# with an "@" character.  The line is copied with just the leading
+# @ removed.
+
+$1 ~ /^@/{
+   # sub(/^[ 	]*@/, "")
+   $1 = substr($1, 2)
+   print >out
+   next
+}
+
+# Check for unrecognized lines, because of the preprocessing chunk
+# format errors will be detected on the first pass independent of
+# any other format errors.
+{
+   print "options.awk: bad line (" NR "):", $0
+   err = 1 # prevent END{} running
+   exit 1
+}
+
+# For checking purposes names that start with "ok_" or "fail_" are
+# not output to pnglibconf.h and must be either enabled or disabled
+# respectively for the build to succeed.  This allows interdependencies
+# between options of the form "at least one of" or "at most one of"
+# to be checked.  For example:
+#
+# option FLOATING_POINT enables ok_math
+# option FIXED_POINT enables ok_math
+#   This ensures that at least one of FLOATING_POINT and FIXED_POINT
+#   must be set for the build to succeed.
+#
+# option fail_math requires FLOATING_POINT FIXED_POINT
+#   This means the build will fail if *both* FLOATING_POINT and
+#   FIXED_POINT are set (this is an example; in fact both are allowed.)
+#
+# If all these options were given the build would require exactly one
+# of the names to be enabled.
+
+END{
+   # END{} gets run on an exit (a traditional awk feature)
+   if (err) exit 1
+
+   if (pre) {
+      # Record the final value of the variables
+      print "deb =", deb >out
+      if (everything != "") {
+         print "everything =", everything >out
+      }
+      print "logunsupported =", logunsupported >out
+      exit 0
+   }
+
+   # Do the options first (allowing options to set settings).  The dependency
+   # tree is thus:
+   #
+   #   name     >     name
+   #   name requires  name
+   #   name if        name
+   #   name enabledby name
+   #
+   # First build a list 'tree' by option of all the things on which
+   # it depends.
+   print "" >out
+   print "/* OPTIONS */" >out
+   print comment, "options", cend >out
+   for (opt in enabledby) tree[opt] = 1  # may not be explicit options
+   for (opt in option) if (opt != "") {
+      o = option[opt]
+      # option should always be one of the following values
+      if (o != "on" && o != "off" && o != "disabled" && o != "enabled") {
+         print "internal option error (" o ")"
+         exit 1
+      }
+      tree[opt] = ""   # so unlisted options marked
+   }
+   for (opt in tree) if (opt != "") {
+      if (tree[opt] == 1) {
+         tree[opt] = ""
+         if (option[opt] != "") {
+            print "internal error (1)"
+            exit 1
+         }
+         # Macros only listed in 'enables' remain off unless
+         # one of the enabling macros is on.
+         option[opt] = "disabled"
+      }
+
+      split("", list) # clear 'list'
+      # Now add every requires, iffs or enabledby entry to 'list'
+      # so that we can add a unique list of requirements to tree[i]
+      split(requires[opt] iffs[opt] enabledby[opt], r)
+      for (i in r) list[r[i]] = 1
+      for (i in list) tree[opt] = tree[opt] " " i
+   }
+
+   # print the tree for extreme debugging
+   if (deb > 2) for (i in tree) if (i != "") print i, "depends-on" tree[i]
+
+   # Ok, now check all options marked explicitly 'on' or 'off':
+   #
+   # If an option[opt] is 'on' then turn on all requires[opt]
+   # If an option[opt] is 'off' then turn off all enabledby[opt]
+   #
+   # Error out if we have to turn 'on' to an 'off' option or vice versa.
+   npending = 0
+   for (opt in option) if (opt != "") {
+      if (option[opt] == "on" || option[opt] == "off") {
+         pending[++npending] = opt
+      }
+   }
+
+   err = 0 # set on error
+   while (npending > 0) {
+      opt = pending[npending--]
+      if (option[opt] == "on") {
+         nreqs = split(requires[opt], r)
+         for (j=1; j<=nreqs; ++j) {
+            if (option[r[j]] == "off") {
+               print "option", opt, "turned on, but requirement", r[j], "is turned off"
+               err = 1
+            } else if (option[r[j]] != "on") {
+               option[r[j]] = "on"
+               pending[++npending] = r[j]
+            }
+         }
+      } else {
+         if (option[opt] != "off") {
+            print "internal error (2)"
+            exit 1
+         }
+         nreqs = split(enabledby[opt], r)
+         for (j=1; j<=nreqs; ++j) {
+            if (option[r[j]] == "on") {
+               print "option", opt, "turned off, but enabled by", r[j], "which is turned on"
+               err = 1
+            } else if (option[r[j]] != "off") {
+               option[r[j]] = "off"
+               pending[++npending] = r[j]
+            }
+         }
+      }
+   }
+   if (err) exit 1
+
+   # Sort options:
+   print "PNG_DFN_START_SORT 2" >out
+
+   # option[i] is now the complete list of all the tokens we may
+   # need to output, go through it as above, depth first.
+   finished = 0
+   while (!finished) {
+      finished = 1
+      movement = 0 # done nothing
+      for (i in option) if (!done[i]) {
+         nreqs = split(tree[i], r)
+         if (nreqs > 0) {
+            for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
+               break
+            }
+            if (j<=nreqs) {
+               finished = 0
+               continue  # next option
+            }
+         }
+
+         # All the requirements have been processed, output
+         # this option.  An option is _SUPPORTED if:
+         #
+         # all 'requires' are _SUPPORTED AND
+         # at least one of the 'if' options are _SUPPORTED AND
+         # EITHER:
+         #   The name is _SUPPORTED (on the command line)
+         # OR:
+         #   an 'enabledby' is _SUPPORTED
+         # OR:
+         #   NO_name is not defined AND
+         #   the option is not disabled; an option is disabled if:
+         #    option == off
+         #    option == disabled && everything != on
+         #    option == "" && everything == off
+         if (deb) print "option", i
+         print "" >out
+         print "/* option:", i, option[i] >out
+         print " *   requires:  " requires[i] >out
+         print " *   if:        " iffs[i] >out
+         print " *   enabled-by:" enabledby[i] >out
+         print " *   sets:      " sets[i], "*/" >out
+         print "#undef PNG_on" >out
+         print "#define PNG_on 1" >out
+
+         # requires
+         nreqs = split(requires[i], r)
+         for (j=1; j<=nreqs; ++j) {
+            print "#ifndef PNG_" r[j] "_SUPPORTED" >out
+            print "#   undef PNG_on /*!" r[j] "*/" >out
+            # This error appears in the final output if something
+            # was switched 'on' but the processing above to force
+            # the requires did not work
+            if (option[i] == "on") {
+               print error, i, "requires", r[j] end >out
+            }
+            print "#endif" >out
+         }
+
+         # if
+         have_ifs = 0
+         nreqs = split(iffs[i], r)
+         print "#undef PNG_no_if" >out
+         if (nreqs > 0) {
+            have_ifs = 1
+            print "/* if" iffs[i], "*/" >out
+            print "#define PNG_no_if 1" >out
+            for (j=1; j<=nreqs; ++j) {
+               print "#ifdef PNG_" r[j] "_SUPPORTED" >out
+               print "#   undef PNG_no_if /*" r[j] "*/" >out
+               print "#endif" >out
+            }
+            print "#ifdef PNG_no_if /*missing if*/" >out
+            print "#   undef PNG_on" >out
+            # There is no checking above for this, because we
+            # don't know which 'if' to choose, so whine about
+            # it here:
+            if (option[i] == "on") {
+               print error, i, "needs one of:", iffs[i] end >out
+            }
+            print "#endif" >out
+         }
+
+         print "#ifdef PNG_on /*requires, if*/" >out
+         # enables
+         print "#   undef PNG_not_enabled" >out
+         print "#   define PNG_not_enabled 1" >out
+         print "   /* enabled by" enabledby[i], "*/" >out
+         nreqs = split(enabledby[i], r)
+         for (j=1; j<=nreqs; ++j) {
+            print "#ifdef PNG_" r[j] "_SUPPORTED" >out
+            print "#   undef PNG_not_enabled /*" r[j] "*/" >out
+            # Oops, probably not intended (should be factored
+            # out by the checks above).
+            if (option[i] == "off") {
+               print error, i, "enabled by:", r[j] end >out
+            }
+            print "#endif" >out
+         }
+
+         print "#   ifndef PNG_" i "_SUPPORTED /*!command line*/" >out
+         print "#    ifdef PNG_not_enabled /*!enabled*/" >out
+         # 'have_ifs' here means that everything = "off" still allows an 'if' on
+         # an otherwise enabled option to turn it on; otherwise the 'if'
+         # handling is effectively disabled by 'everything = off'
+         if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off" && !have_ifs) {
+            print "#      undef PNG_on /*default off*/" >out
+         } else {
+            print "#      ifdef PNG_NO_" i >out
+            print "#       undef PNG_on /*turned off*/" >out
+            print "#      endif" >out
+            print "#      ifdef PNG_NO_" i "_SUPPORTED" >out
+            print "#       undef PNG_on /*turned off*/" >out
+            print "#      endif" >out
+         }
+         print "#    endif /*!enabled*/" >out
+         print "#    ifdef PNG_on" >out
+         # The _SUPPORTED macro must be defined so that dependent
+         # options output later work.
+         print "#      define PNG_" i "_SUPPORTED" >out
+         print "#    endif" >out
+         print "#   endif /*!command line*/" >out
+         # If PNG_on is still set the option should be defined in
+         # pnglibconf.h
+         print "#   ifdef PNG_on" >out
+         if (i ~ /^fail_/) {
+            print error, i, "is on: enabled by:" iffs[i] enabledby[i] ", requires" requires[i] end >out
+         } else if (i !~ /^ok_/) {
+            print def i sup >out
+            # Supported option, set required settings
+            nreqs = split(sets[i], r)
+            for (j=1; j<=nreqs; ++j) {
+               print "#    ifdef PNG_set_" r[j] >out
+               # Some other option has already set a value:
+               print error, i, "sets", r[j] ": duplicate setting" end >out
+               print error, "   previous value: " end "PNG_set_" r[j] >out
+               print "#    else" >out
+               # Else set the default: note that this won't accept arbitrary
+               # values, the setval string must be acceptable to all the C
+               # compilers we use.  That means it must be VERY simple; a number,
+               # a name or a string.
+               print "#     define PNG_set_" r[j], setval[i " " r[j]] >out
+               print "#    endif" >out
+            }
+         }
+         print "#   endif /* definition */" >out
+         print "#endif /*requires, if*/" >out
+         if (logunsupported || i ~ /^ok_/) {
+            print "#ifndef  PNG_on" >out
+            if (logunsupported) {
+               print und i une >out
+            }
+            if (i ~ /^ok_/) {
+               print error, i, "not enabled: requires:" requires[i] ", enabled by:" iffs[i] enabledby[i] end >out
+            }
+            print "#endif" >out
+         }
+
+         done[i] = 1
+         ++movement
+      }
+
+      if (!finished && !movement) {
+         print "option: loop or missing option in dependency tree, cannot process:"
+         for (i in option) if (!done[i]) {
+            print "  option", i, "depends on" tree[i], "needs:"
+            nreqs = split(tree[i], r)
+            if (nreqs > 0) for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
+               print "   " r[j]
+            }
+         }
+         exit 1
+      }
+   }
+   print "PNG_DFN_END_SORT" >out
+   print comment, "end of options", cend >out
+
+   # Do the 'setting' values second, the algorithm the standard
+   # tree walk (O(1)) done in an O(2) while/for loop; iterations
+   # settings x depth, outputting the deepest required macros
+   # first.
+   print "" >out
+   print "/* SETTINGS */" >out
+   print comment, "settings", cend >out
+   # Sort (in dfn.awk) on field 2, the setting name
+   print "PNG_DFN_START_SORT 2" >out
+   finished = 0
+   while (!finished) {
+      finished = 1
+      movement = 0 # done nothing
+      for (i in setting) if (!doneset[i]) {
+         nreqs = split(setting[i], r)
+         if (nreqs > 0) {
+            # By default assume the requires values are options, but if there
+            # is no option with that name check for a setting
+            for (j=1; j<=nreqs; ++j) if (option[r[j]] == "" && !doneset[r[j]]) {
+               break
+            }
+            if (j<=nreqs) {
+               finished = 0
+               continue # try a different setting
+            }
+         }
+
+         # All the requirements have been processed, output
+         # this setting.
+         if (deb) print "setting", i
+         deflt = defaults[i]
+         # Remove any spurious trailing spaces
+         sub(/ *$/,"",deflt)
+         # A leading @ means leave it unquoted so the preprocessor
+         # can substitute the build time value
+         if (deflt ~ /^ @/)
+            deflt = " " subs substr(deflt, 3) sube
+         print "" >out
+         print "/* setting: ", i >out
+         print " *   requires:" setting[i] >out
+         print " *   default: ", defaults[i] deflt, "*/" >out
+         for (j=1; j<=nreqs; ++j) {
+            if (option[r[j]] != "")
+               print "#ifndef PNG_" r[j] "_SUPPORTED" >out
+            else
+               print "#ifndef PNG_" r[j] >out
+            print error, i, "requires", r[j] end >out
+            print "# endif" >out
+         }
+         # The precedence is:
+         #
+         #  1) External definition; trumps:
+         #  2) Option 'sets' value; trumps:
+         #  3) Setting 'default'
+         #
+         print "#ifdef PNG_" i >out
+         # PNG_<i> is defined, so substitute the value:
+         print def i, subs "PNG_" i sube end >out
+         print "#else /* use default */" >out
+         print "# ifdef PNG_set_" i >out
+         # Value from an option 'sets' argument
+         print def i, subs "PNG_set_" i sube end >out
+         # This is so that subsequent tests on the setting work:
+         print "#  define PNG_" i, "1" >out
+         if (defaults[i] != "") {
+            print "# else /*default*/" >out
+            print def i deflt end >out
+            print "#  define PNG_" i, "1" >out
+         }
+         print "# endif /* defaults */" >out
+         print "#endif /* setting", i, "*/" >out
+
+         doneset[i] = 1
+         ++movement
+      }
+
+      if (!finished && !movement) {
+         print "setting: loop or missing setting in 'requires', cannot process:"
+         for (i in setting) if (!doneset[i]) {
+            print "  setting", i, "requires" setting[i]
+         }
+         exit 1
+      }
+   }
+   print "PNG_DFN_END_SORT" >out
+   print comment, "end of settings", cend >out
+
+   # Regular end - everything looks ok
+   if (protect != "") {
+      print start "#endif", "/*", protect, "*/" end >out
+   }
+}

xs/src/png/libpng/scripts/pnglibconf.dfa

@@ -0,0 +1,919 @@
+# scripts/pnglibconf.dfa - library build configuration control
+#
+@/*- pnglibconf.dfn intermediate file
+@ *  generated from scripts/pnglibconf.dfa
+@ */
+#
+com pnglibconf.h - library build configuration
+com
+version
+com
+com Copyright (c) 1998-2017 Glenn Randers-Pehrson
+com
+com This code is released under the libpng license.
+com For conditions of distribution and use, see the disclaimer
+com and license in png.h
+com
+
+file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
+
+# This file is preprocessed by scripts/options.awk and the
+# C compiler to generate 'pnglibconf.h' - a list of all the
+# configuration options.  The file lists the various options
+# that can *only* be specified during the libpng build;
+# pnglibconf.h freezes the definitions selected for the specific
+# build.
+#
+# The syntax is detailed in scripts/options.awk; this is a summary
+# only:
+#
+# setting <name> [requires ...] [default]
+#    #define PNG_<name> <value>  /* value comes from current setting */
+# option <name> [requires ...] [if ...] [enables ...] [disabled]
+#    #define PNG_<name>_SUPPORTED if the requirements are met and
+#    enable the other options listed
+# chunk <name> [requires ...] [enables ...] [disabled]
+#    Enable chunk processing for the given ancillary chunk; any
+#    'requires something' expands to READ_something for read and
+#    WRITE_something for write, but the enables list members are
+#    used as given (e.g. enables GAMMA just expands to that on the
+#    correspond READ_name and WRITE_name lines.)
+#
+# "," may be used to separate options on an 'option' line and is ignored; it
+# doesn't change the meaning of the line.  (NOT setting, where "," becomes
+# part of the setting!)  A comma at the end of an option line causes a
+# continuation (the next line is included in the option too.)
+#
+# Note that the 'on' and 'off' keywords, while valid on both option
+# and chunk, should not be used in this file because they force the
+# relevant options on or off.
+
+#----------------------------------------------------------------------
+
+# The following setting, option and chunk values can all be changed
+# while building libpng:
+#
+# setting: change 'setting' lines to fine tune library performance;
+#   changes to the settings don't affect the libpng API functionally
+#
+# option: change 'option' lines to remove or add capabilities from
+#   or to the library; options change the library API
+#
+# chunk: change 'chunk' lines to remove capabilities to process
+#   optional ('ancillary') chunks.  This does not prevent PNG
+#   decoding but does change the libpng API because some chunks
+#   will be ignored.
+#
+# There are three ways of disabling features, in no particular order:
+#
+# 1) Create 'pngusr.h', enter the required private build information
+# detailed below and #define PNG_NO_<option> for each option you
+# don't want in that file in that file.  You can also turn on options
+# using PNG_<option>_SUPPORTED.  When you have finished rerun
+# configure and rebuild pnglibconf.h file with -DPNG_USER_CONFIG:
+#
+#  make clean
+#  CPPFLAGS='-DPNG_USER_CONFIG' ./configure
+#  make pnglibconf.h
+#
+# pngusr.h is only used during the creation of pnglibconf.h, but it
+# is safer to ensure that -DPNG_USER_CONFIG is specified throughout
+# the build by changing the CPPFLAGS passed to the initial ./configure
+#
+# 2) Add definitions of the settings you want to change to
+# CPPFLAGS; for example:
+#
+#   -DPNG_DEFAULT_READ_MACROS=0
+#
+# (This would change the default to *not* use read macros.)  Be
+# very careful to change only settings that don't alter the API
+# because this approach bypasses the private build checking.  You
+# can also change settings from pngpriv.h (read pngpriv.h) safely
+# without API changes.  Do that in the same way.
+#
+# 3) Write a new '.dfa' file (say 'pngusr.dfa') and in this file
+# provide override values for setting entries and turn option or
+# chunk values explicitly 'on' or 'off':
+#
+#    setting FOO default VALUE
+#    option BAR [on|off]
+#
+# Then add this file to the options.awk command line (the *first*
+# one) after this file.  The make macro DFA_XTRA is provided to make
+# this easier (set it like CPPFLAGS prior to running ./configure).
+# Look at the builds below contrib/pngminim for some extreme examples
+# of how this can be used.
+#
+# Don't edit this file unless you are contributing a patch to
+# libpng and need new or modified options/settings.
+#----------------------------------------------------------------------
+
+# The following causes commented out #undef lines to be written to
+# pnglibconf.h; this can be stopped by logunsupported=0 in a later
+# file or on the command line (after pnglibconf.dfa)
+
+logunsupported = 1
+
+# The following allows the output from configure to modify the contents of
+# pnglibconf.h
+
+@#ifdef HAVE_CONFIG_H
+@#  include "config.h"
+@#endif
+
+# PNG_USER_CONFIG has to be defined on the compiler command line
+# to cause pngusr.h to be read while constructing pnglibconf.h
+#
+# If you create a private DLL you need to define the following
+# macros in the file 'pngusr.h' and set -DPNG_USER_CONFIG for
+# compilation (i.e. in CPPFLAGS.)
+# #define PNG_USER_PRIVATEBUILD \
+#     <Describes by whom and why this version of the DLL was built>
+#  e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
+# #define PNG_USER_DLLFNAME_POSTFIX <two-letter postfix that serve to
+#        distinguish your DLL from those of the official release. These
+#        correspond to the trailing letters that come after the version
+#        number and must match your private DLL name>
+#  e.g. // private DLL "libpng13gx.dll"
+#       #define PNG_USER_DLLFNAME_POSTFIX "gx"
+#
+# The following macros are also at your disposal if you want to complete the
+# DLL VERSIONINFO structure.
+# - PNG_USER_VERSIONINFO_COMMENTS
+# - PNG_USER_VERSIONINFO_COMPANYNAME
+# - PNG_USER_VERSIONINFO_LEGALTRADEMARKS
+
+# It is necessary to include configures definitions here so that AC_DEFINE
+# in configure.ac works in a comprehensible way
+@#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+@#  include "config.h"
+@#endif
+
+@#ifdef PNG_USER_CONFIG
+@#  include "pngusr.h"
+@#endif
+
+# This is a special fixup for the Watcom C compiler on Windows, which has
+# multiple procedure call standards.  Unless PNG_API_RULE is set explicitly
+# (i.e. if it is not defined at this point) it will be forced to '2' here when
+# using Watcom.  This indicates to the other header files that Watcom behaviour
+# is required where appropriate.
+
+@#ifdef __WATCOMC__
+@#  ifndef PNG_API_RULE
+@#     define PNG_API_RULE 2 /* Use Watcom calling conventions */
+@#  endif
+@#endif
+
+# IN DEVELOPMENT
+# These are currently experimental features; define them if you want (NOTE:
+# experimental options must be disabled before they are defined in this file!)
+
+# NONE
+
+# Note that PNG_USER_CONFIG only has an effect when building
+# pnglibconf.h
+
+setting USER_CONFIG
+setting USER_PRIVATEBUILD
+setting USER_DLLFNAME_POSTFIX
+setting USER_VERSIONINFO_COMMENTS
+setting USER_VERSIONINFO_COMPANYNAME
+setting USER_VERSIONINFO_LEGALTRADEMARKS
+
+# Record the 'API rule' used to select calling conventions on
+# those systems that support such things (see all the comments in
+# pngconf.h)
+# Changing this setting has a fundamental affect on the PNG ABI,
+# do not release shared libraries with this changed.
+
+setting API_RULE default 0
+
+# This allows a prefix to be added to the front of every API function name (and
+# therefore every symbol) by redefining all the function names with the prefix
+# at the end of pnglibconf.h.  It also turns on similar internal symbol renaming
+# by causing a similar build-time only file, pngprefix.h, to be generated.
+
+setting PREFIX
+
+# Implementation specific control of the optimizations, enabled by those
+# hardware or software options that need it (typically when run-time choices
+# must be made by the user)
+option SET_OPTION disabled
+
+# These options are specific to the ARM NEON hardware optimizations.  At present
+# these optimizations depend on GCC specific pre-processing of an assembler (.S)
+# file so they probably won't work with other compilers.
+#
+# ARM_NEON_OPT: unset: check at compile time (__ARM_NEON__ must be defined by
+#                      the compiler, typically as a result of specifying
+#                      CC="gcc -mfpu=neon".)
+#                   0: disable (even if the CPU has a NEON FPU.)
+#                   1: check at run time (via ARM_NEON_{API,CHECK})
+#                   2: switch on unconditionally (inadvisable - instead pass
+#                      -mfpu=neon to GCC in CC)
+#           When building libpng avoid using any setting other than '0'; '1' is
+#           set automatically when either 'API' or 'CHECK' are configured in,
+#           '2' should not be necessary as -mfpu=neon will achieve the same
+#           effect as well as applying NEON optimizations to the rest of the
+#           libpng code.
+#           NOTE: any setting other than '0' requires ALIGNED_MEMORY
+# ARM_NEON_API:   (PNG_ARM_NEON == 1) allow the optimization to be switched on
+#                 with png_set_option
+# ARM_NEON_CHECK: (PNG_ARM_NEON == 1) compile a run-time check to see if Neon
+#                 extensions are supported. This is poorly supported and
+#                 deprecated - use the png_set_option API.
+setting ARM_NEON_OPT
+option ARM_NEON_API disabled requires ALIGNED_MEMORY enables SET_OPTION,
+   sets ARM_NEON_OPT 1
+option ARM_NEON_CHECK disabled requires ALIGNED_MEMORY,
+   sets ARM_NEON_OPT 1
+
+# These options are specific to the PowerPC VSX hardware optimizations.
+#
+# POWERPC_VSX_OPT: unset: check at compile time (__PPC64__,__ALTIVEC__,__VSX__
+#                      must be defined by the compiler, typically as a result
+#                      of specifying
+#                      "-mvsx -maltivec" compiler flags)
+#                   0: disable (even if the CPU supports VSX.)
+#                   1: check at run time (via POWERPC_VSX_{API,CHECK})
+#                   2: switch on unconditionally (inadvisable - instead pass
+#                      -mvsx -maltivec to compiler options)
+#           When building libpng avoid using any setting other than '0'; '1' is
+#           set automatically when either 'API' or 'CHECK' are configured in,
+#           '2' should not be necessary as "-mvsx -maltivec" will achieve the same
+#           effect as well as applying VSX optimizations to the rest of the
+#           libpng code.
+# POWERPC_VSX_API:   (PNG_POWERPC_VSX == 1) allow the optimization to be switched on
+#                 with png_set_option
+# POWERPC_VSX_CHECK: (PNG_POWERPC_VSX == 1) compile a run-time check to see if VSX
+#                 extensions are supported. This is supported not for all OSes
+#                 (see contrib/powerpc/README)
+setting POWERPC_VSX_OPT
+option POWERPC_VSX_API disabled enables SET_OPTION,
+  sets POWERPC_VSX_OPT 1
+option POWERPC_VSX_CHECK disabled,
+  sets POWERPC_VSX_OPT 1
+
+
+# These settings configure the default compression level (0-9) and 'strategy';
+# strategy is as defined by the implementors of zlib. It describes the input
+# data and modifies the zlib parameters in an attempt to optimize the balance
+# between search and huffman encoding in the zlib algorithms.  The defaults are
+# the zlib.h defaults - the apparently recursive definition does not arise
+# because the name of the setting is prefixed by PNG_
+#
+# The TEXT values are the defaults when writing compressed text (all forms)
+
+# Include the zlib header so that the defaults below are known
+@#  include <zlib.h>
+
+# The '@' here means to substitute the value when pnglibconf.h is built
+setting Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
+# TODO: why aren't these Z_RLE; zlib.h says that Z_RLE, specifically, is
+# appropriate for PNG images, maybe it doesn't exist in all versions?
+setting Z_DEFAULT_STRATEGY default @Z_FILTERED
+setting Z_DEFAULT_NOFILTER_STRATEGY default @Z_DEFAULT_STRATEGY
+setting ZLIB_VERNUM default @ZLIB_VERNUM
+
+# Linkage of:
+#
+#  API:      libpng API functions
+#  CALLBACK: internal non-file-local callbacks
+#  FUNCTION: internal non-file-local functions
+#  DATA:     internal non-file-local (const) data
+setting LINKAGE_API default extern
+setting LINKAGE_CALLBACK default extern
+setting LINKAGE_FUNCTION default extern
+setting LINKAGE_DATA default extern
+
+setting TEXT_Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
+setting TEXT_Z_DEFAULT_STRATEGY default @Z_DEFAULT_STRATEGY
+
+# Default to using the read macros
+
+setting DEFAULT_READ_MACROS default 1
+
+# The alternative is to call functions to read PNG values, if
+# the functions are turned *off* the read macros must always
+# be enabled, so turning this off will actually force the
+# USE_READ_MACROS option on (see pngconf.h)
+
+option READ_INT_FUNCTIONS requires READ
+
+# The same for write  but these can only be switched off if no writing
+# is required at all - hence the use of a 'disabled', not a 'requires'.
+# If these are needed, they are enabled in the 'WRITE options' section
+# below.
+
+option WRITE_INT_FUNCTIONS disabled
+
+# Error controls
+#
+# WARNINGS: normally on, if off no warnings are generated
+# ERROR_TEXT: normally on, if off errors happen but there is no message
+# ERROR_NUMBERS: unimplemented feature, therefore disabled
+# BENIGN_ERRORS: support for just issuing warnings for recoverable errors
+#
+# BENIGN_READ_ERRORS:
+#     By default recoverable errors on read should just generate warnings,
+#     generally safe but PNG files that don't conform to the specification will
+#     be accepted if a meaningful result can be produced.
+#
+# BENIGN_WRITE_ERRORS:
+#     By default recoverable errors on write should just generate warnings,
+#     not generally safe because this allows the application to write invalid
+#     PNG files.  Applications should enable this themselves; it's useful
+#     because it means that a failure to write an ancillary chunk can often be
+#     ignored.
+
+option WARNINGS
+option ERROR_TEXT
+option ERROR_NUMBERS disabled
+
+option BENIGN_ERRORS
+option BENIGN_WRITE_ERRORS requires BENIGN_ERRORS disabled
+option BENIGN_READ_ERRORS requires BENIGN_ERRORS
+
+
+# Generic options - affect both read and write.
+
+option MNG_FEATURES
+
+# Arithmetic options, the first is the big switch that chooses between internal
+# floating and fixed point arithmetic implementations - it does not affect any
+# APIs.  The second two (the _POINT settings) switch off individual APIs.
+#
+# Prior to libpng 1.6.8 one of the API (_POINT) variants had to be selected.  At
+# 1.6.8 this restriction has been removed; the simplified API can be used
+# without enabling any of the low level fixed/floating APIs.
+
+option FLOATING_ARITHMETIC
+option FLOATING_POINT
+option FIXED_POINT
+
+# This protects us against compilers that run on a windowing system
+# and thus don't have or would rather us not use the stdio types:
+# stdin, stdout, and stderr.  The only one currently used is stderr
+# in png_error() and png_warning().  #defining PNG_NO_CONSOLE_IO will
+# prevent these from being compiled and used. #defining PNG_NO_STDIO
+# will also prevent these, plus will prevent the entire set of stdio
+# macros and functions (FILE *, printf, etc.) from being compiled and used,
+# unless (PNG_DEBUG > 0) has been #defined.
+
+option STDIO
+option CONSOLE_IO requires STDIO
+
+# Note: prior to 1.5.0 this option could not be disabled if STDIO
+# was enabled.  Prior to 1.5.3 this option required STDIO
+
+option TIME_RFC1123
+
+# PNG_SETJMP_NOT_SUPPORTED is an old equivalent for NO_SETJMP
+
+option SETJMP
+= NO_SETJMP SETJMP_NOT_SUPPORTED
+
+# If this is disabled it is not possible for apps to get the
+# values from the 'info' structure, this effectively removes
+# quite a lot of the READ API.
+
+option EASY_ACCESS
+
+# Added at libpng-1.2.0
+
+option USER_MEM
+
+# Added at libpng-1.4.0
+
+option IO_STATE
+
+# Libpng limits: limit the size of images and data on read.
+#
+# If this option is disabled all the limit checking code will be disabled:
+
+option USER_LIMITS requires READ
+
+# The default settings given below for the limits mean that libpng will
+# limit the size of images or the size of data in ancillary chunks to less
+# than the specification or implementation limits. Settings have the
+# following interpretations:
+#
+# USER_WIDTH_MAX: maximum width of an image that will be read
+# USER_HEIGHT_MAX: maximum height
+# USER_CHUNK_MALLOC_MAX: maximum in-memory (decompressed) size of a single chunk
+# USER_CHUNK_CACHE_MAX: maximum number of chunks to be cached
+#
+# Only chunks that are variable in number are counted towards the
+
+# Use 0x7fffffff for unlimited
+setting USER_WIDTH_MAX default        1000000
+setting USER_HEIGHT_MAX default       1000000
+
+# Use 0 for unlimited
+setting USER_CHUNK_CACHE_MAX default     1000
+setting USER_CHUNK_MALLOC_MAX default 8000000
+
+# If this option is enabled APIs to set the above limits at run time are added;
+# without this the hardwired (compile time) limits will be used.
+option SET_USER_LIMITS requires USER_LIMITS
+
+# All of the following options relate to code capabilities for
+# processing image data before creating a PNG or after reading one.
+# You can remove these capabilities safely and still be PNG
+# conformant, however the library that results is still non-standard.
+# See the comments above about how to change options and settings.
+
+# READ options
+#
+# WARNING: in libpng 1.5 maintained configuration compatibility with earlier
+# versions.  In some cases turning off an option turned off other options, in
+# others it was ineffective unless dependent options were also turned off.
+# Libpng 1.6 changes this: in general if you turn off an option that affects
+# APIs it stays off and simply disables APIs that depend on it.
+#
+# As a result if you simply port the libpng 1.5 configuration to libpng 1.6 you
+# will probably see build failures due to missing APIs.  Fixing these failures
+# requires some, perhaps considerable, knowledge of what your libpng using
+# applications are doing, fortunately there is no great reason for you to move
+# to libpng 1.6; the new interfaces in 1.6 will take several years to become
+# popular.
+
+option READ enables READ_INTERLACING SET_OPTION
+
+# Disabling READ_16BIT does not disable reading 16-bit PNG files, but it
+# forces them to be chopped down to 8-bit, and disables any 16-bit
+# processing after that has happened.  You need to be sure to enable
+# READ_SCALE_16_TO_8 or READ_STRIP_16_TO_8 when you disable READ_16BIT for
+# this to work properly.  You should disable the other option if you need to
+# ensure a particular conversion (otherwise the app can chose.)
+
+option READ_16BIT requires READ enables 16BIT
+
+option READ_QUANTIZE requires READ
+
+option READ_TRANSFORMS requires READ
+= NO_READ_TRANSFORMS READ_TRANSFORMS_NOT_SUPPORTED
+
+# Read gamma handling.  Gamma processing is a core part of libpng and many of
+# the capabilities are dependent on libpng performing gamma correction.
+#
+# In libpng 1.6 disabling gamma processing (setting PNG_NO_READ_GAMMA)
+# consistently disables those parts of the API that depend on it.  Prior to
+# 1.6.0 this was not true; the results were unpredictable and varied between
+# releases.
+#
+# If you disable gamma processing and your program no longer compiles you need
+# to ask whether you really need the APIs that are missing.  If you do then you
+# almost certainly need the gamma processing.
+#
+# If you handle gamma issues outside libpng then you do not need the libpng
+# gamma processing; and it is an enormous waste of space.  You just need to
+# remove the use of libpng APIs that depend on it.
+option READ_GAMMA requires READ_TRANSFORMS, READ_gAMA, READ_sRGB
+
+option READ_ALPHA_MODE requires READ_TRANSFORMS, READ_GAMMA
+option READ_BACKGROUND requires READ_TRANSFORMS, READ_STRIP_ALPHA, READ_GAMMA
+option READ_BGR requires READ_TRANSFORMS
+option READ_EXPAND_16 requires READ_TRANSFORMS, READ_16BIT, READ_EXPAND
+option READ_EXPAND requires READ_TRANSFORMS
+option READ_FILLER requires READ_TRANSFORMS
+option READ_GRAY_TO_RGB requires READ_TRANSFORMS
+option READ_INVERT_ALPHA requires READ_TRANSFORMS
+option READ_INVERT requires READ_TRANSFORMS
+option READ_PACK requires READ_TRANSFORMS
+option READ_PACKSWAP requires READ_TRANSFORMS
+option READ_RGB_TO_GRAY requires READ_TRANSFORMS, READ_GAMMA enables COLORSPACE
+option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
+option READ_SHIFT requires READ_TRANSFORMS
+option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
+option READ_STRIP_ALPHA requires READ_TRANSFORMS
+option READ_SWAP_ALPHA requires READ_TRANSFORMS
+option READ_SWAP requires READ_TRANSFORMS, READ_16BIT
+option READ_USER_TRANSFORM requires READ_TRANSFORMS
+
+option PROGRESSIVE_READ requires READ
+option SEQUENTIAL_READ requires READ
+
+# You can define PNG_NO_PROGRESSIVE_READ if you don't do progressive reading.
+# This is not talking about interlacing capability!  You'll still have
+# interlacing unless you turn off the following which is required
+# for PNG-compliant decoders.  (In other words, do not do this - in
+# fact it can't be disabled from the command line!)
+#option READ_INTERLACING requires READ
+
+option READ_COMPOSITE_NODIV requires READ
+= NO_READ_COMPOSITE_NODIV NO_READ_COMPOSITED_NODIV
+
+# Inch conversions
+
+option INCH_CONVERSIONS
+= INCH_CONVERSIONS INCH_CONVERSIONS
+
+# API to build a grayscale palette
+# NOTE: this is not used internally by libpng at present.
+
+option BUILD_GRAYSCALE_PALETTE
+
+# WRITE options
+
+option WRITE enables WRITE_INT_FUNCTIONS
+
+# Disabling WRITE_16BIT prevents 16-bit PNG files from being
+# generated.
+option WRITE_16BIT requires WRITE enables 16BIT
+
+option WRITE_TRANSFORMS requires WRITE
+= NO_WRITE_TRANSFORMS WRITE_TRANSFORMS_NOT_SUPPORTED
+
+option WRITE_SHIFT requires WRITE_TRANSFORMS
+option WRITE_PACK requires WRITE_TRANSFORMS
+option WRITE_BGR requires WRITE_TRANSFORMS
+option WRITE_SWAP requires WRITE_TRANSFORMS, WRITE_16BIT
+option WRITE_PACKSWAP requires WRITE_TRANSFORMS
+option WRITE_INVERT requires WRITE_TRANSFORMS
+option WRITE_FILLER requires WRITE_TRANSFORMS
+option WRITE_SWAP_ALPHA requires WRITE_TRANSFORMS
+option WRITE_INVERT_ALPHA requires WRITE_TRANSFORMS
+option WRITE_USER_TRANSFORM requires WRITE_TRANSFORMS
+
+# This is not required for PNG-compliant encoders, but can cause
+# trouble if left undefined
+
+option WRITE_INTERLACING requires WRITE
+
+# Deprecated, will be removed.
+option WRITE_WEIGHTED_FILTER requires WRITE
+
+option WRITE_FLUSH requires WRITE
+
+# Note: these can be turned off explicitly if not required by the
+# apps implementing the user transforms
+option USER_TRANSFORM_PTR if READ_USER_TRANSFORM, WRITE_USER_TRANSFORM
+option USER_TRANSFORM_INFO if READ_USER_TRANSFORM, WRITE_USER_TRANSFORM
+
+# This enables API to set compression parameters for compressing
+# non-IDAT chunks (zTXt, iTXt, iCCP, and unknown chunks).  This feature
+# was added at libpng-1.5.3.
+option WRITE_CUSTOMIZE_ZTXT_COMPRESSION requires WRITE
+option WRITE_CUSTOMIZE_COMPRESSION requires WRITE
+
+# Any chunks you are not interested in, you can undef here.  The
+# ones that allocate memory may be especially important (hIST,
+# tEXt, zTXt, tRNS, pCAL).  Others will just save time and make png_info
+# a bit smaller.
+
+# The size of the png_text structure changed in libpng-1.0.6 when
+# iTXt support was added.  iTXt support was turned off by default through
+# libpng-1.2.x, to support old apps that malloc the png_text structure
+# instead of calling png_set_text() and letting libpng malloc it.  It
+# was turned on by default in libpng-1.4.0.
+
+option READ_ANCILLARY_CHUNKS requires READ
+# PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated.
+= NO_READ_ANCILLARY_CHUNKS READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+
+option WRITE_ANCILLARY_CHUNKS requires WRITE
+# PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED is deprecated.
+= NO_WRITE_ANCILLARY_CHUNKS WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+
+# These options disable *all* the text chunks if turned off
+
+option TEXT disabled
+option READ_TEXT requires READ_ANCILLARY_CHUNKS enables TEXT
+option WRITE_TEXT requires WRITE_ANCILLARY_CHUNKS enables TEXT
+
+# Moved to pnglibconf.h at libpng-1.5.0
+# Feature support: in 1.4 this was in pngconf.h, but the following
+# features have no affect on the libpng API.  Add library
+# only features to the end of this list.  Add features that
+# affect the API above.  (Note: the list of chunks follows
+# the library-only settings.)
+#
+# BUILD TIME ONLY OPTIONS
+#   These options do not affect the API but rather alter how the
+#   API is implemented, they get recorded in pnglibconf.h, but
+#   can't be changed by the application.
+
+# Colorspace support (enabled as required); just the support for colorant
+# information.  Gamma support, likewise, is just support for the gamma
+# information, READ_GAMMA is required for gamma transformations (so it
+# is possible to read PNG gamma without enabling all the libpng transform
+# code - do this for applications that do their own gamma processing)
+#
+# As of 1.6.0 COLORSPACE is only useful if the application processes the
+# information; this is because the library does not do any colorspace
+# processing, it just validates the data in the PNG file.
+
+option GAMMA disabled
+option COLORSPACE enables GAMMA disabled
+
+# When an ICC profile is read, or png_set, it will be checked for a match
+# against known sRGB profiles if the sRGB handling is enabled.  The
+# PNG_sRGB_PROFILE_CHECKS setting controls how much work is done during the
+# check:
+#
+# -1: Don't do any sRGB profile checking.
+#
+#  0: Just validate the profile MD5 signature if present, otherwise use
+#     the checks in option 1.
+#
+#  1: Additionally check the length, intent and adler32 checksum of the
+#     actual data.   If enabled this will reject known profiles that have
+#     had the rendering intent in the header changed as well as other edits
+#     done without updating the checksum.  See the discussion below.
+#
+#  2: Additionally checksum all the data using the ethernet CRC32 algorithm.
+#     This makes it more difficult to fake profiles and makes it less likely
+#     to get a false positive on profiles with no signature, but is probably
+#     just a waste of time since all currently approved ICC sRGB profiles have
+#     a secure MD5 signature.
+#
+# The rendering intent.  An ICC profile stores an intended rendering intent,
+# but does not include the value in the signature.  The intent is documented
+# as the intent that should be used when combining two profiles.  The sRGB
+# profile is intended, however, to be used with any of the four defined intents.
+# For this reason the sRGB chunk includes an 'intent' to be used when displaying
+# the image (intent is really a property of the image not the profile.)
+#
+# Unfortunately the iCCP chunk does not.  It may therefore be that some
+# applications modify the intent in profiles (including sRGB profiles) to work
+# round this problem.  Selecting an option other than option '0' will cause such
+# modified profiles to be rejected.
+#
+# Security.  The use of Adler32 and CRC32 checksums does not help significantly
+# with any security issues.  It is relatively easy to produce arbitrary profiles
+# with the required checksums on current computer systems.  Nevertheless
+# security does not seem to be an issue because the only consequence of a false
+# positive is a false assertion that the profile is an sRGB profile.  This might
+# be used to hide data from libpng using applications, but it doesn't seem
+# possible to damage them.
+
+setting sRGB_PROFILE_CHECKS default 2
+
+# Artificially align memory - the code typically aligns to 8 byte
+# boundaries if this is switched on, it's a small waste of space
+# but can help (in theory) on some architectures.  Only affects
+# internal structures.  Added at libpng 1.4.0
+
+option ALIGNED_MEMORY
+
+# Buggy compilers (e.g., gcc 2.7.2.2) need PNG_NO_POINTER_INDEXING
+# See png[wr]util.c, normally this should always be *on*
+
+option POINTER_INDEXING
+
+# Other defines for things like memory and the like can go here.
+
+# BUILD TIME SETTINGS
+# Like build time options these do not affect the API, but they
+# may be useful to applications because they record details of
+# how the API will behave particularly with regard to overall
+# accuracy.
+
+# This controls how fine the quantizing gets.  As this allocates
+# a largish chunk of memory (32K), those who are not as concerned
+# with quantizing quality can decrease some or all of these.
+
+setting QUANTIZE_RED_BITS default 5
+setting QUANTIZE_GREEN_BITS default 5
+setting QUANTIZE_BLUE_BITS default 5
+
+# This controls how fine the gamma correction becomes when you
+# are only interested in 8 bits anyway.  Increasing this value
+# results in more memory being used, and more pow() functions
+# being called to fill in the gamma tables.  Don't set this value
+# less than 8, and even that may not work (I haven't tested it).
+
+setting MAX_GAMMA_8 default 11
+
+# This controls how much a difference in gamma we can tolerate before
+# we actually start doing gamma conversion, it's a fixed point value,
+# so the default below is 0.05, meaning libpng ignores corrections in
+# the range 0.95 to 1.05
+
+setting GAMMA_THRESHOLD_FIXED default 5000
+
+# Precision to use when converting a floating point value to a PNG
+# extension format string in an sCAL chunk (only relevant if the
+# floating point API is enabled)
+
+setting sCAL_PRECISION default 5
+
+# This is the size of the compression buffer, and thus the size of
+# an IDAT chunk.  Make this whatever size you feel is best for your
+# machine.  One of these will be allocated per png_struct.  When this
+# is full, it writes the data to the disk, and does some other
+# calculations.  Making this an extremely small size may slow
+# the library down, but you may want to experiment to determine
+# where it becomes significant, if you are concerned with memory
+# usage.  Note that zlib allocates at least 32Kb also.  For readers,
+# this describes the size of the buffer available to read the data in.
+# Unless this gets smaller than the size of a row (compressed),
+# it should not make much difference how big this is.
+
+setting ZBUF_SIZE default 8192
+
+# This is the size of the decompression buffer used when counting or checking
+# the decompressed size of an LZ stream from a compressed ancillary chunk; the
+# decompressed data is never used so a different size may be optimal.  This size
+# was determined using contrib/libtests/timepng.c with compressed zTXt data
+# around 11MByte in size.  Slight speed improvements (up to about 14% in
+# timepng) can be achieved by very large increases (to 32kbyte) on regular data,
+# but highly compressible data shows only around 2% improvement.   The size is
+# chosen to minimize the effects of DoS attacks based on using very large
+# amounts of highly compressible data.
+
+setting INFLATE_BUF_SIZE default 1024
+
+# This is the maximum amount of IDAT data that the sequential reader will
+# process at one time.  The setting does not affect the size of IDAT chunks
+# read, just the amount read at once.  Neither does it affect the progressive
+# reader, which processes just the amount of data the application gives it.
+# The sequential reader is currently unable to process more than one IDAT at
+# once - it has to read and process each one in turn.  There is no point setting
+# this to a value larger than the IDAT chunks typically encountered (it would
+# just waste memory) but there may be some point in reducing it below the value
+# of ZBUF_SIZE (the size of IDAT chunks written by libpng.)
+
+setting IDAT_READ_SIZE default PNG_ZBUF_SIZE
+
+# Ancillary chunks
+chunk bKGD
+chunk cHRM enables COLORSPACE
+chunk eXIf
+chunk gAMA enables GAMMA
+chunk hIST
+chunk iCCP enables COLORSPACE, GAMMA
+chunk iTXt enables TEXT
+chunk oFFs
+chunk pCAL
+chunk pHYs
+chunk sBIT
+chunk sCAL
+chunk sPLT
+chunk sRGB enables COLORSPACE, GAMMA, SET_OPTION
+chunk tEXt requires TEXT
+chunk tIME
+chunk tRNS
+chunk zTXt enables TEXT
+
+# This only affects support of the optional PLTE chunk in RGB and RGBA
+# images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
+# of the regular chunk reading too.
+
+option READ_OPT_PLTE requires READ_ANCILLARY_CHUNKS
+
+# Unknown chunk handling
+#
+# 'UNKNOWN_CHUNKS' is a global option to disable all unknown chunk handling on
+# read or write; everything else below requires it (directly or indirectly).
+option UNKNOWN_CHUNKS
+
+# There are three main options to control the ability to read and write unknown
+# chunks.  If either read option is turned on then unknown chunks will be read,
+# otherwise they are skipped.  If the write option is turned on unknown chunks
+# set by png_set_unknown_chunks will be written otherwise it is an error to call
+# that API on a write struct.
+option WRITE_UNKNOWN_CHUNKS requires WRITE requires UNKNOWN_CHUNKS
+option WRITE_UNKNOWN_CHUNKS enables STORE_UNKNOWN_CHUNKS
+
+# The first way to read user chunks is to have libpng save them for a later call
+# to png_get_unknown_chunks, the application must call
+# png_set_keep_unknown_chunks to cause this to actually happen (see png.h)
+option SAVE_UNKNOWN_CHUNKS requires READ requires SET_UNKNOWN_CHUNKS
+option SAVE_UNKNOWN_CHUNKS enables READ_UNKNOWN_CHUNKS, STORE_UNKNOWN_CHUNKS
+
+# The second approach is to use an application provided callback to process the
+# chunks, the callback can either handle the chunk entirely itself or request
+# that libpng store the chunk for later retrieval via png_get_unknown_chunks.
+#
+# NOTE: If STORE_UNKNOWN_CHUNKS is not enabled (which is the default if
+# both SAVE_UNKNOWN_CHUNKS and WRITE_UNKNOWN_CHUNKS are disabled) then a
+# 0 result from the callback will be ignored because no support for saving
+# unknown chunks has been compiled in.  The normal symptom is that your app
+# fails to compile because png_get_unknown_chunks is no longer defined in png.h.
+# If you encounter this issue simply enable STORE_UNKNOWN_CHUNKS in your build.
+#
+# Note that there is no 'WRITE_USER_CHUNKS' so the USER_CHUNKS option is always
+# the same as READ_USER_CHUNKS at present
+option READ_USER_CHUNKS requires READ, UNKNOWN_CHUNKS
+option READ_USER_CHUNKS enables READ_UNKNOWN_CHUNKS, USER_CHUNKS
+
+# Two further options are provided to allow detailed control of the handling.
+# The first enables png_set_keep_unknown_chunks; this allows the default to be
+# changed from discarding unknown chunks and allows per-chunk control.  This is
+# required to use the SAVE_UNKNOWN_CHUNKS option.  If enabled this option also
+# applies to write (see png.h), otherwise the write API simply writes all the
+# chunks it is given.
+#
+# The second option extends the unknown handling to allow known chunks to be
+# handled as though they were unknown.  This option doesn't change any APIs, it
+# merely turns on the code to check known as well as unknown chunks.
+#
+# This option no longer affects the write code.  It can be safely disabled and
+# will prevent applications stopping libpng reading known chunks.
+option SET_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS
+option HANDLE_AS_UNKNOWN requires SET_UNKNOWN_CHUNKS
+
+# The following options are derived from the above and should not be turned on
+# explicitly.
+option READ_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS disabled
+option STORE_UNKNOWN_CHUNKS requires UNKNOWN_CHUNKS disabled
+
+option CONVERT_tIME requires WRITE_ANCILLARY_CHUNKS
+# The "tm" structure is not supported on WindowsCE
+
+@#ifdef _WIN32_WCE
+@#   define PNG_NO_CONVERT_tIME
+@#endif
+
+option WRITE_FILTER requires WRITE
+
+option SAVE_INT_32 disabled
+# png_save_int_32 is required internally for writing the ancillary chunks oFFs
+# and pCAL and for both reading and writing iCCP (for the generation/checking of
+# the corresponding cHRM/gAMA chunks) if full ICC is supported.
+
+# added at libpng-1.5.4
+
+option WRITE_OPTIMIZE_CMF requires WRITE
+
+option READ_COMPRESSED_TEXT disabled
+option READ_iCCP enables READ_COMPRESSED_TEXT
+option READ_iTXt enables READ_COMPRESSED_TEXT
+option READ_zTXt enables READ_COMPRESSED_TEXT
+
+option WRITE_oFFs enables SAVE_INT_32
+option WRITE_pCAL enables SAVE_INT_32
+option WRITE_cHRM enables SAVE_INT_32
+
+option WRITE_COMPRESSED_TEXT disabled
+option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
+option WRITE_iTXt enables WRITE_COMPRESSED_TEXT
+option WRITE_zTXt enables WRITE_COMPRESSED_TEXT
+
+# Turn this off to disable png_read_png() and png_write_png() and
+# leave the row_pointers member out of the info structure.
+
+option INFO_IMAGE
+
+# added at libpng-1.5.10
+# Turn this off to disable warning about invalid palette index and
+# leave the num_palette_max member out of the png structure.
+
+option CHECK_FOR_INVALID_INDEX enables READ_CHECK_FOR_INVALID_INDEX
+option CHECK_FOR_INVALID_INDEX enables WRITE_CHECK_FOR_INVALID_INDEX
+option READ_CHECK_FOR_INVALID_INDEX requires READ, CHECK_FOR_INVALID_INDEX
+option WRITE_CHECK_FOR_INVALID_INDEX requires WRITE, CHECK_FOR_INVALID_INDEX
+
+# added at libpng-1.5.15
+option GET_PALETTE_MAX enables READ_GET_PALETTE_MAX WRITE_GET_PALETTE_MAX
+option READ_GET_PALETTE_MAX requires READ_CHECK_FOR_INVALID_INDEX disabled
+option WRITE_GET_PALETTE_MAX requires WRITE_CHECK_FOR_INVALID_INDEX disabled
+
+# Simplified API options (added at libpng-1.6.0)
+#  In libpng 1.6.8 the handling of these options was changed to used 'requires'
+#  throughout, so that disabling some of the low level support always disables
+#  the base simplified read/write API.  This much simplifies the handling and
+#  makes 'everything = off' work in a more intuitive way.  It eliminates a
+#  previously reported feature that APIs previously enabled by the simplified
+#  API couldn't be turned off without explicitly turning off the simplified
+#  APIs.
+#
+# Read:
+option SIMPLIFIED_READ,
+   requires SEQUENTIAL_READ, READ_TRANSFORMS, SETJMP, BENIGN_ERRORS,
+      READ_EXPAND, READ_16BIT, READ_EXPAND_16, READ_SCALE_16_TO_8,
+      READ_RGB_TO_GRAY, READ_ALPHA_MODE, READ_BACKGROUND, READ_STRIP_ALPHA,
+      READ_FILLER, READ_SWAP, READ_PACK, READ_GRAY_TO_RGB, READ_GAMMA,
+      READ_tRNS, READ_bKGD, READ_gAMA, READ_cHRM, READ_sRGB, READ_sBIT
+
+# AFIRST and BGR read options:
+#  Prior to libpng 1.6.8 these were disabled but switched on if the low level
+#  libpng routines that do the swaps were enabled.  This worked but was
+#  confusing.  In libpng 1.6.8 the options were changed to simple 'requires'
+#  and are enabled by default.  This should work the same way in practice.
+option SIMPLIFIED_READ_AFIRST enables FORMAT_AFIRST,
+   requires SIMPLIFIED_READ READ_SWAP_ALPHA
+
+option SIMPLIFIED_READ_BGR enables FORMAT_BGR,
+   requires SIMPLIFIED_READ READ_BGR
+
+# Write:
+option SIMPLIFIED_WRITE,
+   requires WRITE, SETJMP, WRITE_SWAP, WRITE_PACK,
+      WRITE_tRNS, WRITE_gAMA, WRITE_sRGB, WRITE_cHRM
+
+# 1.6.22: allow simplified write without stdio support:
+option SIMPLIFIED_WRITE_STDIO requires SIMPLIFIED_WRITE STDIO
+
+option SIMPLIFIED_WRITE_AFIRST enables FORMAT_AFIRST,
+   requires SIMPLIFIED_WRITE WRITE_SWAP_ALPHA
+
+option SIMPLIFIED_WRITE_BGR enables FORMAT_BGR,
+   requires SIMPLIFIED_WRITE WRITE_BGR
+
+# Formats:
+option FORMAT_AFIRST disabled
+option FORMAT_BGR disabled

xs/src/png/libpng/scripts/pnglibconf.h.prebuilt

@@ -0,0 +1,220 @@
+/* libpng 1.6.34 STANDARD API DEFINITION */
+
+/* pnglibconf.h - library build configuration */
+
+/* Libpng version 1.6.34 - September 29, 2017 */
+
+/* Copyright (c) 1998-2017 Glenn Randers-Pehrson */
+
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+
+/* pnglibconf.h */
+/* Machine generated file: DO NOT EDIT */
+/* Derived from: scripts/pnglibconf.dfa */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGNED_MEMORY_SUPPORTED
+/*#undef PNG_ARM_NEON_API_SUPPORTED*/
+/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
+/*#undef PNG_POWERPC_VSX_API_SUPPORTED*/
+/*#undef PNG_POWERPC_VSX_CHECK_SUPPORTED*/
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_BENIGN_READ_ERRORS_SUPPORTED
+/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_COLORSPACE_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_FORMAT_AFIRST_SUPPORTED
+#define PNG_FORMAT_BGR_SUPPORTED
+#define PNG_GAMMA_SUPPORTED
+#define PNG_GET_PALETTE_MAX_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GET_PALETTE_MAX_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_eXIf_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_OPTION_SUPPORTED
+#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_READ_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_eXIf_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_eXIf_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE
+#define PNG_INFLATE_BUF_SIZE 1024
+#define PNG_LINKAGE_API extern
+#define PNG_LINKAGE_CALLBACK extern
+#define PNG_LINKAGE_DATA extern
+#define PNG_LINKAGE_FUNCTION extern
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
+#define PNG_USER_CHUNK_CACHE_MAX 1000
+#define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_ZBUF_SIZE 8192
+#define PNG_ZLIB_VERNUM 0 /* unknown */
+#define PNG_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
+#define PNG_Z_DEFAULT_STRATEGY 1
+#define PNG_sCAL_PRECISION 5
+#define PNG_sRGB_PROFILE_CHECKS 2
+/* end of settings */
+#endif /* PNGLCONF_H */