Merge branch 'lm_tm_hollowing'

CMakeLists.txt

@@ -104,7 +104,7 @@ list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/modules/)
 
 enable_testing ()
 
-# Enable C++11 language standard.
+# Enable C++17 language standard.
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
@@ -426,6 +426,12 @@ if(SLIC3R_STATIC)
     set(USE_BLOSC TRUE)
 endif()
 
+find_package(OpenVDB 5.0 REQUIRED COMPONENTS openvdb)
+if(OpenVDB_FOUND)
+    slic3r_remap_configs(IlmBase::Half RelWithDebInfo Release)
+    slic3r_remap_configs(Blosc::blosc RelWithDebInfo Release)
+endif()
+
 set(TOP_LEVEL_PROJECT_DIR ${PROJECT_SOURCE_DIR})
 function(prusaslicer_copy_dlls target)
     if ("${CMAKE_SIZEOF_VOID_P}" STREQUAL "8")
@@ -449,8 +455,6 @@ function(prusaslicer_copy_dlls target)
 
 endfunction()
 
-#find_package(OpenVDB 5.0 COMPONENTS openvdb)
-#slic3r_remap_configs(IlmBase::Half RelWithDebInfo Release)
 
 # libslic3r, PrusaSlicer GUI and the PrusaSlicer executable.
 add_subdirectory(src)

cmake/modules/CheckAtomic.cmake

@@ -0,0 +1,106 @@
+# atomic builtins are required for threading support.
+
+INCLUDE(CheckCXXSourceCompiles)
+INCLUDE(CheckLibraryExists)
+
+# Sometimes linking against libatomic is required for atomic ops, if
+# the platform doesn't support lock-free atomics.
+
+function(check_working_cxx_atomics varname)
+  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11")
+  CHECK_CXX_SOURCE_COMPILES("
+#include <atomic>
+std::atomic<int> x;
+int main() {
+  return x;
+}
+" ${varname})
+  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
+endfunction(check_working_cxx_atomics)
+
+function(check_working_cxx_atomics64 varname)
+  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
+  set(CMAKE_REQUIRED_FLAGS "-std=c++11 ${CMAKE_REQUIRED_FLAGS}")
+  CHECK_CXX_SOURCE_COMPILES("
+#include <atomic>
+#include <cstdint>
+std::atomic<uint64_t> x (0);
+int main() {
+  uint64_t i = x.load(std::memory_order_relaxed);
+  return 0;
+}
+" ${varname})
+  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
+endfunction(check_working_cxx_atomics64)
+
+
+# This isn't necessary on MSVC, so avoid command-line switch annoyance
+# by only running on GCC-like hosts.
+if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
+  # First check if atomics work without the library.
+  check_working_cxx_atomics(HAVE_CXX_ATOMICS_WITHOUT_LIB)
+  # If not, check if the library exists, and atomics work with it.
+  if(NOT HAVE_CXX_ATOMICS_WITHOUT_LIB)
+    check_library_exists(atomic __atomic_fetch_add_4 "" HAVE_LIBATOMIC)
+    if( HAVE_LIBATOMIC )
+      list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
+      check_working_cxx_atomics(HAVE_CXX_ATOMICS_WITH_LIB)
+      if (NOT HAVE_CXX_ATOMICS_WITH_LIB)
+	message(FATAL_ERROR "Host compiler must support std::atomic!")
+      endif()
+    else()
+      message(FATAL_ERROR "Host compiler appears to require libatomic, but cannot find it.")
+    endif()
+  endif()
+endif()
+
+# Check for 64 bit atomic operations.
+if(MSVC)
+  set(HAVE_CXX_ATOMICS64_WITHOUT_LIB True)
+else()
+  check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITHOUT_LIB)
+endif()
+
+# If not, check if the library exists, and atomics work with it.
+if(NOT HAVE_CXX_ATOMICS64_WITHOUT_LIB)
+  check_library_exists(atomic __atomic_load_8 "" HAVE_CXX_LIBATOMICS64)
+  if(HAVE_CXX_LIBATOMICS64)
+    list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
+    check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITH_LIB)
+    if (NOT HAVE_CXX_ATOMICS64_WITH_LIB)
+      message(FATAL_ERROR "Host compiler must support 64-bit std::atomic!")
+    endif()
+  else()
+    message(FATAL_ERROR "Host compiler appears to require libatomic for 64-bit operations, but cannot find it.")
+  endif()
+endif()
+
+## TODO: This define is only used for the legacy atomic operations in
+## llvm's Atomic.h, which should be replaced.  Other code simply
+## assumes C++11 <atomic> works.
+CHECK_CXX_SOURCE_COMPILES("
+#ifdef _MSC_VER
+#include <windows.h>
+#endif
+int main() {
+#ifdef _MSC_VER
+        volatile LONG val = 1;
+        MemoryBarrier();
+        InterlockedCompareExchange(&val, 0, 1);
+        InterlockedIncrement(&val);
+        InterlockedDecrement(&val);
+#else
+        volatile unsigned long val = 1;
+        __sync_synchronize();
+        __sync_val_compare_and_swap(&val, 1, 0);
+        __sync_add_and_fetch(&val, 1);
+        __sync_sub_and_fetch(&val, 1);
+#endif
+        return 0;
+      }
+" LLVM_HAS_ATOMICS)
+
+if( NOT LLVM_HAS_ATOMICS )
+  message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing")
+endif()

cmake/modules/FindOpenVDB.cmake

@@ -108,6 +108,18 @@ if(POLICY CMP0074)
   cmake_policy(SET CMP0074 NEW)
 endif()
 
+if(OpenVDB_FIND_QUIETLY)
+  set (_quiet "QUIET")
+else()
+  set (_quiet "")
+endif()
+
+if(OpenVDB_FIND_REQUIRED)
+  set (_required "REQUIRED")
+else()
+  set (_required "")
+endif()
+
 # Include utility functions for version information
 include(${CMAKE_CURRENT_LIST_DIR}/OpenVDBUtils.cmake)
 
@@ -146,7 +158,7 @@ set(_OPENVDB_ROOT_SEARCH_DIR "")
 
 # Additionally try and use pkconfig to find OpenVDB
 
-find_package(PkgConfig)
+find_package(PkgConfig ${_quiet} )
 pkg_check_modules(PC_OpenVDB QUIET OpenVDB)
 
 # ------------------------------------------------------------------------
@@ -230,12 +242,14 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
     else()
       set(OpenVDB_${COMPONENT}_FOUND FALSE)
     endif()
+
+    set(OpenVDB_${COMPONENT}_LIBRARY ${OpenVDB_${COMPONENT}_LIBRARY_RELEASE})
   else ()
     string(TOUPPER "${CMAKE_BUILD_TYPE}" _BUILD_TYPE)
 
     set(OpenVDB_${COMPONENT}_LIBRARY ${OpenVDB_${COMPONENT}_LIBRARY_${_BUILD_TYPE}})
 
-    if (NOT MSVC AND NOT OpenVDB_${COMPONENT}_LIBRARY)
+    if (NOT OpenVDB_${COMPONENT}_LIBRARY)
       set(OpenVDB_${COMPONENT}_LIBRARY ${OpenVDB_${COMPONENT}_LIBRARY_RELEASE})
     endif ()
 
@@ -247,6 +261,7 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
       set(OpenVDB_${COMPONENT}_FOUND FALSE)
     endif()
   endif ()
+
 endforeach()
 
 if(UNIX AND OPENVDB_USE_STATIC_LIBS)
@@ -280,7 +295,7 @@ OPENVDB_ABI_VERSION_FROM_PRINT(
   ABI OpenVDB_ABI
 )
 
-if(NOT OpenVDB_FIND_QUIET)
+if(NOT OpenVDB_FIND_QUIETLY)
   if(NOT OpenVDB_ABI)
     message(WARNING "Unable to determine OpenVDB ABI version from OpenVDB "
       "installation. The library major version \"${OpenVDB_MAJOR_VERSION}\" "
@@ -298,7 +313,17 @@ endif()
 
 # Add standard dependencies
 
-find_package(IlmBase COMPONENTS Half)
+macro(just_fail msg)
+  set(OpenVDB_FOUND FALSE)
+  if(OpenVDB_FIND_REQUIRED)
+    message(FATAL_ERROR ${msg})
+  elseif(NOT OpenVDB_FIND_QUIETLY)
+    message(WARNING ${msg})
+  endif()
+  return()
+endmacro()
+
+find_package(IlmBase QUIET COMPONENTS Half)
 if(NOT IlmBase_FOUND)
   pkg_check_modules(IlmBase QUIET IlmBase)
 endif()
@@ -306,20 +331,20 @@ if (IlmBase_FOUND AND NOT TARGET IlmBase::Half)
   message(STATUS "Falling back to IlmBase found by pkg-config...")
 
   find_library(IlmHalf_LIBRARY NAMES Half)
-  if(IlmHalf_LIBRARY-NOTFOUND)
+  if(IlmHalf_LIBRARY-NOTFOUND OR NOT IlmBase_INCLUDE_DIRS)
-    message(FATAL_ERROR "IlmBase::Half can not be found!")
+    just_fail("IlmBase::Half can not be found!")
   endif()
   
   add_library(IlmBase::Half UNKNOWN IMPORTED)
   set_target_properties(IlmBase::Half PROPERTIES
     IMPORTED_LOCATION "${IlmHalf_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES ${IlmBase_INCLUDE_DIRS})
+    INTERFACE_INCLUDE_DIRECTORIES "${IlmBase_INCLUDE_DIRS}")
 elseif(NOT IlmBase_FOUND)
-  message(FATAL_ERROR "IlmBase::Half can not be found!")
+  just_fail("IlmBase::Half can not be found!")
 endif()
-find_package(TBB REQUIRED COMPONENTS tbb)
+find_package(TBB ${_quiet} ${_required} COMPONENTS tbb)
-find_package(ZLIB REQUIRED)
+find_package(ZLIB ${_quiet} ${_required})
-find_package(Boost REQUIRED COMPONENTS iostreams system)
+find_package(Boost ${_quiet} ${_required} COMPONENTS iostreams system )
 
 # Use GetPrerequisites to see which libraries this OpenVDB lib has linked to
 # which we can query for optional deps. This basically runs ldd/otoll/objdump
@@ -380,7 +405,7 @@ unset(_OPENVDB_PREREQUISITE_LIST)
 unset(_HAS_DEP)
 
 if(OpenVDB_USES_BLOSC)
-  find_package(Blosc )
+  find_package(Blosc QUIET)
   if(NOT Blosc_FOUND OR NOT TARGET Blosc::blosc) 
     message(STATUS "find_package could not find Blosc. Using fallback blosc search...")
     find_path(Blosc_INCLUDE_DIR blosc.h)
@@ -392,25 +417,25 @@ if(OpenVDB_USES_BLOSC)
         IMPORTED_LOCATION "${Blosc_LIBRARY}"
         INTERFACE_INCLUDE_DIRECTORIES ${Blosc_INCLUDE_DIR})
     elseif()
-      message(FATAL_ERROR "Blosc library can not be found!")
+      just_fail("Blosc library can not be found!")
     endif()
   endif()
 endif()
 
 if(OpenVDB_USES_LOG4CPLUS)
-  find_package(Log4cplus REQUIRED)
+  find_package(Log4cplus ${_quiet} ${_required})
 endif()
 
 if(OpenVDB_USES_ILM)
-  find_package(IlmBase REQUIRED)
+  find_package(IlmBase ${_quiet} ${_required})
 endif()
 
 if(OpenVDB_USES_EXR)
-  find_package(OpenEXR REQUIRED)
+  find_package(OpenEXR ${_quiet} ${_required})
 endif()
 
 if(UNIX)
-  find_package(Threads REQUIRED)
+  find_package(Threads ${_quiet} ${_required})
 endif()
 
 # Set deps. Note that the order here is important. If we're building against
@@ -500,6 +525,7 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
       IMPORTED_LINK_DEPENDENT_LIBRARIES "${_OPENVDB_HIDDEN_DEPENDENCIES}" # non visible deps
       INTERFACE_LINK_LIBRARIES "${_OPENVDB_VISIBLE_DEPENDENCIES}" # visible deps (headers)
       INTERFACE_COMPILE_FEATURES cxx_std_11
+      IMPORTED_LOCATION "${OpenVDB_${COMPONENT}_LIBRARY}"
    )
 
    if (_is_multi)
@@ -507,10 +533,6 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
        IMPORTED_LOCATION_RELEASE "${OpenVDB_${COMPONENT}_LIBRARY_RELEASE}"
        IMPORTED_LOCATION_DEBUG "${OpenVDB_${COMPONENT}_LIBRARY_DEBUG}"
      )
-  else ()
-    set_target_properties(OpenVDB::${COMPONENT} PROPERTIES 
-      IMPORTED_LOCATION "${OpenVDB_${COMPONENT}_LIBRARY}"
-    )
    endif ()
 
    if (OPENVDB_USE_STATIC_LIBS)
@@ -521,7 +543,7 @@ foreach(COMPONENT ${OpenVDB_FIND_COMPONENTS})
   endif()
 endforeach()
 
-if(OpenVDB_FOUND AND NOT ${CMAKE_FIND_PACKAGE_NAME}_FIND_QUIETLY)
+if(OpenVDB_FOUND AND NOT OpenVDB_FIND_QUIETLY)
   message(STATUS "OpenVDB libraries: ${OpenVDB_LIBRARIES}")
 endif()
 

cmake/modules/OpenVDBUtils.cmake

@@ -125,7 +125,9 @@ function(OPENVDB_ABI_VERSION_FROM_PRINT OPENVDB_PRINT)
   cmake_parse_arguments(_VDB "QUIET" "ABI" "" ${ARGN})
 
   if(NOT EXISTS ${OPENVDB_PRINT})
+    if(NOT OpenVDB_FIND_QUIETLY)
       message(WARNING "vdb_print not found! ${OPENVDB_PRINT}")
+    endif()
     return()
   endif()
 
@@ -148,7 +150,9 @@ function(OPENVDB_ABI_VERSION_FROM_PRINT OPENVDB_PRINT)
   endif()
 
   if(${_VDB_PRINT_RETURN_STATUS})
+    if(NOT OpenVDB_FIND_QUIETLY)
       message(WARNING "vdb_print returned with status ${_VDB_PRINT_RETURN_STATUS}")
+    endif()
     return()
   endif()
 

deps/GMP/GMP.cmake

@@ -18,7 +18,8 @@ if (MSVC)
 
 else ()
     ExternalProject_Add(dep_GMP
-        URL  https://gmplib.org/download/gmp/gmp-6.1.2.tar.bz2
+        # URL  https://gmplib.org/download/gmp/gmp-6.1.2.tar.bz2
+        URL https://gmplib.org/download/gmp/gmp-6.2.0.tar.lz
         BUILD_IN_SOURCE ON 
         CONFIGURE_COMMAND ./configure --enable-shared=no --enable-cxx=yes --enable-static=yes "--prefix=${DESTDIR}/usr/local" --with-pic
         BUILD_COMMAND     make -j

deps/openvdb-mods.patch

@@ -1,24 +1,25 @@
-From dbe038fce8a15ddc9a5c83ec5156d7bc9e178015 Mon Sep 17 00:00:00 2001
+From d359098d9989ac7dbd149611d6ac941529fb4157 Mon Sep 17 00:00:00 2001
 From: tamasmeszaros <meszaros.q@gmail.com>
-Date: Wed, 16 Oct 2019 17:42:50 +0200
+Date: Thu, 23 Jan 2020 17:17:36 +0100
-Subject: [PATCH] Build fixes for PrusaSlicer integration
+Subject: [PATCH] openvdb-mods
 
-Signed-off-by: tamasmeszaros <meszaros.q@gmail.com>
 ---
  CMakeLists.txt                  |   3 -
- cmake/FindBlosc.cmake           | 218 ---------------
+ cmake/CheckAtomic.cmake         | 106 ++++++
+ cmake/FindBlosc.cmake           | 218 ------------
  cmake/FindCppUnit.cmake         |   4 +-
- cmake/FindIlmBase.cmake         | 337 ----------------------
+ cmake/FindIlmBase.cmake         | 337 ------------------
- cmake/FindOpenEXR.cmake         | 329 ----------------------
+ cmake/FindOpenEXR.cmake         | 329 ------------------
  cmake/FindOpenVDB.cmake         |  19 +-
- cmake/FindTBB.cmake             | 605 ++++++++++++++++++++--------------------
+ cmake/FindTBB.cmake             | 599 ++++++++++++++++----------------
- openvdb/CMakeLists.txt          |  13 +-
+ openvdb/CMakeLists.txt          |  16 +-
  openvdb/Grid.cc                 |   3 +
  openvdb/PlatformConfig.h        |   9 +-
  openvdb/cmd/CMakeLists.txt      |   4 +-
  openvdb/unittest/CMakeLists.txt |   3 +-
  openvdb/unittest/TestFile.cc    |   2 +-
- 13 files changed, 336 insertions(+), 1213 deletions(-)
+ 14 files changed, 442 insertions(+), 1210 deletions(-)
+ create mode 100644 cmake/CheckAtomic.cmake
  delete mode 100644 cmake/FindBlosc.cmake
  delete mode 100644 cmake/FindIlmBase.cmake
  delete mode 100644 cmake/FindOpenEXR.cmake
@@ -40,6 +41,119 @@ index 580b353..6d364c1 100644
      cmake/FindOpenVDB.cmake
      cmake/FindTBB.cmake
      cmake/OpenVDBGLFW3Setup.cmake
+diff --git a/cmake/CheckAtomic.cmake b/cmake/CheckAtomic.cmake
+new file mode 100644
+index 0000000..c045e30
+--- /dev/null
++++ b/cmake/CheckAtomic.cmake
+@@ -0,0 +1,106 @@
++# atomic builtins are required for threading support.
++
++INCLUDE(CheckCXXSourceCompiles)
++INCLUDE(CheckLibraryExists)
++
++# Sometimes linking against libatomic is required for atomic ops, if
++# the platform doesn't support lock-free atomics.
++
++function(check_working_cxx_atomics varname)
++  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
++  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11")
++  CHECK_CXX_SOURCE_COMPILES("
++#include <atomic>
++std::atomic<int> x;
++int main() {
++  return x;
++}
++" ${varname})
++  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
++endfunction(check_working_cxx_atomics)
++
++function(check_working_cxx_atomics64 varname)
++  set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
++  set(CMAKE_REQUIRED_FLAGS "-std=c++11 ${CMAKE_REQUIRED_FLAGS}")
++  CHECK_CXX_SOURCE_COMPILES("
++#include <atomic>
++#include <cstdint>
++std::atomic<uint64_t> x (0);
++int main() {
++  uint64_t i = x.load(std::memory_order_relaxed);
++  return 0;
++}
++" ${varname})
++  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
++endfunction(check_working_cxx_atomics64)
++
++
++# This isn't necessary on MSVC, so avoid command-line switch annoyance
++# by only running on GCC-like hosts.
++if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
++  # First check if atomics work without the library.
++  check_working_cxx_atomics(HAVE_CXX_ATOMICS_WITHOUT_LIB)
++  # If not, check if the library exists, and atomics work with it.
++  if(NOT HAVE_CXX_ATOMICS_WITHOUT_LIB)
++    check_library_exists(atomic __atomic_fetch_add_4 "" HAVE_LIBATOMIC)
++    if( HAVE_LIBATOMIC )
++      list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
++      check_working_cxx_atomics(HAVE_CXX_ATOMICS_WITH_LIB)
++      if (NOT HAVE_CXX_ATOMICS_WITH_LIB)
++	message(FATAL_ERROR "Host compiler must support std::atomic!")
++      endif()
++    else()
++      message(FATAL_ERROR "Host compiler appears to require libatomic, but cannot find it.")
++    endif()
++  endif()
++endif()
++
++# Check for 64 bit atomic operations.
++if(MSVC)
++  set(HAVE_CXX_ATOMICS64_WITHOUT_LIB True)
++else()
++  check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITHOUT_LIB)
++endif()
++
++# If not, check if the library exists, and atomics work with it.
++if(NOT HAVE_CXX_ATOMICS64_WITHOUT_LIB)
++  check_library_exists(atomic __atomic_load_8 "" HAVE_CXX_LIBATOMICS64)
++  if(HAVE_CXX_LIBATOMICS64)
++    list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
++    check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITH_LIB)
++    if (NOT HAVE_CXX_ATOMICS64_WITH_LIB)
++      message(FATAL_ERROR "Host compiler must support 64-bit std::atomic!")
++    endif()
++  else()
++    message(FATAL_ERROR "Host compiler appears to require libatomic for 64-bit operations, but cannot find it.")
++  endif()
++endif()
++
++## TODO: This define is only used for the legacy atomic operations in
++## llvm's Atomic.h, which should be replaced.  Other code simply
++## assumes C++11 <atomic> works.
++CHECK_CXX_SOURCE_COMPILES("
++#ifdef _MSC_VER
++#include <windows.h>
++#endif
++int main() {
++#ifdef _MSC_VER
++        volatile LONG val = 1;
++        MemoryBarrier();
++        InterlockedCompareExchange(&val, 0, 1);
++        InterlockedIncrement(&val);
++        InterlockedDecrement(&val);
++#else
++        volatile unsigned long val = 1;
++        __sync_synchronize();
++        __sync_val_compare_and_swap(&val, 1, 0);
++        __sync_add_and_fetch(&val, 1);
++        __sync_sub_and_fetch(&val, 1);
++#endif
++        return 0;
++      }
++" LLVM_HAS_ATOMICS)
++
++if( NOT LLVM_HAS_ATOMICS )
++  message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing")
++endif()
+\ No newline at end of file
 diff --git a/cmake/FindBlosc.cmake b/cmake/FindBlosc.cmake
 deleted file mode 100644
 index 5aacfdd..0000000
@@ -965,7 +1079,7 @@ index 339c1a2..0000000
 -  message(FATAL_ERROR "Unable to find OpenEXR")
 -endif()
 diff --git a/cmake/FindOpenVDB.cmake b/cmake/FindOpenVDB.cmake
-index 63a2eda..6211071 100644
+index 63a2eda..d9f6d07 100644
 --- a/cmake/FindOpenVDB.cmake
 +++ b/cmake/FindOpenVDB.cmake
 @@ -244,7 +244,7 @@ set(OpenVDB_LIB_COMPONENTS "")
@@ -1012,7 +1126,7 @@ index 63a2eda..6211071 100644
  endforeach()
  
 diff --git a/cmake/FindTBB.cmake b/cmake/FindTBB.cmake
-index bdf9c81..c6bdec9 100644
+index bdf9c81..06093a4 100644
 --- a/cmake/FindTBB.cmake
 +++ b/cmake/FindTBB.cmake
 @@ -1,333 +1,332 @@
@@ -1022,35 +1136,21 @@ index bdf9c81..c6bdec9 100644
 -# All rights reserved. This software is distributed under the
 -# Mozilla Public License 2.0 ( http://www.mozilla.org/MPL/2.0/ )
 +# Copyright (c) 2015 Justus Calvin
-+# 
+ #
+-# Redistributions of source code must retain the above copyright
+-# and license notice and the following restrictions and disclaimer.
 +# Permission is hereby granted, free of charge, to any person obtaining a copy
 +# of this software and associated documentation files (the "Software"), to deal
 +# in the Software without restriction, including without limitation the rights
 +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 +# copies of the Software, and to permit persons to whom the Software is
 +# furnished to do so, subject to the following conditions:
-+# 
-+# The above copyright notice and this permission notice shall be included in all
-+# copies or substantial portions of the Software.
-+# 
-+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-+# SOFTWARE.
-+
- #
--# Redistributions of source code must retain the above copyright
--# and license notice and the following restrictions and disclaimer.
-+# FindTBB
-+# -------
  #
 -# *     Neither the name of DreamWorks Animation nor the names of
 -# its contributors may be used to endorse or promote products derived
 -# from this software without specific prior written permission.
-+# Find TBB include directories and libraries.
++# The above copyright notice and this permission notice shall be included in all
++# copies or substantial portions of the Software.
  #
 -# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 -# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
@@ -1065,7 +1165,14 @@ index bdf9c81..c6bdec9 100644
 -# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 -# IN NO EVENT SHALL THE COPYRIGHT HOLDERS' AND CONTRIBUTORS' AGGREGATE
 -# LIABILITY FOR ALL CLAIMS REGARDLESS OF THEIR BASIS EXCEED US$250.00.
-+# Usage:
++# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
++# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
++# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
++# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
++# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
++# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
++# SOFTWARE.
++
  #
 -#[=======================================================================[.rst:
 -
@@ -1142,6 +1249,13 @@ index bdf9c81..c6bdec9 100644
 -if(POLICY CMP0057)
 -  cmake_policy(SET CMP0057 NEW)
 -endif()
++# FindTBB
++# -------
++#
++# Find TBB include directories and libraries.
++#
++# Usage:
++#
 +#  find_package(TBB [major[.minor]] [EXACT]
 +#               [QUIET] [REQUIRED]
 +#               [[COMPONENTS] [components...]]
@@ -1244,12 +1358,10 @@ index bdf9c81..c6bdec9 100644
 -  set(TBB_FIND_COMPONENTS ${_TBB_COMPONENT_LIST})
 -endif()
 +include(FindPackageHandleStandardArgs)
-+
-+find_package(Threads QUIET REQUIRED)
  
 -# Append TBB_ROOT or $ENV{TBB_ROOT} if set (prioritize the direct cmake var)
 -set(_TBB_ROOT_SEARCH_DIR "")
-+if(NOT TBB_FOUND)
++find_package(Threads QUIET REQUIRED)
  
 -if(TBB_ROOT)
 -  list(APPEND _TBB_ROOT_SEARCH_DIR ${TBB_ROOT})
@@ -1257,41 +1369,9 @@ index bdf9c81..c6bdec9 100644
 -  set(_ENV_TBB_ROOT $ENV{TBB_ROOT})
 -  if(_ENV_TBB_ROOT)
 -    list(APPEND _TBB_ROOT_SEARCH_DIR ${_ENV_TBB_ROOT})
-+  ##################################
-+  # Check the build type
-+  ##################################
-+  
-+  if(NOT DEFINED TBB_USE_DEBUG_BUILD)
-+    if(CMAKE_BUILD_TYPE MATCHES "(Debug|DEBUG|debug)")
-+      set(TBB_BUILD_TYPE DEBUG)
-+    else()
-+      set(TBB_BUILD_TYPE RELEASE)
-+    endif()
-+  elseif(TBB_USE_DEBUG_BUILD)
-+    set(TBB_BUILD_TYPE DEBUG)
-+  else()
-+    set(TBB_BUILD_TYPE RELEASE)
-   endif()
 -  endif()
-+  
+-endif()
-+  ##################################
++if(NOT TBB_FOUND)
-+  # Set the TBB search directories
-+  ##################################
-+  
-+  # Define search paths based on user input and environment variables
-+  set(TBB_SEARCH_DIR ${TBB_ROOT_DIR} $ENV{TBB_INSTALL_DIR} $ENV{TBBROOT})
-+  
-+  # Define the search directories based on the current platform
-+  if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
-+    set(TBB_DEFAULT_SEARCH_DIR "C:/Program Files/Intel/TBB"
-+                               "C:/Program Files (x86)/Intel/TBB")
-+
-+    # Set the target architecture
-+    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
-+      set(TBB_ARCHITECTURE "intel64")
-+    else()
-+      set(TBB_ARCHITECTURE "ia32")
-+    endif()
  
 -# Additionally try and use pkconfig to find Tbb
 -
@@ -1339,6 +1419,57 @@ index bdf9c81..c6bdec9 100644
 -
 -  set(Tbb_VERSION ${Tbb_VERSION_MAJOR}.${Tbb_VERSION_MINOR})
 -endif()
++  ##################################
++  # Check the build type
++  ##################################
++
++  if(NOT DEFINED TBB_USE_DEBUG_BUILD)
++    if(CMAKE_BUILD_TYPE MATCHES "(Debug|DEBUG|debug)")
++      set(TBB_BUILD_TYPE DEBUG)
++    else()
++      set(TBB_BUILD_TYPE RELEASE)
++    endif()
++  elseif(TBB_USE_DEBUG_BUILD)
++    set(TBB_BUILD_TYPE DEBUG)
++  else()
++    set(TBB_BUILD_TYPE RELEASE)
++  endif()
+ 
+-# ------------------------------------------------------------------------
+-#  Search for TBB lib DIR
+-# ------------------------------------------------------------------------
++  ##################################
++  # Set the TBB search directories
++  ##################################
+ 
+-set(_TBB_LIBRARYDIR_SEARCH_DIRS "")
++  # Define search paths based on user input and environment variables
++  set(TBB_SEARCH_DIR ${TBB_ROOT_DIR} $ENV{TBB_INSTALL_DIR} $ENV{TBBROOT})
+ 
+-# Append to _TBB_LIBRARYDIR_SEARCH_DIRS in priority order
++  # Define the search directories based on the current platform
++  if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
++    set(TBB_DEFAULT_SEARCH_DIR "C:/Program Files/Intel/TBB"
++                               "C:/Program Files (x86)/Intel/TBB")
+ 
+-set(_TBB_LIBRARYDIR_SEARCH_DIRS "")
+-list(APPEND _TBB_LIBRARYDIR_SEARCH_DIRS
+-  ${TBB_LIBRARYDIR}
+-  ${_TBB_ROOT_SEARCH_DIR}
+-  ${PC_Tbb_LIBRARY_DIRS}
+-  ${SYSTEM_LIBRARY_PATHS}
+-)
++    # Set the target architecture
++    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
++      set(TBB_ARCHITECTURE "intel64")
++    else()
++      set(TBB_ARCHITECTURE "ia32")
++    endif()
+ 
+-set(TBB_PATH_SUFFIXES
+-  lib64
+-  lib
+-)
 +    # Set the TBB search library path search suffix based on the version of VC
 +    if(WINDOWS_STORE)
 +      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc11_ui")
@@ -1352,104 +1483,16 @@ index bdf9c81..c6bdec9 100644
 +      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc10")
 +    endif()
  
--# ------------------------------------------------------------------------
+-# platform branching
--#  Search for TBB lib DIR
--# ------------------------------------------------------------------------
 +    # Add the library path search suffix for the VC independent version of TBB
 +    list(APPEND TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc_mt")
-+
-+  elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
-+    # OS X
-+    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb")
-+    
-+    # TODO: Check to see which C++ library is being used by the compiler.
-+    if(NOT ${CMAKE_SYSTEM_VERSION} VERSION_LESS 13.0)
-+      # The default C++ library on OS X 10.9 and later is libc++
-+      set(TBB_LIB_PATH_SUFFIX "lib/libc++" "lib")
-+    else()
-+      set(TBB_LIB_PATH_SUFFIX "lib")
-+    endif()
-+  elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-+    # Linux
-+    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb")
-+    
-+    # TODO: Check compiler version to see the suffix should be <arch>/gcc4.1 or
-+    #       <arch>/gcc4.1. For now, assume that the compiler is more recent than
-+    #       gcc 4.4.x or later.
-+    if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
-+      set(TBB_LIB_PATH_SUFFIX "lib/intel64/gcc4.4")
-+    elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
-+      set(TBB_LIB_PATH_SUFFIX "lib/ia32/gcc4.4")
-+    endif()
-+  endif()
-+  
-+  ##################################
-+  # Find the TBB include dir
-+  ##################################
-+  
-+  find_path(TBB_INCLUDE_DIRS tbb/tbb.h
-+      HINTS ${TBB_INCLUDE_DIR} ${TBB_SEARCH_DIR}
-+      PATHS ${TBB_DEFAULT_SEARCH_DIR}
-+      PATH_SUFFIXES include)
-+
-+  ##################################
-+  # Set version strings
-+  ##################################
-+
-+  if(TBB_INCLUDE_DIRS)
-+    file(READ "${TBB_INCLUDE_DIRS}/tbb/tbb_stddef.h" _tbb_version_file)
-+    string(REGEX REPLACE ".*#define TBB_VERSION_MAJOR ([0-9]+).*" "\\1"
-+        TBB_VERSION_MAJOR "${_tbb_version_file}")
-+    string(REGEX REPLACE ".*#define TBB_VERSION_MINOR ([0-9]+).*" "\\1"
-+        TBB_VERSION_MINOR "${_tbb_version_file}")
-+    string(REGEX REPLACE ".*#define TBB_INTERFACE_VERSION ([0-9]+).*" "\\1"
-+        TBB_INTERFACE_VERSION "${_tbb_version_file}")
-+    set(TBB_VERSION "${TBB_VERSION_MAJOR}.${TBB_VERSION_MINOR}")
-+  endif()
- 
--set(_TBB_LIBRARYDIR_SEARCH_DIRS "")
-+  ##################################
-+  # Find TBB components
-+  ##################################
- 
--# Append to _TBB_LIBRARYDIR_SEARCH_DIRS in priority order
-+  if(TBB_VERSION VERSION_LESS 4.3)
-+    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc tbb)
-+  else()
-+    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc_proxy tbbmalloc tbb)
-+  endif()
- 
--set(_TBB_LIBRARYDIR_SEARCH_DIRS "")
--list(APPEND _TBB_LIBRARYDIR_SEARCH_DIRS
--  ${TBB_LIBRARYDIR}
--  ${_TBB_ROOT_SEARCH_DIR}
--  ${PC_Tbb_LIBRARY_DIRS}
--  ${SYSTEM_LIBRARY_PATHS}
--)
-+  if(TBB_STATIC)
-+    set(TBB_STATIC_SUFFIX "_static")
-+  endif()
- 
--set(TBB_PATH_SUFFIXES
--  lib64
--  lib
--)
-+  # Find each component
-+  foreach(_comp ${TBB_SEARCH_COMPOMPONENTS})
-+    if(";${TBB_FIND_COMPONENTS};tbb;" MATCHES ";${_comp};")
- 
--# platform branching
-+      unset(TBB_${_comp}_LIBRARY_DEBUG CACHE)
-+      unset(TBB_${_comp}_LIBRARY_RELEASE CACHE)
  
 -if(UNIX)
 -  list(INSERT TBB_PATH_SUFFIXES 0 lib/x86_64-linux-gnu)
 -endif()
-+      # Search for the libraries
++  elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
-+      find_library(TBB_${_comp}_LIBRARY_RELEASE ${_comp}${TBB_STATIC_SUFFIX}
++    # OS X
-+          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
++    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb")
-+          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
-+          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
  
 -if(APPLE)
 -  if(TBB_FOR_CLANG)
@@ -1471,29 +1514,33 @@ index bdf9c81..c6bdec9 100644
 -      list(GET GCC_VERSION_COMPONENTS 0 GCC_MAJOR)
 -      list(GET GCC_VERSION_COMPONENTS 1 GCC_MINOR)
 -      list(INSERT TBB_PATH_SUFFIXES 0 lib/intel64/gcc${GCC_MAJOR}.${GCC_MINOR})
--    else()
++    # TODO: Check to see which C++ library is being used by the compiler.
++    if(NOT ${CMAKE_SYSTEM_VERSION} VERSION_LESS 13.0)
++      # The default C++ library on OS X 10.9 and later is libc++
++      set(TBB_LIB_PATH_SUFFIX "lib/libc++" "lib")
+     else()
 -      list(INSERT TBB_PATH_SUFFIXES 0 lib/intel64/gcc4.4)
++      set(TBB_LIB_PATH_SUFFIX "lib")
++    endif()
++  elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
++    # Linux
++    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb")
++
++    # TODO: Check compiler version to see the suffix should be <arch>/gcc4.1 or
++    #       <arch>/gcc4.1. For now, assume that the compiler is more recent than
++    #       gcc 4.4.x or later.
++    if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
++      set(TBB_LIB_PATH_SUFFIX "lib/intel64/gcc4.4")
++    elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
++      set(TBB_LIB_PATH_SUFFIX "lib/ia32/gcc4.4")
+     endif()
+   endif()
 -endif()
--  endif()
+-
--endif()
-+      find_library(TBB_${_comp}_LIBRARY_DEBUG ${_comp}${TBB_STATIC_SUFFIX}_debug
-+          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
-+          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
-+          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
- 
 -if(UNIX AND TBB_USE_STATIC_LIBS)
 -  set(_TBB_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})
 -  set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
 -endif()
-+      if(TBB_${_comp}_LIBRARY_DEBUG)
-+        list(APPEND TBB_LIBRARIES_DEBUG "${TBB_${_comp}_LIBRARY_DEBUG}")
-+      endif()
-+      if(TBB_${_comp}_LIBRARY_RELEASE)
-+        list(APPEND TBB_LIBRARIES_RELEASE "${TBB_${_comp}_LIBRARY_RELEASE}")
-+      endif()
-+      if(TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE} AND NOT TBB_${_comp}_LIBRARY)
-+        set(TBB_${_comp}_LIBRARY "${TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE}}")
-+      endif()
  
 -set(Tbb_LIB_COMPONENTS "")
 -
@@ -1516,39 +1563,44 @@ index bdf9c81..c6bdec9 100644
 -        # Extract the directory and apply the matched text (in brackets)
 -        get_filename_component(Tbb_${COMPONENT}_DIR "${Tbb_${COMPONENT}_LIBRARY}" DIRECTORY)
 -        set(Tbb_${COMPONENT}_LIBRARY "${Tbb_${COMPONENT}_DIR}/${CMAKE_MATCH_1}")
-+      if(TBB_${_comp}_LIBRARY AND EXISTS "${TBB_${_comp}_LIBRARY}")
-+        set(TBB_${_comp}_FOUND TRUE)
-+      else()
-+        set(TBB_${_comp}_FOUND FALSE)
-       endif()
-+
-+      # Mark internal variables as advanced
-+      mark_as_advanced(TBB_${_comp}_LIBRARY_RELEASE)
-+      mark_as_advanced(TBB_${_comp}_LIBRARY_DEBUG)
-+      mark_as_advanced(TBB_${_comp}_LIBRARY)
-+
-     endif()
 -      endif()
-+  endforeach()
+-    endif()
++  ##################################
++  # Find the TBB include dir
++  ##################################
++
++  find_path(TBB_INCLUDE_DIRS tbb/tbb.h
++      HINTS ${TBB_INCLUDE_DIR} ${TBB_SEARCH_DIR}
++      PATHS ${TBB_DEFAULT_SEARCH_DIR}
++      PATH_SUFFIXES include)
++
++  ##################################
++  # Set version strings
++  ##################################
++
++  if(TBB_INCLUDE_DIRS)
++    file(READ "${TBB_INCLUDE_DIRS}/tbb/tbb_stddef.h" _tbb_version_file)
++    string(REGEX REPLACE ".*#define TBB_VERSION_MAJOR ([0-9]+).*" "\\1"
++        TBB_VERSION_MAJOR "${_tbb_version_file}")
++    string(REGEX REPLACE ".*#define TBB_VERSION_MINOR ([0-9]+).*" "\\1"
++        TBB_VERSION_MINOR "${_tbb_version_file}")
++    string(REGEX REPLACE ".*#define TBB_INTERFACE_VERSION ([0-9]+).*" "\\1"
++        TBB_INTERFACE_VERSION "${_tbb_version_file}")
++    set(TBB_VERSION "${TBB_VERSION_MAJOR}.${TBB_VERSION_MINOR}")
+   endif()
  
 -  list(APPEND Tbb_LIB_COMPONENTS ${Tbb_${COMPONENT}_LIBRARY})
 +  ##################################
-+  # Set compile flags and libraries
++  # Find TBB components
 +  ##################################
  
 -  if(Tbb_${COMPONENT}_LIBRARY)
 -    set(TBB_${COMPONENT}_FOUND TRUE)
--  else()
++  if(TBB_VERSION VERSION_LESS 4.3)
++    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc tbb)
+   else()
 -    set(TBB_${COMPONENT}_FOUND FALSE)
-+  set(TBB_DEFINITIONS_RELEASE "")
++    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc_proxy tbbmalloc tbb)
-+  set(TBB_DEFINITIONS_DEBUG "TBB_USE_DEBUG=1")
-+    
-+  if(TBB_LIBRARIES_${TBB_BUILD_TYPE})
-+    set(TBB_LIBRARIES "${TBB_LIBRARIES_${TBB_BUILD_TYPE}}")
-+  endif()
-+  
-+  if(NOT MSVC AND NOT TBB_LIBRARIES)
-+    set(TBB_LIBRARIES ${TBB_LIBRARIES_RELEASE})
    endif()
 -endforeach()
  
@@ -1556,61 +1608,51 @@ index bdf9c81..c6bdec9 100644
 -  set(CMAKE_FIND_LIBRARY_SUFFIXES ${_TBB_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES})
 -  unset(_TBB_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES)
 -endif()
-+  set(TBB_DEFINITIONS "")
++  if(TBB_STATIC)
-+  if (MSVC AND TBB_STATIC)
++    set(TBB_STATIC_SUFFIX "_static")
-+    set(TBB_DEFINITIONS __TBB_NO_IMPLICIT_LINKAGE)
-+  endif ()
-+
-+  unset (TBB_STATIC_SUFFIX)
-+
-+  find_package_handle_standard_args(TBB 
-+      REQUIRED_VARS TBB_INCLUDE_DIRS TBB_LIBRARIES
-+      FAIL_MESSAGE "TBB library cannot be found. Consider set TBBROOT environment variable."
-+      HANDLE_COMPONENTS
-+      VERSION_VAR TBB_VERSION)
-+
-+  ##################################
-+  # Create targets
-+  ##################################
-+
-+  if(NOT CMAKE_VERSION VERSION_LESS 3.0 AND TBB_FOUND)
-+    add_library(TBB::tbb UNKNOWN IMPORTED)
-+    set_target_properties(TBB::tbb PROPERTIES
-+          INTERFACE_COMPILE_DEFINITIONS "${TBB_DEFINITIONS}"
-+          INTERFACE_LINK_LIBRARIES  "Threads::Threads;${CMAKE_DL_LIBS}"
-+          INTERFACE_INCLUDE_DIRECTORIES  ${TBB_INCLUDE_DIRS}
-+          IMPORTED_LOCATION              ${TBB_LIBRARIES})
-+    if(TBB_LIBRARIES_RELEASE AND TBB_LIBRARIES_DEBUG)
-+      set_target_properties(TBB::tbb PROPERTIES
-+          INTERFACE_COMPILE_DEFINITIONS "${TBB_DEFINITIONS};$<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:${TBB_DEFINITIONS_DEBUG}>;$<$<CONFIG:Release>:${TBB_DEFINITIONS_RELEASE}>"
-+          IMPORTED_LOCATION_DEBUG          ${TBB_LIBRARIES_DEBUG}
-+          IMPORTED_LOCATION_RELWITHDEBINFO ${TBB_LIBRARIES_RELEASE}
-+          IMPORTED_LOCATION_RELEASE        ${TBB_LIBRARIES_RELEASE}
-+          IMPORTED_LOCATION_MINSIZEREL     ${TBB_LIBRARIES_RELEASE}
-+          )
-+    endif()
 +  endif()
  
 -# ------------------------------------------------------------------------
 -#  Cache and set TBB_FOUND
 -# ------------------------------------------------------------------------
-+  mark_as_advanced(TBB_INCLUDE_DIRS TBB_LIBRARIES)
++  # Find each component
++  foreach(_comp ${TBB_SEARCH_COMPOMPONENTS})
++    if(";${TBB_FIND_COMPONENTS};tbb;" MATCHES ";${_comp};")
 +
-+  unset(TBB_ARCHITECTURE)
++      unset(TBB_${_comp}_LIBRARY_DEBUG CACHE)
-+  unset(TBB_BUILD_TYPE)
++      unset(TBB_${_comp}_LIBRARY_RELEASE CACHE)
-+  unset(TBB_LIB_PATH_SUFFIX)
-+  unset(TBB_DEFAULT_SEARCH_DIR)
 +
-+  if(TBB_DEBUG)
++      # Search for the libraries
-+    message(STATUS "  TBB_FOUND               = ${TBB_FOUND}")
++      find_library(TBB_${_comp}_LIBRARY_RELEASE ${_comp}${TBB_STATIC_SUFFIX}
-+    message(STATUS "  TBB_INCLUDE_DIRS        = ${TBB_INCLUDE_DIRS}")
++          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
-+    message(STATUS "  TBB_DEFINITIONS         = ${TBB_DEFINITIONS}")
++          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
-+    message(STATUS "  TBB_LIBRARIES           = ${TBB_LIBRARIES}")
++          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
-+    message(STATUS "  TBB_DEFINITIONS_DEBUG   = ${TBB_DEFINITIONS_DEBUG}")
++
-+    message(STATUS "  TBB_LIBRARIES_DEBUG     = ${TBB_LIBRARIES_DEBUG}")
++      find_library(TBB_${_comp}_LIBRARY_DEBUG ${_comp}${TBB_STATIC_SUFFIX}_debug
-+    message(STATUS "  TBB_DEFINITIONS_RELEASE = ${TBB_DEFINITIONS_RELEASE}")
++          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
-+    message(STATUS "  TBB_LIBRARIES_RELEASE   = ${TBB_LIBRARIES_RELEASE}")
++          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
++          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
++
++      if(TBB_${_comp}_LIBRARY_DEBUG)
++        list(APPEND TBB_LIBRARIES_DEBUG "${TBB_${_comp}_LIBRARY_DEBUG}")
 +      endif()
++      if(TBB_${_comp}_LIBRARY_RELEASE)
++        list(APPEND TBB_LIBRARIES_RELEASE "${TBB_${_comp}_LIBRARY_RELEASE}")
++      endif()
++      if(TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE} AND NOT TBB_${_comp}_LIBRARY)
++        set(TBB_${_comp}_LIBRARY "${TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE}}")
++      endif()
++
++      if(TBB_${_comp}_LIBRARY AND EXISTS "${TBB_${_comp}_LIBRARY}")
++        set(TBB_${_comp}_FOUND TRUE)
++      else()
++        set(TBB_${_comp}_FOUND FALSE)
++      endif()
++
++      # Mark internal variables as advanced
++      mark_as_advanced(TBB_${_comp}_LIBRARY_RELEASE)
++      mark_as_advanced(TBB_${_comp}_LIBRARY_DEBUG)
++      mark_as_advanced(TBB_${_comp}_LIBRARY)
  
 -include(FindPackageHandleStandardArgs)
 -find_package_handle_standard_args(TBB
@@ -1646,13 +1688,82 @@ index bdf9c81..c6bdec9 100644
 -        INTERFACE_COMPILE_OPTIONS "${Tbb_DEFINITIONS}"
 -        INTERFACE_INCLUDE_DIRECTORIES "${Tbb_INCLUDE_DIR}"
 -      )
--    endif()
+     endif()
--  endforeach()
+   endforeach()
 -elseif(TBB_FIND_REQUIRED)
 -  message(FATAL_ERROR "Unable to find TBB")
++
++  ##################################
++  # Set compile flags and libraries
++  ##################################
++
++  set(TBB_DEFINITIONS_RELEASE "")
++  set(TBB_DEFINITIONS_DEBUG "TBB_USE_DEBUG=1")
++
++  if(TBB_LIBRARIES_${TBB_BUILD_TYPE})
++    set(TBB_LIBRARIES "${TBB_LIBRARIES_${TBB_BUILD_TYPE}}")
++  endif()
++
++  if(NOT MSVC AND NOT TBB_LIBRARIES)
++    set(TBB_LIBRARIES ${TBB_LIBRARIES_RELEASE})
++  endif()
++
++  set(TBB_DEFINITIONS "")
++  if (MSVC AND TBB_STATIC)
++    set(TBB_DEFINITIONS __TBB_NO_IMPLICIT_LINKAGE)
++  endif ()
++
++  unset (TBB_STATIC_SUFFIX)
++
++  find_package_handle_standard_args(TBB
++      REQUIRED_VARS TBB_INCLUDE_DIRS TBB_LIBRARIES
++      FAIL_MESSAGE "TBB library cannot be found. Consider set TBBROOT environment variable."
++      HANDLE_COMPONENTS
++      VERSION_VAR TBB_VERSION)
++
++  ##################################
++  # Create targets
++  ##################################
++
++  if(NOT CMAKE_VERSION VERSION_LESS 3.0 AND TBB_FOUND)
++    add_library(TBB::tbb UNKNOWN IMPORTED)
++    set_target_properties(TBB::tbb PROPERTIES
++          INTERFACE_COMPILE_DEFINITIONS "${TBB_DEFINITIONS}"
++          INTERFACE_LINK_LIBRARIES  "Threads::Threads;${CMAKE_DL_LIBS}"
++          INTERFACE_INCLUDE_DIRECTORIES  ${TBB_INCLUDE_DIRS}
++          IMPORTED_LOCATION              ${TBB_LIBRARIES})
++    if(TBB_LIBRARIES_RELEASE AND TBB_LIBRARIES_DEBUG)
++      set_target_properties(TBB::tbb PROPERTIES
++          INTERFACE_COMPILE_DEFINITIONS "${TBB_DEFINITIONS};$<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:${TBB_DEFINITIONS_DEBUG}>;$<$<CONFIG:Release>:${TBB_DEFINITIONS_RELEASE}>"
++          IMPORTED_LOCATION_DEBUG          ${TBB_LIBRARIES_DEBUG}
++          IMPORTED_LOCATION_RELWITHDEBINFO ${TBB_LIBRARIES_RELEASE}
++          IMPORTED_LOCATION_RELEASE        ${TBB_LIBRARIES_RELEASE}
++          IMPORTED_LOCATION_MINSIZEREL     ${TBB_LIBRARIES_RELEASE}
++          )
++    endif()
++  endif()
++
++  mark_as_advanced(TBB_INCLUDE_DIRS TBB_LIBRARIES)
++
++  unset(TBB_ARCHITECTURE)
++  unset(TBB_BUILD_TYPE)
++  unset(TBB_LIB_PATH_SUFFIX)
++  unset(TBB_DEFAULT_SEARCH_DIR)
++
++  if(TBB_DEBUG)
++    message(STATUS "  TBB_FOUND               = ${TBB_FOUND}")
++    message(STATUS "  TBB_INCLUDE_DIRS        = ${TBB_INCLUDE_DIRS}")
++    message(STATUS "  TBB_DEFINITIONS         = ${TBB_DEFINITIONS}")
++    message(STATUS "  TBB_LIBRARIES           = ${TBB_LIBRARIES}")
++    message(STATUS "  TBB_DEFINITIONS_DEBUG   = ${TBB_DEFINITIONS_DEBUG}")
++    message(STATUS "  TBB_LIBRARIES_DEBUG     = ${TBB_LIBRARIES_DEBUG}")
++    message(STATUS "  TBB_DEFINITIONS_RELEASE = ${TBB_DEFINITIONS_RELEASE}")
++    message(STATUS "  TBB_LIBRARIES_RELEASE   = ${TBB_LIBRARIES_RELEASE}")
++  endif()
++
  endif()
 diff --git a/openvdb/CMakeLists.txt b/openvdb/CMakeLists.txt
-index 89301bd..df27aae 100644
+index 89301bd..6a3c90c 100644
 --- a/openvdb/CMakeLists.txt
 +++ b/openvdb/CMakeLists.txt
 @@ -78,7 +78,7 @@ else()
@@ -1664,7 +1775,21 @@ index 89301bd..df27aae 100644
    message(DEPRECATION "Support for TBB versions < ${FUTURE_MINIMUM_TBB_VERSION} "
      "is deprecated and will be removed.")
  endif()
-@@ -185,11 +185,6 @@ if(WIN32)
+@@ -129,10 +129,13 @@ endif()
+ # include paths from shared installs (including houdini) may pull in the wrong
+ # headers
+ 
++include (CheckAtomic)
++
+ set(OPENVDB_CORE_DEPENDENT_LIBS
+   Boost::iostreams
+   Boost::system
+   IlmBase::Half
++  ${CMAKE_REQUIRED_LIBRARIES}
+ )
+ 
+ if(USE_EXR)
+@@ -185,11 +188,6 @@ if(WIN32)
    endif()
  endif()
  
@@ -1676,7 +1801,7 @@ index 89301bd..df27aae 100644
  ##### Core library configuration
  
  set(OPENVDB_LIBRARY_SOURCE_FILES
-@@ -374,10 +369,16 @@ set(OPENVDB_LIBRARY_UTIL_INCLUDE_FILES
+@@ -374,10 +372,16 @@ set(OPENVDB_LIBRARY_UTIL_INCLUDE_FILES
  
  if(OPENVDB_CORE_SHARED)
    add_library(openvdb_shared SHARED ${OPENVDB_LIBRARY_SOURCE_FILES})
@@ -1779,5 +1904,5 @@ index df51830..0ab0c12 100644
          /// @todo This changes the compressor setting globally.
          if (blosc_set_compressor(compname) < 0) continue;
 -- 
-2.16.2.windows.1
+2.17.1
 

resources/icons/hollow.svg

@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 24.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.0" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 128 128" enable-background="new 0 0 128 128" xml:space="preserve">
+<g id="hollow">
+	<g>
+		<g>
+			<path fill="#FFFFFF" d="M64,121.87c-0.39,0-0.77-0.11-1.11-0.34l-17.93-11.95c-0.92-0.61-1.17-1.85-0.55-2.77
+				s1.86-1.17,2.77-0.55L64,117.47l17.03-11.35c0.92-0.61,2.16-0.36,2.77,0.55c0.61,0.92,0.36,2.16-0.55,2.77l-18.14,12.09
+				C64.77,121.76,64.39,121.87,64,121.87z"/>
+		</g>
+		<g>
+			<path fill="#FFFFFF" d="M90.96,103.89c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l20.04-13.36V41.13L64,10.53
+				L18.11,41.13v45.75l20.03,13.36c0.92,0.61,1.17,1.85,0.55,2.77c-0.61,0.92-1.85,1.17-2.77,0.55L15,89.61
+				c-0.56-0.37-0.89-1-0.89-1.66V40.06c0-0.67,0.33-1.29,0.89-1.66L62.89,6.47c0.67-0.45,1.55-0.45,2.22,0L113,38.39
+				c0.56,0.37,0.89,1,0.89,1.66v47.89c0,0.67-0.33,1.29-0.89,1.66l-20.93,13.95C91.73,103.79,91.34,103.89,90.96,103.89z"/>
+		</g>
+	</g>
+	<g>
+		<g>
+			<path fill="#ED6B21" d="M67.33,23.81c-0.38,0-0.77-0.11-1.11-0.34L64,22l-2.22,1.48c-0.92,0.61-2.16,0.36-2.77-0.55
+				c-0.61-0.92-0.36-2.16,0.55-2.77l3.33-2.22c0.67-0.45,1.55-0.45,2.22,0l3.33,2.22c0.92,0.61,1.17,1.85,0.55,2.77
+				C68.61,23.5,67.97,23.81,67.33,23.81z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M36.09,40.2c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l5.46-3.64
+				c0.92-0.61,2.16-0.36,2.77,0.55c0.61,0.92,0.36,2.16-0.55,2.77l-5.46,3.64C36.86,40.09,36.48,40.2,36.09,40.2z M48.38,32.01
+				c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l5.46-3.64c0.92-0.61,2.16-0.36,2.77,0.55s0.36,2.16-0.55,2.77
+				l-5.46,3.64C49.15,31.9,48.77,32.01,48.38,32.01z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M25.94,50.97c-1.1,0-2-0.9-2-2v-4c0-0.67,0.33-1.29,0.89-1.66l3.33-2.22c0.92-0.62,2.16-0.36,2.77,0.55
+				s0.36,2.16-0.55,2.77l-2.44,1.62v2.93C27.94,50.07,27.04,50.97,25.94,50.97z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M25.94,70.29c-1.1,0-2-0.9-2-2v-8.59c0-1.1,0.9-2,2-2s2,0.9,2,2v8.59C27.94,69.4,27.04,70.29,25.94,70.29
+				z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M29.26,87.25c-0.38,0-0.77-0.11-1.11-0.34l-3.33-2.22c-0.56-0.37-0.89-1-0.89-1.66v-4c0-1.1,0.9-2,2-2
+				s2,0.9,2,2v2.93l2.44,1.62c0.92,0.61,1.17,1.85,0.55,2.77C30.54,86.94,29.91,87.25,29.26,87.25z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M53.84,103.64c-0.38,0-0.77-0.11-1.11-0.34l-5.46-3.64c-0.92-0.61-1.17-1.85-0.55-2.77
+				c0.61-0.92,1.85-1.17,2.77-0.55l5.46,3.64c0.92,0.61,1.17,1.85,0.55,2.77C55.12,103.32,54.49,103.64,53.84,103.64z M41.55,95.44
+				c-0.38,0-0.77-0.11-1.11-0.34l-5.46-3.64c-0.92-0.61-1.17-1.85-0.55-2.77c0.61-0.92,1.86-1.17,2.77-0.55l5.46,3.64
+				c0.92,0.61,1.17,1.85,0.55,2.77C42.83,95.13,42.2,95.44,41.55,95.44z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M64,110.41c-0.39,0-0.77-0.11-1.11-0.34l-3.33-2.22c-0.92-0.61-1.17-1.85-0.55-2.77
+				c0.61-0.92,1.85-1.17,2.77-0.55L64,106l2.22-1.48c0.92-0.61,2.16-0.37,2.77,0.55c0.61,0.92,0.36,2.16-0.55,2.77l-3.33,2.22
+				C64.77,110.29,64.39,110.41,64,110.41z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M74.16,103.64c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l5.46-3.64
+				c0.92-0.61,2.16-0.36,2.77,0.55c0.61,0.92,0.36,2.16-0.55,2.77l-5.46,3.64C74.92,103.53,74.54,103.64,74.16,103.64z M86.45,95.44
+				c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l5.46-3.64c0.92-0.61,2.16-0.36,2.77,0.55
+				c0.61,0.92,0.36,2.16-0.55,2.77l-5.46,3.64C87.21,95.33,86.83,95.44,86.45,95.44z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M98.74,87.25c-0.65,0-1.28-0.31-1.67-0.89c-0.61-0.92-0.36-2.16,0.55-2.77l2.44-1.62v-2.93
+				c0-1.1,0.9-2,2-2s2,0.9,2,2v4c0,0.67-0.33,1.29-0.89,1.66l-3.33,2.22C99.5,87.14,99.12,87.25,98.74,87.25z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M102.06,70.29c-1.1,0-2-0.9-2-2v-8.59c0-1.1,0.9-2,2-2s2,0.9,2,2v8.59
+				C104.06,69.4,103.17,70.29,102.06,70.29z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M102.06,50.97c-1.1,0-2-0.9-2-2v-2.93l-2.44-1.62c-0.92-0.61-1.17-1.85-0.55-2.77s1.85-1.17,2.77-0.55
+				l3.33,2.22c0.56,0.37,0.89,1,0.89,1.66v4C104.06,50.07,103.17,50.97,102.06,50.97z"/>
+		</g>
+		<g>
+			<path fill="#ED6B21" d="M91.91,40.2c-0.38,0-0.77-0.11-1.11-0.34l-5.46-3.64c-0.92-0.61-1.17-1.85-0.55-2.77
+				c0.61-0.92,1.85-1.17,2.77-0.55l5.46,3.64c0.92,0.61,1.17,1.85,0.55,2.77C93.19,39.89,92.55,40.2,91.91,40.2z M79.62,32.01
+				c-0.38,0-0.77-0.11-1.11-0.34l-5.46-3.64c-0.92-0.61-1.17-1.85-0.55-2.77s1.85-1.17,2.77-0.55l5.46,3.64
+				c0.92,0.61,1.17,1.85,0.55,2.77C80.9,31.69,80.26,32.01,79.62,32.01z"/>
+		</g>
+	</g>
+</g>
+</svg>

resources/icons/hollowing.svg

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 23.0.3, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.0" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 16 16" enable-background="new 0 0 16 16" xml:space="preserve">
+<g id="support">
+	<polygon fill="none" stroke="#808080" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" points="8,1 
+		2.31,4.79 2.31,8.57 2.31,8.79 2.31,10.47 8,14.25 13.69,10.47 13.69,8.79 13.69,8.57 13.69,4.79 	"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="12.69" y1="15" x2="12.69" y2="12.44"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="13.87" y1="15" x2="13.87" y2="11.64"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="2.13" y1="15" x2="2.13" y2="11.64"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="3.33" y1="15" x2="3.33" y2="12.44"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="4.51" y1="15" x2="4.51" y2="13.22"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="5.66" y1="15" x2="5.66" y2="14"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="10.34" y1="15" x2="10.34" y2="14"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="11.5" y1="15" x2="11.5" y2="13.22"/>
+</g>
+</svg>

resources/icons/white/hollowing.svg

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 23.0.3, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.0" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 16 16" enable-background="new 0 0 16 16" xml:space="preserve">
+<g id="support">
+	<polygon fill="none" stroke="#808080" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" points="8,1 
+		2.31,4.79 2.31,8.57 2.31,8.79 2.31,10.47 8,14.25 13.69,10.47 13.69,8.79 13.69,8.57 13.69,4.79 	"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="12.69" y1="15" x2="12.69" y2="12.44"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="13.87" y1="15" x2="13.87" y2="11.64"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="2.13" y1="15" x2="2.13" y2="11.64"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="3.33" y1="15" x2="3.33" y2="12.44"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="4.51" y1="15" x2="4.51" y2="13.22"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="5.66" y1="15" x2="5.66" y2="14"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="10.34" y1="15" x2="10.34" y2="14"/>
+	
+		<line fill="none" stroke="#ED6B21" stroke-linecap="round" stroke-linejoin="round" stroke-miterlimit="10" x1="11.5" y1="15" x2="11.5" y2="13.22"/>
+</g>
+</svg>

sandboxes/CMakeLists.txt

@@ -1,3 +1,4 @@
 #add_subdirectory(slasupporttree)
 #add_subdirectory(openvdb)
 add_subdirectory(meshboolean)
+add_subdirectory(opencsg)

sandboxes/meshboolean/CMakeLists.txt

@@ -1,12 +1,6 @@
-if (SLIC3R_STATIC)
-    set(CGAL_Boost_USE_STATIC_LIBS ON)
-endif ()
-
-find_package(CGAL REQUIRED)
-
 add_executable(meshboolean MeshBoolean.cpp)
 
-target_link_libraries(meshboolean libslic3r CGAL::CGAL)
+target_link_libraries(meshboolean libslic3r)
 
 if (WIN32)
     prusaslicer_copy_dlls(meshboolean)

sandboxes/meshboolean/MeshBoolean.cpp

@@ -1,85 +1,76 @@
-#include <libslic3r/TriangleMesh.hpp>
-#undef PI
-#include <igl/readOFF.h>
-//#undef IGL_STATIC_LIBRARY
-#include <igl/copyleft/cgal/mesh_boolean.h>
-
-#include <Eigen/Core>
 #include <iostream>
+#include <vector>
 
-#include <admesh/stl.h>
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/Model.hpp>
+#include <libslic3r/SLAPrint.hpp>
+#include <libslic3r/SLAPrintSteps.hpp>
+#include <libslic3r/MeshBoolean.hpp>
+
+#include <libnest2d/tools/benchmark.h>
 
-#include <boost/nowide/cstdio.hpp>
 #include <boost/log/trivial.hpp>
 
 namespace Slic3r {
 
-bool its_write_obj(const Eigen::MatrixXd &V, Eigen::MatrixXi &F, const char *file)
-{
-
-  	FILE *fp = boost::nowide::fopen(file, "w");
-  	if (fp == nullptr) {
-		BOOST_LOG_TRIVIAL(error) << "stl_write_obj: Couldn't open " << file << " for writing";
-    	return false;
-  	}
-
-	for (size_t i = 0; i < V.rows(); ++ i)
-    	fprintf(fp, "v %lf %lf %lf\n", V(i, 0), V(i, 1), V(i, 2));
-  	for (size_t i = 0; i < F.rows(); ++ i)
-    	fprintf(fp, "f %d %d %d\n", F(i, 0) + 1, F(i, 1) + 1, F(i, 2) + 1);
-  	fclose(fp);
-  	return true;
-}
-
-void mesh_boolean_test(const std::string &fname)
-{
-  using namespace Eigen;
-  using namespace std;
-//  igl::readOFF(TUTORIAL_SHARED_PATH "/cheburashka.off",VA,FA);
-//  igl::readOFF(TUTORIAL_SHARED_PATH "/decimated-knight.off",VB,FB);
-  // Plot the mesh with pseudocolors
-//  igl::opengl::glfw::Viewer viewer;
-
-  // Initialize
-//  update(viewer);
-
-  //igl::copyleft::cgal::mesh_boolean(VA,FA,VB,FB,boolean_type,VC,FC,J);
-  
-  
-    std::cout << fname.c_str() << std::endl;
-	TriangleMesh mesh;
-    
-	mesh.ReadSTLFile(fname.c_str());
-	mesh.repair(true);
-    its_write_obj(mesh.its, (fname + "-imported0.obj").c_str());
-    
-
-	Eigen::MatrixXd VA,VB,VC;
-	Eigen::VectorXi J,I;
-	Eigen::MatrixXi FA,FB,FC;
-	igl::MeshBooleanType boolean_type(igl::MESH_BOOLEAN_TYPE_UNION);
-
-
-  	typedef Eigen::Map<const Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXfUnaligned;
-    typedef Eigen::Map<const Eigen::Matrix<int,   Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXiUnaligned;
-
-	Eigen::MatrixXd V = MapMatrixXfUnaligned(mesh.its.vertices.front().data(), mesh.its.vertices.size(), 3).cast<double>();
-    Eigen::MatrixXi F = MapMatrixXiUnaligned(mesh.its.indices.front().data(), mesh.its.indices.size(), 3);
-
-    its_write_obj(V, F, (fname + "-imported.obj").c_str());
-    // Self-union to clean up
-    igl::copyleft::cgal::mesh_boolean(V, F, Eigen::MatrixXd(), Eigen::MatrixXi(), boolean_type, VC, FC);
-
-    its_write_obj(VC, FC, (fname + "-fixed.obj").c_str());
-}
-
 } // namespace Slic3r
 
 int main(const int argc, const char * argv[])
 {
-    if (argc < 1) return -1;
+    using namespace Slic3r;
     
-    Slic3r::mesh_boolean_test(argv[1]);
+    if (argc <= 1) return EXIT_FAILURE;
+    
+    DynamicPrintConfig cfg;
+    auto model = Model::read_from_file(argv[1], &cfg);
+    
+    if (model.objects.empty()) return EXIT_SUCCESS;
+    
+    SLAPrint print;
+    print.apply(model, cfg);
+    PrintBase::TaskParams task;
+    task.to_object_step = slaposHollowing;
+    
+    print.set_task(task);
+    print.process();
+    
+    Benchmark bench;
+    
+    for (SLAPrintObject *po : print.objects()) {
+        TriangleMesh holes;
+        sla::DrainHoles holepts = po->transformed_drainhole_points();
+        
+        for (auto &hole: holepts)
+            holes.merge(sla::to_triangle_mesh(hole.to_mesh()));
+        
+        TriangleMesh hollowed_mesh = po->transformed_mesh();
+        hollowed_mesh.merge(po->hollowed_interior_mesh());
+        
+        hollowed_mesh.require_shared_vertices();
+        holes.require_shared_vertices();
+        
+        TriangleMesh drilled_mesh_igl = hollowed_mesh;
+        bench.start();
+        MeshBoolean::minus(drilled_mesh_igl, holes);
+        bench.stop();
+        
+        std::cout << "Mesh boolean duration with IGL: " << bench.getElapsedSec() << std::endl;
+        
+        TriangleMesh drilled_mesh_cgal = hollowed_mesh;
+        bench.start();
+        MeshBoolean::cgal::self_union(drilled_mesh_cgal);
+        MeshBoolean::cgal::minus(drilled_mesh_cgal, holes);
+        bench.stop();
+        
+        std::cout << "Mesh boolean duration with CGAL: " << bench.getElapsedSec() << std::endl;
+        
+        std::string name("obj"), outf;
+        outf = name + "igl" + std::to_string(po->model_object()->id().id) + ".obj";
+        drilled_mesh_igl.WriteOBJFile(outf.c_str());
+        
+        outf = name + "cgal" + std::to_string(po->model_object()->id().id) + ".obj";
+        drilled_mesh_cgal.WriteOBJFile(outf.c_str());
+    }
     
     return 0;
 }

sandboxes/opencsg/CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.0)
+
+project(OpenCSG-example)
+
+add_executable(opencsg_example WIN32 
+    main.cpp 
+    Engine.hpp Engine.cpp 
+    ShaderCSGDisplay.hpp ShaderCSGDisplay.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/ProgressStatusBar.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/I18N.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/I18N.cpp)
+
+find_package(wxWidgets 3.1 REQUIRED COMPONENTS core base gl html)
+find_package(OpenGL REQUIRED)
+find_package(GLEW REQUIRED)
+find_package(OpenCSG REQUIRED)
+include(${wxWidgets_USE_FILE})
+
+target_link_libraries(opencsg_example libslic3r)
+target_include_directories(opencsg_example PRIVATE ${wxWidgets_INCLUDE_DIRS})
+target_compile_definitions(opencsg_example PRIVATE ${wxWidgets_DEFINITIONS})
+
+slic3r_remap_configs(OpenCSG::opencsg RelWithDebInfo Release)
+target_link_libraries(opencsg_example ${wxWidgets_LIBRARIES} 
+    OpenCSG::opencsg 
+    GLEW::GLEW
+    OpenGL::GL 
+    #-lXrandr -lXext -lX11
+    )

sandboxes/opencsg/Engine.cpp

@@ -0,0 +1,498 @@
+#include "Engine.hpp"
+#include <libslic3r/Utils.hpp>
+#include <libslic3r/SLAPrint.hpp>
+
+#include <GL/glew.h>
+
+#include <boost/log/trivial.hpp>
+
+#ifndef NDEBUG
+#define HAS_GLSAFE
+#endif
+
+#ifdef HAS_GLSAFE
+extern void glAssertRecentCallImpl(const char *file_name, unsigned int line, const char *function_name);
+inline void glAssertRecentCall() { glAssertRecentCallImpl(__FILE__, __LINE__, __FUNCTION__); }
+#define glsafe(cmd) do { cmd; glAssertRecentCallImpl(__FILE__, __LINE__, __FUNCTION__); } while (false)
+#define glcheck() do { glAssertRecentCallImpl(__FILE__, __LINE__, __FUNCTION__); } while (false)
+
+void glAssertRecentCallImpl(const char *file_name, unsigned int line, const char *function_name)
+{
+    GLenum err = glGetError();
+    if (err == GL_NO_ERROR)
+        return;
+    const char *sErr = 0;
+    switch (err) {
+    case GL_INVALID_ENUM:       sErr = "Invalid Enum";      break;
+    case GL_INVALID_VALUE:      sErr = "Invalid Value";     break;
+    // be aware that GL_INVALID_OPERATION is generated if glGetError is executed between the execution of glBegin and the corresponding execution of glEnd 
+    case GL_INVALID_OPERATION:  sErr = "Invalid Operation"; break;
+    case GL_STACK_OVERFLOW:     sErr = "Stack Overflow";    break;
+    case GL_STACK_UNDERFLOW:    sErr = "Stack Underflow";   break;
+    case GL_OUT_OF_MEMORY:      sErr = "Out Of Memory";     break;
+    default:                    sErr = "Unknown";           break;
+    }
+    BOOST_LOG_TRIVIAL(error) << "OpenGL error in " << file_name << ":" << line << ", function " << function_name << "() : " << (int)err << " - " << sErr;
+    assert(false);
+}
+
+#else
+inline void glAssertRecentCall() { }
+#define glsafe(cmd) cmd
+#define glcheck()
+#endif
+
+namespace Slic3r { namespace GL {
+
+Scene::Scene() = default;
+Scene::~Scene() = default;
+
+void CSGDisplay::render_scene()
+{
+    GLfloat color[] = {1.f, 1.f, 0.f, 0.f};
+    glsafe(::glColor4fv(color));
+    
+    if (m_csgsettings.is_enabled()) {
+        OpenCSG::render(m_scene_cache.primitives_csg);
+        glDepthFunc(GL_EQUAL);
+    }
+    
+    for (auto& p : m_scene_cache.primitives_csg) p->render();
+    if (m_csgsettings.is_enabled()) glDepthFunc(GL_LESS);
+    
+    for (auto& p : m_scene_cache.primitives_free) p->render();
+    
+    glFlush();
+}
+
+void Scene::set_print(uqptr<SLAPrint> &&print)
+{   
+    m_print = std::move(print);
+        
+    // Notify displays
+    call(&Listener::on_scene_updated, m_listeners, *this);
+}
+
+BoundingBoxf3 Scene::get_bounding_box() const
+{
+    return m_print->model().bounding_box();
+}
+
+void CSGDisplay::SceneCache::clear()
+{
+    primitives_csg.clear();
+    primitives_free.clear();
+    primitives.clear();
+}
+
+shptr<Primitive> CSGDisplay::SceneCache::add_mesh(const TriangleMesh &mesh)
+{
+    auto p = std::make_shared<Primitive>();
+    p->load_mesh(mesh);
+    primitives.emplace_back(p);
+    primitives_free.emplace_back(p.get());
+    return p;
+}
+
+shptr<Primitive> CSGDisplay::SceneCache::add_mesh(const TriangleMesh &mesh,
+                                                   OpenCSG::Operation  o,
+                                                   unsigned            c)
+{
+    auto p = std::make_shared<Primitive>(o, c);
+    p->load_mesh(mesh);
+    primitives.emplace_back(p);
+    primitives_csg.emplace_back(p.get());
+    return p;
+}
+
+void IndexedVertexArray::push_geometry(float x, float y, float z, float nx, float ny, float nz)
+{
+    assert(this->vertices_and_normals_interleaved_VBO_id == 0);
+    if (this->vertices_and_normals_interleaved_VBO_id != 0)
+        return;
+    
+    if (this->vertices_and_normals_interleaved.size() + 6 > this->vertices_and_normals_interleaved.capacity())
+        this->vertices_and_normals_interleaved.reserve(next_highest_power_of_2(this->vertices_and_normals_interleaved.size() + 6));
+    this->vertices_and_normals_interleaved.emplace_back(nx);
+    this->vertices_and_normals_interleaved.emplace_back(ny);
+    this->vertices_and_normals_interleaved.emplace_back(nz);
+    this->vertices_and_normals_interleaved.emplace_back(x);
+    this->vertices_and_normals_interleaved.emplace_back(y);
+    this->vertices_and_normals_interleaved.emplace_back(z);
+    
+    this->vertices_and_normals_interleaved_size = this->vertices_and_normals_interleaved.size();
+}
+
+void IndexedVertexArray::push_triangle(int idx1, int idx2, int idx3) {
+    assert(this->vertices_and_normals_interleaved_VBO_id == 0);
+    if (this->vertices_and_normals_interleaved_VBO_id != 0)
+        return;
+    
+    if (this->triangle_indices.size() + 3 > this->vertices_and_normals_interleaved.capacity())
+        this->triangle_indices.reserve(next_highest_power_of_2(this->triangle_indices.size() + 3));
+    this->triangle_indices.emplace_back(idx1);
+    this->triangle_indices.emplace_back(idx2);
+    this->triangle_indices.emplace_back(idx3);
+    this->triangle_indices_size = this->triangle_indices.size();
+}
+
+void IndexedVertexArray::load_mesh(const TriangleMesh &mesh)
+{
+    assert(triangle_indices.empty() && vertices_and_normals_interleaved_size == 0);
+    assert(quad_indices.empty() && triangle_indices_size == 0);
+    assert(vertices_and_normals_interleaved.size() % 6 == 0 && quad_indices_size == vertices_and_normals_interleaved.size());
+    
+    this->vertices_and_normals_interleaved.reserve(this->vertices_and_normals_interleaved.size() + 3 * 3 * 2 * mesh.facets_count());
+    
+    int vertices_count = 0;
+    for (size_t i = 0; i < mesh.stl.stats.number_of_facets; ++i) {
+        const stl_facet &facet = mesh.stl.facet_start[i];
+        for (int j = 0; j < 3; ++j)
+            this->push_geometry(facet.vertex[j](0), facet.vertex[j](1), facet.vertex[j](2), facet.normal(0), facet.normal(1), facet.normal(2));
+                
+                this->push_triangle(vertices_count, vertices_count + 1, vertices_count + 2);
+        vertices_count += 3;
+    }
+}
+
+void IndexedVertexArray::finalize_geometry()
+{
+    assert(this->vertices_and_normals_interleaved_VBO_id == 0);
+    assert(this->triangle_indices_VBO_id == 0);
+    assert(this->quad_indices_VBO_id == 0);
+
+    if (!this->vertices_and_normals_interleaved.empty()) {
+        glsafe(
+            ::glGenBuffers(1, &this->vertices_and_normals_interleaved_VBO_id));
+        glsafe(::glBindBuffer(GL_ARRAY_BUFFER,
+                              this->vertices_and_normals_interleaved_VBO_id));
+        glsafe(
+            ::glBufferData(GL_ARRAY_BUFFER,
+                           GLsizeiptr(
+                               this->vertices_and_normals_interleaved.size() *
+                               4),
+                           this->vertices_and_normals_interleaved.data(),
+                           GL_STATIC_DRAW));
+        glsafe(::glBindBuffer(GL_ARRAY_BUFFER, 0));
+        this->vertices_and_normals_interleaved.clear();
+    }
+    if (!this->triangle_indices.empty()) {
+        glsafe(::glGenBuffers(1, &this->triangle_indices_VBO_id));
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
+                              this->triangle_indices_VBO_id));
+        glsafe(::glBufferData(GL_ELEMENT_ARRAY_BUFFER,
+                              GLsizeiptr(this->triangle_indices.size() * 4),
+                              this->triangle_indices.data(), GL_STATIC_DRAW));
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
+        this->triangle_indices.clear();
+    }
+    if (!this->quad_indices.empty()) {
+        glsafe(::glGenBuffers(1, &this->quad_indices_VBO_id));
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
+                              this->quad_indices_VBO_id));
+        glsafe(::glBufferData(GL_ELEMENT_ARRAY_BUFFER,
+                              GLsizeiptr(this->quad_indices.size() * 4),
+                              this->quad_indices.data(), GL_STATIC_DRAW));
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
+        this->quad_indices.clear();
+    }
+}
+
+void IndexedVertexArray::release_geometry()
+{
+    if (this->vertices_and_normals_interleaved_VBO_id) {
+        glsafe(
+            ::glDeleteBuffers(1,
+                              &this->vertices_and_normals_interleaved_VBO_id));
+        this->vertices_and_normals_interleaved_VBO_id = 0;
+    }
+    if (this->triangle_indices_VBO_id) {
+        glsafe(::glDeleteBuffers(1, &this->triangle_indices_VBO_id));
+        this->triangle_indices_VBO_id = 0;
+    }
+    if (this->quad_indices_VBO_id) {
+        glsafe(::glDeleteBuffers(1, &this->quad_indices_VBO_id));
+        this->quad_indices_VBO_id = 0;
+    }
+    this->clear();
+}
+
+void IndexedVertexArray::render() const
+{
+    assert(this->vertices_and_normals_interleaved_VBO_id != 0);
+    assert(this->triangle_indices_VBO_id != 0 ||
+           this->quad_indices_VBO_id != 0);
+
+    glsafe(::glBindBuffer(GL_ARRAY_BUFFER,
+                          this->vertices_and_normals_interleaved_VBO_id));
+    glsafe(::glVertexPointer(3, GL_FLOAT, 6 * sizeof(float),
+                             reinterpret_cast<const void *>(3 * sizeof(float))));
+    glsafe(::glNormalPointer(GL_FLOAT, 6 * sizeof(float), nullptr));
+
+    glsafe(::glEnableClientState(GL_VERTEX_ARRAY));
+    glsafe(::glEnableClientState(GL_NORMAL_ARRAY));
+
+    // Render using the Vertex Buffer Objects.
+    if (this->triangle_indices_size > 0) {
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
+                              this->triangle_indices_VBO_id));
+        glsafe(::glDrawElements(GL_TRIANGLES,
+                                GLsizei(this->triangle_indices_size),
+                                GL_UNSIGNED_INT, nullptr));
+        glsafe(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
+    }
+    if (this->quad_indices_size > 0) {
+        glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
+                              this->quad_indices_VBO_id));
+        glsafe(::glDrawElements(GL_QUADS, GLsizei(this->quad_indices_size),
+                                GL_UNSIGNED_INT, nullptr));
+        glsafe(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
+    }
+
+    glsafe(::glDisableClientState(GL_VERTEX_ARRAY));
+    glsafe(::glDisableClientState(GL_NORMAL_ARRAY));
+
+    glsafe(::glBindBuffer(GL_ARRAY_BUFFER, 0));
+}
+
+void IndexedVertexArray::clear() {
+    this->vertices_and_normals_interleaved.clear();
+    this->triangle_indices.clear();
+    this->quad_indices.clear();
+    vertices_and_normals_interleaved_size = 0;
+    triangle_indices_size = 0;
+    quad_indices_size = 0;
+}
+
+void IndexedVertexArray::shrink_to_fit() {
+    this->vertices_and_normals_interleaved.shrink_to_fit();
+    this->triangle_indices.shrink_to_fit();
+    this->quad_indices.shrink_to_fit();
+}
+
+void Volume::render()
+{
+    glsafe(::glPushMatrix());
+    glsafe(::glMultMatrixd(m_trafo.get_matrix().data()));
+    m_geom.render();
+    glsafe(::glPopMatrix());
+}
+
+void Display::clear_screen()
+{
+    glViewport(0, 0, GLsizei(m_size.x()), GLsizei(m_size.y()));
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+}
+
+Display::~Display()
+{
+    OpenCSG::freeResources();
+}
+
+void Display::set_active(long width, long height)
+{   
+    if (!m_initialized) {
+        glewInit();
+        m_initialized = true;
+    }
+
+    // gray background
+    glClearColor(0.9f, 0.9f, 0.9f, 1.0f);
+
+    // Enable two OpenGL lights
+    GLfloat light_diffuse[]   = { 1.0f,  1.0f,  0.0f,  1.0f};  // White diffuse light
+    GLfloat light_position0[] = {-1.0f, -1.0f, -1.0f,  0.0f};  // Infinite light location
+    GLfloat light_position1[] = { 1.0f,  1.0f,  1.0f,  0.0f};  // Infinite light location
+    
+    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
+    glLightfv(GL_LIGHT0, GL_POSITION, light_position0);
+    glEnable(GL_LIGHT0);  
+    glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
+    glLightfv(GL_LIGHT1, GL_POSITION, light_position1);
+    glEnable(GL_LIGHT1);
+    glEnable(GL_LIGHTING);
+    glEnable(GL_NORMALIZE);
+    
+    // Use depth buffering for hidden surface elimination
+    glEnable(GL_DEPTH_TEST);
+    glEnable(GL_STENCIL_TEST);
+    
+    set_screen_size(width, height);
+}
+
+void Display::set_screen_size(long width, long height)
+{
+    if (m_size.x() != width || m_size.y() != height)
+        m_camera->set_screen(width, height);
+    
+    m_size = {width, height};
+}
+
+void Display::repaint()
+{
+    clear_screen();
+    
+    m_camera->view();
+    render_scene();
+    
+    m_fps_counter.update();
+    
+    swap_buffers();
+}
+
+void Controller::on_scene_updated(const Scene &scene)
+{
+    const SLAPrint *print = scene.get_print();
+    if (!print) return;
+    
+    auto bb = scene.get_bounding_box();
+    double d = std::max(std::max(bb.size().x(), bb.size().y()), bb.size().z());
+    m_wheel_pos = long(2 * d);
+    
+    call_cameras(&Camera::set_zoom, m_wheel_pos);
+    call(&Display::on_scene_updated, m_displays, scene);    
+}
+
+void Controller::on_scroll(long v, long d, MouseInput::WheelAxis /*wa*/)
+{
+    m_wheel_pos += v / d;
+    
+    call_cameras(&Camera::set_zoom, m_wheel_pos);
+    call(&Display::repaint, m_displays);
+}
+
+void Controller::on_moved_to(long x, long y)
+{
+    if (m_left_btn) {
+        call_cameras(&Camera::rotate, (Vec2i{x, y} - m_mouse_pos).cast<float>());
+        call(&Display::repaint, m_displays);
+    }
+    
+    m_mouse_pos = {x, y};
+}
+
+void CSGDisplay::apply_csgsettings(const CSGSettings &settings)
+{
+    using namespace OpenCSG;
+    
+    bool needupdate = m_csgsettings.get_convexity() != settings.get_convexity();
+    
+    m_csgsettings = settings;
+    setOption(AlgorithmSetting, m_csgsettings.get_algo());
+    setOption(DepthComplexitySetting, m_csgsettings.get_depth_algo());
+    setOption(DepthBoundsOptimization, m_csgsettings.get_optimization());
+    
+    if (needupdate) {
+        for (OpenCSG::Primitive * p : m_scene_cache.primitives_csg)
+            if (p->getConvexity() > 1)
+                p->setConvexity(m_csgsettings.get_convexity());
+    }
+}
+
+void CSGDisplay::on_scene_updated(const Scene &scene)
+{
+    const SLAPrint *print = scene.get_print();
+    if (!print) return;
+    
+    m_scene_cache.clear();
+    
+    for (const SLAPrintObject *po : print->objects()) {
+        const ModelObject *mo = po->model_object();
+        TriangleMesh msh = mo->raw_mesh();
+        
+        sla::DrainHoles holedata = mo->sla_drain_holes;
+        
+        for (const ModelInstance *mi : mo->instances) {
+            
+            TriangleMesh mshinst = msh;
+            auto interior = po->hollowed_interior_mesh();
+            interior.transform(po->trafo().inverse());
+            
+            mshinst.merge(interior);
+            mshinst.require_shared_vertices();
+            
+            mi->transform_mesh(&mshinst);
+            
+            auto bb = mshinst.bounding_box();
+            auto center = bb.center().cast<float>();
+            mshinst.translate(-center);
+            
+            mshinst.require_shared_vertices();
+            m_scene_cache.add_mesh(mshinst, OpenCSG::Intersection,
+                                   m_csgsettings.get_convexity());
+        }
+        
+        for (const sla::DrainHole &holept : holedata) {
+            TriangleMesh holemesh = sla::to_triangle_mesh(holept.to_mesh());
+            holemesh.require_shared_vertices();
+            m_scene_cache.add_mesh(holemesh, OpenCSG::Subtraction, 1);
+        }
+    }
+    
+    repaint();
+}
+
+void Camera::view()
+{
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+    gluLookAt(0.0, m_zoom, 0.0,  /* eye is at (0,zoom,0) */
+              m_referene.x(), m_referene.y(), m_referene.z(),
+              0.0, 0.0, 1.0); /* up is in positive Y direction */
+    
+    // TODO Could have been set in prevoius gluLookAt in first argument
+    glRotatef(m_rot.y(), 1.0, 0.0, 0.0);
+    glRotatef(m_rot.x(), 0.0, 0.0, 1.0);
+    
+    if (m_clip_z > 0.) {
+        GLdouble plane[] = {0., 0., 1., m_clip_z};
+        glClipPlane(GL_CLIP_PLANE0, plane);
+        glEnable(GL_CLIP_PLANE0);
+    } else {
+        glDisable(GL_CLIP_PLANE0);
+    }
+}
+
+void PerspectiveCamera::set_screen(long width, long height)
+{
+    // Setup the view of the CSG shape
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluPerspective(45.0, width / double(height), .1, 200.0);
+    glMatrixMode(GL_MODELVIEW);
+}
+
+bool enable_multisampling(bool e)
+{
+    if (!e) { glDisable(GL_MULTISAMPLE); return false; }
+    
+    GLint is_ms_context;
+    glGetIntegerv(GL_SAMPLE_BUFFERS, &is_ms_context);
+    
+    if (is_ms_context) { glEnable(GL_MULTISAMPLE); return true; }
+    else return false;
+}
+
+MouseInput::Listener::~Listener() = default;
+
+void FpsCounter::update()
+{
+    ++m_frames;
+    
+    TimePoint msec = Clock::now();
+    
+    double seconds_window = to_sec(msec - m_window);
+    m_fps = 0.5 * m_fps + 0.5 * (m_frames / seconds_window);
+    
+    if (to_sec(msec - m_last) >= m_resolution) {
+        m_last = msec;
+        for (auto &l : m_listeners) l(m_fps);
+    }
+    
+    if (seconds_window >= m_window_size) {
+        m_frames = 0;
+        m_window = msec;
+    }
+}
+
+}} // namespace Slic3r::GL

sandboxes/opencsg/Engine.hpp

@@ -0,0 +1,493 @@
+#ifndef SLIC3R_OCSG_EXMP_ENGINE_HPP
+#define SLIC3R_OCSG_EXMP_ENGINE_HPP
+
+#include <vector>
+#include <memory>
+#include <chrono>
+
+#include <libslic3r/Geometry.hpp>
+#include <libslic3r/Model.hpp>
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/SLA/Hollowing.hpp>
+#include <opencsg/opencsg.h>
+
+namespace Slic3r {
+
+class SLAPrint;
+
+namespace GL {
+
+// Simple shorthands for smart pointers
+template<class T> using shptr = std::shared_ptr<T>;
+template<class T> using uqptr = std::unique_ptr<T>;
+template<class T> using wkptr = std::weak_ptr<T>;
+
+template<class T, class A = std::allocator<T>> using vector = std::vector<T, A>;
+
+// remove empty weak pointers from a vector
+template<class L> inline void cleanup(vector<std::weak_ptr<L>> &listeners) {
+    auto it = std::remove_if(listeners.begin(), listeners.end(),
+                             [](auto &l) { return !l.lock(); });
+    listeners.erase(it, listeners.end());
+}
+
+// Call a class method on each element of a vector of objects (weak pointers)
+// of the same type.
+template<class F, class L, class...Args>
+inline void call(F &&f, vector<std::weak_ptr<L>> &listeners, Args&&... args) {
+    for (auto &l : listeners)
+        if (auto p = l.lock()) ((p.get())->*f)(std::forward<Args>(args)...);
+}
+
+// A representation of a mouse input for the engine.
+class MouseInput
+{
+public:
+    enum WheelAxis { waVertical, waHorizontal };
+    
+    // Interface to implement if an object wants to receive notifications
+    // about mouse events.
+    class Listener {
+    public:
+        virtual ~Listener();
+        
+        virtual void on_left_click_down() {}
+        virtual void on_left_click_up() {}
+        virtual void on_right_click_down() {}
+        virtual void on_right_click_up() {}
+        virtual void on_double_click() {}
+        virtual void on_scroll(long /*v*/, long /*delta*/, WheelAxis ) {}
+        virtual void on_moved_to(long /*x*/, long /*y*/) {}
+    };
+    
+private:
+    vector<wkptr<Listener>> m_listeners;
+        
+public:
+    virtual ~MouseInput() = default;
+
+    virtual void left_click_down()
+    {
+        call(&Listener::on_left_click_down, m_listeners);
+    }
+    virtual void left_click_up()
+    {
+        call(&Listener::on_left_click_up, m_listeners);
+    }
+    virtual void right_click_down()
+    {
+        call(&Listener::on_right_click_down, m_listeners);
+    }
+    virtual void right_click_up()
+    {
+        call(&Listener::on_right_click_up, m_listeners);
+    }
+    virtual void double_click()
+    {
+        call(&Listener::on_double_click, m_listeners);
+    }
+    virtual void scroll(long v, long d, WheelAxis wa)
+    {
+        call(&Listener::on_scroll, m_listeners, v, d, wa);
+    }
+    virtual void move_to(long x, long y)
+    {
+        call(&Listener::on_moved_to, m_listeners, x, y);
+    }
+    
+    void add_listener(shptr<Listener> listener)
+    {
+        m_listeners.emplace_back(listener);
+        cleanup(m_listeners);
+    }
+};
+
+// This is a stripped down version of Slic3r::IndexedVertexArray
+class IndexedVertexArray {
+public:
+    ~IndexedVertexArray() { release_geometry(); }
+
+    // Vertices and their normals, interleaved to be used by void
+    // glInterleavedArrays(GL_N3F_V3F, 0, x)
+    vector<float> vertices_and_normals_interleaved;
+    vector<int>   triangle_indices;
+    vector<int>   quad_indices;
+
+    // When the geometry data is loaded into the graphics card as Vertex
+    // Buffer Objects, the above mentioned std::vectors are cleared and the
+    // following variables keep their original length.
+    size_t vertices_and_normals_interleaved_size{ 0 };
+    size_t triangle_indices_size{ 0 };
+    size_t quad_indices_size{ 0 };
+    
+    // IDs of the Vertex Array Objects, into which the geometry has been loaded.
+    // Zero if the VBOs are not sent to GPU yet.
+    unsigned int       vertices_and_normals_interleaved_VBO_id{ 0 };
+    unsigned int       triangle_indices_VBO_id{ 0 };
+    unsigned int       quad_indices_VBO_id{ 0 };
+    
+    
+    void push_geometry(float x, float y, float z, float nx, float ny, float nz);
+
+    inline void push_geometry(
+        double x, double y, double z, double nx, double ny, double nz)
+    {
+        push_geometry(float(x), float(y), float(z), float(nx), float(ny), float(nz));
+    }
+
+    inline void push_geometry(const Vec3d &p, const Vec3d &n)
+    {
+        push_geometry(p(0), p(1), p(2), n(0), n(1), n(2));
+    }
+
+    void push_triangle(int idx1, int idx2, int idx3);
+    
+    void load_mesh(const TriangleMesh &mesh);
+
+    inline bool has_VBOs() const
+    {
+        return vertices_and_normals_interleaved_VBO_id != 0;
+    }
+
+    // Finalize the initialization of the geometry & indices,
+    // upload the geometry and indices to OpenGL VBO objects
+    // and shrink the allocated data, possibly relasing it if it has been
+    // loaded into the VBOs.
+    void finalize_geometry();
+    // Release the geometry data, release OpenGL VBOs.
+    void release_geometry();
+    
+    void render() const;
+    
+    // Is there any geometry data stored?
+    bool empty() const { return vertices_and_normals_interleaved_size == 0; }
+    
+    void clear();
+    
+    // Shrink the internal storage to tighly fit the data stored.
+    void shrink_to_fit();
+};
+
+// Try to enable or disable multisampling.
+bool enable_multisampling(bool e = true);
+
+class Volume {
+    IndexedVertexArray m_geom;
+    Geometry::Transformation m_trafo;
+    
+public:
+    
+    void render();
+    
+    void translation(const Vec3d &offset) { m_trafo.set_offset(offset); }
+    void rotation(const Vec3d &rot) { m_trafo.set_rotation(rot); }
+    void scale(const Vec3d &scaleing) { m_trafo.set_scaling_factor(scaleing); }
+    void scale(double s) { scale({s, s, s}); }
+    
+    inline void load_mesh(const TriangleMesh &mesh)
+    {
+        m_geom.load_mesh(mesh);
+        m_geom.finalize_geometry();
+    }
+};
+
+// A primitive that can be used with OpenCSG rendering algorithms.
+// Does a similar job to GLVolume.
+class Primitive : public Volume, public OpenCSG::Primitive
+{
+public:
+    using OpenCSG::Primitive::Primitive;
+    
+    Primitive() : OpenCSG::Primitive(OpenCSG::Intersection, 1) {}
+    
+    void render() override { Volume::render(); }
+};
+
+// A simple representation of a camera in a 3D scene
+class Camera {
+protected:
+    Vec2f m_rot = {0., 0.};
+    Vec3d m_referene = {0., 0., 0.};
+    double m_zoom = 0.;
+    double m_clip_z = 0.;
+public:
+    
+    virtual ~Camera() = default;
+    
+    virtual void view();
+    virtual void set_screen(long width, long height) = 0;
+    
+    void set_rotation(const Vec2f &rotation) { m_rot = rotation; }    
+    void rotate(const Vec2f &rotation) { m_rot += rotation; }
+    void set_zoom(double z) { m_zoom = z; }
+    void set_reference_point(const Vec3d &p) { m_referene = p; }
+    void set_clip_z(double z) { m_clip_z = z; }
+};
+
+// Reset a camera object
+inline void reset(Camera &cam)
+{
+    cam.set_rotation({0., 0.});
+    cam.set_zoom(0.);
+    cam.set_reference_point({0., 0., 0.});
+    cam.set_clip_z(0.);
+}
+
+// Specialization of a camera which shows in perspective projection
+class PerspectiveCamera: public Camera {
+public:
+    
+    void set_screen(long width, long height) override;
+};
+
+// A simple counter of FPS. Subscribed objects will receive updates of the
+// current fps.
+class FpsCounter {
+    vector<std::function<void(double)>> m_listeners;
+    
+    using Clock = std::chrono::high_resolution_clock;
+    using Duration = Clock::duration;
+    using TimePoint = Clock::time_point;
+    
+    int m_frames = 0;
+    TimePoint m_last = Clock::now(), m_window = m_last;
+    
+    double m_resolution = 0.1, m_window_size = 1.0;
+    double m_fps = 0.;
+    
+    static double to_sec(Duration d)
+    {
+        return d.count() * double(Duration::period::num) / Duration::period::den;
+    }    
+    
+public:
+    
+    void update();
+
+    void add_listener(std::function<void(double)> lst)
+    {
+        m_listeners.emplace_back(lst);
+    }
+    
+    void clear_listeners() { m_listeners = {}; }
+
+    void set_notification_interval(double seconds);
+    void set_measure_window_size(double seconds);
+    
+    double get_notification_interval() const { return m_resolution; }
+    double get_mesure_window_size() const { return m_window_size; }
+};
+
+// Collection of the used OpenCSG library settings.
+class CSGSettings {
+public:
+    static const constexpr unsigned DEFAULT_CONVEXITY = 10;
+    
+private:
+    OpenCSG::Algorithm m_csgalg = OpenCSG::Algorithm::Automatic;
+    OpenCSG::DepthComplexityAlgorithm m_depth_algo = OpenCSG::NoDepthComplexitySampling;
+    OpenCSG::Optimization m_optim = OpenCSG::OptimizationDefault;
+    bool m_enable = true;
+    unsigned int m_convexity = DEFAULT_CONVEXITY;
+    
+public:
+    int get_algo() const { return int(m_csgalg); }
+    void set_algo(int alg)
+    {
+        if (alg < OpenCSG::Algorithm::AlgorithmUnused)
+            m_csgalg = OpenCSG::Algorithm(alg);
+    }
+    
+    int get_depth_algo() const { return int(m_depth_algo); }
+    void set_depth_algo(int alg)
+    {
+        if (alg < OpenCSG::DepthComplexityAlgorithmUnused)
+            m_depth_algo = OpenCSG::DepthComplexityAlgorithm(alg);
+    }
+    
+    int  get_optimization() const { return int(m_optim); }
+    void set_optimization(int o)
+    {
+        if (o < OpenCSG::Optimization::OptimizationUnused)
+            m_optim = OpenCSG::Optimization(o);
+    }
+    
+    void enable_csg(bool en = true) { m_enable = en; }
+    bool is_enabled() const { return m_enable; }
+    
+    unsigned get_convexity() const { return m_convexity; }
+    void set_convexity(unsigned c) { m_convexity = c; }
+};
+
+// The scene is a wrapper around SLAPrint which holds the data to be visualized.
+class Scene
+{
+    uqptr<SLAPrint> m_print;
+public:
+    
+    // Subscribers will be notified if the model is changed. This might be a
+    // display which will have to load the meshes and repaint itself when
+    // the scene data changes.
+    // eg. We load a new 3mf through the UI, this will notify the controller
+    // associated with the scene and all the displays that the controller is
+    // connected with.
+    class Listener {
+    public:
+        virtual ~Listener() = default;
+        virtual void on_scene_updated(const Scene &scene) = 0;
+    };
+    
+    Scene();
+    ~Scene();
+    
+    void set_print(uqptr<SLAPrint> &&print);
+    const SLAPrint * get_print() const { return m_print.get(); }
+    
+    BoundingBoxf3 get_bounding_box() const;
+    
+    void add_listener(shptr<Listener> listener)
+    {
+        m_listeners.emplace_back(listener);
+        cleanup(m_listeners);
+    }
+    
+private:
+    vector<wkptr<Listener>> m_listeners;
+};
+
+// The basic Display. This is almost just an interface but will do all the
+// initialization and show the fps values. Overriding the render_scene is
+// needed to show the scene content. The specific method of displaying the
+// scene is up the the particular implementation (OpenCSG or other screen space
+// boolean algorithms)
+class Display : public Scene::Listener
+{
+protected:
+    Vec2i m_size;
+    bool m_initialized = false;
+    
+    shptr<Camera>  m_camera;
+    FpsCounter m_fps_counter;
+    
+public:
+    
+    explicit Display(shptr<Camera> camera = nullptr)
+        : m_camera(camera ? camera : std::make_shared<PerspectiveCamera>())
+    {}
+    
+    ~Display() override;
+    
+    shptr<const Camera> get_camera() const { return m_camera; }
+    shptr<Camera> get_camera() { return m_camera; }
+    void set_camera(shptr<Camera> cam) { m_camera = cam; }
+    
+    virtual void swap_buffers() = 0;
+    virtual void set_active(long width, long height);
+    virtual void set_screen_size(long width, long height);
+    Vec2i get_screen_size() const { return m_size; }
+    
+    virtual void repaint();
+    
+    bool is_initialized() const { return m_initialized; }
+    
+    virtual void clear_screen();
+    virtual void render_scene() {}
+    
+    template<class _FpsCounter> void set_fps_counter(_FpsCounter &&fpsc)
+    {
+        m_fps_counter = std::forward<_FpsCounter>(fpsc);
+    }
+
+    const FpsCounter &get_fps_counter() const { return m_fps_counter; }
+    FpsCounter &get_fps_counter() { return m_fps_counter; }
+};
+
+// Special dispaly using OpenCSG for rendering the scene.
+class CSGDisplay : public Display {
+protected:
+    CSGSettings m_csgsettings;
+    
+    // Cache the renderable primitives. These will be fetched when the scene
+    // is modified.
+    struct SceneCache {
+        vector<shptr<Primitive>> primitives;
+        vector<Primitive *> primitives_free;
+        vector<OpenCSG::Primitive *> primitives_csg;
+        
+        void clear();
+        
+        shptr<Primitive> add_mesh(const TriangleMesh &mesh);
+        shptr<Primitive> add_mesh(const TriangleMesh &mesh,
+                                  OpenCSG::Operation  op,
+                                  unsigned            covexity);
+    } m_scene_cache;
+    
+public:
+    
+    // Receive or apply the new settings.
+    const CSGSettings & get_csgsettings() const { return m_csgsettings; }
+    void apply_csgsettings(const CSGSettings &settings);
+    
+    void render_scene() override;
+    
+    void on_scene_updated(const Scene &scene) override;
+};
+
+
+// The controller is a hub which dispatches mouse events to the connected
+// displays. It keeps track of the mouse wheel position, the states whether
+// the mouse is being held, dragged, etc... All the connected displays will
+// mirror the camera movement (if there is more than one display).
+class Controller : public std::enable_shared_from_this<Controller>,
+                   public MouseInput::Listener,
+                   public Scene::Listener
+{
+    long m_wheel_pos = 0;
+    Vec2i m_mouse_pos, m_mouse_pos_rprev, m_mouse_pos_lprev;
+    bool m_left_btn = false, m_right_btn = false;
+
+    shptr<Scene>           m_scene;
+    vector<wkptr<Display>> m_displays;
+    
+    // Call a method of Camera on all the cameras of the attached displays
+    template<class F, class...Args>
+    void call_cameras(F &&f, Args&&... args) {
+        for (wkptr<Display> &l : m_displays)
+            if (auto disp = l.lock()) if (auto cam = disp->get_camera())
+                (cam.get()->*f)(std::forward<Args>(args)...);
+    }
+    
+public:
+    
+    // Set the scene that will be controlled.
+    void set_scene(shptr<Scene> scene)
+    {
+        m_scene = scene;
+        m_scene->add_listener(shared_from_this());
+    }
+    
+    const Scene * get_scene() const { return m_scene.get(); }
+
+    void add_display(shptr<Display> disp)
+    {
+        m_displays.emplace_back(disp);
+        cleanup(m_displays);
+    }
+    
+    void remove_displays() { m_displays = {}; }
+    
+    void on_scene_updated(const Scene &scene) override;
+    
+    void on_left_click_down() override { m_left_btn = true; }
+    void on_left_click_up() override { m_left_btn = false;  }
+    void on_right_click_down() override { m_right_btn = true;  }
+    void on_right_click_up() override { m_right_btn = false; }
+    
+    void on_scroll(long v, long d, MouseInput::WheelAxis wa) override;
+    void on_moved_to(long x, long y) override;
+
+    void move_clip_plane(double z) { call_cameras(&Camera::set_clip_z, z); }
+};
+
+}}     // namespace Slic3r::GL
+#endif // SLIC3R_OCSG_EXMP_ENGINE_HPP

sandboxes/opencsg/ShaderCSGDisplay.cpp

@@ -0,0 +1,68 @@
+#include "ShaderCSGDisplay.hpp"
+#include "libslic3r/SLAPrint.hpp"
+#include <GL/glew.h>
+
+namespace Slic3r { namespace GL {
+
+void ShaderCSGDisplay::add_mesh(const TriangleMesh &mesh)
+{
+    auto v = std::make_shared<CSGVolume>();
+    v->load_mesh(mesh);
+    m_volumes.emplace_back(v);
+}
+
+void ShaderCSGDisplay::render_scene()
+{
+    GLfloat color[] = {1.f, 1.f, 0.f, 0.f};
+    glColor4fv(color);
+    glDepthFunc(GL_LESS);
+    for (auto &v : m_volumes) v->render();
+    glFlush();
+}
+
+void ShaderCSGDisplay::on_scene_updated(const Scene &scene)
+{
+    // TriangleMesh mesh = print->objects().front()->hollowed_interior_mesh();
+    // Look at CSGDisplay::on_scene_updated to see how its done there.
+    
+    const SLAPrint *print = scene.get_print();
+    if (!print) return;
+    
+    m_volumes.clear();
+    
+    for (const SLAPrintObject *po : print->objects()) {
+        const ModelObject *mo = po->model_object();
+        TriangleMesh msh = mo->raw_mesh();
+        
+        sla::DrainHoles holedata = mo->sla_drain_holes;
+        
+        for (const ModelInstance *mi : mo->instances) {
+            
+            TriangleMesh mshinst = msh;
+            auto interior = po->hollowed_interior_mesh();
+            interior.transform(po->trafo().inverse());
+            
+            mshinst.merge(interior);
+            mshinst.require_shared_vertices();
+            
+            mi->transform_mesh(&mshinst);
+            
+            auto bb = mshinst.bounding_box();
+            auto center = bb.center().cast<float>();
+            mshinst.translate(-center);
+            
+            mshinst.require_shared_vertices();
+            add_mesh(mshinst);
+        }
+        
+        for (const sla::DrainHole &holept : holedata) {
+            TriangleMesh holemesh = sla::to_triangle_mesh(holept.to_mesh());
+            holemesh.require_shared_vertices();
+            add_mesh(holemesh);
+        }
+    }
+    
+    repaint();
+}
+
+}} // namespace Slic3r::GL

sandboxes/opencsg/ShaderCSGDisplay.hpp

@@ -0,0 +1,27 @@
+#ifndef SHADERCSGDISPLAY_HPP
+#define SHADERCSGDISPLAY_HPP
+
+#include "Engine.hpp"
+
+namespace Slic3r { namespace GL {
+
+class CSGVolume: public Volume
+{
+    // Extend...    
+};
+
+class ShaderCSGDisplay: public Display {
+protected:
+    vector<shptr<CSGVolume>> m_volumes;
+    
+    void add_mesh(const TriangleMesh &mesh);
+public:
+    
+    void render_scene() override;
+    
+    void on_scene_updated(const Scene &scene) override;
+};
+
+}}
+
+#endif // SHADERCSGDISPLAY_HPP

sandboxes/opencsg/main.cpp

@@ -0,0 +1,734 @@
+#include <iostream>
+#include <utility>
+#include <memory>
+
+#include "Engine.hpp"
+#include "ShaderCSGDisplay.hpp"
+
+#include <GL/glew.h>
+
+#include <opencsg/opencsg.h>
+// For compilers that support precompilation, includes "wx/wx.h".
+#include <wx/wxprec.h>
+#ifndef WX_PRECOMP
+#include <wx/wx.h>
+#endif
+
+#include <wx/slider.h>
+#include <wx/tglbtn.h>
+#include <wx/combobox.h>
+#include <wx/spinctrl.h>
+#include <wx/msgdlg.h>
+#include <wx/glcanvas.h>
+#include <wx/cmdline.h>
+
+#include "libslic3r/Model.hpp"
+#include "libslic3r/Format/3mf.hpp"
+#include "libslic3r/SLAPrint.hpp"
+
+#include "slic3r/GUI/Job.hpp"
+#include "slic3r/GUI/ProgressStatusBar.hpp"
+
+using namespace Slic3r::GL;
+
+class Renderer {
+protected:
+    wxGLCanvas *m_canvas;
+    shptr<wxGLContext> m_context;
+public:
+    
+    Renderer(wxGLCanvas *c): m_canvas{c} {
+        auto ctx = new wxGLContext(m_canvas);
+        if (!ctx || !ctx->IsOK()) {
+            wxMessageBox("Could not create OpenGL context.", "Error",
+                         wxOK | wxICON_ERROR);
+            return;
+        }
+        
+        m_context.reset(ctx);
+    }
+    
+    wxGLContext * context() { return m_context.get(); }
+    const wxGLContext * context() const { return m_context.get(); }
+};
+
+// Tell the CSGDisplay how to swap buffers and set the gl context.
+class OCSGRenderer: public Renderer, public Slic3r::GL::CSGDisplay {
+public:
+    
+    OCSGRenderer(wxGLCanvas *c): Renderer{c} {}
+    
+    void set_active(long w, long h) override
+    {
+        m_canvas->SetCurrent(*m_context);
+        Slic3r::GL::Display::set_active(w, h);
+    }
+    
+    void swap_buffers() override { m_canvas->SwapBuffers(); }
+};
+
+// Tell the CSGDisplay how to swap buffers and set the gl context.
+class ShaderCSGRenderer : public Renderer, public Slic3r::GL::ShaderCSGDisplay {
+public:
+    
+    ShaderCSGRenderer(wxGLCanvas *c): Renderer{c} {}
+    
+    void set_active(long w, long h) override
+    {
+        m_canvas->SetCurrent(*m_context);
+        Slic3r::GL::Display::set_active(w, h);
+    }
+    
+    void swap_buffers() override { m_canvas->SwapBuffers(); }
+};
+
+// The opengl rendering facility. Here we implement the rendering objects.
+class Canvas: public wxGLCanvas
+{    
+    // One display is active at a time, the OCSGRenderer by default.
+    shptr<Slic3r::GL::Display> m_display;
+    
+public:
+    
+    template<class...Args>
+    Canvas(Args &&...args): wxGLCanvas(std::forward<Args>(args)...) {}
+    
+    shptr<Slic3r::GL::Display> get_display() const { return m_display; }
+
+    void set_display(shptr<Slic3r::GL::Display> d) { m_display = d; }
+};
+
+// Enumerate possible mouse events, we will record them.
+enum EEvents { LCLK_U, RCLK_U, LCLK_D, RCLK_D, DDCLK, SCRL, MV };
+struct Event
+{
+    EEvents type;
+    long    a, b;
+    Event(EEvents t, long x = 0, long y = 0) : type{t}, a{x}, b{y} {}
+};
+
+// Create a special mouse input adapter, which can store (record) the received
+// mouse signals into a file and play back the stored events later.
+class RecorderMouseInput: public MouseInput {
+    std::vector<Event> m_events;
+    bool m_recording = false, m_playing = false;
+    
+public:
+    void left_click_down() override
+    {
+        if (m_recording) m_events.emplace_back(LCLK_D);
+        if (!m_playing) MouseInput::left_click_down();
+    }
+    void left_click_up() override
+    {
+        if (m_recording) m_events.emplace_back(LCLK_U);
+        if (!m_playing) MouseInput::left_click_up();
+    }
+    void right_click_down() override
+    {
+        if (m_recording) m_events.emplace_back(RCLK_D);
+        if (!m_playing) MouseInput::right_click_down();
+    }
+    void right_click_up() override
+    {
+        if (m_recording) m_events.emplace_back(RCLK_U);
+        if (!m_playing) MouseInput::right_click_up();
+    }
+    void double_click() override
+    {
+        if (m_recording) m_events.emplace_back(DDCLK);
+        if (!m_playing) MouseInput::double_click();
+    }
+    void scroll(long v, long d, WheelAxis wa) override
+    {
+        if (m_recording) m_events.emplace_back(SCRL, v, d);
+        if (!m_playing) MouseInput::scroll(v, d, wa);
+    }
+    void move_to(long x, long y) override
+    {
+        if (m_recording) m_events.emplace_back(MV, x, y);
+        if (!m_playing) MouseInput::move_to(x, y);
+    }
+    
+    void save(std::ostream &stream)
+    {
+        for (const Event &evt : m_events)
+            stream << evt.type << " " << evt.a << " " << evt.b << std::endl;
+    }
+    
+    void load(std::istream &stream)
+    {
+        m_events.clear();
+        while (stream.good()) {
+            int type; long a, b;
+            stream >> type >> a >> b;
+            m_events.emplace_back(EEvents(type), a, b);
+        }
+    }    
+    
+    void record(bool r) { m_recording = r; if (r) m_events.clear(); }
+    
+    void play()
+    {
+        m_playing = true;
+        for (const Event &evt : m_events) {
+            switch (evt.type) {
+            case LCLK_U: MouseInput::left_click_up(); break;
+            case LCLK_D: MouseInput::left_click_down(); break;
+            case RCLK_U: MouseInput::right_click_up(); break;
+            case RCLK_D: MouseInput::right_click_down(); break;
+            case DDCLK:  MouseInput::double_click(); break;
+            case SCRL:   MouseInput::scroll(evt.a, evt.b, WheelAxis::waVertical); break;
+            case MV:     MouseInput::move_to(evt.a, evt.b); break;
+            }
+            
+            wxTheApp->Yield();
+            if (!m_playing)
+                break;
+        }
+        m_playing = false;
+    }
+    
+    void stop() { m_playing = false; }
+    bool is_playing() const { return m_playing; }
+};
+
+// The top level frame of the application.
+class MyFrame: public wxFrame
+{
+    // Instantiate the 3D engine.
+    shptr<Scene>             m_scene;             // Model
+    shptr<Canvas>            m_canvas;            // Views store
+    shptr<OCSGRenderer>      m_ocsgdisplay;       // View
+    shptr<ShaderCSGRenderer> m_shadercsg_display; // Another view
+    shptr<Controller>        m_ctl;               // Controller
+
+    // Add a status bar with progress indication.
+    shptr<Slic3r::GUI::ProgressStatusBar> m_stbar;
+    
+    RecorderMouseInput m_mouse;
+    
+    // When loading a Model from 3mf and preparing it, we use a separate thread.
+    class SLAJob: public Slic3r::GUI::Job {
+        MyFrame *m_parent;
+        std::unique_ptr<Slic3r::SLAPrint> m_print;
+        std::string m_fname;
+        
+    public:
+        SLAJob(MyFrame *frame, const std::string &fname)
+            : Slic3r::GUI::Job{frame->m_stbar}
+            , m_parent{frame}
+            , m_fname{fname}
+        {}
+        
+        // Runs in separate thread
+        void process() override;
+        
+        const std::string & get_project_fname() const { return m_fname; }
+        
+    protected:
+        
+        // Runs in the UI thread.
+        void finalize() override 
+        {
+            m_parent->m_scene->set_print(std::move(m_print));
+            m_parent->m_stbar->set_status_text(
+                        wxString::Format("Model %s loaded.", m_fname));
+        }
+    };
+    
+    uqptr<SLAJob> m_ui_job;
+    
+    // To keep track of the running average of measured fps values.
+    double m_fps_avg = 0.;
+    
+    // We need the record button across methods
+    wxToggleButton *m_record_btn;
+    wxComboBox *    m_alg_select;
+    wxComboBox *    m_depth_select;
+    wxComboBox *    m_optimization_select;
+    wxSpinCtrl *    m_convexity_spin;
+    wxToggleButton *m_csg_toggle;
+    wxToggleButton *m_ms_toggle;
+    wxStaticText   *m_fpstext;
+    
+    CSGSettings     m_csg_settings;
+    
+    void read_csg_settings(const wxCmdLineParser &parser);
+    
+    void set_renderer_algorithm(const wxString &alg);
+    
+    void activate_canvas_display();
+    
+public:
+    MyFrame(const wxString &       title,
+            const wxPoint &        pos,
+            const wxSize &         size,
+            const wxCmdLineParser &parser);
+
+    // Grab a 3mf and load (hollow it out) within the UI job.
+    void load_model(const std::string &fname) {
+        m_ui_job = std::make_unique<SLAJob>(this, fname);
+        m_ui_job->start();
+    }
+    
+    // Load a previously stored mouse event log and play it back.
+    void play_back_mouse(const std::string &events_fname)
+    {
+        std::fstream stream(events_fname, std::fstream::in);
+
+        if (stream.good()) {
+            std::string model_name;
+            std::getline(stream, model_name);
+            load_model(model_name);
+            
+            while (!m_ui_job->is_finalized())
+                wxTheApp->Yield();;
+            
+            int w, h;
+            stream >> w >> h;
+            SetSize(w, h);
+            
+            m_mouse.load(stream);
+            if (m_record_btn) m_record_btn->Disable();
+            m_mouse.play();
+        }
+    }
+    
+    Canvas * canvas() { return m_canvas.get(); }
+    const Canvas * canvas() const { return m_canvas.get(); }
+    
+    // Bind the canvas mouse events to a class implementing MouseInput interface
+    void bind_canvas_events(MouseInput &msinput);
+    
+    double get_fps_average() const { return m_fps_avg; }
+};
+
+// Possible OpenCSG configuration values. Will be used on the command line and
+// on the UI widgets.
+static const std::vector<wxString> CSG_ALGS  = {"Auto", "Goldfeather", "SCS", "EnricoShader"};
+static const std::vector<wxString> CSG_DEPTH = {"Off", "OcclusionQuery", "On"};
+static const std::vector<wxString> CSG_OPT   = { "Default", "ForceOn", "On", "Off" };
+
+inline long get_idx(const wxString &a, const std::vector<wxString> &v)
+{
+    auto it = std::find(v.begin(), v.end(), a.ToStdString());
+    return it - v.begin();
+};
+
+class App : public wxApp {
+    MyFrame *m_frame = nullptr;
+    wxString m_fname;
+public:
+    bool OnInit() override {
+        
+        wxCmdLineParser parser(argc, argv);
+        
+        parser.AddOption("p", "play", "play back file", wxCMD_LINE_VAL_STRING, wxCMD_LINE_PARAM_OPTIONAL);
+        parser.AddOption("a", "algorithm", "OpenCSG algorithm [Auto|Goldfeather|SCS]", wxCMD_LINE_VAL_STRING, wxCMD_LINE_PARAM_OPTIONAL);
+        parser.AddOption("d", "depth", "OpenCSG depth strategy [Off|OcclusionQuery|On]", wxCMD_LINE_VAL_STRING, wxCMD_LINE_PARAM_OPTIONAL);
+        parser.AddOption("o", "optimization", "OpenCSG optimization strategy [Default|ForceOn|On|Off]", wxCMD_LINE_VAL_STRING, wxCMD_LINE_PARAM_OPTIONAL);
+        parser.AddOption("c", "convexity", "OpenCSG convexity parameter for generic meshes", wxCMD_LINE_VAL_NUMBER, wxCMD_LINE_PARAM_OPTIONAL);
+        parser.AddSwitch("", "disable-csg", "Disable csg rendering", wxCMD_LINE_PARAM_OPTIONAL);
+        
+        parser.Parse();
+        
+        bool is_play = parser.Found("play", &m_fname);
+        
+        m_frame = new MyFrame("PrusaSlicer OpenCSG Demo", wxDefaultPosition, wxSize(1024, 768), parser);
+
+        if (is_play) {
+            Bind(wxEVT_IDLE, &App::Play, this);
+            m_frame->Show( true );
+        } else m_frame->Show( true );
+        
+        return true;
+    }
+    
+    void Play(wxIdleEvent &) {
+        Unbind(wxEVT_IDLE, &App::Play, this);
+        m_frame->play_back_mouse(m_fname.ToStdString());
+        m_frame->Destroy();
+    }
+};
+
+wxIMPLEMENT_APP(App);
+
+void MyFrame::read_csg_settings(const wxCmdLineParser &parser)
+{
+    wxString alg;
+    parser.Found("algorithm", &alg);
+    
+    wxString depth;
+    parser.Found("depth", &depth);
+    
+    wxString opt;
+    parser.Found("optimization", &opt);
+    
+    long convexity = 1;
+    parser.Found("convexity", &convexity);
+    
+    bool csg_off = parser.Found("disable-csg");
+    
+    if (auto a = get_idx(alg, CSG_ALGS) < OpenCSG::AlgorithmUnused) 
+            m_csg_settings.set_algo(OpenCSG::Algorithm(a));
+    
+    if (auto a = get_idx(depth, CSG_DEPTH) < OpenCSG::DepthComplexityAlgorithmUnused) 
+            m_csg_settings.set_depth_algo(OpenCSG::DepthComplexityAlgorithm(a));
+    
+    if (auto a = get_idx(opt, CSG_OPT) < OpenCSG::OptimizationUnused) 
+            m_csg_settings.set_optimization(OpenCSG::Optimization(a));
+    
+    m_csg_settings.set_convexity(unsigned(convexity));
+    m_csg_settings.enable_csg(!csg_off);
+    
+    if (m_ocsgdisplay) m_ocsgdisplay->apply_csgsettings(m_csg_settings);
+}
+
+void MyFrame::set_renderer_algorithm(const wxString &alg)
+{
+    long alg_idx = get_idx(alg, CSG_ALGS);
+    if (alg_idx < 0 || alg_idx >= long(CSG_ALGS.size())) return;
+    
+    // If there is a valid display in place, save its camera.
+    auto cam = m_canvas->get_display() ?
+                   m_canvas->get_display()->get_camera() : nullptr;
+
+    if (alg == "EnricoShader") {
+        m_alg_select->SetSelection(int(alg_idx));
+        m_depth_select->Disable();
+        m_optimization_select->Disable();
+        m_csg_toggle->Disable();
+        
+        m_ocsgdisplay.reset();
+        canvas()->set_display(nullptr);
+        m_shadercsg_display = std::make_shared<ShaderCSGRenderer>(canvas());
+        canvas()->set_display(m_shadercsg_display);
+    } else {
+        if (m_csg_settings.get_algo() > 0) m_depth_select->Enable(true);
+        m_alg_select->SetSelection(m_csg_settings.get_algo());
+        m_depth_select->SetSelection(m_csg_settings.get_depth_algo());
+        m_optimization_select->SetSelection(m_csg_settings.get_optimization());
+        m_convexity_spin->SetValue(int(m_csg_settings.get_convexity()));
+        m_csg_toggle->SetValue(m_csg_settings.is_enabled());
+        m_optimization_select->Enable();
+        m_csg_toggle->Enable();
+        
+        m_shadercsg_display.reset();
+        canvas()->set_display(nullptr);
+        m_ocsgdisplay = std::make_shared<OCSGRenderer>(canvas());
+        m_ocsgdisplay->apply_csgsettings(m_csg_settings);
+        canvas()->set_display(m_ocsgdisplay);
+    }
+    
+    if (cam)
+        m_canvas->get_display()->set_camera(cam);
+    
+    m_ctl->remove_displays();
+    m_ctl->add_display(m_canvas->get_display());
+    m_canvas->get_display()->get_fps_counter().add_listener([this](double fps) {
+        m_fpstext->SetLabel(wxString::Format("fps: %.2f", fps));
+        m_fps_avg = 0.9 * m_fps_avg + 0.1 * fps;
+    });
+    
+    if (IsShown()) {
+        activate_canvas_display();
+        m_canvas->get_display()->on_scene_updated(*m_scene);
+    }
+}
+
+void MyFrame::activate_canvas_display()
+{
+    const wxSize ClientSize = m_canvas->GetClientSize();
+    m_canvas->get_display()->set_active(ClientSize.x, ClientSize.y);
+    enable_multisampling(m_ms_toggle->GetValue());
+    
+    m_canvas->Bind(wxEVT_PAINT, [this](wxPaintEvent &) {
+        // This is required even though dc is not used otherwise.
+        wxPaintDC dc(m_canvas.get());
+        const wxSize csize = m_canvas->GetClientSize();
+        m_canvas->get_display()->set_screen_size(csize.x, csize.y);
+        m_canvas->get_display()->repaint();
+    });
+    
+    m_canvas->Bind(wxEVT_SIZE, [this](wxSizeEvent &) {
+        const wxSize csize = m_canvas->GetClientSize();
+        m_canvas->get_display()->set_screen_size(csize.x, csize.y);
+        m_canvas->get_display()->repaint();
+    });
+    
+    // Do the repaint continuously
+    m_canvas->Bind(wxEVT_IDLE, [this](wxIdleEvent &evt) {
+        m_canvas->get_display()->repaint();
+        evt.RequestMore();
+    });
+    
+    bind_canvas_events(m_mouse);
+}
+
+MyFrame::MyFrame(const wxString &title, const wxPoint &pos, const wxSize &size, 
+                 const wxCmdLineParser &parser):
+    wxFrame(nullptr, wxID_ANY, title, pos, size)
+{
+    wxMenu *menuFile = new wxMenu;
+    menuFile->Append(wxID_OPEN);
+    menuFile->Append(wxID_EXIT);
+    wxMenuBar *menuBar = new wxMenuBar;
+    menuBar->Append( menuFile, "&File" );
+    SetMenuBar( menuBar );
+    
+    m_stbar = std::make_shared<Slic3r::GUI::ProgressStatusBar>(this);
+    m_stbar->embed(this);
+    
+    SetStatusText( "Welcome to wxWidgets!" );
+    
+    int attribList[] =
+    {WX_GL_RGBA, WX_GL_DOUBLEBUFFER,
+     // RGB channels each should be allocated with 8 bit depth. One
+     // should almost certainly get these bit depths by default.
+     WX_GL_MIN_RED, 8, WX_GL_MIN_GREEN, 8, WX_GL_MIN_BLUE, 8,
+     // Requesting an 8 bit alpha channel. Interestingly, the NVIDIA
+     // drivers would most likely work with some alpha plane, but
+     // glReadPixels would not return the alpha channel on NVIDIA if
+     // not requested when the GL context is created.
+     WX_GL_MIN_ALPHA, 8, WX_GL_DEPTH_SIZE, 8, WX_GL_STENCIL_SIZE, 8,
+     WX_GL_SAMPLE_BUFFERS, GL_TRUE, WX_GL_SAMPLES, 4, 0};
+    
+    m_scene = std::make_shared<Scene>();
+    m_ctl = std::make_shared<Controller>();
+    m_ctl->set_scene(m_scene);
+    
+    m_canvas = std::make_shared<Canvas>(this, wxID_ANY, attribList,
+                                        wxDefaultPosition, wxDefaultSize,
+                                        wxWANTS_CHARS | wxFULL_REPAINT_ON_RESIZE);
+    
+    read_csg_settings(parser);
+
+    wxPanel *control_panel = new wxPanel(this);
+
+    auto controlsizer = new wxBoxSizer(wxHORIZONTAL);
+    auto slider_sizer = new wxBoxSizer(wxVERTICAL);
+    auto console_sizer = new wxBoxSizer(wxVERTICAL);
+    
+    auto slider = new wxSlider(control_panel, wxID_ANY, 0, 0, 100,
+                               wxDefaultPosition, wxDefaultSize,
+                               wxSL_VERTICAL);
+    slider_sizer->Add(slider, 1, wxEXPAND);
+    
+    m_ms_toggle = new wxToggleButton(control_panel, wxID_ANY, "Multisampling");
+    console_sizer->Add(m_ms_toggle, 0, wxALL | wxEXPAND, 5);
+    
+    m_csg_toggle = new wxToggleButton(control_panel, wxID_ANY, "CSG");
+    m_csg_toggle->SetValue(true);
+    console_sizer->Add(m_csg_toggle, 0, wxALL | wxEXPAND, 5);
+    
+    auto add_combobox = [control_panel, console_sizer]
+            (const wxString &label, const std::vector<wxString> &list)
+    {
+        auto widget = new wxComboBox(control_panel, wxID_ANY, list[0],
+                wxDefaultPosition, wxDefaultSize,
+                int(list.size()), list.data());
+        
+        auto sz = new wxBoxSizer(wxHORIZONTAL);
+        sz->Add(new wxStaticText(control_panel, wxID_ANY, label), 0,
+                wxALL | wxALIGN_CENTER, 5);
+        sz->Add(widget, 1, wxALL | wxEXPAND, 5);
+        console_sizer->Add(sz, 0, wxEXPAND);
+        return widget;
+    };
+    
+    auto add_spinctl = [control_panel, console_sizer]
+            (const wxString &label, int initial, int min, int max)
+    {    
+        auto widget = new wxSpinCtrl(
+                    control_panel, wxID_ANY,
+                    wxString::Format("%d", initial),
+                    wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS, min, max,
+                    initial);
+        
+        auto sz = new wxBoxSizer(wxHORIZONTAL);
+        sz->Add(new wxStaticText(control_panel, wxID_ANY, label), 0,
+                wxALL | wxALIGN_CENTER, 5);
+        sz->Add(widget, 1, wxALL | wxEXPAND, 5);
+        console_sizer->Add(sz, 0, wxEXPAND);
+        return widget;
+    };
+    
+    m_convexity_spin = add_spinctl("Convexity", CSGSettings::DEFAULT_CONVEXITY, 0, 100);
+    
+    m_alg_select = add_combobox("Algorithm", CSG_ALGS);
+    m_depth_select = add_combobox("Depth Complexity", CSG_DEPTH);
+    m_optimization_select = add_combobox("Optimization", CSG_OPT);
+    
+    m_fpstext = new wxStaticText(control_panel, wxID_ANY, "");
+    console_sizer->Add(m_fpstext, 0, wxALL, 5);
+    
+    m_record_btn = new wxToggleButton(control_panel, wxID_ANY, "Record");
+    console_sizer->Add(m_record_btn, 0, wxALL | wxEXPAND, 5);
+    
+    controlsizer->Add(slider_sizer, 0, wxEXPAND);
+    controlsizer->Add(console_sizer, 1, wxEXPAND);
+    
+    control_panel->SetSizer(controlsizer);
+    
+    auto sizer = new wxBoxSizer(wxHORIZONTAL);
+    sizer->Add(m_canvas.get(), 1, wxEXPAND);
+    sizer->Add(control_panel, 0, wxEXPAND);
+    SetSizer(sizer);
+    
+    wxString alg;
+    if (!parser.Found("algorithm", &alg)) alg = "Auto";
+    
+    set_renderer_algorithm(alg);
+    
+    Bind(wxEVT_CLOSE_WINDOW, [this](wxCloseEvent &evt){
+        if (m_canvas) RemoveChild(m_canvas.get());
+        m_canvas.reset();
+        if (!m_mouse.is_playing()) evt.Skip();
+        else m_mouse.stop();
+    });    
+    
+    Bind(wxEVT_MENU, [this](wxCommandEvent &) {
+        wxFileDialog dlg(this, "Select project file",  wxEmptyString,
+                         wxEmptyString, "*.3mf", wxFD_OPEN|wxFD_FILE_MUST_EXIST);
+
+        if (dlg.ShowModal() == wxID_OK) load_model(dlg.GetPath().ToStdString());
+    }, wxID_OPEN);
+    
+    Bind(wxEVT_MENU, [this](wxCommandEvent &) { Close(true); }, wxID_EXIT);
+    
+    Bind(wxEVT_SHOW, [this](wxShowEvent &) {
+        activate_canvas_display();
+    });
+    
+    Bind(wxEVT_SLIDER, [this, slider](wxCommandEvent &) {
+        m_ctl->move_clip_plane(double(slider->GetValue()));
+    });
+    
+    m_ms_toggle->Bind(wxEVT_TOGGLEBUTTON, [this](wxCommandEvent &){
+        enable_multisampling(m_ms_toggle->GetValue());
+        m_canvas->get_display()->repaint();
+    });
+    
+    m_csg_toggle->Bind(wxEVT_TOGGLEBUTTON, [this](wxCommandEvent &){
+        CSGSettings stt = m_ocsgdisplay->get_csgsettings();
+        stt.enable_csg(m_csg_toggle->GetValue());
+        m_ocsgdisplay->apply_csgsettings(stt);
+    });
+    
+    m_alg_select->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent &) {
+        wxString alg = m_alg_select->GetValue();
+        int sel = m_alg_select->GetSelection();
+        m_csg_settings.set_algo(sel);
+        set_renderer_algorithm(alg);
+    });
+    
+    m_depth_select->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent &) {
+        int sel = m_depth_select->GetSelection();
+        m_csg_settings.set_depth_algo(sel);
+        if (m_ocsgdisplay) m_ocsgdisplay->apply_csgsettings(m_csg_settings);
+    });
+    
+    m_optimization_select->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent &) {
+        int sel = m_optimization_select->GetSelection();
+        m_csg_settings.set_optimization(sel);
+        if (m_ocsgdisplay) m_ocsgdisplay->apply_csgsettings(m_csg_settings);
+    });
+    
+    m_convexity_spin->Bind(wxEVT_SPINCTRL, [this](wxSpinEvent &) {
+        int c = m_convexity_spin->GetValue();
+        if (c > 0) {
+            m_csg_settings.set_convexity(unsigned(c));
+            if (m_ocsgdisplay) m_ocsgdisplay->apply_csgsettings(m_csg_settings);
+        }
+    });
+    
+    m_record_btn->Bind(wxEVT_TOGGLEBUTTON, [this](wxCommandEvent &) {
+        if (!m_ui_job) {
+            m_stbar->set_status_text("No project loaded!");
+            return;
+        }
+        
+        if (m_record_btn->GetValue()) {
+            if (auto c = m_canvas->get_display()->get_camera()) reset(*c);
+            m_ctl->on_scene_updated(*m_scene);
+            m_mouse.record(true);
+        } else {
+            m_mouse.record(false);
+            wxFileDialog dlg(this, "Select output file",
+                             wxEmptyString, wxEmptyString, "*.events",
+                             wxFD_SAVE|wxFD_OVERWRITE_PROMPT);
+            
+            if (dlg.ShowModal() == wxID_OK) {
+                std::fstream stream(dlg.GetPath().ToStdString(),
+                                    std::fstream::out);
+                
+                if (stream.good()) {
+                    stream << m_ui_job->get_project_fname() << "\n";
+                    wxSize winsize = GetSize();
+                    stream << winsize.x << " " << winsize.y << "\n";
+                    m_mouse.save(stream);
+                }
+            }
+        }
+    });
+}
+
+void MyFrame::bind_canvas_events(MouseInput &ms)
+{
+    m_canvas->Bind(wxEVT_MOUSEWHEEL, [&ms](wxMouseEvent &evt) {
+        ms.scroll(evt.GetWheelRotation(), evt.GetWheelDelta(),
+                  evt.GetWheelAxis() == wxMOUSE_WHEEL_VERTICAL ?
+                      Slic3r::GL::MouseInput::waVertical :
+                      Slic3r::GL::MouseInput::waHorizontal);
+    });
+
+    m_canvas->Bind(wxEVT_MOTION, [&ms](wxMouseEvent &evt) {
+        ms.move_to(evt.GetPosition().x, evt.GetPosition().y);
+    });
+
+    m_canvas->Bind(wxEVT_RIGHT_DOWN, [&ms](wxMouseEvent & /*evt*/) {
+        ms.right_click_down();
+    });
+
+    m_canvas->Bind(wxEVT_RIGHT_UP, [&ms](wxMouseEvent & /*evt*/) {
+        ms.right_click_up();
+    });
+
+    m_canvas->Bind(wxEVT_LEFT_DOWN, [&ms](wxMouseEvent & /*evt*/) {
+        ms.left_click_down();
+    });
+
+    m_canvas->Bind(wxEVT_LEFT_UP, [&ms](wxMouseEvent & /*evt*/) {
+        ms.left_click_up();
+    });
+    
+    ms.add_listener(m_ctl);
+}
+
+void MyFrame::SLAJob::process() 
+{
+    using SlStatus = Slic3r::PrintBase::SlicingStatus;
+    
+    Slic3r::DynamicPrintConfig cfg;
+    auto model = Slic3r::Model::read_from_file(m_fname, &cfg);
+    
+    m_print = std::make_unique<Slic3r::SLAPrint>();
+    m_print->apply(model, cfg);
+    
+    Slic3r::PrintBase::TaskParams params;
+    params.to_object_step = Slic3r::slaposHollowing;
+    m_print->set_task(params);
+    
+    m_print->set_status_callback([this](const SlStatus &status) {
+        update_status(status.percent, status.text);
+    });
+    
+    try {
+        m_print->process();
+    } catch(std::exception &e) {
+        update_status(0, wxString("Exception during processing: ") + e.what());
+    }
+}
+
+//int main() {}

sandboxes/openvdb/CMakeLists.txt

@@ -1,2 +1,7 @@
+if(TARGET OpenVDB::openvdb)
     add_executable(openvdb_example openvdb_example.cpp)
+
     target_link_libraries(openvdb_example libslic3r)
+    target_link_libraries(openvdb_example OpenVDB::openvdb)
+endif()
+

src/libslic3r/CMakeLists.txt

@@ -9,6 +9,11 @@ if (MINGW)
     add_compile_options(-Wa,-mbig-obj)
 endif ()
 
+set(OpenVDBUtils_SOURCES "")
+if (TARGET OpenVDB::openvdb)
+    set(OpenVDBUtils_SOURCES OpenVDBUtils.cpp OpenVDBUtils.hpp)
+endif()
+
 add_library(libslic3r STATIC
     pchheader.cpp
     pchheader.hpp
@@ -149,9 +154,9 @@ add_library(libslic3r STATIC
     ShortestPath.cpp
     ShortestPath.hpp
     SLAPrint.cpp
+    SLAPrintSteps.cpp
+    SLAPrintSteps.hpp
     SLAPrint.hpp
-    SLA/SLAAutoSupports.hpp
-    SLA/SLAAutoSupports.cpp
     Slicing.cpp
     Slicing.hpp
     SlicingAdaptive.cpp
@@ -180,35 +185,65 @@ add_library(libslic3r STATIC
     MinAreaBoundingBox.cpp
     miniz_extension.hpp
     miniz_extension.cpp
-    SLA/SLACommon.hpp
+    SimplifyMesh.hpp
-    SLA/SLABoilerPlate.hpp
+    SimplifyMeshImpl.hpp
-    SLA/SLAPad.hpp
+    SimplifyMesh.cpp
-    SLA/SLAPad.cpp
+    ${OpenVDBUtils_SOURCES}
-    SLA/SLASupportTreeBuilder.hpp
+    SLA/Common.hpp
-    SLA/SLASupportTreeBuildsteps.hpp
+    SLA/Common.cpp
-    SLA/SLASupportTreeBuildsteps.cpp
+    SLA/Pad.hpp
-    SLA/SLASupportTreeBuilder.cpp
+    SLA/Pad.cpp
-    SLA/SLAConcurrency.hpp
+    SLA/SupportTreeBuilder.hpp
-    SLA/SLASupportTree.hpp
+    SLA/SupportTreeBuildsteps.hpp
-    SLA/SLASupportTree.cpp
+    SLA/SupportTreeBuildsteps.cpp
-    SLA/SLASupportTreeIGL.cpp
+    SLA/SupportTreeBuilder.cpp
-    SLA/SLARotfinder.hpp
+    SLA/Concurrency.hpp
-    SLA/SLARotfinder.cpp
+    SLA/SupportTree.hpp
-    SLA/SLABoostAdapter.hpp
+    SLA/SupportTree.cpp
-    SLA/SLASpatIndex.hpp
+#    SLA/SupportTreeIGL.cpp
-    SLA/SLARaster.hpp
+    SLA/Rotfinder.hpp
-    SLA/SLARaster.cpp
+    SLA/Rotfinder.cpp
-    SLA/SLARasterWriter.hpp
+    SLA/BoostAdapter.hpp
-    SLA/SLARasterWriter.cpp
+    SLA/SpatIndex.hpp
+    SLA/Raster.hpp
+    SLA/Raster.cpp
+    SLA/RasterWriter.hpp
+    SLA/RasterWriter.cpp
     SLA/ConcaveHull.hpp
     SLA/ConcaveHull.cpp
+    SLA/Hollowing.hpp
+    SLA/Hollowing.cpp
+    SLA/JobController.hpp
+    SLA/SupportPoint.hpp
+    SLA/SupportPointGenerator.hpp
+    SLA/SupportPointGenerator.cpp
+    SLA/Contour3D.hpp
+    SLA/Contour3D.cpp
+    SLA/EigenMesh3D.hpp
+    SLA/Clustering.hpp
 )
 
-encoding_check(libslic3r)
+if (SLIC3R_STATIC)
-
+    set(CGAL_Boost_USE_STATIC_LIBS ON CACHE BOOL "" FORCE)
-if (SLIC3R_PCH AND NOT SLIC3R_SYNTAXONLY)
-    add_precompiled_header(libslic3r pchheader.hpp FORCEINCLUDE)
 endif ()
+set(CGAL_DO_NOT_WARN_ABOUT_CMAKE_BUILD_TYPE ON CACHE BOOL "" FORCE)
+
+cmake_policy(PUSH)
+cmake_policy(SET CMP0011 NEW)
+find_package(CGAL REQUIRED)
+cmake_policy(POP)
+
+add_library(libslic3r_cgal OBJECT MeshBoolean.cpp MeshBoolean.hpp)
+target_include_directories(libslic3r_cgal PRIVATE
+    ${CMAKE_CURRENT_BINARY_DIR}
+    $<TARGET_PROPERTY:libigl,INTERFACE_INCLUDE_DIRECTORIES>
+    $<TARGET_PROPERTY:CGAL::CGAL,INTERFACE_INCLUDE_DIRECTORIES>)
+target_compile_definitions(libslic3r_cgal PRIVATE 
+    $<TARGET_PROPERTY:CGAL::CGAL,INTERFACE_COMPILE_DEFINITIONS>)
+target_compile_options(libslic3r_cgal PRIVATE 
+    $<TARGET_PROPERTY:CGAL::CGAL,INTERFACE_COMPILE_OPTIONS>)
+
+encoding_check(libslic3r)
 
 target_compile_definitions(libslic3r PUBLIC -DUSE_TBB -DTBB_USE_CAPTURED_EXCEPTION=0)
 target_include_directories(libslic3r PRIVATE ${CMAKE_CURRENT_SOURCE_DIR} ${LIBNEST2D_INCLUDES} PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
@@ -228,10 +263,14 @@ target_link_libraries(libslic3r
     qhull
     semver
     TBB::tbb
-    # OpenVDB::openvdb
+    $<TARGET_PROPERTY:CGAL::CGAL,INTERFACE_LINK_LIBRARIES>
     ${CMAKE_DL_LIBS}
     )
 
+if (TARGET OpenVDB::openvdb)
+    target_link_libraries(libslic3r OpenVDB::openvdb)
+endif()
+
 if(WIN32)
     target_link_libraries(libslic3r Psapi.lib)
 endif()
@@ -239,3 +278,9 @@ endif()
 if(SLIC3R_PROFILE)
     target_link_libraries(slic3r Shiny)
 endif()
+
+if (SLIC3R_PCH AND NOT SLIC3R_SYNTAXONLY)
+    add_precompiled_header(libslic3r pchheader.hpp FORCEINCLUDE)
+endif ()
+
+target_sources(libslic3r PRIVATE $<TARGET_OBJECTS:libslic3r_cgal>)

src/libslic3r/Format/3mf.cpp

@@ -55,6 +55,7 @@ const std::string MODEL_CONFIG_FILE = "Metadata/Slic3r_PE_model.config";
 const std::string LAYER_HEIGHTS_PROFILE_FILE = "Metadata/Slic3r_PE_layer_heights_profile.txt";
 const std::string LAYER_CONFIG_RANGES_FILE = "Metadata/Prusa_Slicer_layer_config_ranges.xml";
 const std::string SLA_SUPPORT_POINTS_FILE = "Metadata/Slic3r_PE_sla_support_points.txt";
+const std::string SLA_DRAIN_HOLES_FILE = "Metadata/Slic3r_PE_sla_drain_holes.txt";
 const std::string CUSTOM_GCODE_PER_PRINT_Z_FILE = "Metadata/Prusa_Slicer_custom_gcode_per_print_z.xml";
 
 const char* MODEL_TAG = "model";
@@ -385,6 +386,7 @@ namespace Slic3r {
         typedef std::map<int, std::vector<coordf_t>> IdToLayerHeightsProfileMap;
         typedef std::map<int, t_layer_config_ranges> IdToLayerConfigRangesMap;
         typedef std::map<int, std::vector<sla::SupportPoint>> IdToSlaSupportPointsMap;
+        typedef std::map<int, std::vector<sla::DrainHole>> IdToSlaDrainHolesMap;
 
         // Version of the 3mf file
         unsigned int m_version;
@@ -403,6 +405,7 @@ namespace Slic3r {
         IdToLayerHeightsProfileMap m_layer_heights_profiles;
         IdToLayerConfigRangesMap m_layer_config_ranges;
         IdToSlaSupportPointsMap m_sla_support_points;
+        IdToSlaDrainHolesMap    m_sla_drain_holes;
         std::string m_curr_metadata_name;
         std::string m_curr_characters;
         std::string m_name;
@@ -422,6 +425,7 @@ namespace Slic3r {
         void _extract_layer_heights_profile_config_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat);
         void _extract_layer_config_ranges_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat);
         void _extract_sla_support_points_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat);
+        void _extract_sla_drain_holes_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat);
 
         void _extract_custom_gcode_per_print_z_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat);
 
@@ -629,6 +633,11 @@ namespace Slic3r {
                     // extract sla support points file
                     _extract_sla_support_points_from_archive(archive, stat);
                 }
+                else if (boost::algorithm::iequals(name, SLA_DRAIN_HOLES_FILE))
+                {
+                    // extract sla support points file
+                    _extract_sla_drain_holes_from_archive(archive, stat);
+                }
                 else if (boost::algorithm::iequals(name, PRINT_CONFIG_FILE))
                 {
                     // extract slic3r print config file
@@ -684,6 +693,11 @@ namespace Slic3r {
                 model_object->sla_points_status = sla::PointsStatus::UserModified;
             }
             
+            IdToSlaDrainHolesMap::iterator obj_drain_holes = m_sla_drain_holes.find(object.second + 1);
+            if (obj_drain_holes != m_sla_drain_holes.end() && !obj_drain_holes->second.empty()) {
+                model_object->sla_drain_holes = obj_drain_holes->second;
+            }
+
             IdToMetadataMap::iterator obj_metadata = m_objects_metadata.find(object.first);
             if (obj_metadata != m_objects_metadata.end())
             {
@@ -955,8 +969,9 @@ namespace Slic3r {
 
             // Info on format versioning - see 3mf.hpp
             int version = 0;
-            if (!objects.empty() && objects[0].find("support_points_format_version=") != std::string::npos) {
+            std::string key("support_points_format_version=");
-                objects[0].erase(objects[0].begin(), objects[0].begin() + 30); // removes the string
+            if (!objects.empty() && objects[0].find(key) != std::string::npos) {
+                objects[0].erase(objects[0].begin(), objects[0].begin() + long(key.size())); // removes the string
                 version = std::stoi(objects[0]);
                 objects.erase(objects.begin()); // pop the header
             }
@@ -1023,6 +1038,90 @@ namespace Slic3r {
         }
     }
     
+    void _3MF_Importer::_extract_sla_drain_holes_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat)
+    {
+        if (stat.m_uncomp_size > 0)
+        {
+            std::string buffer(size_t(stat.m_uncomp_size), 0);
+            mz_bool res = mz_zip_reader_extract_file_to_mem(&archive, stat.m_filename, (void*)buffer.data(), (size_t)stat.m_uncomp_size, 0);
+            if (res == 0)
+            {
+                add_error("Error while reading sla support points data to buffer");
+                return;
+            }
+            
+            if (buffer.back() == '\n')
+                buffer.pop_back();
+            
+            std::vector<std::string> objects;
+            boost::split(objects, buffer, boost::is_any_of("\n"), boost::token_compress_off);
+            
+            // Info on format versioning - see 3mf.hpp
+            int version = 0;
+            std::string key("drain_holes_format_version=");
+            if (!objects.empty() && objects[0].find(key) != std::string::npos) {
+                objects[0].erase(objects[0].begin(), objects[0].begin() + long(key.size())); // removes the string
+                version = std::stoi(objects[0]);
+                objects.erase(objects.begin()); // pop the header
+            }
+            
+            for (const std::string& object : objects)
+            {
+                std::vector<std::string> object_data;
+                boost::split(object_data, object, boost::is_any_of("|"), boost::token_compress_off);
+                
+                if (object_data.size() != 2)
+                {
+                    add_error("Error while reading object data");
+                    continue;
+                }
+                
+                std::vector<std::string> object_data_id;
+                boost::split(object_data_id, object_data[0], boost::is_any_of("="), boost::token_compress_off);
+                if (object_data_id.size() != 2)
+                {
+                    add_error("Error while reading object id");
+                    continue;
+                }
+                
+                int object_id = std::atoi(object_data_id[1].c_str());
+                if (object_id == 0)
+                {
+                    add_error("Found invalid object id");
+                    continue;
+                }
+                
+                IdToSlaDrainHolesMap::iterator object_item = m_sla_drain_holes.find(object_id);
+                if (object_item != m_sla_drain_holes.end())
+                {
+                    add_error("Found duplicated SLA drain holes");
+                    continue;
+                }
+                
+                std::vector<std::string> object_data_points;
+                boost::split(object_data_points, object_data[1], boost::is_any_of(" "), boost::token_compress_off);
+                
+                sla::DrainHoles sla_drain_holes;
+
+                if (version == 1) {
+                    for (unsigned int i=0; i<object_data_points.size(); i+=8)
+                        sla_drain_holes.emplace_back(Vec3f{float(std::atof(object_data_points[i+0].c_str())),
+                                                      float(std::atof(object_data_points[i+1].c_str())),
+                                                      float(std::atof(object_data_points[i+2].c_str()))},
+                                                     Vec3f{float(std::atof(object_data_points[i+3].c_str())),
+                                                      float(std::atof(object_data_points[i+4].c_str())),
+                                                      float(std::atof(object_data_points[i+5].c_str()))},
+                                                      float(std::atof(object_data_points[i+6].c_str())),
+                                                      float(std::atof(object_data_points[i+7].c_str())));
+                }
+                
+                if (!sla_drain_holes.empty())
+                    m_sla_drain_holes.insert(IdToSlaDrainHolesMap::value_type(object_id, sla_drain_holes));
+            }
+        }
+    }
+    
+
 
     bool _3MF_Importer::_extract_model_config_from_archive(mz_zip_archive& archive, const mz_zip_archive_file_stat& stat, Model& model)
     {
@@ -1904,6 +2003,7 @@ namespace Slic3r {
         bool _add_layer_height_profile_file_to_archive(mz_zip_archive& archive, Model& model);
         bool _add_layer_config_ranges_file_to_archive(mz_zip_archive& archive, Model& model);
         bool _add_sla_support_points_file_to_archive(mz_zip_archive& archive, Model& model);
+        bool _add_sla_drain_holes_file_to_archive(mz_zip_archive& archive, Model& model);
         bool _add_print_config_file_to_archive(mz_zip_archive& archive, const DynamicPrintConfig &config);
         bool _add_model_config_file_to_archive(mz_zip_archive& archive, const Model& model, const IdToObjectDataMap &objects_data);
         bool _add_custom_gcode_per_print_z_file_to_archive(mz_zip_archive& archive, Model& model);
@@ -2026,6 +2126,14 @@ namespace Slic3r {
             return false;
         }
         
+        if (!_add_sla_drain_holes_file_to_archive(archive, model))
+        {
+            close_zip_writer(&archive);
+            boost::filesystem::remove(filename);
+            return false;
+        }
+        
+
         // Adds custom gcode per height file ("Metadata/Prusa_Slicer_custom_gcode_per_print_z.xml").
         // All custom gcode per height of whole Model are stored here
         if (!_add_custom_gcode_per_print_z_file_to_archive(archive, model))
@@ -2483,6 +2591,50 @@ namespace Slic3r {
         return true;
     }
     
+    bool _3MF_Exporter::_add_sla_drain_holes_file_to_archive(mz_zip_archive& archive, Model& model)
+    {
+        const char *const fmt = "object_id=%d|";
+        std::string out;
+        
+        unsigned int count = 0;
+        for (const ModelObject* object : model.objects)
+        {
+            ++count;
+            auto& drain_holes = object->sla_drain_holes;
+            if (!drain_holes.empty())
+            {
+                out += string_printf(fmt, count);
+                
+                // Store the layer height profile as a single space separated list.
+                for (size_t i = 0; i < drain_holes.size(); ++i)
+                    out += string_printf((i == 0 ? "%f %f %f %f %f %f %f %f" : " %f %f %f %f %f %f %f %f"),
+                                         drain_holes[i].pos(0),
+                                         drain_holes[i].pos(1),
+                                         drain_holes[i].pos(2),
+                                         drain_holes[i].normal(0),
+                                         drain_holes[i].normal(1),
+                                         drain_holes[i].normal(2),
+                                         drain_holes[i].radius,
+                                         drain_holes[i].height);
+                
+                out += "\n";
+            }
+        }
+        
+        if (!out.empty())
+        {
+            // Adds version header at the beginning:
+            out = std::string("drain_holes_format_version=") + std::to_string(drain_holes_format_version) + std::string("\n") + out;
+            
+            if (!mz_zip_writer_add_mem(&archive, SLA_DRAIN_HOLES_FILE.c_str(), static_cast<const void*>(out.data()), out.length(), mz_uint(MZ_DEFAULT_COMPRESSION)))
+            {
+                add_error("Unable to add sla support points file to archive");
+                return false;
+            }
+        }
+        return true;
+    }
+
     bool _3MF_Exporter::_add_print_config_file_to_archive(mz_zip_archive& archive, const DynamicPrintConfig &config)
     {
         char buffer[1024];

src/libslic3r/Format/3mf.hpp

@@ -20,6 +20,10 @@ namespace Slic3r {
         support_points_format_version = 1
     };
     
+    enum {
+        drain_holes_format_version = 1
+    };
+
     class Model;
     class DynamicPrintConfig;
 #if ENABLE_THUMBNAIL_GENERATOR

src/libslic3r/Format/objparser.cpp

@@ -355,6 +355,35 @@ bool objparse(const char *path, ObjData &data)
 	return true;
 }
 
+bool objparse(std::istream &stream, ObjData &data)
+{
+    try {
+        char buf[65536 * 2];
+        size_t len = 0;
+        size_t lenPrev = 0;
+        while ((len = size_t(stream.read(buf + lenPrev, 65536).gcount())) != 0) {
+            len += lenPrev;
+            size_t lastLine = 0;
+            for (size_t i = 0; i < len; ++ i)
+                if (buf[i] == '\r' || buf[i] == '\n') {
+                    buf[i] = 0;
+                    char *c = buf + lastLine;
+                    while (*c == ' ' || *c == '\t')
+                        ++ c;
+                    obj_parseline(c, data);
+                    lastLine = i + 1;
+                }
+            lenPrev = len - lastLine;
+            memmove(buf, buf + lastLine, lenPrev);
+        }
+    }
+    catch (std::bad_alloc&) {
+        printf("Out of memory\r\n");
+    }
+    
+    return true;
+}
+
 template<typename T> 
 bool savevector(FILE *pFile, const std::vector<T> &v)
 {

src/libslic3r/Format/objparser.hpp

@@ -3,6 +3,7 @@
 
 #include <string>
 #include <vector>
+#include <istream>
 
 namespace ObjParser {
 
@@ -97,6 +98,7 @@ struct ObjData {
 };
 
 extern bool objparse(const char *path, ObjData &data);
+extern bool objparse(std::istream &stream, ObjData &data);
 
 extern bool objbinsave(const char *path, const ObjData &data);
 

src/libslic3r/MeshBoolean.cpp

@@ -0,0 +1,170 @@
+#include "MeshBoolean.hpp"
+#include "libslic3r/TriangleMesh.hpp"
+#undef PI
+
+// Include igl first. It defines "L" macro which then clashes with our localization
+#include <igl/copyleft/cgal/mesh_boolean.h>
+#undef L
+
+// CGAL headers
+#include <CGAL/Polygon_mesh_processing/corefinement.h>
+#include <CGAL/Exact_integer.h>
+#include <CGAL/Surface_mesh.h>
+
+namespace Slic3r {
+namespace MeshBoolean {
+
+typedef Eigen::Map<const Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXfUnaligned;
+typedef Eigen::Map<const Eigen::Matrix<int,   Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXiUnaligned;
+
+typedef std::pair<Eigen::MatrixXd, Eigen::MatrixXi> EigenMesh;
+
+static TriangleMesh eigen_to_triangle_mesh(const Eigen::MatrixXd& VC, const Eigen::MatrixXi& FC)
+{
+    Pointf3s points(size_t(VC.rows())); 
+    std::vector<Vec3crd> facets(size_t(FC.rows()));
+    
+    for (Eigen::Index i = 0; i < VC.rows(); ++i)
+        points[size_t(i)] = VC.row(i);
+    
+    for (Eigen::Index i = 0; i < FC.rows(); ++i)
+        facets[size_t(i)] = FC.row(i);
+    
+    TriangleMesh out{points, facets};
+    out.require_shared_vertices();
+    return out;
+}
+
+static EigenMesh triangle_mesh_to_eigen_mesh(const TriangleMesh &mesh)
+{
+    EigenMesh emesh;
+    emesh.first = MapMatrixXfUnaligned(mesh.its.vertices.front().data(),
+                                       Eigen::Index(mesh.its.vertices.size()),
+                                       3).cast<double>();
+
+    emesh.second = MapMatrixXiUnaligned(mesh.its.indices.front().data(),
+                                        Eigen::Index(mesh.its.indices.size()),
+                                        3);
+    return emesh;
+}
+
+void minus(TriangleMesh& A, const TriangleMesh& B)
+{
+    auto [VA, FA] = triangle_mesh_to_eigen_mesh(A);
+    auto [VB, FB] = triangle_mesh_to_eigen_mesh(B);
+
+    Eigen::MatrixXd VC;
+    Eigen::MatrixXi FC;
+    igl::MeshBooleanType boolean_type(igl::MESH_BOOLEAN_TYPE_MINUS);
+    igl::copyleft::cgal::mesh_boolean(VA, FA, VB, FB, boolean_type, VC, FC);
+
+    A = eigen_to_triangle_mesh(VC, FC);
+}
+
+void self_union(TriangleMesh& mesh)
+{
+    auto [V, F] = triangle_mesh_to_eigen_mesh(mesh);
+
+    Eigen::MatrixXd VC;
+    Eigen::MatrixXi FC;
+
+    igl::MeshBooleanType boolean_type(igl::MESH_BOOLEAN_TYPE_UNION);
+    igl::copyleft::cgal::mesh_boolean(V, F, Eigen::MatrixXd(), Eigen::MatrixXi(), boolean_type, VC, FC);
+    
+    mesh = eigen_to_triangle_mesh(VC, FC);
+}
+
+namespace cgal {
+
+namespace CGALProc   = CGAL::Polygon_mesh_processing;
+namespace CGALParams = CGAL::Polygon_mesh_processing::parameters;
+
+using Kernel = CGAL::Exact_predicates_inexact_constructions_kernel;
+using _CGALMesh = CGAL::Surface_mesh<Kernel::Point_3>;
+
+struct CGALMesh { _CGALMesh m; };
+
+static void triangle_mesh_to_cgal(const TriangleMesh &M, _CGALMesh &out)
+{
+    for (const Vec3f &v : M.its.vertices)
+        out.add_vertex(_CGALMesh::Point(v.x(), v.y(), v.z()));
+
+    for (const Vec3crd &face : M.its.indices) {
+        auto f = face.cast<CGAL::SM_Vertex_index>();
+        out.add_face(f(0), f(1), f(2));
+    }
+}
+
+static TriangleMesh cgal_to_triangle_mesh(const _CGALMesh &cgalmesh)
+{
+    Pointf3s points;
+    std::vector<Vec3crd> facets;
+    points.reserve(cgalmesh.num_vertices());
+    facets.reserve(cgalmesh.num_faces());
+
+    for (auto &vi : cgalmesh.vertices()) {
+        auto &v = cgalmesh.point(vi); // Don't ask...
+        points.emplace_back(v.x(), v.y(), v.z());
+    }
+
+    for (auto &face : cgalmesh.faces()) {
+        auto    vtc = cgalmesh.vertices_around_face(cgalmesh.halfedge(face));
+        int     i   = 0;
+        Vec3crd trface;
+        for (auto v : vtc) trface(i++) = int(v.idx());
+        facets.emplace_back(trface);
+    }
+    
+    TriangleMesh out{points, facets};
+    out.require_shared_vertices();
+    return out;
+}
+
+std::unique_ptr<CGALMesh> triangle_mesh_to_cgal(const TriangleMesh &M)
+{
+    auto out = std::make_unique<CGALMesh>();
+    triangle_mesh_to_cgal(M, out->m);
+    return out;
+}
+
+void cgal_to_triangle_mesh(const CGALMesh &cgalmesh, TriangleMesh &out)
+{
+    out = cgal_to_triangle_mesh(cgalmesh.m);
+}
+
+void minus(CGALMesh &A, CGALMesh &B)
+{
+    CGALProc::corefine_and_compute_difference(A.m, B.m, A.m);
+}
+
+void self_union(CGALMesh &A)
+{
+    CGALProc::corefine(A.m, A.m);
+}
+
+void minus(TriangleMesh &A, const TriangleMesh &B)
+{   
+    CGALMesh meshA;
+    CGALMesh meshB;
+    triangle_mesh_to_cgal(A, meshA.m);
+    triangle_mesh_to_cgal(B, meshB.m);
+    
+    CGALMesh meshResult;
+    CGALProc::corefine_and_compute_difference(meshA.m, meshB.m, meshResult.m);
+    
+    A = cgal_to_triangle_mesh(meshResult.m);
+}
+
+void self_union(TriangleMesh &m)
+{
+    _CGALMesh cgalmesh;
+    triangle_mesh_to_cgal(m, cgalmesh);
+    CGALProc::corefine(cgalmesh, cgalmesh);
+    
+    m = cgal_to_triangle_mesh(cgalmesh);
+}
+
+} // namespace cgal
+
+} // namespace MeshBoolean
+} // namespace Slic3r

src/libslic3r/MeshBoolean.hpp

@@ -0,0 +1,38 @@
+#ifndef libslic3r_MeshBoolean_hpp_
+#define libslic3r_MeshBoolean_hpp_
+
+#include <memory>
+
+namespace Slic3r {
+
+class TriangleMesh;
+
+namespace MeshBoolean {
+
+void minus(TriangleMesh& A, const TriangleMesh& B);
+void self_union(TriangleMesh& mesh);
+
+namespace cgal {
+
+struct CGALMesh;
+
+std::unique_ptr<CGALMesh> triangle_mesh_to_cgal(const TriangleMesh &M);
+void cgal_to_triangle_mesh(const CGALMesh &cgalmesh, TriangleMesh &out);
+    
+// Do boolean mesh difference with CGAL bypassing igl.
+void minus(TriangleMesh &A, const TriangleMesh &B);
+
+// Do self union only with CGAL.
+void self_union(TriangleMesh& mesh);
+
+// does A = A - B
+// CGAL takes non-const objects as arguments. I suppose it doesn't change B but
+// there is no official garantee.
+void minus(CGALMesh &A, CGALMesh &B);
+void self_union(CGALMesh &A);
+
+}
+
+} // namespace MeshBoolean
+} // namespace Slic3r
+#endif // libslic3r_MeshBoolean_hpp_

src/libslic3r/Model.cpp

@@ -620,6 +620,7 @@ ModelObject& ModelObject::assign_copy(const ModelObject &rhs)
     assert(this->config.id() == rhs.config.id());
     this->sla_support_points          = rhs.sla_support_points;
     this->sla_points_status           = rhs.sla_points_status;
+    this->sla_drain_holes             = rhs.sla_drain_holes;
     this->layer_config_ranges         = rhs.layer_config_ranges;    // #ys_FIXME_experiment
     this->layer_height_profile        = rhs.layer_height_profile;
     this->printable                   = rhs.printable;
@@ -660,6 +661,7 @@ ModelObject& ModelObject::assign_copy(ModelObject &&rhs)
     assert(this->config.id() == rhs.config.id());
     this->sla_support_points          = std::move(rhs.sla_support_points);
     this->sla_points_status           = std::move(rhs.sla_points_status);
+    this->sla_drain_holes             = std::move(rhs.sla_drain_holes);
     this->layer_config_ranges         = std::move(rhs.layer_config_ranges); // #ys_FIXME_experiment
     this->layer_height_profile        = std::move(rhs.layer_height_profile);
     this->origin_translation          = std::move(rhs.origin_translation);
@@ -1113,6 +1115,7 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
     if (keep_upper) {
         upper->set_model(nullptr);
         upper->sla_support_points.clear();
+        lower->sla_drain_holes.clear();
         upper->sla_points_status = sla::PointsStatus::NoPoints;
         upper->clear_volumes();
         upper->input_file = "";
@@ -1121,6 +1124,7 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
     if (keep_lower) {
         lower->set_model(nullptr);
         lower->sla_support_points.clear();
+        lower->sla_drain_holes.clear();
         lower->sla_points_status = sla::PointsStatus::NoPoints;
         lower->clear_volumes();
         lower->input_file = "";
@@ -1156,7 +1160,8 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
             if (keep_upper) { upper->add_volume(*volume); }
             if (keep_lower) { lower->add_volume(*volume); }
         }
-        else {
+        else if (! volume->mesh().empty()) {
+            
             TriangleMesh upper_mesh, lower_mesh;
 
             // Transform the mesh by the combined transformation matrix.
@@ -1165,6 +1170,8 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
 			mesh.transform(instance_matrix * volume_matrix, true);
 			volume->reset_mesh();
             
+            mesh.require_shared_vertices();
+            
             // Perform cut
             TriangleMeshSlicer tms(&mesh);
             tms.cut(float(z), &upper_mesh, &lower_mesh);

src/libslic3r/Model.hpp

@@ -8,7 +8,8 @@
 #include "Point.hpp"
 #include "PrintConfig.hpp"
 #include "Slicing.hpp"
-#include "SLA/SLACommon.hpp"
+#include "SLA/SupportPoint.hpp"
+#include "SLA/Hollowing.hpp"
 #include "TriangleMesh.hpp"
 #include "Arrange.hpp"
 #include "CustomGCode.hpp"
@@ -199,11 +200,14 @@ public:
     // This vector holds position of selected support points for SLA. The data are
     // saved in mesh coordinates to allow using them for several instances.
     // The format is (x, y, z, point_size, supports_island)
-    std::vector<sla::SupportPoint>      sla_support_points;
+    sla::SupportPoints      sla_support_points;
     // To keep track of where the points came from (used for synchronization between
     // the SLA gizmo and the backend).
     sla::PointsStatus       sla_points_status = sla::PointsStatus::NoPoints;
 
+    // Holes to be drilled into the object so resin can flow out
+    sla::DrainHoles         sla_drain_holes;
+
     /* This vector accumulates the total translation applied to the object by the
         center_around_origin() method. Callers might want to apply the same translation
         to new volumes before adding them to this object in order to preserve alignment
@@ -373,7 +377,7 @@ private:
 	template<class Archive> void serialize(Archive &ar) {
 		ar(cereal::base_class<ObjectBase>(this));
 		Internal::StaticSerializationWrapper<ModelConfig> config_wrapper(config);
-        ar(name, input_file, instances, volumes, config_wrapper, layer_config_ranges, layer_height_profile, sla_support_points, sla_points_status, printable, origin_translation,
+        ar(name, input_file, instances, volumes, config_wrapper, layer_config_ranges, layer_height_profile, sla_support_points, sla_points_status, sla_drain_holes, printable, origin_translation,
             m_bounding_box, m_bounding_box_valid, m_raw_bounding_box, m_raw_bounding_box_valid, m_raw_mesh_bounding_box, m_raw_mesh_bounding_box_valid);
 	}
 };

src/libslic3r/OpenVDBUtils.cpp

@@ -0,0 +1,135 @@
+#define NOMINMAX
+#include "OpenVDBUtils.hpp"
+#include <openvdb/tools/MeshToVolume.h>
+#include <openvdb/tools/VolumeToMesh.h>
+#include <openvdb/tools/LevelSetRebuild.h>
+
+//#include "MTUtils.hpp"
+
+namespace Slic3r {
+
+class TriangleMeshDataAdapter {
+public:
+    const TriangleMesh &mesh;
+    
+    size_t polygonCount() const { return mesh.its.indices.size(); }
+    size_t pointCount() const   { return mesh.its.vertices.size(); }
+    size_t vertexCount(size_t) const { return 3; }
+    
+    // Return position pos in local grid index space for polygon n and vertex v
+    void getIndexSpacePoint(size_t n, size_t v, openvdb::Vec3d& pos) const;
+};
+
+class Contour3DDataAdapter {
+public:
+    const sla::Contour3D &mesh;
+    
+    size_t polygonCount() const { return mesh.faces3.size() + mesh.faces4.size(); }
+    size_t pointCount() const   { return mesh.points.size(); }
+    size_t vertexCount(size_t n) const { return n < mesh.faces3.size() ? 3 : 4; }
+    
+    // Return position pos in local grid index space for polygon n and vertex v
+    void getIndexSpacePoint(size_t n, size_t v, openvdb::Vec3d& pos) const;
+};
+
+void TriangleMeshDataAdapter::getIndexSpacePoint(size_t          n,
+                                                 size_t          v,
+                                                 openvdb::Vec3d &pos) const
+{
+    auto vidx = size_t(mesh.its.indices[n](Eigen::Index(v)));
+    Slic3r::Vec3d p = mesh.its.vertices[vidx].cast<double>();
+    pos = {p.x(), p.y(), p.z()};
+}
+
+void Contour3DDataAdapter::getIndexSpacePoint(size_t          n,
+                                              size_t          v,
+                                              openvdb::Vec3d &pos) const
+{
+    size_t vidx = 0;
+    if (n < mesh.faces3.size()) vidx = size_t(mesh.faces3[n](Eigen::Index(v)));
+    else vidx = size_t(mesh.faces4[n - mesh.faces3.size()](Eigen::Index(v)));
+    
+    Slic3r::Vec3d p = mesh.points[vidx];
+    pos = {p.x(), p.y(), p.z()};
+}
+
+
+// TODO: Do I need to call initialize? Seems to work without it as well but the
+// docs say it should be called ones. It does a mutex lock-unlock sequence all
+// even if was called previously.
+
+openvdb::FloatGrid::Ptr mesh_to_grid(const TriangleMesh &mesh,
+                                     const openvdb::math::Transform &tr,
+                                     float               exteriorBandWidth,
+                                     float               interiorBandWidth,
+                                     int                 flags)
+{
+    openvdb::initialize();
+    return openvdb::tools::meshToVolume<openvdb::FloatGrid>(
+        TriangleMeshDataAdapter{mesh}, tr, exteriorBandWidth,
+        interiorBandWidth, flags);
+}
+
+openvdb::FloatGrid::Ptr mesh_to_grid(const sla::Contour3D &mesh,
+                                     const openvdb::math::Transform &tr,
+                                     float exteriorBandWidth,
+                                     float interiorBandWidth,
+                                     int flags)
+{
+    openvdb::initialize();
+    return openvdb::tools::meshToVolume<openvdb::FloatGrid>(
+        Contour3DDataAdapter{mesh}, tr, exteriorBandWidth, interiorBandWidth,
+        flags);
+}
+
+template<class Grid>
+sla::Contour3D _volumeToMesh(const Grid &grid,
+                             double      isovalue,
+                             double      adaptivity,
+                             bool        relaxDisorientedTriangles)
+{
+    openvdb::initialize();
+    
+    std::vector<openvdb::Vec3s> points;
+    std::vector<openvdb::Vec3I> triangles;
+    std::vector<openvdb::Vec4I> quads;
+    
+    openvdb::tools::volumeToMesh(grid, points, triangles, quads, isovalue,
+                                 adaptivity, relaxDisorientedTriangles);
+    
+    sla::Contour3D ret;
+    ret.points.reserve(points.size());
+    ret.faces3.reserve(triangles.size());
+    ret.faces4.reserve(quads.size());
+
+    for (auto &v : points) ret.points.emplace_back(to_vec3d(v));
+    for (auto &v : triangles) ret.faces3.emplace_back(to_vec3i(v));
+    for (auto &v : quads) ret.faces4.emplace_back(to_vec4i(v));
+
+    return ret;
+}
+
+TriangleMesh grid_to_mesh(const openvdb::FloatGrid &grid,
+                          double                    isovalue,
+                          double                    adaptivity,
+                          bool                      relaxDisorientedTriangles)
+{
+    return to_triangle_mesh(
+        _volumeToMesh(grid, isovalue, adaptivity, relaxDisorientedTriangles));
+}
+
+sla::Contour3D grid_to_contour3d(const openvdb::FloatGrid &grid,
+                                 double                    isovalue,
+                                 double                    adaptivity,
+                                 bool relaxDisorientedTriangles)
+{
+    return _volumeToMesh(grid, isovalue, adaptivity,
+                         relaxDisorientedTriangles);
+}
+
+openvdb::FloatGrid::Ptr redistance_grid(const openvdb::FloatGrid &grid, double iso, double er, double ir)
+{
+    return openvdb::tools::levelSetRebuild(grid, float(iso), float(er), float(ir));
+}
+
+} // namespace Slic3r

src/libslic3r/OpenVDBUtils.hpp

@@ -0,0 +1,45 @@
+#ifndef OPENVDBUTILS_HPP
+#define OPENVDBUTILS_HPP
+
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <openvdb/openvdb.h>
+
+namespace Slic3r {
+
+inline Vec3f to_vec3f(const openvdb::Vec3s &v) { return Vec3f{v.x(), v.y(), v.z()}; }
+inline Vec3d to_vec3d(const openvdb::Vec3s &v) { return to_vec3f(v).cast<double>(); }
+inline Vec3i to_vec3i(const openvdb::Vec3I &v) { return Vec3i{int(v[0]), int(v[1]), int(v[2])}; }
+inline Vec4i to_vec4i(const openvdb::Vec4I &v) { return Vec4i{int(v[0]), int(v[1]), int(v[2]), int(v[3])}; }
+
+openvdb::FloatGrid::Ptr mesh_to_grid(const TriangleMesh &            mesh,
+                                     const openvdb::math::Transform &tr = {},
+                                     float exteriorBandWidth = 3.0f,
+                                     float interiorBandWidth = 3.0f,
+                                     int   flags             = 0);
+
+openvdb::FloatGrid::Ptr mesh_to_grid(const sla::Contour3D &          mesh,
+                                     const openvdb::math::Transform &tr = {},
+                                     float exteriorBandWidth = 3.0f,
+                                     float interiorBandWidth = 3.0f,
+                                     int   flags             = 0);
+
+sla::Contour3D grid_to_contour3d(const openvdb::FloatGrid &grid,
+                                 double                    isovalue,
+                                 double                    adaptivity,
+                                 bool relaxDisorientedTriangles = true);
+
+TriangleMesh grid_to_mesh(const openvdb::FloatGrid &grid,
+                          double                    isovalue   = 0.0,
+                          double                    adaptivity = 0.0,
+                          bool relaxDisorientedTriangles       = true);
+
+openvdb::FloatGrid::Ptr redistance_grid(const openvdb::FloatGrid &grid,
+                                        double                    iso,
+                                        double ext_range = 3.,
+                                        double int_range = 3.);
+
+} // namespace Slic3r
+
+#endif // OPENVDBUTILS_HPP

src/libslic3r/PrintConfig.cpp

@@ -2873,6 +2873,41 @@ void PrintConfigDef::init_sla_params()
     def->min = 0;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloat(0.3));
+    
+    def = this->add("hollowing_enable", coBool);
+    def->label = L("Enable hollowing");
+    def->category = L("Hollowing");
+    def->tooltip = L("Hollow out a model to have an empty interior");
+    def->mode = comSimple;
+    def->set_default_value(new ConfigOptionBool(false));
+    
+    def = this->add("hollowing_min_thickness", coFloat);
+    def->label = L("Hollowing thickness");
+    def->category = L("Hollowing");
+    def->tooltip  = L("Minimum wall thickness of a hollowed model.");
+    def->sidetext = L("mm");
+    def->min = 1;
+    def->max = 10;
+    def->mode = comSimple;
+    def->set_default_value(new ConfigOptionFloat(3.));
+    
+    def = this->add("hollowing_quality", coFloat);
+    def->label = L("Hollowing accuracy");
+    def->category = L("Hollowing");
+    def->tooltip  = L("Performance vs accuracy of calculation. Lower values may produce unwanted artifacts.");
+    def->min = 0;
+    def->max = 1;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionFloat(0.5));
+    
+    def = this->add("hollowing_closing_distance", coFloat);
+    def->label = L("Hollowing closing distance");
+    def->category = L("Hollowing");
+    def->tooltip  = L("");
+    def->min = 0;
+    def->max = 10;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionFloat(2.0));
 }
 
 void PrintConfigDef::handle_legacy(t_config_option_key &opt_key, std::string &value)

src/libslic3r/PrintConfig.hpp

@@ -1017,7 +1017,7 @@ public:
     ConfigOptionFloat support_base_height /*= 1.0*/;
 
     // The minimum distance of the pillar base from the model in mm.
-    ConfigOptionFloat support_base_safety_distance; /*= 1.0*/;
+    ConfigOptionFloat support_base_safety_distance; /*= 1.0*/
 
     // The default angle for connecting support sticks and junctions.
     ConfigOptionFloat support_critical_angle /*= 45*/;
@@ -1062,7 +1062,7 @@ public:
 
     // /////////////////////////////////////////////////////////////////////////
     // Zero elevation mode parameters:
-    //    - The object pad will be derived from the the model geometry.
+    //    - The object pad will be derived from the model geometry.
     //    - There will be a gap between the object pad and the generated pad
     //      according to the support_base_safety_distance parameter.
     //    - The two pads will be connected with tiny connector sticks
@@ -1085,6 +1085,28 @@ public:
     // How much should the tiny connectors penetrate into the model body
     ConfigOptionFloat pad_object_connector_penetration;
     
+    // /////////////////////////////////////////////////////////////////////////
+    // Model hollowing parameters:
+    //   - Models can be hollowed out as part of the SLA print process
+    //   - Thickness of the hollowed model walls can be adjusted
+    //   -
+    //   - Additional holes will be drilled into the hollow model to allow for
+    //   - resin removal.
+    // /////////////////////////////////////////////////////////////////////////
+    
+    ConfigOptionBool hollowing_enable;
+    
+    // The minimum thickness of the model walls to maintain. Note that the 
+    // resulting walls may be thicker due to smoothing out fine cavities where
+    // resin could stuck.
+    ConfigOptionFloat hollowing_min_thickness;
+    
+    // Indirectly controls the voxel size (resolution) used by openvdb
+    ConfigOptionFloat hollowing_quality;
+   
+    // Indirectly controls the minimum size of created cavities.
+    ConfigOptionFloat hollowing_closing_distance;
+
 protected:
     void initialize(StaticCacheBase &cache, const char *base_ptr)
     {
@@ -1121,6 +1143,10 @@ protected:
         OPT_PTR(pad_object_connector_stride);
         OPT_PTR(pad_object_connector_width);
         OPT_PTR(pad_object_connector_penetration);
+        OPT_PTR(hollowing_enable);
+        OPT_PTR(hollowing_min_thickness);
+        OPT_PTR(hollowing_quality);
+        OPT_PTR(hollowing_closing_distance);
     }
 };
 

src/libslic3r/SLA/BoostAdapter.hpp

@@ -1,7 +1,7 @@
-#ifndef SLABOOSTADAPTER_HPP
+#ifndef SLA_BOOSTADAPTER_HPP
-#define SLABOOSTADAPTER_HPP
+#define SLA_BOOSTADAPTER_HPP
 
-#include "SLA/SLABoilerPlate.hpp"
+#include <libslic3r/SLA/Common.hpp>
 #include <boost/geometry.hpp>
 
 namespace boost {

src/libslic3r/SLA/Clustering.hpp

@@ -0,0 +1,30 @@
+#ifndef SLA_CLUSTERING_HPP
+#define SLA_CLUSTERING_HPP
+
+#include <vector>
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/SLA/SpatIndex.hpp>
+
+namespace Slic3r { namespace sla {
+
+using ClusterEl = std::vector<unsigned>;
+using ClusteredPoints = std::vector<ClusterEl>;
+
+// Clustering a set of points by the given distance.
+ClusteredPoints cluster(const std::vector<unsigned>& indices,
+                        std::function<Vec3d(unsigned)> pointfn,
+                        double dist,
+                        unsigned max_points);
+
+ClusteredPoints cluster(const PointSet& points,
+                        double dist,
+                        unsigned max_points);
+
+ClusteredPoints cluster(
+    const std::vector<unsigned>& indices,
+    std::function<Vec3d(unsigned)> pointfn,
+    std::function<bool(const PointIndexEl&, const PointIndexEl&)> predicate,
+    unsigned max_points);
+
+}}
+#endif // CLUSTERING_HPP

src/libslic3r/SLA/Common.cpp

@@ -0,0 +1,741 @@
+#include <cmath>
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/SLA/Concurrency.hpp>
+#include <libslic3r/SLA/SupportTree.hpp>
+#include <libslic3r/SLA/SpatIndex.hpp>
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <libslic3r/SLA/Clustering.hpp>
+#include <libslic3r/SLA/Hollowing.hpp>
+
+
+// Workaround: IGL signed_distance.h will define PI in the igl namespace.
+#undef PI
+
+// HEAVY headers... takes eternity to compile
+
+// for concave hull merging decisions
+#include <libslic3r/SLA/BoostAdapter.hpp>
+#include "boost/geometry/index/rtree.hpp"
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4244)
+#pragma warning(disable: 4267)
+#endif
+#include <igl/ray_mesh_intersect.h>
+#include <igl/point_mesh_squared_distance.h>
+#include <igl/remove_duplicate_vertices.h>
+#include <igl/signed_distance.h>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+#include <tbb/parallel_for.h>
+
+#include "ClipperUtils.hpp"
+
+namespace Slic3r {
+namespace sla {
+
+// Bring back PI from the igl namespace
+using igl::PI;
+
+/* **************************************************************************
+ * PointIndex implementation
+ * ************************************************************************** */
+
+class PointIndex::Impl {
+public:
+    using BoostIndex = boost::geometry::index::rtree< PointIndexEl,
+                                                     boost::geometry::index::rstar<16, 4> /* ? */ >;
+    
+    BoostIndex m_store;
+};
+
+PointIndex::PointIndex(): m_impl(new Impl()) {}
+PointIndex::~PointIndex() {}
+
+PointIndex::PointIndex(const PointIndex &cpy): m_impl(new Impl(*cpy.m_impl)) {}
+PointIndex::PointIndex(PointIndex&& cpy): m_impl(std::move(cpy.m_impl)) {}
+
+PointIndex& PointIndex::operator=(const PointIndex &cpy)
+{
+    m_impl.reset(new Impl(*cpy.m_impl));
+    return *this;
+}
+
+PointIndex& PointIndex::operator=(PointIndex &&cpy)
+{
+    m_impl.swap(cpy.m_impl);
+    return *this;
+}
+
+void PointIndex::insert(const PointIndexEl &el)
+{
+    m_impl->m_store.insert(el);
+}
+
+bool PointIndex::remove(const PointIndexEl& el)
+{
+    return m_impl->m_store.remove(el) == 1;
+}
+
+std::vector<PointIndexEl>
+PointIndex::query(std::function<bool(const PointIndexEl &)> fn) const
+{
+    namespace bgi = boost::geometry::index;
+    
+    std::vector<PointIndexEl> ret;
+    m_impl->m_store.query(bgi::satisfies(fn), std::back_inserter(ret));
+    return ret;
+}
+
+std::vector<PointIndexEl> PointIndex::nearest(const Vec3d &el, unsigned k = 1) const
+{
+    namespace bgi = boost::geometry::index;
+    std::vector<PointIndexEl> ret; ret.reserve(k);
+    m_impl->m_store.query(bgi::nearest(el, k), std::back_inserter(ret));
+    return ret;
+}
+
+size_t PointIndex::size() const
+{
+    return m_impl->m_store.size();
+}
+
+void PointIndex::foreach(std::function<void (const PointIndexEl &)> fn)
+{
+    for(auto& el : m_impl->m_store) fn(el);
+}
+
+void PointIndex::foreach(std::function<void (const PointIndexEl &)> fn) const
+{
+    for(const auto &el : m_impl->m_store) fn(el);
+}
+
+/* **************************************************************************
+ * BoxIndex implementation
+ * ************************************************************************** */
+
+class BoxIndex::Impl {
+public:
+    using BoostIndex = boost::geometry::index::
+        rtree<BoxIndexEl, boost::geometry::index::rstar<16, 4> /* ? */>;
+    
+    BoostIndex m_store;
+};
+
+BoxIndex::BoxIndex(): m_impl(new Impl()) {}
+BoxIndex::~BoxIndex() {}
+
+BoxIndex::BoxIndex(const BoxIndex &cpy): m_impl(new Impl(*cpy.m_impl)) {}
+BoxIndex::BoxIndex(BoxIndex&& cpy): m_impl(std::move(cpy.m_impl)) {}
+
+BoxIndex& BoxIndex::operator=(const BoxIndex &cpy)
+{
+    m_impl.reset(new Impl(*cpy.m_impl));
+    return *this;
+}
+
+BoxIndex& BoxIndex::operator=(BoxIndex &&cpy)
+{
+    m_impl.swap(cpy.m_impl);
+    return *this;
+}
+
+void BoxIndex::insert(const BoxIndexEl &el)
+{
+    m_impl->m_store.insert(el);
+}
+
+bool BoxIndex::remove(const BoxIndexEl& el)
+{
+    return m_impl->m_store.remove(el) == 1;
+}
+
+std::vector<BoxIndexEl> BoxIndex::query(const BoundingBox &qrbb,
+                                        BoxIndex::QueryType qt)
+{
+    namespace bgi = boost::geometry::index;
+    
+    std::vector<BoxIndexEl> ret; ret.reserve(m_impl->m_store.size());
+    
+    switch (qt) {
+    case qtIntersects:
+        m_impl->m_store.query(bgi::intersects(qrbb), std::back_inserter(ret));
+        break;
+    case qtWithin:
+        m_impl->m_store.query(bgi::within(qrbb), std::back_inserter(ret));
+    }
+    
+    return ret;
+}
+
+size_t BoxIndex::size() const
+{
+    return m_impl->m_store.size();
+}
+
+void BoxIndex::foreach(std::function<void (const BoxIndexEl &)> fn)
+{
+    for(auto& el : m_impl->m_store) fn(el);
+}
+
+
+/* ****************************************************************************
+ * EigenMesh3D implementation
+ * ****************************************************************************/
+
+class EigenMesh3D::AABBImpl: public igl::AABB<Eigen::MatrixXd, 3> {
+public:
+#ifdef SLIC3R_SLA_NEEDS_WINDTREE
+    igl::WindingNumberAABB<Vec3d, Eigen::MatrixXd, Eigen::MatrixXi> windtree;
+#endif /* SLIC3R_SLA_NEEDS_WINDTREE */
+};
+
+EigenMesh3D::EigenMesh3D(const TriangleMesh& tmesh): m_aabb(new AABBImpl()) {
+    static const double dEPS = 1e-6;
+    
+    const stl_file& stl = tmesh.stl;
+    
+    auto&& bb = tmesh.bounding_box();
+    m_ground_level += bb.min(Z);
+    
+    Eigen::MatrixXd V;
+    Eigen::MatrixXi F;
+    
+    V.resize(3*stl.stats.number_of_facets, 3);
+    F.resize(stl.stats.number_of_facets, 3);
+    for (unsigned int i = 0; i < stl.stats.number_of_facets; ++i) {
+        const stl_facet &facet = stl.facet_start[i];
+        V.block<1, 3>(3 * i + 0, 0) = facet.vertex[0].cast<double>();
+        V.block<1, 3>(3 * i + 1, 0) = facet.vertex[1].cast<double>();
+        V.block<1, 3>(3 * i + 2, 0) = facet.vertex[2].cast<double>();
+        F(i, 0) = int(3*i+0);
+        F(i, 1) = int(3*i+1);
+        F(i, 2) = int(3*i+2);
+    }
+    
+    // We will convert this to a proper 3d mesh with no duplicate points.
+    Eigen::VectorXi SVI, SVJ;
+    igl::remove_duplicate_vertices(V, F, dEPS, m_V, SVI, SVJ, m_F);
+    
+    // Build the AABB accelaration tree
+    m_aabb->init(m_V, m_F);
+#ifdef SLIC3R_SLA_NEEDS_WINDTREE
+    m_aabb->windtree.set_mesh(m_V, m_F);
+#endif /* SLIC3R_SLA_NEEDS_WINDTREE */
+}
+
+EigenMesh3D::~EigenMesh3D() {}
+
+EigenMesh3D::EigenMesh3D(const EigenMesh3D &other):
+    m_V(other.m_V), m_F(other.m_F), m_ground_level(other.m_ground_level),
+    m_aabb( new AABBImpl(*other.m_aabb) ) {}
+
+EigenMesh3D::EigenMesh3D(const Contour3D &other)
+{
+    m_V.resize(Eigen::Index(other.points.size()), 3);
+    m_F.resize(Eigen::Index(other.faces3.size() + 2 * other.faces4.size()), 3);
+    
+    for (Eigen::Index i = 0; i < Eigen::Index(other.points.size()); ++i)
+        m_V.row(i) = other.points[size_t(i)];
+    
+    for (Eigen::Index i = 0; i < Eigen::Index(other.faces3.size()); ++i)
+        m_F.row(i) = other.faces3[size_t(i)];
+    
+    size_t N = other.faces3.size() + 2 * other.faces4.size();
+    for (size_t i = other.faces3.size(); i < N; i += 2) {
+        size_t quad_idx = (i - other.faces3.size()) / 2;
+        auto & quad     = other.faces4[quad_idx];
+        m_F.row(Eigen::Index(i)) = Vec3i{quad(0), quad(1), quad(2)};
+        m_F.row(Eigen::Index(i + 1)) = Vec3i{quad(2), quad(3), quad(0)};
+    }
+}
+
+EigenMesh3D &EigenMesh3D::operator=(const EigenMesh3D &other)
+{
+    m_V = other.m_V;
+    m_F = other.m_F;
+    m_ground_level = other.m_ground_level;
+    m_aabb.reset(new AABBImpl(*other.m_aabb)); return *this;
+}
+
+EigenMesh3D::hit_result
+EigenMesh3D::query_ray_hit(const Vec3d &s, const Vec3d &dir) const
+{
+    assert(is_approx(dir.norm(), 1.));
+    igl::Hit hit;
+    hit.t = std::numeric_limits<float>::infinity();
+
+    if (m_holes.empty()) {
+        m_aabb->intersect_ray(m_V, m_F, s, dir, hit);
+        hit_result ret(*this);
+        ret.m_t = double(hit.t);
+        ret.m_dir = dir;
+        ret.m_source = s;
+        if(!std::isinf(hit.t) && !std::isnan(hit.t))
+            ret.m_normal = this->normal_by_face_id(hit.id);
+
+        return ret;
+    }
+    else {
+        // If there are holes, the hit_results will be made by
+        // query_ray_hits (object) and filter_hits (holes):
+        return filter_hits(query_ray_hits(s, dir));
+    }
+}
+
+std::vector<EigenMesh3D::hit_result>
+EigenMesh3D::query_ray_hits(const Vec3d &s, const Vec3d &dir) const
+{
+    std::vector<EigenMesh3D::hit_result> outs;
+    std::vector<igl::Hit> hits;
+    m_aabb->intersect_ray(m_V, m_F, s, dir, hits);
+    
+    // The sort is necessary, the hits are not always sorted.
+    std::sort(hits.begin(), hits.end(),
+              [](const igl::Hit& a, const igl::Hit& b) { return a.t < b.t; });
+
+    // Remove duplicates. They sometimes appear, for example when the ray is cast
+    // along an axis of a cube due to floating-point approximations in igl (?)
+    hits.erase(std::unique(hits.begin(), hits.end(),
+                           [](const igl::Hit& a, const igl::Hit& b)
+                              { return a.t == b.t; }),
+               hits.end());
+
+    //  Convert the igl::Hit into hit_result
+    outs.reserve(hits.size());
+    for (const igl::Hit& hit : hits) {
+        outs.emplace_back(EigenMesh3D::hit_result(*this));
+        outs.back().m_t = double(hit.t);
+        outs.back().m_dir = dir;
+        outs.back().m_source = s;
+        if(!std::isinf(hit.t) && !std::isnan(hit.t))
+            outs.back().m_normal = this->normal_by_face_id(hit.id);
+    }
+
+    return outs;
+}
+
+EigenMesh3D::hit_result EigenMesh3D::filter_hits(
+                     const std::vector<EigenMesh3D::hit_result>& object_hits) const
+{
+    assert(! m_holes.empty());
+    hit_result out(*this);
+
+    if (object_hits.empty())
+        return out;
+
+    const Vec3d& s = object_hits.front().source();
+    const Vec3d& dir = object_hits.front().direction();
+
+    // A helper struct to save an intersetion with a hole
+    struct HoleHit {
+        HoleHit(float t_p, const Vec3d& normal_p, bool entry_p) :
+            t(t_p), normal(normal_p), entry(entry_p) {}
+        float t;
+        Vec3d normal;
+        bool entry;
+    };
+    std::vector<HoleHit> hole_isects;
+    hole_isects.reserve(m_holes.size());
+    
+    auto sf = s.cast<float>();
+    auto dirf = dir.cast<float>();
+
+    // Collect hits on all holes, preserve information about entry/exit
+    for (const sla::DrainHole& hole : m_holes) {
+        std::array<std::pair<float, Vec3d>, 2> isects;
+        if (hole.get_intersections(sf, dirf, isects)) {
+            // Ignore hole hits behind the source
+            if (isects[0].first > 0.f) hole_isects.emplace_back(isects[0].first, isects[0].second, true);
+            if (isects[1].first > 0.f) hole_isects.emplace_back(isects[1].first, isects[1].second, false);
+        }
+    }
+
+    // Holes can intersect each other, sort the hits by t
+    std::sort(hole_isects.begin(), hole_isects.end(),
+              [](const HoleHit& a, const HoleHit& b) { return a.t < b.t; });
+
+    // Now inspect the intersections with object and holes, in the order of
+    // increasing distance. Keep track how deep are we nested in mesh/holes and
+    // pick the correct intersection.
+    // This needs to be done twice - first to find out how deep in the structure
+    // the source is, then to pick the correct intersection.
+    int hole_nested = 0;
+    int object_nested = 0;
+    for (int dry_run=1; dry_run>=0; --dry_run) {
+        hole_nested = -hole_nested;
+        object_nested = -object_nested;
+
+        bool is_hole = false;
+        bool is_entry = false;
+        const HoleHit* next_hole_hit = hole_isects.empty() ? nullptr : &hole_isects.front();
+        const hit_result* next_mesh_hit = &object_hits.front();
+
+        while (next_hole_hit || next_mesh_hit) {
+            if (next_hole_hit && next_mesh_hit) // still have hole and obj hits
+                is_hole = (next_hole_hit->t < next_mesh_hit->m_t);
+            else
+                is_hole = next_hole_hit; // one or the other ran out
+
+            // Is this entry or exit hit?
+            is_entry = is_hole ? next_hole_hit->entry : ! next_mesh_hit->is_inside();
+
+            if (! dry_run) {
+                if (! is_hole && hole_nested == 0) {
+                    // This is a valid object hit
+                    return *next_mesh_hit;
+                }
+                if (is_hole && ! is_entry && object_nested != 0) {
+                    // This holehit is the one we seek
+                    out.m_t = next_hole_hit->t;
+                    out.m_normal = next_hole_hit->normal;
+                    out.m_source = s;
+                    out.m_dir = dir;
+                    return out;
+                }
+            }
+
+            // Increase/decrease the counter
+            (is_hole ? hole_nested : object_nested) += (is_entry ? 1 : -1);
+
+            // Advance the respective pointer
+            if (is_hole && next_hole_hit++ == &hole_isects.back())
+                next_hole_hit = nullptr;
+            if (! is_hole && next_mesh_hit++ == &object_hits.back())
+                next_mesh_hit = nullptr;
+        }
+    }
+
+    // if we got here, the ray ended up in infinity
+    return out;
+}
+
+#ifdef SLIC3R_SLA_NEEDS_WINDTREE
+EigenMesh3D::si_result EigenMesh3D::signed_distance(const Vec3d &p) const {
+    double sign = 0; double sqdst = 0; int i = 0;  Vec3d c;
+    igl::signed_distance_winding_number(*m_aabb, m_V, m_F, m_aabb->windtree,
+                                        p, sign, sqdst, i, c);
+    
+    return si_result(sign * std::sqrt(sqdst), i, c);
+}
+
+bool EigenMesh3D::inside(const Vec3d &p) const {
+    return m_aabb->windtree.inside(p);
+}
+#endif /* SLIC3R_SLA_NEEDS_WINDTREE */
+
+double EigenMesh3D::squared_distance(const Vec3d &p, int& i, Vec3d& c) const {
+    double sqdst = 0;
+    Eigen::Matrix<double, 1, 3> pp = p;
+    Eigen::Matrix<double, 1, 3> cc;
+    sqdst = m_aabb->squared_distance(m_V, m_F, pp, i, cc);
+    c = cc;
+    return sqdst;
+}
+
+/* ****************************************************************************
+ * Misc functions
+ * ****************************************************************************/
+
+namespace  {
+
+bool point_on_edge(const Vec3d& p, const Vec3d& e1, const Vec3d& e2,
+                   double eps = 0.05)
+{
+    using Line3D = Eigen::ParametrizedLine<double, 3>;
+    
+    auto line = Line3D::Through(e1, e2);
+    double d = line.distance(p);
+    return std::abs(d) < eps;
+}
+
+template<class Vec> double distance(const Vec& pp1, const Vec& pp2) {
+    auto p = pp2 - pp1;
+    return std::sqrt(p.transpose() * p);
+}
+
+}
+
+PointSet normals(const PointSet& points,
+                 const EigenMesh3D& mesh,
+                 double eps,
+                 std::function<void()> thr, // throw on cancel
+                 const std::vector<unsigned>& pt_indices)
+{
+    if (points.rows() == 0 || mesh.V().rows() == 0 || mesh.F().rows() == 0)
+        return {};
+
+    std::vector<unsigned> range = pt_indices;
+    if (range.empty()) {
+        range.resize(size_t(points.rows()), 0);
+        std::iota(range.begin(), range.end(), 0);
+    }
+
+    PointSet ret(range.size(), 3);
+
+    //    for (size_t ridx = 0; ridx < range.size(); ++ridx)
+    ccr::enumerate(
+        range.begin(), range.end(),
+        [&ret, &mesh, &points, thr, eps](unsigned el, size_t ridx) {
+            thr();
+            auto  eidx   = Eigen::Index(el);
+            int   faceid = 0;
+            Vec3d p;
+
+            mesh.squared_distance(points.row(eidx), faceid, p);
+
+            auto trindex = mesh.F().row(faceid);
+
+            const Vec3d &p1 = mesh.V().row(trindex(0));
+            const Vec3d &p2 = mesh.V().row(trindex(1));
+            const Vec3d &p3 = mesh.V().row(trindex(2));
+
+            // We should check if the point lies on an edge of the hosting
+            // triangle. If it does then all the other triangles using the
+            // same two points have to be searched and the final normal should
+            // be some kind of aggregation of the participating triangle
+            // normals. We should also consider the cases where the support
+            // point lies right on a vertex of its triangle. The procedure is
+            // the same, get the neighbor triangles and calculate an average
+            // normal.
+
+            // mark the vertex indices of the edge. ia and ib marks and edge
+            // ic will mark a single vertex.
+            int ia = -1, ib = -1, ic = -1;
+
+            if (std::abs(distance(p, p1)) < eps) {
+                ic = trindex(0);
+            } else if (std::abs(distance(p, p2)) < eps) {
+                ic = trindex(1);
+            } else if (std::abs(distance(p, p3)) < eps) {
+                ic = trindex(2);
+            } else if (point_on_edge(p, p1, p2, eps)) {
+                ia = trindex(0);
+                ib = trindex(1);
+            } else if (point_on_edge(p, p2, p3, eps)) {
+                ia = trindex(1);
+                ib = trindex(2);
+            } else if (point_on_edge(p, p1, p3, eps)) {
+                ia = trindex(0);
+                ib = trindex(2);
+            }
+
+            // vector for the neigboring triangles including the detected one.
+            std::vector<Vec3i> neigh;
+            if (ic >= 0) { // The point is right on a vertex of the triangle
+                for (int n = 0; n < mesh.F().rows(); ++n) {
+                    thr();
+                    Vec3i ni = mesh.F().row(n);
+                    if ((ni(X) == ic || ni(Y) == ic || ni(Z) == ic))
+                        neigh.emplace_back(ni);
+                }
+            } else if (ia >= 0 && ib >= 0) { // the point is on and edge
+                // now get all the neigboring triangles
+                for (int n = 0; n < mesh.F().rows(); ++n) {
+                    thr();
+                    Vec3i ni = mesh.F().row(n);
+                    if ((ni(X) == ia || ni(Y) == ia || ni(Z) == ia) &&
+                        (ni(X) == ib || ni(Y) == ib || ni(Z) == ib))
+                        neigh.emplace_back(ni);
+                }
+            }
+
+            // Calculate the normals for the neighboring triangles
+            std::vector<Vec3d> neighnorms;
+            neighnorms.reserve(neigh.size());
+            for (const Vec3i &tri : neigh) {
+                const Vec3d &   pt1 = mesh.V().row(tri(0));
+                const Vec3d &   pt2 = mesh.V().row(tri(1));
+                const Vec3d &   pt3 = mesh.V().row(tri(2));
+                Eigen::Vector3d U   = pt2 - pt1;
+                Eigen::Vector3d V   = pt3 - pt1;
+                neighnorms.emplace_back(U.cross(V).normalized());
+            }
+
+            // Throw out duplicates. They would cause trouble with summing. We
+            // will use std::unique which works on sorted ranges. We will sort
+            // by the coefficient-wise sum of the normals. It should force the
+            // same elements to be consecutive.
+            std::sort(neighnorms.begin(), neighnorms.end(),
+                      [](const Vec3d &v1, const Vec3d &v2) {
+                          return v1.sum() < v2.sum();
+                      });
+
+            auto lend = std::unique(neighnorms.begin(), neighnorms.end(),
+                                    [](const Vec3d &n1, const Vec3d &n2) {
+                                        // Compare normals for equivalence.
+                                        // This is controvers stuff.
+                                        auto deq = [](double a, double b) {
+                                            return std::abs(a - b) < 1e-3;
+                                        };
+                                        return deq(n1(X), n2(X)) &&
+                                               deq(n1(Y), n2(Y)) &&
+                                               deq(n1(Z), n2(Z));
+                                    });
+
+            if (!neighnorms.empty()) { // there were neighbors to count with
+                // sum up the normals and then normalize the result again.
+                // This unification seems to be enough.
+                Vec3d sumnorm(0, 0, 0);
+                sumnorm = std::accumulate(neighnorms.begin(), lend, sumnorm);
+                sumnorm.normalize();
+                ret.row(long(ridx)) = sumnorm;
+            } else { // point lies safely within its triangle
+                Eigen::Vector3d U   = p2 - p1;
+                Eigen::Vector3d V   = p3 - p1;
+                ret.row(long(ridx)) = U.cross(V).normalized();
+            }
+        });
+
+    return ret;
+}
+
+namespace bgi = boost::geometry::index;
+using Index3D = bgi::rtree< PointIndexEl, bgi::rstar<16, 4> /* ? */ >;
+
+namespace {
+
+bool cmp_ptidx_elements(const PointIndexEl& e1, const PointIndexEl& e2)
+{
+    return e1.second < e2.second;
+};
+
+ClusteredPoints cluster(Index3D &sindex,
+                        unsigned max_points,
+                        std::function<std::vector<PointIndexEl>(
+                            const Index3D &, const PointIndexEl &)> qfn)
+{
+    using Elems = std::vector<PointIndexEl>;
+    
+    // Recursive function for visiting all the points in a given distance to
+    // each other
+    std::function<void(Elems&, Elems&)> group =
+        [&sindex, &group, max_points, qfn](Elems& pts, Elems& cluster)
+    {        
+        for(auto& p : pts) {
+            std::vector<PointIndexEl> tmp = qfn(sindex, p);
+            
+            std::sort(tmp.begin(), tmp.end(), cmp_ptidx_elements);
+            
+            Elems newpts;
+            std::set_difference(tmp.begin(), tmp.end(),
+                                cluster.begin(), cluster.end(),
+                                std::back_inserter(newpts), cmp_ptidx_elements);
+            
+            int c = max_points && newpts.size() + cluster.size() > max_points?
+                        int(max_points - cluster.size()) : int(newpts.size());
+            
+            cluster.insert(cluster.end(), newpts.begin(), newpts.begin() + c);
+            std::sort(cluster.begin(), cluster.end(), cmp_ptidx_elements);
+            
+            if(!newpts.empty() && (!max_points || cluster.size() < max_points))
+                group(newpts, cluster);
+        }
+    };
+    
+    std::vector<Elems> clusters;
+    for(auto it = sindex.begin(); it != sindex.end();) {
+        Elems cluster = {};
+        Elems pts = {*it};
+        group(pts, cluster);
+        
+        for(auto& c : cluster) sindex.remove(c);
+        it = sindex.begin();
+        
+        clusters.emplace_back(cluster);
+    }
+    
+    ClusteredPoints result;
+    for(auto& cluster : clusters) {
+        result.emplace_back();
+        for(auto c : cluster) result.back().emplace_back(c.second);
+    }
+    
+    return result;
+}
+
+std::vector<PointIndexEl> distance_queryfn(const Index3D& sindex,
+                                           const PointIndexEl& p,
+                                           double dist,
+                                           unsigned max_points)
+{
+    std::vector<PointIndexEl> tmp; tmp.reserve(max_points);
+    sindex.query(
+        bgi::nearest(p.first, max_points),
+        std::back_inserter(tmp)
+        );
+    
+    for(auto it = tmp.begin(); it < tmp.end(); ++it)
+        if(distance(p.first, it->first) > dist) it = tmp.erase(it);
+    
+    return tmp;
+}
+
+} // namespace
+
+// Clustering a set of points by the given criteria
+ClusteredPoints cluster(
+    const std::vector<unsigned>& indices,
+    std::function<Vec3d(unsigned)> pointfn,
+    double dist,
+    unsigned max_points)
+{
+    // A spatial index for querying the nearest points
+    Index3D sindex;
+    
+    // Build the index
+    for(auto idx : indices) sindex.insert( std::make_pair(pointfn(idx), idx));
+    
+    return cluster(sindex, max_points,
+                   [dist, max_points](const Index3D& sidx, const PointIndexEl& p)
+                   {
+                       return distance_queryfn(sidx, p, dist, max_points);
+                   });
+}
+
+// Clustering a set of points by the given criteria
+ClusteredPoints cluster(
+    const std::vector<unsigned>& indices,
+    std::function<Vec3d(unsigned)> pointfn,
+    std::function<bool(const PointIndexEl&, const PointIndexEl&)> predicate,
+    unsigned max_points)
+{
+    // A spatial index for querying the nearest points
+    Index3D sindex;
+    
+    // Build the index
+    for(auto idx : indices) sindex.insert( std::make_pair(pointfn(idx), idx));
+    
+    return cluster(sindex, max_points,
+                   [max_points, predicate](const Index3D& sidx, const PointIndexEl& p)
+                   {
+                       std::vector<PointIndexEl> tmp; tmp.reserve(max_points);
+                       sidx.query(bgi::satisfies([p, predicate](const PointIndexEl& e){
+                                      return predicate(p, e);
+                                  }), std::back_inserter(tmp));
+                       return tmp;
+                   });
+}
+
+ClusteredPoints cluster(const PointSet& pts, double dist, unsigned max_points)
+{
+    // A spatial index for querying the nearest points
+    Index3D sindex;
+    
+    // Build the index
+    for(Eigen::Index i = 0; i < pts.rows(); i++)
+        sindex.insert(std::make_pair(Vec3d(pts.row(i)), unsigned(i)));
+    
+    return cluster(sindex, max_points,
+                   [dist, max_points](const Index3D& sidx, const PointIndexEl& p)
+                   {
+                       return distance_queryfn(sidx, p, dist, max_points);
+                   });
+}
+
+} // namespace sla
+} // namespace Slic3r

src/libslic3r/SLA/Common.hpp

@@ -0,0 +1,32 @@
+#ifndef SLA_COMMON_HPP
+#define SLA_COMMON_HPP
+
+#include <memory>
+#include <vector>
+#include <numeric>
+#include <functional>
+#include <Eigen/Geometry>
+
+//#include "SLASpatIndex.hpp"
+
+//#include <libslic3r/ExPolygon.hpp>
+//#include <libslic3r/TriangleMesh.hpp>
+
+// #define SLIC3R_SLA_NEEDS_WINDTREE
+
+namespace Slic3r {
+    
+// Typedefs from Point.hpp
+typedef Eigen::Matrix<float, 3, 1, Eigen::DontAlign> Vec3f;
+typedef Eigen::Matrix<double, 3, 1, Eigen::DontAlign> Vec3d;
+typedef Eigen::Matrix<int, 4, 1, Eigen::DontAlign> Vec4i;
+
+namespace sla {
+
+using PointSet = Eigen::MatrixXd;
+
+} // namespace sla
+} // namespace Slic3r
+
+
+#endif // SLASUPPORTTREE_HPP

src/libslic3r/SLA/ConcaveHull.cpp

@@ -1,7 +1,9 @@
-#include "ConcaveHull.hpp"
+#include <libslic3r/SLA/ConcaveHull.hpp>
+#include <libslic3r/SLA/SpatIndex.hpp>
+
 #include <libslic3r/MTUtils.hpp>
 #include <libslic3r/ClipperUtils.hpp>
-#include "SLASpatIndex.hpp"
+
 #include <boost/log/trivial.hpp>
 
 namespace Slic3r {
@@ -40,7 +42,7 @@ Point ConcaveHull::centroid(const Points &pp)
 
 // As it shows, the current offset_ex in ClipperUtils hangs if used in jtRound
 // mode
-ClipperLib::Paths fast_offset(const ClipperLib::Paths &paths,
+static ClipperLib::Paths fast_offset(const ClipperLib::Paths &paths,
                                      coord_t                  delta,
                                      ClipperLib::JoinType     jointype)
 {
@@ -73,7 +75,7 @@ Points ConcaveHull::calculate_centroids() const
     Points centroids = reserve_vector<Point>(m_polys.size());
     std::transform(m_polys.begin(), m_polys.end(),
                    std::back_inserter(centroids),
-                   [this](const Polygon &poly) { return centroid(poly); });
+                   [](const Polygon &poly) { return centroid(poly); });
 
     return centroids;
 }

src/libslic3r/SLA/ConcaveHull.hpp

@@ -1,5 +1,5 @@
-#ifndef CONCAVEHULL_HPP
+#ifndef SLA_CONCAVEHULL_HPP
-#define CONCAVEHULL_HPP
+#define SLA_CONCAVEHULL_HPP
 
 #include <libslic3r/ExPolygon.hpp>
 

src/libslic3r/SLA/Concurrency.hpp

@@ -1,5 +1,5 @@
-#ifndef SLACONCURRENCY_H
+#ifndef SLA_CONCURRENCY_H
-#define SLACONCURRENCY_H
+#define SLA_CONCURRENCY_H
 
 #include <tbb/spin_mutex.h>
 #include <tbb/mutex.h>

src/libslic3r/SLA/Contour3D.cpp

@@ -0,0 +1,149 @@
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+
+#include <libslic3r/Format/objparser.hpp>
+
+namespace Slic3r { namespace sla {
+
+Contour3D::Contour3D(const TriangleMesh &trmesh)
+{
+    points.reserve(trmesh.its.vertices.size());
+    faces3.reserve(trmesh.its.indices.size());
+    
+    for (auto &v : trmesh.its.vertices)
+        points.emplace_back(v.cast<double>());
+    
+    std::copy(trmesh.its.indices.begin(), trmesh.its.indices.end(),
+              std::back_inserter(faces3));
+}
+
+Contour3D::Contour3D(TriangleMesh &&trmesh)
+{
+    points.reserve(trmesh.its.vertices.size());
+    
+    for (auto &v : trmesh.its.vertices)
+        points.emplace_back(v.cast<double>());
+    
+    faces3.swap(trmesh.its.indices);
+}
+
+Contour3D::Contour3D(const EigenMesh3D &emesh) {
+    points.reserve(size_t(emesh.V().rows()));
+    faces3.reserve(size_t(emesh.F().rows()));
+    
+    for (int r = 0; r < emesh.V().rows(); r++)
+        points.emplace_back(emesh.V().row(r).cast<double>());
+    
+    for (int i = 0; i < emesh.F().rows(); i++)
+        faces3.emplace_back(emesh.F().row(i));
+}
+
+Contour3D &Contour3D::merge(const Contour3D &ctr)
+{
+    auto N = coord_t(points.size());
+    auto N_f3 = faces3.size();
+    auto N_f4 = faces4.size();
+    
+    points.insert(points.end(), ctr.points.begin(), ctr.points.end());
+    faces3.insert(faces3.end(), ctr.faces3.begin(), ctr.faces3.end());
+    faces4.insert(faces4.end(), ctr.faces4.begin(), ctr.faces4.end());
+    
+    for(size_t n = N_f3; n < faces3.size(); n++) {
+        auto& idx = faces3[n]; idx.x() += N; idx.y() += N; idx.z() += N;
+    }
+    
+    for(size_t n = N_f4; n < faces4.size(); n++) {
+        auto& idx = faces4[n]; for (int k = 0; k < 4; k++) idx(k) += N;
+    }        
+    
+    return *this;
+}
+
+Contour3D &Contour3D::merge(const Pointf3s &triangles)
+{
+    const size_t offs = points.size();
+    points.insert(points.end(), triangles.begin(), triangles.end());
+    faces3.reserve(faces3.size() + points.size() / 3);
+    
+    for(int i = int(offs); i < int(points.size()); i += 3)
+        faces3.emplace_back(i, i + 1, i + 2);
+    
+    return *this;
+}
+
+void Contour3D::to_obj(std::ostream &stream)
+{
+    for(auto& p : points)
+        stream << "v " << p.transpose() << "\n";
+    
+    for(auto& f : faces3) 
+        stream << "f " << (f + Vec3i(1, 1, 1)).transpose() << "\n";
+    
+    for(auto& f : faces4)
+        stream << "f " << (f + Vec4i(1, 1, 1, 1)).transpose() << "\n";
+}
+
+void Contour3D::from_obj(std::istream &stream)
+{
+    ObjParser::ObjData data;
+    ObjParser::objparse(stream, data);
+    
+    points.reserve(data.coordinates.size() / 4 + 1);
+    auto &coords = data.coordinates;
+    for (size_t i = 0; i < coords.size(); i += 4)
+        points.emplace_back(coords[i], coords[i + 1], coords[i + 2]);
+    
+    Vec3i triangle;
+    Vec4i quad;
+    size_t v = 0;
+    while(v < data.vertices.size()) {
+        size_t N = 0;
+        size_t i = v;
+        while (data.vertices[v++].coordIdx != -1) ++N;
+        
+        std::function<void(int, int)> setfn;
+        if (N < 3 || N > 4) continue;
+        else if (N == 3) setfn = [&triangle](int k, int f) { triangle(k) = f; };
+        else setfn = [&quad](int k, int f) { quad(k) = f; };
+        
+        for (size_t j = 0; j < N; ++j)
+            setfn(int(j), data.vertices[i + j].coordIdx);
+    }
+}
+
+TriangleMesh to_triangle_mesh(const Contour3D &ctour) {
+    if (ctour.faces4.empty()) return {ctour.points, ctour.faces3};
+    
+    std::vector<Vec3i> triangles;
+    
+    triangles.reserve(ctour.faces3.size() + 2 * ctour.faces4.size());
+    std::copy(ctour.faces3.begin(), ctour.faces3.end(),
+              std::back_inserter(triangles));
+    
+    for (auto &quad : ctour.faces4) {
+        triangles.emplace_back(quad(0), quad(1), quad(2));
+        triangles.emplace_back(quad(2), quad(3), quad(0));
+    }
+    
+    return {ctour.points, std::move(triangles)};
+}
+
+TriangleMesh to_triangle_mesh(Contour3D &&ctour) {
+    if (ctour.faces4.empty())
+        return {std::move(ctour.points), std::move(ctour.faces3)};
+    
+    std::vector<Vec3i> triangles;
+    
+    triangles.reserve(ctour.faces3.size() + 2 * ctour.faces4.size());
+    std::copy(ctour.faces3.begin(), ctour.faces3.end(),
+              std::back_inserter(triangles));
+    
+    for (auto &quad : ctour.faces4) {
+        triangles.emplace_back(quad(0), quad(1), quad(2));
+        triangles.emplace_back(quad(2), quad(3), quad(0));
+    }
+    
+    return {std::move(ctour.points), std::move(triangles)};
+}
+
+}} // namespace Slic3r::sla

src/libslic3r/SLA/Contour3D.hpp

@@ -0,0 +1,45 @@
+#ifndef SLA_CONTOUR3D_HPP
+#define SLA_CONTOUR3D_HPP
+
+#include <libslic3r/SLA/Common.hpp>
+
+#include <libslic3r/TriangleMesh.hpp>
+
+namespace Slic3r { namespace sla {
+
+class EigenMesh3D;
+
+/// Dumb vertex mesh consisting of triangles (or) quads. Capable of merging with
+/// other meshes of this type and converting to and from other mesh formats.
+struct Contour3D {
+    std::vector<Vec3d> points;
+    std::vector<Vec3i> faces3;
+    std::vector<Vec4i> faces4;
+    
+    Contour3D() = default;
+    Contour3D(const TriangleMesh &trmesh);
+    Contour3D(TriangleMesh &&trmesh);
+    Contour3D(const EigenMesh3D  &emesh);
+    
+    Contour3D& merge(const Contour3D& ctr);
+    Contour3D& merge(const Pointf3s& triangles);
+    
+    // Write the index triangle structure to OBJ file for debugging purposes.
+    void to_obj(std::ostream& stream);
+    void from_obj(std::istream &stream);
+
+    inline bool empty() const
+    {
+        return points.empty() || (faces4.empty() && faces3.empty());
+    }
+};
+
+/// Mesh from an existing contour.
+TriangleMesh to_triangle_mesh(const Contour3D& ctour);
+
+/// Mesh from an evaporating 3D contour
+TriangleMesh to_triangle_mesh(Contour3D&& ctour);
+
+}} // namespace Slic3r::sla
+
+#endif // CONTOUR3D_HPP

src/libslic3r/SLA/EigenMesh3D.hpp

@@ -0,0 +1,156 @@
+#ifndef SLA_EIGENMESH3D_H
+#define SLA_EIGENMESH3D_H
+
+#include <libslic3r/SLA/Common.hpp>
+#include "libslic3r/SLA/Hollowing.hpp"
+
+namespace Slic3r {
+
+class TriangleMesh;
+
+namespace sla {
+
+struct Contour3D;
+
+/// An index-triangle structure for libIGL functions. Also serves as an
+/// alternative (raw) input format for the SLASupportTree.
+//  Implemented in libslic3r/SLA/Common.cpp
+class EigenMesh3D {
+    class AABBImpl;
+    
+    Eigen::MatrixXd m_V;
+    Eigen::MatrixXi m_F;
+    double m_ground_level = 0, m_gnd_offset = 0;
+    
+    std::unique_ptr<AABBImpl> m_aabb;
+
+    // This holds a copy of holes in the mesh. Initialized externally
+    // by load_mesh setter.
+    std::vector<DrainHole> m_holes;
+
+public:
+    
+    EigenMesh3D(const TriangleMesh&);
+    EigenMesh3D(const EigenMesh3D& other);
+    EigenMesh3D(const Contour3D &other);
+    EigenMesh3D& operator=(const EigenMesh3D&);
+    
+    ~EigenMesh3D();
+    
+    inline double ground_level() const { return m_ground_level + m_gnd_offset; }
+    inline void ground_level_offset(double o) { m_gnd_offset = o; }
+    inline double ground_level_offset() const { return m_gnd_offset; }
+    
+    inline const Eigen::MatrixXd& V() const { return m_V; }
+    inline const Eigen::MatrixXi& F() const { return m_F; }
+    
+    // Result of a raycast
+    class hit_result {
+        // m_t holds a distance from m_source to the intersection.
+        double m_t = infty();
+        const EigenMesh3D *m_mesh = nullptr;
+        Vec3d m_dir;
+        Vec3d m_source;
+        Vec3d m_normal;
+        friend class EigenMesh3D;
+        
+        // A valid object of this class can only be obtained from
+        // EigenMesh3D::query_ray_hit method.
+        explicit inline hit_result(const EigenMesh3D& em): m_mesh(&em) {}
+    public:
+        // This denotes no hit on the mesh.
+        static inline constexpr double infty() { return std::numeric_limits<double>::infinity(); }
+        
+        explicit inline hit_result(double val = infty()) : m_t(val) {}
+        
+        inline double distance() const { return m_t; }
+        inline const Vec3d& direction() const { return m_dir; }
+        inline const Vec3d& source() const { return m_source; }
+        inline Vec3d position() const { return m_source + m_dir * m_t; }
+        inline bool is_valid() const { return m_mesh != nullptr; }
+        inline bool is_hit() const { return !std::isinf(m_t); }
+
+        // Hit_result can decay into a double as the hit distance.
+        inline operator double() const { return distance(); }
+
+        inline const Vec3d& normal() const {
+            assert(is_valid());
+            return m_normal;
+        }
+
+        inline bool is_inside() const {
+            return is_hit() && normal().dot(m_dir) > 0;
+        }
+    };
+    
+    // Inform the object about location of holes
+    // creates internal copy of the vector
+    void load_holes(const std::vector<DrainHole>& holes) {
+        m_holes = holes;
+    }
+
+    // Casting a ray on the mesh, returns the distance where the hit occures.
+    hit_result query_ray_hit(const Vec3d &s, const Vec3d &dir) const;
+    
+    // Casts a ray on the mesh and returns all hits
+    std::vector<hit_result> query_ray_hits(const Vec3d &s, const Vec3d &dir) const;
+
+    // Iterates over hits and holes and returns the true hit, possibly
+    // on the inside of a hole.
+    hit_result filter_hits(const std::vector<EigenMesh3D::hit_result>& obj_hits) const;
+
+    class si_result {
+        double m_value;
+        int m_fidx;
+        Vec3d m_p;
+        si_result(double val, int i, const Vec3d& c):
+            m_value(val), m_fidx(i), m_p(c) {}
+        friend class EigenMesh3D;
+    public:
+        
+        si_result() = delete;
+        
+        double value() const { return m_value; }
+        operator double() const { return m_value; }
+        const Vec3d& point_on_mesh() const { return m_p; }
+        int F_idx() const { return m_fidx; }
+    };
+
+#ifdef SLIC3R_SLA_NEEDS_WINDTREE
+    // The signed distance from a point to the mesh. Outputs the distance,
+    // the index of the triangle and the closest point in mesh coordinate space.
+    si_result signed_distance(const Vec3d& p) const;
+    
+    bool inside(const Vec3d& p) const;
+#endif /* SLIC3R_SLA_NEEDS_WINDTREE */
+    
+    double squared_distance(const Vec3d& p, int& i, Vec3d& c) const;
+    inline double squared_distance(const Vec3d &p) const
+    {
+        int   i;
+        Vec3d c;
+        return squared_distance(p, i, c);
+    }
+
+    Vec3d normal_by_face_id(int face_id) const {
+        auto trindex    = F().row(face_id);
+        const Vec3d& p1 = V().row(trindex(0));
+        const Vec3d& p2 = V().row(trindex(1));
+        const Vec3d& p3 = V().row(trindex(2));
+        Eigen::Vector3d U = p2 - p1;
+        Eigen::Vector3d V = p3 - p1;
+        return U.cross(V).normalized();
+    }
+};
+
+// Calculate the normals for the selected points (from 'points' set) on the
+// mesh. This will call squared distance for each point.
+PointSet normals(const PointSet& points,
+    const EigenMesh3D& convert_mesh,
+    double eps = 0.05,  // min distance from edges
+    std::function<void()> throw_on_cancel = [](){},
+    const std::vector<unsigned>& selected_points = {});
+
+}} // namespace Slic3r::sla
+
+#endif // EIGENMESH3D_H

src/libslic3r/SLA/Hollowing.cpp

@@ -0,0 +1,283 @@
+#include <functional>
+
+#include <libslic3r/OpenVDBUtils.hpp>
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/SLA/Hollowing.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+#include <libslic3r/SLA/SupportTreeBuilder.hpp>
+#include <libslic3r/ClipperUtils.hpp>
+#include <libslic3r/SimplifyMesh.hpp>
+
+#include <boost/log/trivial.hpp>
+
+#include <libslic3r/MTUtils.hpp>
+#include <libslic3r/I18N.hpp>
+
+//! macro used to mark string used at localization,
+//! return same string
+#define L(s) Slic3r::I18N::translate(s)
+
+namespace Slic3r {
+namespace sla {
+
+template<class S, class = FloatingOnly<S>>
+inline void _scale(S s, TriangleMesh &m) { m.scale(float(s)); }
+
+template<class S, class = FloatingOnly<S>>
+inline void _scale(S s, Contour3D &m) { for (auto &p : m.points) p *= s; }
+
+static TriangleMesh _generate_interior(const TriangleMesh  &mesh,
+                                       const JobController &ctl,
+                                       double               min_thickness,
+                                       double               voxel_scale,
+                                       double               closing_dist)
+{
+    TriangleMesh imesh{mesh};
+    
+    _scale(voxel_scale, imesh);
+    
+    double offset = voxel_scale * min_thickness;
+    double D = voxel_scale * closing_dist;
+    float  out_range = 0.1f * float(offset);
+    float  in_range = 1.1f * float(offset + D);
+    
+    if (ctl.stopcondition()) return {};
+    else ctl.statuscb(0, L("Hollowing"));
+    
+    auto gridptr = mesh_to_grid(imesh, {}, out_range, in_range);
+    
+    assert(gridptr);
+    
+    if (!gridptr) {
+        BOOST_LOG_TRIVIAL(error) << "Returned OpenVDB grid is NULL";
+        return {};
+    }
+    
+    if (ctl.stopcondition()) return {};
+    else ctl.statuscb(30, L("Hollowing"));
+    
+    if (closing_dist > .0) {
+        gridptr = redistance_grid(*gridptr, -(offset + D), double(in_range));
+    } else {
+        D = -offset;
+    }
+    
+    if (ctl.stopcondition()) return {};
+    else ctl.statuscb(70, L("Hollowing"));
+    
+    double iso_surface = D;
+    double adaptivity = 0.;
+    auto omesh = grid_to_mesh(*gridptr, iso_surface, adaptivity);
+    
+    _scale(1. / voxel_scale, omesh);
+    
+    if (ctl.stopcondition()) return {};
+    else ctl.statuscb(100, L("Hollowing"));
+    
+    return omesh;
+}
+
+std::unique_ptr<TriangleMesh> generate_interior(const TriangleMesh &   mesh,
+                                                const HollowingConfig &hc,
+                                                const JobController &  ctl)
+{
+    static const double MIN_OVERSAMPL = 3.;
+    static const double MAX_OVERSAMPL = 8.;
+        
+    // I can't figure out how to increase the grid resolution through openvdb
+    // API so the model will be scaled up before conversion and the result
+    // scaled down. Voxels have a unit size. If I set voxelSize smaller, it
+    // scales the whole geometry down, and doesn't increase the number of
+    // voxels.
+    //
+    // max 8x upscale, min is native voxel size
+    auto voxel_scale = MIN_OVERSAMPL + (MAX_OVERSAMPL - MIN_OVERSAMPL) * hc.quality;
+    auto meshptr = std::make_unique<TriangleMesh>(
+        _generate_interior(mesh, ctl, hc.min_thickness, voxel_scale,
+                           hc.closing_distance));
+    
+    if (meshptr) {
+        
+        // This flips the normals to be outward facing...
+        meshptr->require_shared_vertices();
+        indexed_triangle_set its = std::move(meshptr->its);
+        
+        Slic3r::simplify_mesh(its);
+        
+        // flip normals back...
+        for (stl_triangle_vertex_indices &ind : its.indices)
+            std::swap(ind(0), ind(2));
+        
+        *meshptr = Slic3r::TriangleMesh{its};
+    }
+    
+    return meshptr;
+}
+
+Contour3D DrainHole::to_mesh() const
+{
+    auto r = double(radius);
+    auto h = double(height);
+    sla::Contour3D hole = sla::cylinder(r, h);
+    Eigen::Quaterniond q;
+    q.setFromTwoVectors(Vec3d{0., 0., 1.}, normal.cast<double>());
+    for(auto& p : hole.points) p = q * p + pos.cast<double>();
+    return hole;
+}
+
+bool DrainHole::operator==(const DrainHole &sp) const
+{
+    return (pos == sp.pos) && (normal == sp.normal) &&
+            is_approx(radius, sp.radius) &&
+            is_approx(height, sp.height);
+}
+
+bool DrainHole::is_inside(const Vec3f& pt) const
+{
+    Eigen::Hyperplane<float, 3> plane(normal, pos);
+    float dist = plane.signedDistance(pt);
+    if (dist < float(EPSILON) || dist > height)
+        return false;
+
+    Eigen::ParametrizedLine<float, 3> axis(pos, normal);
+    if ( axis.squaredDistance(pt) < pow(radius, 2.f))
+        return true;
+
+    return false;
+}
+
+
+// Given a line s+dir*t, find parameter t of intersections with the hole
+// and the normal (points inside the hole). Outputs through out reference,
+// returns true if two intersections were found.
+bool DrainHole::get_intersections(const Vec3f& s, const Vec3f& dir,
+                                  std::array<std::pair<float, Vec3d>, 2>& out)
+                                  const
+{
+    assert(is_approx(normal.norm(), 1.f));
+    const Eigen::ParametrizedLine<float, 3> ray(s, dir.normalized());
+
+    for (size_t i=0; i<2; ++i)
+        out[i] = std::make_pair(sla::EigenMesh3D::hit_result::infty(), Vec3d::Zero());
+
+    const float sqr_radius = pow(radius, 2.f);
+
+    // first check a bounding sphere of the hole:
+    Vec3f center = pos+normal*height/2.f;
+    float sqr_dist_limit = pow(height/2.f, 2.f) + sqr_radius ;
+    if (ray.squaredDistance(center) > sqr_dist_limit)
+        return false;
+
+    // The line intersects the bounding sphere, look for intersections with
+    // bases of the cylinder.
+
+    size_t found = 0; // counts how many intersections were found
+    Eigen::Hyperplane<float, 3> base;
+    if (! is_approx(ray.direction().dot(normal), 0.f)) {
+        for (size_t i=1; i<=1; --i) {
+            Vec3f cylinder_center = pos+i*height*normal;
+            if (i == 0) {
+                // The hole base can be identical to mesh surface if it is flat
+                // let's better move the base outward a bit
+                cylinder_center -= EPSILON*normal;
+            }
+            base = Eigen::Hyperplane<float, 3>(normal, cylinder_center);
+            Vec3f intersection = ray.intersectionPoint(base);
+            // Only accept the point if it is inside the cylinder base.
+            if ((cylinder_center-intersection).squaredNorm() < sqr_radius) {
+                out[found].first = ray.intersectionParameter(base);
+                out[found].second = (i==0 ? 1. : -1.) * normal.cast<double>();
+                ++found;
+            }
+        }
+    }
+    else
+    {
+        // In case the line was perpendicular to the cylinder axis, previous
+        // block was skipped, but base will later be assumed to be valid.
+        base = Eigen::Hyperplane<float, 3>(normal, pos-EPSILON*normal);
+    }
+
+    // In case there is still an intersection to be found, check the wall
+    if (found != 2 && ! is_approx(std::abs(ray.direction().dot(normal)), 1.f)) {
+        // Project the ray onto the base plane
+        Vec3f proj_origin = base.projection(ray.origin());
+        Vec3f proj_dir = base.projection(ray.origin()+ray.direction())-proj_origin;
+        // save how the parameter scales and normalize the projected direction
+        float par_scale = proj_dir.norm();
+        proj_dir = proj_dir/par_scale;
+        Eigen::ParametrizedLine<float, 3> projected_ray(proj_origin, proj_dir);
+        // Calculate point on the secant that's closest to the center
+        // and its distance to the circle along the projected line
+        Vec3f closest = projected_ray.projection(pos);
+        float dist = sqrt((sqr_radius - (closest-pos).squaredNorm()));
+        // Unproject both intersections on the original line and check
+        // they are on the cylinder and not past it:
+        for (int i=-1; i<=1 && found !=2; i+=2) {
+            Vec3f isect = closest + i*dist * projected_ray.direction();
+            Vec3f to_isect = isect-proj_origin;
+            float par = to_isect.norm() / par_scale;
+            if (to_isect.normalized().dot(proj_dir.normalized()) < 0.f)
+                par *= -1.f;
+            Vec3d hit_normal = (pos-isect).normalized().cast<double>();
+            isect = ray.pointAt(par);
+            // check that the intersection is between the base planes:
+            float vert_dist = base.signedDistance(isect);
+            if (vert_dist > 0.f && vert_dist < height) {
+                out[found].first = par;
+                out[found].second = hit_normal;
+                ++found;
+            }
+        }
+    }
+
+    // If only one intersection was found, it is some corner case,
+    // no intersection will be returned:
+    if (found != 2)
+        return false;
+
+    // Sort the intersections:
+    if (out[0].first > out[1].first)
+        std::swap(out[0], out[1]);
+
+    return true;
+}
+
+void cut_drainholes(std::vector<ExPolygons> & obj_slices,
+                    const std::vector<float> &slicegrid,
+                    float                     closing_radius,
+                    const sla::DrainHoles &   holes,
+                    std::function<void(void)> thr)
+{
+    TriangleMesh mesh;
+    for (const sla::DrainHole &holept : holes) {
+        auto r = double(holept.radius);
+        auto h = double(holept.height);
+        sla::Contour3D hole = sla::cylinder(r, h);
+        Eigen::Quaterniond q;
+        q.setFromTwoVectors(Vec3d{0., 0., 1.}, holept.normal.cast<double>());
+        for(auto& p : hole.points) p = q * p + holept.pos.cast<double>();
+        mesh.merge(sla::to_triangle_mesh(hole));
+    }
+    
+    if (mesh.empty()) return;
+    
+    mesh.require_shared_vertices();
+    
+    TriangleMeshSlicer slicer(&mesh);
+    
+    std::vector<ExPolygons> hole_slices;
+    slicer.slice(slicegrid, closing_radius, &hole_slices, thr);
+    
+    if (obj_slices.size() != hole_slices.size())
+        BOOST_LOG_TRIVIAL(warning)
+            << "Sliced object and drain-holes layer count does not match!";
+
+    size_t until = std::min(obj_slices.size(), hole_slices.size());
+    
+    for (size_t i = 0; i < until; ++i)
+        obj_slices[i] = diff_ex(obj_slices[i], hole_slices[i]);
+}
+
+}} // namespace Slic3r::sla

src/libslic3r/SLA/Hollowing.hpp

@@ -0,0 +1,70 @@
+#ifndef SLA_HOLLOWING_HPP
+#define SLA_HOLLOWING_HPP
+
+#include <memory>
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <libslic3r/SLA/JobController.hpp>
+
+namespace Slic3r {
+
+class TriangleMesh;
+
+namespace sla {
+
+struct HollowingConfig
+{
+    double min_thickness    = 2.;
+    double quality          = 0.5;
+    double closing_distance = 0.5;
+    bool enabled = true;
+};
+
+struct DrainHole
+{
+    Vec3f pos;
+    Vec3f normal;
+    float radius;
+    float height;
+
+    DrainHole()
+        : pos(Vec3f::Zero()), normal(Vec3f::UnitZ()), radius(5.f), height(10.f)
+    {}
+
+    DrainHole(Vec3f p, Vec3f n, float r, float h)
+        : pos(p), normal(n), radius(r), height(h)
+    {}
+    
+    bool operator==(const DrainHole &sp) const;
+    
+    bool operator!=(const DrainHole &sp) const { return !(sp == (*this)); }
+
+    bool is_inside(const Vec3f& pt) const;
+
+    bool get_intersections(const Vec3f& s, const Vec3f& dir,
+                           std::array<std::pair<float, Vec3d>, 2>& out) const;
+    
+    Contour3D to_mesh() const;
+    
+    template<class Archive> inline void serialize(Archive &ar)
+    {
+        ar(pos, normal, radius, height);
+    }
+};
+
+using DrainHoles = std::vector<DrainHole>;
+
+std::unique_ptr<TriangleMesh> generate_interior(const TriangleMesh &mesh,
+                                                const HollowingConfig &  = {},
+                                                const JobController &ctl = {});
+
+void cut_drainholes(std::vector<ExPolygons> & obj_slices,
+                    const std::vector<float> &slicegrid,
+                    float                     closing_radius,
+                    const sla::DrainHoles &   holes,
+                    std::function<void(void)> thr);
+
+}
+}
+
+#endif // HOLLOWINGFILTER_H

src/libslic3r/SLA/JobController.hpp

@@ -0,0 +1,31 @@
+#ifndef SLA_JOBCONTROLLER_HPP
+#define SLA_JOBCONTROLLER_HPP
+
+#include <functional>
+
+namespace Slic3r { namespace sla {
+
+/// A Control structure for the support calculation. Consists of the status
+/// indicator callback and the stop condition predicate.
+struct JobController
+{
+    using StatusFn = std::function<void(unsigned, const std::string&)>;
+    using StopCond = std::function<bool(void)>;
+    using CancelFn = std::function<void(void)>;
+    
+    // This will signal the status of the calculation to the front-end
+    StatusFn statuscb = [](unsigned, const std::string&){};
+    
+    // Returns true if the calculation should be aborted.
+    StopCond stopcondition = [](){ return false; };
+    
+    // Similar to cancel callback. This should check the stop condition and
+    // if true, throw an appropriate exception. (TriangleMeshSlicer needs this)
+    // consider it a hard abort. stopcondition is permits the algorithm to
+    // terminate itself
+    CancelFn cancelfn = [](){};
+};
+
+}} // namespace Slic3r::sla
+
+#endif // JOBCONTROLLER_HPP

src/libslic3r/SLA/Pad.cpp

@@ -1,10 +1,12 @@
-#include "SLAPad.hpp"
+#include <libslic3r/SLA/Pad.hpp>
-#include "SLABoilerPlate.hpp"
+#include <libslic3r/SLA/Common.hpp>
-#include "SLASpatIndex.hpp"
+#include <libslic3r/SLA/SpatIndex.hpp>
+#include <libslic3r/SLA/BoostAdapter.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
+
 #include "ConcaveHull.hpp"
 
 #include "boost/log/trivial.hpp"
-#include "SLABoostAdapter.hpp"
 #include "ClipperUtils.hpp"
 #include "Tesselate.hpp"
 #include "MTUtils.hpp"
@@ -69,7 +71,7 @@ Contour3D walls(
 
     // Shorthand for the vertex arrays
     auto& upts = upper.points, &lpts = lower.points;
-    auto& rpts = ret.points; auto& ind = ret.indices;
+    auto& rpts = ret.points; auto& ind = ret.faces3;
 
     // If the Z levels are flipped, or the offset difference is negative, we
     // will interpret that as the triangles normals should be inverted.
@@ -676,7 +678,7 @@ void create_pad(const ExPolygons &sup_blueprint,
                 ThrowOnCancel thr)
 {
     Contour3D t = create_pad_geometry(sup_blueprint, model_blueprint, cfg, thr);
-    out.merge(mesh(std::move(t)));
+    out.merge(to_triangle_mesh(std::move(t)));
 }
 
 std::string PadConfig::validate() const

src/libslic3r/SLA/Pad.hpp

@@ -1,5 +1,5 @@
-#ifndef SLABASEPOOL_HPP
+#ifndef SLA_PAD_HPP
-#define SLABASEPOOL_HPP
+#define SLA_PAD_HPP
 
 #include <vector>
 #include <functional>

src/libslic3r/SLA/Raster.cpp

@@ -3,7 +3,7 @@
 
 #include <functional>
 
-#include "SLARaster.hpp"
+#include <libslic3r/SLA/Raster.hpp>
 #include "libslic3r/ExPolygon.hpp"
 #include "libslic3r/MTUtils.hpp"
 #include <libnest2d/backends/clipper/clipper_polygon.hpp>

src/libslic3r/SLA/Raster.hpp

@@ -1,5 +1,5 @@
-#ifndef SLARASTER_HPP
+#ifndef SLA_RASTER_HPP
-#define SLARASTER_HPP
+#define SLA_RASTER_HPP
 
 #include <ostream>
 #include <memory>

src/libslic3r/SLA/RasterWriter.cpp

@@ -1,6 +1,8 @@
-#include "SLARasterWriter.hpp"
+#include <libslic3r/SLA/RasterWriter.hpp>
-#include "libslic3r/Zipper.hpp"
+
-#include "libslic3r/Time.hpp"
+#include "libslic3r/PrintConfig.hpp"
+#include <libslic3r/Zipper.hpp>
+#include <libslic3r/Time.hpp>
 
 #include "ExPolygon.hpp"
 #include <libnest2d/backends/clipper/clipper_polygon.hpp>

src/libslic3r/SLA/RasterWriter.hpp

@@ -1,5 +1,5 @@
-#ifndef SLARASTERWRITER_HPP
+#ifndef SLA_RASTERWRITER_HPP
-#define SLARASTERWRITER_HPP
+#define SLA_RASTERWRITER_HPP
 
 // For png export of the sliced model
 #include <fstream>
@@ -9,12 +9,14 @@
 #include <map>
 #include <array>
 
-#include "libslic3r/PrintConfig.hpp"
+#include <libslic3r/SLA/Raster.hpp>
+#include <libslic3r/Zipper.hpp>
 
-#include "SLARaster.hpp"
+namespace Slic3r {
-#include "libslic3r/Zipper.hpp"
 
-namespace Slic3r { namespace sla {
+class DynamicPrintConfig;
+
+namespace sla {
 
 // API to write the zipped sla output layers and metadata.
 // Implementation uses PNG raster output.

src/libslic3r/SLA/Rotfinder.cpp

@@ -2,9 +2,9 @@
 #include <exception>
 
 #include <libnest2d/optimizers/nlopt/genetic.hpp>
-#include "SLABoilerPlate.hpp"
+#include <libslic3r/SLA/Common.hpp>
-#include "SLARotfinder.hpp"
+#include <libslic3r/SLA/Rotfinder.hpp>
-#include "SLASupportTree.hpp"
+#include <libslic3r/SLA/SupportTree.hpp>
 #include "Model.hpp"
 
 namespace Slic3r {

src/libslic3r/SLA/Rotfinder.hpp

@@ -1,5 +1,5 @@
-#ifndef SLAROTFINDER_HPP
+#ifndef SLA_ROTFINDER_HPP
-#define SLAROTFINDER_HPP
+#define SLA_ROTFINDER_HPP
 
 #include <functional>
 #include <array>

src/libslic3r/SLA/SLABoilerPlate.hpp

@@ -1,103 +0,0 @@
-#ifndef SLABOILERPLATE_HPP
-#define SLABOILERPLATE_HPP
-
-#include <iostream>
-#include <functional>
-#include <numeric>
-
-#include <libslic3r/ExPolygon.hpp>
-#include <libslic3r/TriangleMesh.hpp>
-
-#include "SLACommon.hpp"
-#include "SLASpatIndex.hpp"
-
-namespace Slic3r {
-namespace sla {
-
-/// Intermediate struct for a 3D mesh
-struct Contour3D {
-    Pointf3s points;
-    std::vector<Vec3i> indices;
-
-    Contour3D& merge(const Contour3D& ctr)
-    {
-        auto s3 = coord_t(points.size());
-        auto s = indices.size();
-
-        points.insert(points.end(), ctr.points.begin(), ctr.points.end());
-        indices.insert(indices.end(), ctr.indices.begin(), ctr.indices.end());
-
-        for(size_t n = s; n < indices.size(); n++) {
-            auto& idx = indices[n]; idx.x() += s3; idx.y() += s3; idx.z() += s3;
-        }
-        
-        return *this;
-    }
-
-    Contour3D& merge(const Pointf3s& triangles)
-    {
-        const size_t offs = points.size();
-        points.insert(points.end(), triangles.begin(), triangles.end());
-        indices.reserve(indices.size() + points.size() / 3);
-        
-        for(int i = int(offs); i < int(points.size()); i += 3)
-            indices.emplace_back(i, i + 1, i + 2);
-        
-        return *this;
-    }
-
-    // Write the index triangle structure to OBJ file for debugging purposes.
-    void to_obj(std::ostream& stream)
-    {
-        for(auto& p : points) {
-            stream << "v " << p.transpose() << "\n";
-        }
-
-        for(auto& f : indices) {
-            stream << "f " << (f + Vec3i(1, 1, 1)).transpose() << "\n";
-        }
-    }
-};
-
-using ClusterEl = std::vector<unsigned>;
-using ClusteredPoints = std::vector<ClusterEl>;
-
-// Clustering a set of points by the given distance.
-ClusteredPoints cluster(const std::vector<unsigned>& indices,
-                        std::function<Vec3d(unsigned)> pointfn,
-                        double dist,
-                        unsigned max_points);
-
-ClusteredPoints cluster(const PointSet& points,
-                        double dist,
-                        unsigned max_points);
-
-ClusteredPoints cluster(
-    const std::vector<unsigned>& indices,
-    std::function<Vec3d(unsigned)> pointfn,
-    std::function<bool(const PointIndexEl&, const PointIndexEl&)> predicate,
-    unsigned max_points);
-
-
-// Calculate the normals for the selected points (from 'points' set) on the
-// mesh. This will call squared distance for each point.
-PointSet normals(const PointSet& points,
-                 const EigenMesh3D& mesh,
-                 double eps = 0.05,  // min distance from edges
-                 std::function<void()> throw_on_cancel = [](){},
-                 const std::vector<unsigned>& selected_points = {});
-
-/// 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)};
-}
-
-}
-}
-
-#endif // SLABOILERPLATE_HPP

src/libslic3r/SLA/SLACommon.hpp

@@ -1,187 +0,0 @@
-#ifndef SLACOMMON_HPP
-#define SLACOMMON_HPP
-
-#include <memory>
-#include <vector>
-#include <Eigen/Geometry>
-
-// #define SLIC3R_SLA_NEEDS_WINDTREE
-
-namespace Slic3r {
-    
-// Typedefs from Point.hpp
-typedef Eigen::Matrix<float, 3, 1, Eigen::DontAlign> Vec3f;
-typedef Eigen::Matrix<double, 3, 1, Eigen::DontAlign> Vec3d;
-
-class TriangleMesh;
-
-namespace sla {
-    
-// An enum to keep track of where the current points on the ModelObject came from.
-enum class PointsStatus {
-    NoPoints,           // No points were generated so far.
-    Generating,     // The autogeneration algorithm triggered, but not yet finished.
-    AutoGenerated,  // Points were autogenerated (i.e. copied from the backend).
-    UserModified    // User has done some edits.
-};
-
-struct SupportPoint
-{
-    Vec3f pos;
-    float head_front_radius;
-    bool  is_new_island;
-
-    SupportPoint()
-        : pos(Vec3f::Zero()), head_front_radius(0.f), is_new_island(false)
-    {}
-
-    SupportPoint(float pos_x,
-                 float pos_y,
-                 float pos_z,
-                 float head_radius,
-                 bool  new_island)
-        : pos(pos_x, pos_y, pos_z)
-        , head_front_radius(head_radius)
-        , is_new_island(new_island)
-    {}
-
-    SupportPoint(Vec3f position, float head_radius, bool new_island)
-        : pos(position)
-        , head_front_radius(head_radius)
-        , is_new_island(new_island)
-    {}
-
-    SupportPoint(Eigen::Matrix<float, 5, 1, Eigen::DontAlign> data)
-        : pos(data(0), data(1), data(2))
-        , head_front_radius(data(3))
-        , is_new_island(data(4) != 0.f)
-    {}
-
-    bool operator==(const SupportPoint &sp) const
-    {
-        return (pos == sp.pos) && head_front_radius == sp.head_front_radius &&
-               is_new_island == sp.is_new_island;
-    }
-    bool operator!=(const SupportPoint &sp) const { return !(sp == (*this)); }
-
-    template<class Archive> void serialize(Archive &ar)
-    {
-        ar(pos, head_front_radius, is_new_island);
-    }
-};
-
-using SupportPoints = std::vector<SupportPoint>;
-
-/// An index-triangle structure for libIGL functions. Also serves as an
-/// alternative (raw) input format for the SLASupportTree
-class EigenMesh3D {
-    class AABBImpl;
-
-    Eigen::MatrixXd m_V;
-    Eigen::MatrixXi m_F;
-    double m_ground_level = 0, m_gnd_offset = 0;
-
-    std::unique_ptr<AABBImpl> m_aabb;
-public:
-
-    EigenMesh3D(const TriangleMesh&);
-    EigenMesh3D(const EigenMesh3D& other);
-    EigenMesh3D& operator=(const EigenMesh3D&);
-
-    ~EigenMesh3D();
-
-    inline double ground_level() const { return m_ground_level + m_gnd_offset; }
-    inline void ground_level_offset(double o) { m_gnd_offset = o; }
-    inline double ground_level_offset() const { return m_gnd_offset; }
-
-    inline const Eigen::MatrixXd& V() const { return m_V; }
-    inline const Eigen::MatrixXi& F() const { return m_F; }
-
-    // Result of a raycast
-    class hit_result {
-        double m_t = std::nan("");
-        int m_face_id = -1;
-        const EigenMesh3D *m_mesh = nullptr;
-        Vec3d m_dir;
-        Vec3d m_source;
-        friend class EigenMesh3D;
-
-        // A valid object of this class can only be obtained from
-        // EigenMesh3D::query_ray_hit method.
-        explicit inline hit_result(const EigenMesh3D& em): m_mesh(&em) {}
-    public:
-
-        // This can create a placeholder object which is invalid (not created
-        // by a query_ray_hit call) but the distance can be preset to
-        // a specific value for distinguishing the placeholder.
-        inline hit_result(double val = std::nan("")): m_t(val) {}
-
-        inline double distance() const { return m_t; }
-        inline const Vec3d& direction() const { return m_dir; }
-        inline Vec3d position() const { return m_source + m_dir * m_t; }
-        inline int face() const { return m_face_id; }
-        inline bool is_valid() const { return m_mesh != nullptr; }
-
-        // Hit_result can decay into a double as the hit distance.
-        inline operator double() const { return distance(); }
-
-        inline Vec3d normal() const {
-            if(m_face_id < 0 || !is_valid()) return {};
-            auto trindex    = m_mesh->m_F.row(m_face_id);
-            const Vec3d& p1 = m_mesh->V().row(trindex(0));
-            const Vec3d& p2 = m_mesh->V().row(trindex(1));
-            const Vec3d& p3 = m_mesh->V().row(trindex(2));
-            Eigen::Vector3d U = p2 - p1;
-            Eigen::Vector3d V = p3 - p1;
-            return U.cross(V).normalized();
-        }
-
-        inline bool is_inside() {
-            return m_face_id >= 0 && normal().dot(m_dir) > 0;
-        }
-    };
-
-    // Casting a ray on the mesh, returns the distance where the hit occures.
-    hit_result query_ray_hit(const Vec3d &s, const Vec3d &dir) const;
-
-    class si_result {
-        double m_value;
-        int m_fidx;
-        Vec3d m_p;
-        si_result(double val, int i, const Vec3d& c):
-            m_value(val), m_fidx(i), m_p(c) {}
-        friend class EigenMesh3D;
-    public:
-
-        si_result() = delete;
-
-        double value() const { return m_value; }
-        operator double() const { return m_value; }
-        const Vec3d& point_on_mesh() const { return m_p; }
-        int F_idx() const { return m_fidx; }
-    };
-
-#ifdef SLIC3R_SLA_NEEDS_WINDTREE
-    // The signed distance from a point to the mesh. Outputs the distance,
-    // the index of the triangle and the closest point in mesh coordinate space.
-    si_result signed_distance(const Vec3d& p) const;
-
-    bool inside(const Vec3d& p) const;
-#endif /* SLIC3R_SLA_NEEDS_WINDTREE */
-
-    double squared_distance(const Vec3d& p, int& i, Vec3d& c) const;
-    inline double squared_distance(const Vec3d &p) const
-    {
-        int   i;
-        Vec3d c;
-        return squared_distance(p, i, c);
-    }
-};
-
-using PointSet = Eigen::MatrixXd;
-
-} // namespace sla
-} // namespace Slic3r
-
-
-#endif // SLASUPPORTTREE_HPP

src/libslic3r/SLA/SpatIndex.hpp

@@ -1,5 +1,5 @@
-#ifndef SPATINDEX_HPP
+#ifndef SLA_SPATINDEX_HPP
-#define SPATINDEX_HPP
+#define SLA_SPATINDEX_HPP
 
 #include <memory>
 #include <utility>

src/libslic3r/SLA/SupportPoint.hpp

@@ -0,0 +1,69 @@
+#ifndef SLA_SUPPORTPOINT_HPP
+#define SLA_SUPPORTPOINT_HPP
+
+#include <vector>
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/ExPolygon.hpp>
+
+namespace Slic3r { namespace sla {
+
+// An enum to keep track of where the current points on the ModelObject came from.
+enum class PointsStatus {
+    NoPoints,           // No points were generated so far.
+    Generating,     // The autogeneration algorithm triggered, but not yet finished.
+    AutoGenerated,  // Points were autogenerated (i.e. copied from the backend).
+    UserModified    // User has done some edits.
+};
+
+struct SupportPoint
+{
+    Vec3f pos;
+    float head_front_radius;
+    bool  is_new_island;
+    
+    SupportPoint()
+        : pos(Vec3f::Zero()), head_front_radius(0.f), is_new_island(false)
+    {}
+    
+    SupportPoint(float pos_x,
+                 float pos_y,
+                 float pos_z,
+                 float head_radius,
+                 bool  new_island)
+        : pos(pos_x, pos_y, pos_z)
+        , head_front_radius(head_radius)
+        , is_new_island(new_island)
+    {}
+    
+    SupportPoint(Vec3f position, float head_radius, bool new_island)
+        : pos(position)
+        , head_front_radius(head_radius)
+        , is_new_island(new_island)
+    {}
+    
+    SupportPoint(Eigen::Matrix<float, 5, 1, Eigen::DontAlign> data)
+        : pos(data(0), data(1), data(2))
+        , head_front_radius(data(3))
+        , is_new_island(data(4) != 0.f)
+    {}
+    
+    bool operator==(const SupportPoint &sp) const
+    {
+        float rdiff = std::abs(head_front_radius - sp.head_front_radius);
+        return (pos == sp.pos) && rdiff < float(EPSILON) &&
+               is_new_island == sp.is_new_island;
+    }
+    
+    bool operator!=(const SupportPoint &sp) const { return !(sp == (*this)); }
+    
+    template<class Archive> void serialize(Archive &ar)
+    {
+        ar(pos, head_front_radius, is_new_island);
+    }
+};
+
+using SupportPoints = std::vector<SupportPoint>;
+
+}} // namespace Slic3r::sla
+
+#endif // SUPPORTPOINT_HPP

src/libslic3r/SLA/SupportPointGenerator.cpp

@@ -3,7 +3,7 @@
 
 #include <tbb/parallel_for.h>
 
-#include "SLAAutoSupports.hpp"
+#include "SupportPointGenerator.hpp"
 #include "Model.hpp"
 #include "ExPolygon.hpp"
 #include "SVG.hpp"
@@ -18,7 +18,7 @@
 namespace Slic3r {
 namespace sla {
 
-/*float SLAAutoSupports::approximate_geodesic_distance(const Vec3d& p1, const Vec3d& p2, Vec3d& n1, Vec3d& n2)
+/*float SupportPointGenerator::approximate_geodesic_distance(const Vec3d& p1, const Vec3d& p2, Vec3d& n1, Vec3d& n2)
 {
     n1.normalize();
     n2.normalize();
@@ -36,7 +36,7 @@ namespace sla {
 }
 
 
-float SLAAutoSupports::get_required_density(float angle) const
+float SupportPointGenerator::get_required_density(float angle) const
 {
     // calculation would be density_0 * cos(angle). To provide one more degree of freedom, we will scale the angle
     // to get the user-set density for 45 deg. So it ends up as density_0 * cos(K * angle).
@@ -44,27 +44,45 @@ float SLAAutoSupports::get_required_density(float angle) const
     return std::max(0.f, float(m_config.density_at_horizontal * cos(K*angle)));
 }
 
-float SLAAutoSupports::distance_limit(float angle) const
+float SupportPointGenerator::distance_limit(float angle) const
 {
     return 1./(2.4*get_required_density(angle));
 }*/
 
-SLAAutoSupports::SLAAutoSupports(const sla::EigenMesh3D &       emesh,
+SupportPointGenerator::SupportPointGenerator(
+        const sla::EigenMesh3D &emesh,
         const std::vector<ExPolygons> &slices,
         const std::vector<float> &     heights,
         const Config &                 config,
         std::function<void(void)> throw_on_cancel,
         std::function<void(int)>  statusfn)
+    : SupportPointGenerator(emesh, config, throw_on_cancel, statusfn)
+{
+    std::random_device rd;
+    m_rng.seed(rd());
+    execute(slices, heights);
+}
+
+SupportPointGenerator::SupportPointGenerator(
+        const EigenMesh3D &emesh,
+        const SupportPointGenerator::Config &config,
+        std::function<void ()> throw_on_cancel, 
+        std::function<void (int)> statusfn)
     : m_config(config)
     , m_emesh(emesh)
     , m_throw_on_cancel(throw_on_cancel)
     , m_statusfn(statusfn)
+{
+}
+
+void SupportPointGenerator::execute(const std::vector<ExPolygons> &slices,
+                                    const std::vector<float> &     heights)
 {
     process(slices, heights);
     project_onto_mesh(m_output);
 }
 
-void SLAAutoSupports::project_onto_mesh(std::vector<sla::SupportPoint>& points) const
+void SupportPointGenerator::project_onto_mesh(std::vector<sla::SupportPoint>& points) const
 {
     // The function  makes sure that all the points are really exactly placed on the mesh.
 
@@ -77,36 +95,29 @@ void SLAAutoSupports::project_onto_mesh(std::vector<sla::SupportPoint>& points)
                     m_throw_on_cancel();
                 Vec3f& p = points[point_id].pos;
                 // Project the point upward and downward and choose the closer intersection with the mesh.
-                //bool up   = igl::ray_mesh_intersect(p.cast<float>(), Vec3f(0., 0., 1.), m_V, m_F, hit_up);
-                //bool down = igl::ray_mesh_intersect(p.cast<float>(), Vec3f(0., 0., -1.), m_V, m_F, hit_down);
-
                 sla::EigenMesh3D::hit_result hit_up   = m_emesh.query_ray_hit(p.cast<double>(), Vec3d(0., 0., 1.));
                 sla::EigenMesh3D::hit_result hit_down = m_emesh.query_ray_hit(p.cast<double>(), Vec3d(0., 0., -1.));
 
-                bool up   = hit_up.face() != -1;
+                bool up   = hit_up.is_hit();
-                bool down = hit_down.face() != -1;
+                bool down = hit_down.is_hit();
 
                 if (!up && !down)
                     continue;
 
                 sla::EigenMesh3D::hit_result& hit = (!down || (hit_up.distance() < hit_down.distance())) ? hit_up : hit_down;
-                //int fid = hit.face();
-                //Vec3f bc(1-hit.u-hit.v, hit.u, hit.v);
-                //p = (bc(0) * m_V.row(m_F(fid, 0)) + bc(1) * m_V.row(m_F(fid, 1)) + bc(2)*m_V.row(m_F(fid, 2))).cast<float>();
-
                 p = p + (hit.distance() * hit.direction()).cast<float>();
             }
         });
 }
 
-static std::vector<SLAAutoSupports::MyLayer> make_layers(
+static std::vector<SupportPointGenerator::MyLayer> make_layers(
     const std::vector<ExPolygons>& slices, const std::vector<float>& heights,
     std::function<void(void)> throw_on_cancel)
 {
     assert(slices.size() == heights.size());
 
     // Allocate empty layers.
-    std::vector<SLAAutoSupports::MyLayer> layers;
+    std::vector<SupportPointGenerator::MyLayer> layers;
     layers.reserve(slices.size());
     for (size_t i = 0; i < slices.size(); ++ i)
         layers.emplace_back(i, heights[i]);
@@ -122,7 +133,7 @@ static std::vector<SLAAutoSupports::MyLayer> make_layers(
                 if ((layer_id % 8) == 0)
                     // Don't call the following function too often as it flushes CPU write caches due to synchronization primitves.
                     throw_on_cancel();
-                SLAAutoSupports::MyLayer &layer   = layers[layer_id];
+                SupportPointGenerator::MyLayer &layer   = layers[layer_id];
                 const ExPolygons		 &islands = slices[layer_id];
                 //FIXME WTF?
                 const float height = (layer_id>2 ? heights[layer_id-3] : heights[0]-(heights[1]-heights[0]));
@@ -143,8 +154,8 @@ static std::vector<SLAAutoSupports::MyLayer> make_layers(
             if ((layer_id % 2) == 0)
                 // Don't call the following function too often as it flushes CPU write caches due to synchronization primitves.
                 throw_on_cancel();
-            SLAAutoSupports::MyLayer &layer_above = layers[layer_id];
+            SupportPointGenerator::MyLayer &layer_above = layers[layer_id];
-            SLAAutoSupports::MyLayer &layer_below = layers[layer_id - 1];
+            SupportPointGenerator::MyLayer &layer_below = layers[layer_id - 1];
             //FIXME WTF?
             const float layer_height = (layer_id!=0 ? heights[layer_id]-heights[layer_id-1] : heights[0]);
             const float safe_angle = 5.f * (float(M_PI)/180.f); // smaller number - less supports
@@ -152,8 +163,8 @@ static std::vector<SLAAutoSupports::MyLayer> make_layers(
             const float slope_angle = 75.f * (float(M_PI)/180.f); // smaller number - less supports
             const float slope_offset = float(scale_(layer_height / std::tan(slope_angle)));
             //FIXME This has a quadratic time complexity, it will be excessively slow for many tiny islands.
-            for (SLAAutoSupports::Structure &top : layer_above.islands) {
+            for (SupportPointGenerator::Structure &top : layer_above.islands) {
-                for (SLAAutoSupports::Structure &bottom : layer_below.islands) {
+                for (SupportPointGenerator::Structure &bottom : layer_below.islands) {
                     float overlap_area = top.overlap_area(bottom);
                     if (overlap_area > 0) {
                         top.islands_below.emplace_back(&bottom, overlap_area);
@@ -191,13 +202,13 @@ static std::vector<SLAAutoSupports::MyLayer> make_layers(
     return layers;
 }
 
-void SLAAutoSupports::process(const std::vector<ExPolygons>& slices, const std::vector<float>& heights)
+void SupportPointGenerator::process(const std::vector<ExPolygons>& slices, const std::vector<float>& heights)
 {
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
     std::vector<std::pair<ExPolygon, coord_t>> islands;
-#endif /* SLA_AUTOSUPPORTS_DEBUG */
+#endif /* SLA_SUPPORTPOINTGEN_DEBUG */
 
-    std::vector<SLAAutoSupports::MyLayer> layers = make_layers(slices, heights, m_throw_on_cancel);
+    std::vector<SupportPointGenerator::MyLayer> layers = make_layers(slices, heights, m_throw_on_cancel);
 
     PointGrid3D point_grid;
     point_grid.cell_size = Vec3f(10.f, 10.f, 10.f);
@@ -206,8 +217,8 @@ void SLAAutoSupports::process(const std::vector<ExPolygons>& slices, const std::
     double status    = 0;
 
     for (unsigned int layer_id = 0; layer_id < layers.size(); ++ layer_id) {
-        SLAAutoSupports::MyLayer *layer_top     = &layers[layer_id];
+        SupportPointGenerator::MyLayer *layer_top     = &layers[layer_id];
-        SLAAutoSupports::MyLayer *layer_bottom  = (layer_id > 0) ? &layers[layer_id - 1] : nullptr;
+        SupportPointGenerator::MyLayer *layer_bottom  = (layer_id > 0) ? &layers[layer_id - 1] : nullptr;
         std::vector<float>        support_force_bottom;
         if (layer_bottom != nullptr) {
             support_force_bottom.assign(layer_bottom->islands.size(), 0.f);
@@ -263,13 +274,13 @@ void SLAAutoSupports::process(const std::vector<ExPolygons>& slices, const std::
         status += increment;
         m_statusfn(int(std::round(status)));
 
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
         /*std::string layer_num_str = std::string((i<10 ? "0" : "")) + std::string((i<100 ? "0" : "")) + std::to_string(i);
         output_expolygons(expolys_top, "top" + layer_num_str + ".svg");
         output_expolygons(diff, "diff" + layer_num_str + ".svg");
         if (!islands.empty())
             output_expolygons(islands, "islands" + layer_num_str + ".svg");*/
-#endif /* SLA_AUTOSUPPORTS_DEBUG */
+#endif /* SLA_SUPPORTPOINTGEN_DEBUG */
     }
 }
 
@@ -449,7 +460,7 @@ static inline std::vector<Vec2f> poisson_disk_from_samples(const std::vector<Vec
     return out;
 }
 
-void SLAAutoSupports::uniformly_cover(const ExPolygons& islands, Structure& structure, PointGrid3D &grid3d, bool is_new_island, bool just_one)
+void SupportPointGenerator::uniformly_cover(const ExPolygons& islands, Structure& structure, PointGrid3D &grid3d, bool is_new_island, bool just_one)
 {
     //int num_of_points = std::max(1, (int)((island.area()*pow(SCALING_FACTOR, 2) * m_config.tear_pressure)/m_config.support_force));
 
@@ -470,9 +481,8 @@ void SLAAutoSupports::uniformly_cover(const ExPolygons& islands, Structure& stru
     float min_spacing			= poisson_radius;
 
     //FIXME share the random generator. The random generator may be not so cheap to initialize, also we don't want the random generator to be restarted for each polygon.
-    std::random_device  rd;
+    
-    std::mt19937        rng(rd());
+    std::vector<Vec2f>  raw_samples = sample_expolygon_with_boundary(islands, samples_per_mm2, 5.f / poisson_radius, m_rng);
-    std::vector<Vec2f>  raw_samples = sample_expolygon_with_boundary(islands, samples_per_mm2, 5.f / poisson_radius, rng);
     std::vector<Vec2f>  poisson_samples;
     for (size_t iter = 0; iter < 4; ++ iter) {
         poisson_samples = poisson_disk_from_samples(raw_samples, poisson_radius,
@@ -488,7 +498,7 @@ void SLAAutoSupports::uniformly_cover(const ExPolygons& islands, Structure& stru
         min_spacing    = std::max(m_config.minimal_distance, min_spacing * coeff);
     }
 
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
     {
         static int irun = 0;
         Slic3r::SVG svg(debug_out_path("SLA_supports-uniformly_cover-%d.svg", irun ++), get_extents(islands));
@@ -503,7 +513,7 @@ void SLAAutoSupports::uniformly_cover(const ExPolygons& islands, Structure& stru
 
 //    assert(! poisson_samples.empty());
     if (poisson_samples_target < poisson_samples.size()) {
-        std::shuffle(poisson_samples.begin(), poisson_samples.end(), rng);
+        std::shuffle(poisson_samples.begin(), poisson_samples.end(), m_rng);
         poisson_samples.erase(poisson_samples.begin() + poisson_samples_target, poisson_samples.end());
     }
     for (const Vec2f &pt : poisson_samples) {
@@ -528,8 +538,8 @@ void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double
     pts.erase(endit, pts.end());
 }
 
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
-void SLAAutoSupports::output_structures(const std::vector<Structure>& structures)
+void SupportPointGenerator::output_structures(const std::vector<Structure>& structures)
 {
     for (unsigned int i=0 ; i<structures.size(); ++i) {
         std::stringstream ss;
@@ -538,7 +548,7 @@ void SLAAutoSupports::output_structures(const std::vector<Structure>& structures
     }
 }
 
-void SLAAutoSupports::output_expolygons(const ExPolygons& expolys, const std::string &filename)
+void SupportPointGenerator::output_expolygons(const ExPolygons& expolys, const std::string &filename)
 {
     BoundingBox bb(Point(-30000000, -30000000), Point(30000000, 30000000));
     Slic3r::SVG svg_cummulative(filename, bb);

src/libslic3r/SLA/SupportPointGenerator.hpp

@@ -1,19 +1,23 @@
-#ifndef SLAAUTOSUPPORTS_HPP_
+#ifndef SLA_SUPPORTPOINTGENERATOR_HPP
-#define SLAAUTOSUPPORTS_HPP_
+#define SLA_SUPPORTPOINTGENERATOR_HPP
+
+#include <random>
+
+#include <libslic3r/SLA/Common.hpp>
+#include <libslic3r/SLA/SupportPoint.hpp>
+#include <libslic3r/SLA/EigenMesh3D.hpp>
 
 #include <libslic3r/ClipperUtils.hpp>
 #include <libslic3r/Point.hpp>
 #include <libslic3r/TriangleMesh.hpp>
-#include <libslic3r/SLA/SLACommon.hpp>
 
 #include <boost/container/small_vector.hpp>
 
-// #define SLA_AUTOSUPPORTS_DEBUG
+// #define SLA_SUPPORTPOINTGEN_DEBUG
 
-namespace Slic3r {
+namespace Slic3r { namespace sla {
-namespace sla {
 
-class SLAAutoSupports {
+class SupportPointGenerator {
 public:
     struct Config {
         float density_relative {1.f};
@@ -24,19 +28,22 @@ public:
         inline float tear_pressure() const { return 1.f; }  // pressure that the display exerts    (the force unit per mm2)
     };
     
-    SLAAutoSupports(const sla::EigenMesh3D& emesh, const std::vector<ExPolygons>& slices,
+    SupportPointGenerator(const EigenMesh3D& emesh, const std::vector<ExPolygons>& slices,
                     const std::vector<float>& heights, const Config& config, std::function<void(void)> throw_on_cancel, std::function<void(int)> statusfn);
     
-    const std::vector<sla::SupportPoint>& output() { return m_output; }
+    SupportPointGenerator(const EigenMesh3D& emesh, const Config& config, std::function<void(void)> throw_on_cancel, std::function<void(int)> statusfn);
+    
+    const std::vector<SupportPoint>& output() const { return m_output; }
+    std::vector<SupportPoint>& output() { return m_output; }
     
     struct MyLayer;
     
     struct Structure {
         Structure(MyLayer &layer, const ExPolygon& poly, const BoundingBox &bbox, const Vec2f &centroid, float area, float h) : 
             layer(&layer), polygon(&poly), bbox(bbox), centroid(centroid), area(area), height(h)
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
             , unique_id(std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()))
-#endif /* SLA_AUTOSUPPORTS_DEBUG */
+#endif /* SLA_SUPPORTPOINTGEN_DEBUG */
         {}
         MyLayer *layer;
         const ExPolygon* polygon = nullptr;
@@ -49,9 +56,9 @@ public:
         float supports_force_this_layer     = 0.f;
         float supports_force_inherited      = 0.f;
         float supports_force_total() const { return this->supports_force_this_layer + this->supports_force_inherited; }
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
         std::chrono::milliseconds unique_id;
-#endif /* SLA_AUTOSUPPORTS_DEBUG */
+#endif /* SLA_SUPPORTPOINTGEN_DEBUG */
         
         struct Link {
             Link(Structure *island, float overlap_area) : island(island), overlap_area(overlap_area) {}
@@ -74,7 +81,7 @@ public:
         ExPolygons                              overhangs;
         // Overhangs, where the surface must slope.
         ExPolygons                              overhangs_slopes;
-        float                                   overhangs_area;
+        float                                   overhangs_area = 0.f;
         
         bool overlaps(const Structure &rhs) const { 
             return this->bbox.overlap(rhs.bbox) && (this->polygon->overlaps(*rhs.polygon) || rhs.polygon->overlaps(*this->polygon)); 
@@ -182,29 +189,33 @@ public:
         }
     };
     
-private:
+    void execute(const std::vector<ExPolygons> &slices,
-    std::vector<sla::SupportPoint> m_output;
+                 const std::vector<float> &     heights);
     
-    SLAAutoSupports::Config m_config;
+    void seed(std::mt19937::result_type s) { m_rng.seed(s); }
+private:
+    std::vector<SupportPoint> m_output;
+    
+    SupportPointGenerator::Config m_config;
     
     void process(const std::vector<ExPolygons>& slices, const std::vector<float>& heights);
     void uniformly_cover(const ExPolygons& islands, Structure& structure, PointGrid3D &grid3d, bool is_new_island = false, bool just_one = false);
-    void project_onto_mesh(std::vector<sla::SupportPoint>& points) const;
+    void project_onto_mesh(std::vector<SupportPoint>& points) const;
 
-#ifdef SLA_AUTOSUPPORTS_DEBUG
+#ifdef SLA_SUPPORTPOINTGEN_DEBUG
     static void output_expolygons(const ExPolygons& expolys, const std::string &filename);
     static void output_structures(const std::vector<Structure> &structures);
-#endif // SLA_AUTOSUPPORTS_DEBUG
+#endif // SLA_SUPPORTPOINTGEN_DEBUG
     
-    const sla::EigenMesh3D& m_emesh;
+    const EigenMesh3D& m_emesh;
     std::function<void(void)> m_throw_on_cancel;
     std::function<void(int)>  m_statusfn;
+    
+    std::mt19937 m_rng;
 };
 
 void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double tolerance);
 
-} // namespace sla
+}} // namespace Slic3r::sla
-} // namespace Slic3r
 
-
+#endif // SUPPORTPOINTGENERATOR_HPP
-#endif // SLAAUTOSUPPORTS_HPP_

src/libslic3r/SLA/SupportTree.cpp

@@ -4,10 +4,10 @@
  */
 
 #include <numeric>
-#include "SLASupportTree.hpp"
+#include <libslic3r/SLA/SupportTree.hpp>
-#include "SLABoilerPlate.hpp"
+#include <libslic3r/SLA/Common.hpp>
-#include "SLASpatIndex.hpp"
+#include <libslic3r/SLA/SpatIndex.hpp>
-#include "SLASupportTreeBuilder.hpp"
+#include <libslic3r/SLA/SupportTreeBuilder.hpp>
 
 #include <libslic3r/MTUtils.hpp>
 #include <libslic3r/ClipperUtils.hpp>

src/libslic3r/SLA/SupportTree.hpp

@@ -1,12 +1,15 @@
-#ifndef SLASUPPORTTREE_HPP
+#ifndef SLA_SUPPORTTREE_HPP
-#define SLASUPPORTTREE_HPP
+#define SLA_SUPPORTTREE_HPP
 
 #include <vector>
 #include <memory>
 #include <Eigen/Geometry>
 
-#include "SLACommon.hpp"
+#include <libslic3r/SLA/Common.hpp>
-#include "SLAPad.hpp"
+#include <libslic3r/SLA/Pad.hpp>
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+#include <libslic3r/SLA/SupportPoint.hpp>
+#include <libslic3r/SLA/JobController.hpp>
 
 namespace Slic3r {
 
@@ -105,27 +108,6 @@ struct SupportConfig
 
 enum class MeshType { Support, Pad };
 
-/// A Control structure for the support calculation. Consists of the status
-/// indicator callback and the stop condition predicate.
-struct JobController
-{
-    using StatusFn = std::function<void(unsigned, const std::string&)>;
-    using StopCond = std::function<bool(void)>;
-    using CancelFn = std::function<void(void)>;
-    
-    // This will signal the status of the calculation to the front-end
-    StatusFn statuscb = [](unsigned, const std::string&){};
-    
-    // Returns true if the calculation should be aborted.
-    StopCond stopcondition = [](){ return false; };
-    
-    // Similar to cancel callback. This should check the stop condition and
-    // if true, throw an appropriate exception. (TriangleMeshSlicer needs this)
-    // consider it a hard abort. stopcondition is permits the algorithm to
-    // terminate itself
-    CancelFn cancelfn = [](){};
-};
-
 struct SupportableMesh
 {
     EigenMesh3D   emesh;

src/libslic3r/SLA/SupportTreeBuilder.cpp

@@ -1,5 +1,6 @@
-#include "SLASupportTreeBuilder.hpp"
+#include <libslic3r/SLA/SupportTreeBuilder.hpp>
-#include "SLASupportTreeBuildsteps.hpp"
+#include <libslic3r/SLA/SupportTreeBuildsteps.hpp>
+#include <libslic3r/SLA/Contour3D.hpp>
 
 namespace Slic3r {
 namespace sla {
@@ -12,7 +13,7 @@ Contour3D sphere(double rho, Portion portion, double fa) {
     if(rho <= 1e-6 && rho >= -1e-6) return ret;
     
     auto& vertices = ret.points;
-    auto& facets = ret.indices;
+    auto& facets = ret.faces3;
     
     // Algorithm:
     // Add points one-by-one to the sphere grid and form facets using relative
@@ -102,7 +103,7 @@ Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d &sp)
     
     auto steps = int(ssteps);
     auto& points = ret.points;
-    auto& indices = ret.indices;
+    auto& indices = ret.faces3;
     points.reserve(2*ssteps);
     double a = 2*PI/steps;
     
@@ -211,8 +212,8 @@ Head::Head(double       r_big_mm,
         coord_t i1s1 = coord_t(idx1), i1s2 = coord_t(idx2);
         coord_t i2s1 = i1s1 + 1, i2s2 = i1s2 + 1;
         
-        mesh.indices.emplace_back(i1s1, i2s1, i2s2);
+        mesh.faces3.emplace_back(i1s1, i2s1, i2s2);
-        mesh.indices.emplace_back(i1s1, i2s2, i1s2);
+        mesh.faces3.emplace_back(i1s1, i2s2, i1s2);
     }
     
     auto i1s1 = coord_t(s1.points.size()) - coord_t(steps);
@@ -220,8 +221,8 @@ Head::Head(double       r_big_mm,
     auto i1s2 = coord_t(s1.points.size());
     auto i2s2 = coord_t(s1.points.size()) + coord_t(steps) - 1;
     
-    mesh.indices.emplace_back(i2s2, i2s1, i1s1);
+    mesh.faces3.emplace_back(i2s2, i2s1, i1s1);
-    mesh.indices.emplace_back(i1s2, i2s2, i1s1);
+    mesh.faces3.emplace_back(i1s2, i2s2, i1s1);
     
     // To simplify further processing, we translate the mesh so that the
     // last vertex of the pointing sphere (the pinpoint) will be at (0,0,0)
@@ -240,7 +241,7 @@ Pillar::Pillar(const Vec3d &jp, const Vec3d &endp, double radius, size_t st):
         // move the data.
         Contour3D body = cylinder(radius, height, st, endp);
         mesh.points.swap(body.points);
-        mesh.indices.swap(body.indices);
+        mesh.faces3.swap(body.faces3);
     }
 }
 
@@ -275,7 +276,7 @@ Pillar &Pillar::add_base(double baseheight, double radius)
     base.points.emplace_back(endpt);
     base.points.emplace_back(ep);
     
-    auto& indices = base.indices;
+    auto& indices = base.faces3;
     auto hcenter = int(base.points.size() - 1);
     auto lcenter = int(base.points.size() - 2);
     auto offs = int(steps);
@@ -466,7 +467,7 @@ const TriangleMesh &SupportTreeBuilder::merged_mesh() const
         return m_meshcache;
     }
     
-    m_meshcache = mesh(merged);
+    m_meshcache = to_triangle_mesh(merged);
     
     // The mesh will be passed by const-pointer to TriangleMeshSlicer,
     // which will need this.

src/libslic3r/SLA/SupportTreeBuilder.hpp

@@ -1,10 +1,11 @@
-#ifndef SUPPORTTREEBUILDER_HPP
+#ifndef SLA_SUPPORTTREEBUILDER_HPP
-#define SUPPORTTREEBUILDER_HPP
+#define SLA_SUPPORTTREEBUILDER_HPP
 
-#include "SLAConcurrency.hpp"
+#include <libslic3r/SLA/Concurrency.hpp>
-#include "SLABoilerPlate.hpp"
+#include <libslic3r/SLA/Common.hpp>
-#include "SLASupportTree.hpp"
+#include <libslic3r/SLA/SupportTree.hpp>
-#include "SLAPad.hpp"
+#include <libslic3r/SLA/Contour3D.hpp>
+#include <libslic3r/SLA/Pad.hpp>
 #include <libslic3r/MTUtils.hpp>
 
 namespace Slic3r {
@@ -73,7 +74,7 @@ Contour3D sphere(double rho, Portion portion = make_portion(0.0, 2.0*PI),
 // h: Height
 // ssteps: how many edges will create the base circle
 // sp: starting point
-Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d &sp = {0,0,0});
+Contour3D cylinder(double r, double h, size_t ssteps = 45, const Vec3d &sp = {0,0,0});
 
 const constexpr long ID_UNSET = -1;
 

src/libslic3r/SLA/SupportTreeBuildsteps.cpp

@@ -1,4 +1,4 @@
-#include "SLASupportTreeBuildsteps.hpp"
+#include <libslic3r/SLA/SupportTreeBuildsteps.hpp>
 
 #include <libnest2d/optimizers/nlopt/genetic.hpp>
 #include <libnest2d/optimizers/nlopt/subplex.hpp>
@@ -7,6 +7,14 @@
 namespace Slic3r {
 namespace sla {
 
+static const Vec3d DOWN = {0.0, 0.0, -1.0};
+
+using libnest2d::opt::initvals;
+using libnest2d::opt::bound;
+using libnest2d::opt::StopCriteria;
+using libnest2d::opt::GeneticOptimizer;
+using libnest2d::opt::SubplexOptimizer;
+
 SupportTreeBuildsteps::SupportTreeBuildsteps(SupportTreeBuilder &   builder,
                                              const SupportableMesh &sm)
     : m_cfg(sm.cfg)
@@ -560,9 +568,7 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
                                                  double       radius,
                                                  long         head_id)
 {
-    // People were killed for this number (seriously)
+    const double SLOPE = 1. / std::cos(m_cfg.bridge_slope);
-    static const double SQR2 = std::sqrt(2.0);
-    static const Vec3d  DOWN = {0.0, 0.0, -1.0};
     
     double gndlvl       = m_builder.ground_level;
     Vec3d  endp         = {jp(X), jp(Y), gndlvl};
@@ -573,6 +579,11 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
     bool   can_add_base = true;
     bool   normal_mode  = true;
     
+    // If in zero elevation mode and the pillar is too close to the model body,
+    // the support pillar can not be placed in the gap between the model and
+    // the pad, and the pillar bases must not touch the model body either.
+    // To solve this, a corrector bridge is inserted between the starting point
+    // (jp) and the new pillar.
     if (m_cfg.object_elevation_mm < EPSILON
         && (dist = std::sqrt(m_mesh.squared_distance(endp))) < min_dist) {
         // Get the distance from the mesh. This can be later optimized
@@ -580,31 +591,35 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
         // the ground level only.
 
         normal_mode = false;
-        double mind     = min_dist - dist;
-        double azimuth  = std::atan2(sourcedir(Y), sourcedir(X));
-        double sinpolar = std::sin(PI - m_cfg.bridge_slope);
-        double cospolar = std::cos(PI - m_cfg.bridge_slope);
-        double cosazm   = std::cos(azimuth);
-        double sinazm   = std::sin(azimuth);
 
-        auto dir = Vec3d(cosazm * sinpolar, sinazm * sinpolar, cospolar)
+        // The min distance needed to move away from the model in XY plane.
-                       .normalized();
+        double current_d = min_dist - dist;
+        double current_bride_d = SLOPE * current_d;
+
+        // get a suitable direction for the corrector bridge. It is the
+        // original sourcedir's azimuth but the polar angle is saturated to the
+        // configured bridge slope.
+        auto [polar, azimuth] = dir_to_spheric(sourcedir);
+        polar = PI - m_cfg.bridge_slope;
+        auto dir = spheric_to_dir(polar, azimuth).normalized();
         
-        using namespace libnest2d::opt;
         StopCriteria scr;
         scr.stop_score = min_dist;
         SubplexOptimizer solver(scr);
         
+        // Search for a distance along the corrector bridge to move the endpoint
+        // sufficiently away form the model body. The first few optimization
+        // cycles should succeed here.
         auto result = solver.optimize_max(
             [this, dir, jp, gndlvl](double mv) {
-                Vec3d endpt = jp + SQR2 * mv * dir;
+                Vec3d endpt = jp + mv * dir;
                 endpt(Z)    = gndlvl;
                 return std::sqrt(m_mesh.squared_distance(endpt));
             },
-            initvals(mind), bound(0.0, 2 * min_dist));
+            initvals(current_bride_d), 
+            bound(0.0, m_cfg.max_bridge_length_mm - current_bride_d));
         
-        mind           = std::get<0>(result.optimum);
+        endp         = jp + std::get<0>(result.optimum) * dir;
-        endp         = jp + SQR2 * mind * dir;
         Vec3d pgnd   = {endp(X), endp(Y), gndlvl};
         can_add_base = result.score > min_dist;
         
@@ -623,7 +638,7 @@ void SupportTreeBuildsteps::create_ground_pillar(const Vec3d &jp,
         else {
             // If the new endpoint is below ground, do not make a pillar
             if (endp(Z) < gndlvl)
-                endp = endp - SQR2 * (gndlvl - endp(Z)) * dir; // back off
+                endp = endp - SLOPE * (gndlvl - endp(Z)) * dir; // back off
             else {
                 
                 auto hit = bridge_mesh_intersect(endp, DOWN, radius);
@@ -685,11 +700,6 @@ void SupportTreeBuildsteps::filter()
     // not be enough space for the pinhead. Filtering is applied for
     // these reasons.
     
-    using libnest2d::opt::bound;
-    using libnest2d::opt::initvals;
-    using libnest2d::opt::GeneticOptimizer;
-    using libnest2d::opt::StopCriteria;
-    
     ccr::SpinningMutex mutex;
     auto addfn = [&mutex](PtIndices &container, unsigned val) {
         std::lock_guard<ccr::SpinningMutex> lk(mutex);
@@ -708,10 +718,7 @@ void SupportTreeBuildsteps::filter()
         // (Quaternion::FromTwoVectors) and apply the rotation to the
         // arrow head.
         
-        double z       = n(2);
+        auto [polar, azimuth] = dir_to_spheric(n);
-        double r       = 1.0; // for normalized vector
-        double polar   = std::acos(z / r);
-        double azimuth = std::atan2(n(1), n(0));
         
         // skip if the tilt is not sane
         if(polar >= PI - m_cfg.normal_cutoff_angle) {
@@ -729,9 +736,7 @@ void SupportTreeBuildsteps::filter()
             double pin_r = double(m_support_pts[fidx].head_front_radius);
             
             // Reassemble the now corrected normal
-            auto nn = Vec3d(std::cos(azimuth) * std::sin(polar),
+            auto nn = spheric_to_dir(polar, azimuth).normalized();
-                            std::sin(azimuth) * std::sin(polar),
-                            std::cos(polar)).normalized();
             
             // check available distance
             EigenMesh3D::hit_result t
@@ -757,9 +762,7 @@ void SupportTreeBuildsteps::filter()
                 auto oresult = solver.optimize_max(
                     [this, pin_r, w, hp](double plr, double azm)
                     {
-                        auto dir = Vec3d(std::cos(azm) * std::sin(plr),
+                        auto dir = spheric_to_dir(plr, azm).normalized();
-                                         std::sin(azm) * std::sin(plr),
-                                         std::cos(plr)).normalized();
                         
                         double score = pinhead_mesh_intersect(
                             hp, dir, pin_r, m_cfg.head_back_radius_mm, w);
@@ -767,18 +770,15 @@ void SupportTreeBuildsteps::filter()
                         return score;
                     },
                     initvals(polar, azimuth), // start with what we have
-                    bound(3 * PI / 4,
+                    bound(3 * PI / 4, PI),    // Must not exceed the tilt limit
-                          PI),     // Must not exceed the tilt limit
                     bound(-PI, PI) // azimuth can be a full search
                     );
                 
                 if(oresult.score > w) {
                     polar = std::get<0>(oresult.optimum);
                     azimuth = std::get<1>(oresult.optimum);
-                    nn = Vec3d(std::cos(azimuth) * std::sin(polar),
+                    nn = spheric_to_dir(polar, azimuth).normalized();
-                               std::sin(azimuth) * std::sin(polar),
+                    t = EigenMesh3D::hit_result(oresult.score);
-                               std::cos(polar)).normalized();
-                    t = oresult.score;
                 }
             }
             
@@ -837,16 +837,17 @@ void SupportTreeBuildsteps::classify()
         m_thr();
         
         auto& head = m_builder.head(i);
-        Vec3d n(0, 0, -1);
         double r = head.r_back_mm;
         Vec3d headjp = head.junction_point();
         
         // collision check
-        auto hit = bridge_mesh_intersect(headjp, n, r);
+        auto hit = bridge_mesh_intersect(headjp, DOWN, r);
         
         if(std::isinf(hit.distance())) ground_head_indices.emplace_back(i);
         else if(m_cfg.ground_facing_only)  head.invalidate();
-        else m_iheads_onmodel.emplace_back(std::make_pair(i, hit));
+        else m_iheads_onmodel.emplace_back(i);
+        
+        m_head_to_ground_scans[i] = hit;
     }
     
     // We want to search for clusters of points that are far enough
@@ -893,6 +894,7 @@ void SupportTreeBuildsteps::routing_to_ground()
         // get the current cluster centroid
         auto &      thr    = m_thr;
         const auto &points = m_points;
+
         long lcid = cluster_centroid(
             cl, [&points](size_t idx) { return points.row(long(idx)); },
             [thr](const Vec3d &p1, const Vec3d &p2) {
@@ -944,86 +946,36 @@ void SupportTreeBuildsteps::routing_to_ground()
     }
 }
 
-void SupportTreeBuildsteps::routing_to_model()
+bool SupportTreeBuildsteps::connect_to_ground(Head &head, const Vec3d &dir)
 {
-    // We need to check if there is an easy way out to the bed surface.
+    auto hjp = head.junction_point();
-    // If it can be routed there with a bridge shorter than
+    double r = head.r_back_mm;
-    // min_bridge_distance.
+    double t = bridge_mesh_intersect(hjp, dir, head.r_back_mm);
+    double d = 0, tdown = 0;
+    t = std::min(t, m_cfg.max_bridge_length_mm);
 
-    // First we want to index the available pillars. The best is to connect
+    while (d < t && !std::isinf(tdown = bridge_mesh_intersect(hjp + d * dir, DOWN, r)))
-    // these points to the available pillars
+        d += r;
     
-    auto routedown = [this](Head& head, const Vec3d& dir, double dist)
+    if(!std::isinf(tdown)) return false;
-    {
+    
-        head.transform();
+    Vec3d endp = hjp + d * dir;
-        Vec3d endp = head.junction_point() + dist * dir;
     m_builder.add_bridge(head.id, endp);
     m_builder.add_junction(endp, head.r_back_mm);
     
     this->create_ground_pillar(endp, dir, head.r_back_mm);
-    };
     
-    std::vector<unsigned> modelpillars;
+    return true;
-    ccr::SpinningMutex mutex;
+}
 
-    auto onmodelfn =
+bool SupportTreeBuildsteps::connect_to_ground(Head &head)
-    [this, routedown, &modelpillars, &mutex]
-        (const std::pair<unsigned, EigenMesh3D::hit_result> &el, size_t)
 {
-        m_thr();
+    if (connect_to_ground(head, head.dir)) return true;
-        unsigned idx = el.first;
-        EigenMesh3D::hit_result hit = el.second;
-        
-        auto& head = m_builder.head(idx);
-        Vec3d hjp = head.junction_point();
-        
-        // /////////////////////////////////////////////////////////////////
-        // Search nearby pillar
-        // /////////////////////////////////////////////////////////////////
-        
-        if(search_pillar_and_connect(head)) { head.transform(); return; }
-        
-        // /////////////////////////////////////////////////////////////////
-        // Try straight path
-        // /////////////////////////////////////////////////////////////////
-        
-        // Cannot connect to nearby pillar. We will try to search for
-        // a route to the ground.
-        
-        double t = bridge_mesh_intersect(hjp, head.dir, head.r_back_mm);
-        double d = 0, tdown = 0;
-        Vec3d dirdown(0.0, 0.0, -1.0);
-        
-        t = std::min(t, m_cfg.max_bridge_length_mm);
-        
-        while(d < t && !std::isinf(tdown = bridge_mesh_intersect(
-                                        hjp + d*head.dir,
-                                        dirdown, head.r_back_mm))) {
-            d += head.r_back_mm;
-        }
-        
-        if(std::isinf(tdown)) { // we heave found a route to the ground
-            routedown(head, head.dir, d); return;
-        }
-        
-        // /////////////////////////////////////////////////////////////////
-        // Optimize bridge direction
-        // /////////////////////////////////////////////////////////////////
     
+    // Optimize bridge direction:
     // Straight path failed so we will try to search for a suitable
     // direction out of the cavity.
-        
+    auto [polar, azimuth] = dir_to_spheric(head.dir);
-        // Get the spherical representation of the normal. its easier to
-        // work with.
-        double z = head.dir(Z);
-        double r = 1.0;     // for normalized vector
-        double polar = std::acos(z / r);
-        double azimuth = std::atan2(head.dir(Y), head.dir(X));
-        
-        using libnest2d::opt::bound;
-        using libnest2d::opt::initvals;
-        using libnest2d::opt::GeneticOptimizer;
-        using libnest2d::opt::StopCriteria;
     
     StopCriteria stc;
     stc.max_iterations = m_cfg.optimizer_max_iterations;
@@ -1033,13 +985,10 @@ void SupportTreeBuildsteps::routing_to_model()
     solver.seed(0); // we want deterministic behavior
     
     double r_back = head.r_back_mm;
-        
+    Vec3d hjp = head.junction_point();    
     auto oresult = solver.optimize_max(
-            [this, hjp, r_back](double plr, double azm)
+        [this, hjp, r_back](double plr, double azm) {
-            {
+            Vec3d n = spheric_to_dir(plr, azm).normalized();
-                Vec3d n = Vec3d(std::cos(azm) * std::sin(plr),
-                                std::sin(azm) * std::sin(plr),
-                                std::cos(plr)).normalized();
             return bridge_mesh_intersect(hjp, n, r_back);
         },
         initvals(polar, azimuth),  // let's start with what we have
@@ -1047,31 +996,19 @@ void SupportTreeBuildsteps::routing_to_model()
         bound(-PI, PI)      // azimuth can be a full range search
         );
     
-        d = 0; t = oresult.score;
+    Vec3d bridgedir = spheric_to_dir(oresult.optimum).normalized();
-        
+    return connect_to_ground(head, bridgedir);
-        polar = std::get<0>(oresult.optimum);
-        azimuth = std::get<1>(oresult.optimum);
-        Vec3d bridgedir = Vec3d(std::cos(azimuth) * std::sin(polar),
-                                std::sin(azimuth) * std::sin(polar),
-                                std::cos(polar)).normalized();
-        
-        t = std::min(t, m_cfg.max_bridge_length_mm);
-        
-        while(d < t && !std::isinf(tdown = bridge_mesh_intersect(
-                                        hjp + d*bridgedir,
-                                        dirdown,
-                                        head.r_back_mm))) {
-            d += head.r_back_mm;
 }
 
-        if(std::isinf(tdown)) { // we heave found a route to the ground
+bool SupportTreeBuildsteps::connect_to_model_body(Head &head)
-            routedown(head, bridgedir, d); return;
+{
-        }
+    if (head.id <= ID_UNSET) return false;
     
-        // /////////////////////////////////////////////////////////////////
+    auto it = m_head_to_ground_scans.find(unsigned(head.id));
-        // Route to model body
+    if (it == m_head_to_ground_scans.end()) return false;
-        // /////////////////////////////////////////////////////////////////
     
+    auto &hit = it->second;
+    Vec3d hjp = head.junction_point();
     double zangle = std::asin(hit.direction()(Z));
     zangle = std::max(zangle, PI/4);
     double h = std::sin(zangle) * head.fullwidth();
@@ -1079,9 +1016,10 @@ void SupportTreeBuildsteps::routing_to_model()
     // The width of the tail head that we would like to have...
     h = std::min(hit.distance() - head.r_back_mm, h);
     
-        if(h > 0) {
+    if(h <= 0.) return false;
+    
     Vec3d endp{hjp(X), hjp(Y), hjp(Z) - hit.distance() + h};
-            auto center_hit = m_mesh.query_ray_hit(hjp, dirdown);
+    auto center_hit = m_mesh.query_ray_hit(hjp, DOWN);
 
     double hitdiff = center_hit.distance() - hit.distance();
     Vec3d hitp = std::abs(hitdiff) < 2*head.r_back_mm?
@@ -1101,35 +1039,45 @@ void SupportTreeBuildsteps::routing_to_model()
         w = 0.;
     }
 
-            Head tailhead(head.r_back_mm,
+    Head tailhead(head.r_back_mm, head.r_pin_mm, w,
-                          head.r_pin_mm,
+                  m_cfg.head_penetration_mm, taildir, hitp);
-                          w,
-                          m_cfg.head_penetration_mm,
-                          taildir,
-                          hitp);
 
     tailhead.transform();
     pill.base = tailhead.mesh;
     
-            // Experimental: add the pillar to the index for cascading
+    m_pillar_index.guarded_insert(pill.endpoint(), pill.id);
-            std::lock_guard<ccr::SpinningMutex> lk(mutex);
+    
-            modelpillars.emplace_back(unsigned(pill.id));
+    return true;
-            return;
 }
 
+void SupportTreeBuildsteps::routing_to_model()
+{   
+    // We need to check if there is an easy way out to the bed surface.
+    // If it can be routed there with a bridge shorter than
+    // min_bridge_distance.
+
+    ccr::enumerate(m_iheads_onmodel.begin(), m_iheads_onmodel.end(),
+                   [this] (const unsigned idx, size_t) {
+        m_thr();
+        
+        auto& head = m_builder.head(idx);
+        
+        // Search nearby pillar
+        if(search_pillar_and_connect(head)) { head.transform(); return; }
+        
+        // Cannot connect to nearby pillar. We will try to search for
+        // a route to the ground.
+        if(connect_to_ground(head)) { head.transform(); return; }
+        
+        // No route to the ground, so connect to the model body as a last resort
+        if (connect_to_model_body(head)) { return; }
+        
         // We have failed to route this head.
         BOOST_LOG_TRIVIAL(warning)
-            << "Failed to route model facing support point."
+            << "Failed to route model facing support point. ID: " << idx;
-            << " ID: " << idx;
+        
         head.invalidate();
-    };
+    });
-
-    ccr::enumerate(m_iheads_onmodel.begin(), m_iheads_onmodel.end(), onmodelfn);
-    
-    for(auto pillid : modelpillars) {
-        auto& pillar = m_builder.pillar(pillid);
-        m_pillar_index.insert(pillar.endpoint(), pillid);
-    }
 }
 
 void SupportTreeBuildsteps::interconnect_pillars()
@@ -1280,7 +1228,8 @@ void SupportTreeBuildsteps::interconnect_pillars()
                 spts[n] = s;
                 
                 // Check the path vertically down
-                auto hr = bridge_mesh_intersect(s, {0, 0, -1}, pillar().r);
+                Vec3d check_from = s + Vec3d{0., 0., pillar().r};
+                auto hr = bridge_mesh_intersect(check_from, DOWN, pillar().r);
                 Vec3d gndsp{s(X), s(Y), gnd};
                 
                 // If the path is clear, check for pillar base collisions
@@ -1360,12 +1309,11 @@ void SupportTreeBuildsteps::routing_headless()
         Vec3d n = m_support_nmls.row(i);   // mesh outward normal
         Vec3d sp = sph - n * HWIDTH_MM;     // stick head start point
         
-        Vec3d dir = {0, 0, -1};
         Vec3d sj = sp + R * n;              // stick start point
         
         // This is only for checking
-        double idist = bridge_mesh_intersect(sph, dir, R, true);
+        double idist = bridge_mesh_intersect(sph, DOWN, R, true);
-        double realdist = ray_mesh_intersect(sj, dir);
+        double realdist = ray_mesh_intersect(sj, DOWN);
         double dist = realdist;
         
         if (std::isinf(dist)) dist = sph(Z) - m_builder.ground_level;
@@ -1378,7 +1326,7 @@ void SupportTreeBuildsteps::routing_headless()
         }
         
         bool use_endball = !std::isinf(realdist);
-        Vec3d ej = sj + (dist + HWIDTH_MM) * dir;
+        Vec3d ej = sj + (dist + HWIDTH_MM) * DOWN ;
         m_builder.add_compact_bridge(sp, ej, n, R, use_endball);
     }
 }

src/libslic3r/SLA/SupportTreeBuildsteps.hpp

@@ -3,7 +3,8 @@
 
 #include <cstdint>
 
-#include "SLASupportTreeBuilder.hpp"
+#include <libslic3r/SLA/SupportTreeBuilder.hpp>
+#include <libslic3r/SLA/Clustering.hpp>
 
 namespace Slic3r {
 namespace sla {
@@ -19,6 +20,32 @@ inline Vec2d to_vec2(const Vec3d& v3) {
     return {v3(X), v3(Y)};
 }
 
+inline std::pair<double, double> dir_to_spheric(const Vec3d &n, double norm = 1.)
+{
+    double z       = n.z();
+    double r       = norm;
+    double polar   = std::acos(z / r);
+    double azimuth = std::atan2(n(1), n(0));
+    return {polar, azimuth};
+}
+
+inline Vec3d spheric_to_dir(double polar, double azimuth)
+{
+    return {std::cos(azimuth) * std::sin(polar),
+            std::sin(azimuth) * std::sin(polar), std::cos(polar)};
+}
+
+inline Vec3d spheric_to_dir(const std::tuple<double, double> &v)
+{
+    auto [plr, azm] = v;
+    return spheric_to_dir(plr, azm);
+}
+
+inline Vec3d spheric_to_dir(const std::pair<double, double> &v)
+{
+    return spheric_to_dir(v.first, v.second);
+}
+
 // This function returns the position of the centroid in the input 'clust'
 // vector of point indices.
 template<class DistFn>
@@ -150,10 +177,10 @@ class SupportTreeBuildsteps {
     using PtIndices = std::vector<unsigned>;
 
     PtIndices m_iheads;            // support points with pinhead
+    PtIndices m_iheads_onmodel;
     PtIndices m_iheadless;         // headless support points
     
-    // supp. pts. connecting to model: point index and the ray hit data
+    std::map<unsigned, EigenMesh3D::hit_result> m_head_to_ground_scans;
-    std::vector<std::pair<unsigned, EigenMesh3D::hit_result>> m_iheads_onmodel;
 
     // normals for support points from model faces.
     PointSet  m_support_nmls;
@@ -223,14 +250,28 @@ class SupportTreeBuildsteps {
     // For connecting a head to a nearby pillar.
     bool connect_to_nearpillar(const Head& head, long nearpillar_id);
     
+    // Find route for a head to the ground. Inserts additional bridge from the
+    // head to the pillar if cannot create pillar directly.
+    // The optional dir parameter is the direction of the bridge which is the
+    // direction of the pinhead if omitted.
+    bool connect_to_ground(Head& head, const Vec3d &dir);
+    inline bool connect_to_ground(Head& head);
+    
+    bool connect_to_model_body(Head &head);
+    
     bool search_pillar_and_connect(const Head& head);
     
     // This is a proxy function for pillar creation which will mind the gap
     // between the pad and the model bottom in zero elevation mode.
+    // jp is the starting junction point which needs to be routed down.
+    // sourcedir is the allowed direction of an optional bridge between the
+    // jp junction and the final pillar.
     void create_ground_pillar(const Vec3d &jp,
                               const Vec3d &sourcedir,
                               double       radius,
                               long         head_id = ID_UNSET);
+    
+    
 public:
     SupportTreeBuildsteps(SupportTreeBuilder & builder, const SupportableMesh &sm);
 

src/libslic3r/SLA/SupportTreeIGL.cpp

@@ -1,6 +1,6 @@
 #include <cmath>
 #include "SLA/SLASupportTree.hpp"
-#include "SLA/SLABoilerPlate.hpp"
+#include "SLA/SLACommon.hpp"
 #include "SLA/SLASpatIndex.hpp"
 
 // Workaround: IGL signed_distance.h will define PI in the igl namespace.
@@ -228,6 +228,26 @@ EigenMesh3D::EigenMesh3D(const EigenMesh3D &other):
     m_V(other.m_V), m_F(other.m_F), m_ground_level(other.m_ground_level),
     m_aabb( new AABBImpl(*other.m_aabb) ) {}
 
+EigenMesh3D::EigenMesh3D(const Contour3D &other)
+{
+    m_V.resize(Eigen::Index(other.points.size()), 3);
+    m_F.resize(Eigen::Index(other.faces3.size() + 2 * other.faces4.size()), 3);
+    
+    for (Eigen::Index i = 0; i < Eigen::Index(other.points.size()); ++i)
+        m_V.row(i) = other.points[size_t(i)];
+    
+    for (Eigen::Index i = 0; i < Eigen::Index(other.faces3.size()); ++i)
+        m_F.row(i) = other.faces3[size_t(i)];
+    
+    size_t N = other.faces3.size() + 2 * other.faces4.size();
+    for (size_t i = other.faces3.size(); i < N; i += 2) {
+        size_t quad_idx = (i - other.faces3.size()) / 2;
+        auto & quad     = other.faces4[quad_idx];
+        m_F.row(Eigen::Index(i)) = Vec3i{quad(0), quad(1), quad(2)};
+        m_F.row(Eigen::Index(i + 1)) = Vec3i{quad(2), quad(3), quad(0)};
+    }
+}
+
 EigenMesh3D &EigenMesh3D::operator=(const EigenMesh3D &other)
 {
     m_V = other.m_V;
@@ -252,6 +272,31 @@ EigenMesh3D::query_ray_hit(const Vec3d &s, const Vec3d &dir) const
     return ret;
 }
 
+std::vector<EigenMesh3D::hit_result>
+EigenMesh3D::query_ray_hits(const Vec3d &s, const Vec3d &dir) const
+{
+    std::vector<EigenMesh3D::hit_result> outs;
+    std::vector<igl::Hit> hits;
+    m_aabb->intersect_ray(m_V, m_F, s, dir, hits);
+
+    // The sort is necessary, the hits are not always sorted.
+    std::sort(hits.begin(), hits.end(),
+        [](const igl::Hit& a, const igl::Hit& b) { return a.t < b.t; });
+
+    //  Convert the igl::Hit into hit_result
+    outs.reserve(hits.size());
+    for (const igl::Hit& hit : hits) {
+        outs.emplace_back(EigenMesh3D::hit_result(*this));
+        outs.back().m_t = double(hit.t);
+        outs.back().m_dir = dir;
+        outs.back().m_source = s;
+        if(!std::isinf(hit.t) && !std::isnan(hit.t))
+            outs.back().m_face_id = hit.id;
+    }
+
+    return outs;
+}
+
 #ifdef SLIC3R_SLA_NEEDS_WINDTREE
 EigenMesh3D::si_result EigenMesh3D::signed_distance(const Vec3d &p) const {
     double sign = 0; double sqdst = 0; int i = 0;  Vec3d c;

src/libslic3r/SLAPrint.hpp

@@ -3,8 +3,8 @@
 
 #include <mutex>
 #include "PrintBase.hpp"
-//#include "PrintExport.hpp"
+#include "SLA/RasterWriter.hpp"
-#include "SLA/SLARasterWriter.hpp"
+#include "SLA/SupportTree.hpp"
 #include "Point.hpp"
 #include "MTUtils.hpp"
 #include "Zipper.hpp"
@@ -19,7 +19,9 @@ enum SLAPrintStep : unsigned int {
 };
 
 enum SLAPrintObjectStep : unsigned int {
+    slaposHollowing,
 	slaposObjectSlice,
+    slaposDrillHolesIfHollowed,
 	slaposSupportPoints,
 	slaposSupportTree,
 	slaposPad,
@@ -73,13 +75,17 @@ public:
     // Support mesh is only valid if this->is_step_done(slaposSupportTree) is true.
     const TriangleMesh&     support_mesh() const;
     // Get a pad mesh centered around origin in XY, and with zero rotation around Z applied.
-    // Support mesh is only valid if this->is_step_done(slaposBasePool) is true.
+    // Support mesh is only valid if this->is_step_done(slaposPad) is true.
     const TriangleMesh&     pad_mesh() const;
     
+    // Ready after this->is_step_done(slaposHollowing) is true
+    const TriangleMesh&     hollowed_interior_mesh() const;
+
     // This will return the transformed mesh which is cached
     const TriangleMesh&     transformed_mesh() const;
 
-    std::vector<sla::SupportPoint>      transformed_support_points() const;
+    sla::SupportPoints      transformed_support_points() const;
+    sla::DrainHoles         transformed_drainhole_points() const;
 
     // Get the needed Z elevation for the model geometry if supports should be
     // displayed. This Z offset should also be applied to the support
@@ -288,8 +294,34 @@ private:
     // Caching the transformed (m_trafo) raw mesh of the object
     mutable CachedObject<TriangleMesh>      m_transformed_rmesh;
     
-    class SupportData;
+    class SupportData : public sla::SupportableMesh
+    {
+    public:
+        sla::SupportTree::UPtr  support_tree_ptr; // the supports
+        std::vector<ExPolygons> support_slices;   // sliced supports
+        
+        inline SupportData(const TriangleMesh &t)
+            : sla::SupportableMesh{t, {}, {}}
+        {}
+        
+        sla::SupportTree::UPtr &create_support_tree(const sla::JobController &ctl)
+        {
+            support_tree_ptr = sla::SupportTree::create(*this, ctl);
+            return support_tree_ptr;
+        }
+    };
+    
     std::unique_ptr<SupportData> m_supportdata;
+    
+    class HollowingData
+    {
+    public:
+        
+        TriangleMesh interior;
+        // std::vector<drillpoints>
+    };
+    
+    std::unique_ptr<HollowingData> m_hollowing_data;
 };
 
 using PrintObjects = std::vector<SLAPrintObject*>;
@@ -340,6 +372,8 @@ class SLAPrint : public PrintBaseWithState<SLAPrintStep, slapsCount>
 private: // Prevents erroneous use by other classes.
     typedef PrintBaseWithState<SLAPrintStep, slapsCount> Inherited;
     
+    class Steps; // See SLAPrintSteps.cpp
+    
 public:
 
     SLAPrint(): m_stepmask(slapsCount, true) {}
@@ -402,7 +436,7 @@ public:
             m_transformed_slices = std::forward<Container>(c);
         }
         
-        friend void SLAPrint::process();
+        friend class SLAPrint::Steps;
 
     public:
 
@@ -478,6 +512,19 @@ private:
 	friend SLAPrintObject;
 };
 
+// Helper functions:
+
+bool is_zero_elevation(const SLAPrintObjectConfig &c);
+
+sla::SupportConfig make_support_cfg(const SLAPrintObjectConfig& c);
+
+sla::PadConfig::EmbedObject builtin_pad_cfg(const SLAPrintObjectConfig& c);
+
+sla::PadConfig make_pad_cfg(const SLAPrintObjectConfig& c);
+
+bool validate_pad(const TriangleMesh &pad, const sla::PadConfig &pcfg);
+
+
 } // namespace Slic3r
 
 #endif /* slic3r_SLAPrint_hpp_ */

src/libslic3r/SLAPrintSteps.cpp

@@ -0,0 +1,862 @@
+#include <libslic3r/SLAPrintSteps.hpp>
+
+
+// Need the cylinder method for the the drainholes in hollowing step
+#include <libslic3r/SLA/SupportTreeBuilder.hpp>
+
+#include <libslic3r/SLA/Concurrency.hpp>
+#include <libslic3r/SLA/Pad.hpp>
+#include <libslic3r/SLA/SupportPointGenerator.hpp>
+
+#include <libslic3r/ClipperUtils.hpp>
+
+// For geometry algorithms with native Clipper types (no copies and conversions)
+#include <libnest2d/backends/clipper/geometries.hpp>
+
+#include <boost/log/trivial.hpp>
+
+#include "I18N.hpp"
+
+//! macro used to mark string used at localization,
+//! return same string
+#define L(s) Slic3r::I18N::translate(s)
+
+namespace Slic3r {
+
+namespace {
+
+const std::array<unsigned, slaposCount> OBJ_STEP_LEVELS = {
+    5,  // slaposHollowing,
+    20, // slaposObjectSlice,
+    5,  // slaposDrillHolesIfHollowed
+    20, // slaposSupportPoints,
+    10, // slaposSupportTree,
+    10, // slaposPad,
+    30, // slaposSliceSupports,
+};
+
+std::string OBJ_STEP_LABELS(size_t idx)
+{
+    switch (idx) {
+    case slaposHollowing:            return L("Hollowing out the model");
+    case slaposObjectSlice:          return L("Slicing model");
+    case slaposDrillHolesIfHollowed: return L("Drilling holes into hollowed model.");
+    case slaposSupportPoints:        return L("Generating support points");
+    case slaposSupportTree:          return L("Generating support tree");
+    case slaposPad:                  return L("Generating pad");
+    case slaposSliceSupports:        return L("Slicing supports");
+    default:;
+    }
+    assert(false);
+    return "Out of bounds!";
+};
+
+const std::array<unsigned, slapsCount> PRINT_STEP_LEVELS = {
+    10, // slapsMergeSlicesAndEval
+    90, // slapsRasterize
+};
+
+std::string PRINT_STEP_LABELS(size_t idx)
+{
+    switch (idx) {
+    case slapsMergeSlicesAndEval:   return L("Merging slices and calculating statistics");
+    case slapsRasterize:            return L("Rasterizing layers");
+    default:;
+    }
+    assert(false); return "Out of bounds!";
+};
+
+}
+
+SLAPrint::Steps::Steps(SLAPrint *print)
+    : m_print{print}
+    , objcount{m_print->m_objects.size()}
+    , ilhd{m_print->m_material_config.initial_layer_height.getFloat()}
+    , ilh{float(ilhd)}
+    , ilhs{scaled(ilhd)}
+    , objectstep_scale{(max_objstatus - min_objstatus) / (objcount * 100.0)}
+{}
+
+void SLAPrint::Steps::hollow_model(SLAPrintObject &po)
+{
+    if (!po.m_config.hollowing_enable.getBool()) {
+        BOOST_LOG_TRIVIAL(info) << "Skipping hollowing step!";
+        po.m_hollowing_data.reset();
+        return;
+    } else {
+        BOOST_LOG_TRIVIAL(info) << "Performing hollowing step!";
+    }
+    
+    if (!po.m_hollowing_data)
+        po.m_hollowing_data.reset(new SLAPrintObject::HollowingData());
+    
+    double thickness = po.m_config.hollowing_min_thickness.getFloat();
+    double quality  = po.m_config.hollowing_quality.getFloat();
+    double closing_d = po.m_config.hollowing_closing_distance.getFloat();
+    sla::HollowingConfig hlwcfg{thickness, quality, closing_d};
+    auto meshptr = generate_interior(po.transformed_mesh(), hlwcfg);
+    if (meshptr) po.m_hollowing_data->interior = *meshptr;
+    
+    if (po.m_hollowing_data->interior.empty())
+        BOOST_LOG_TRIVIAL(warning) << "Hollowed interior is empty!";
+}
+
+// The slicing will be performed on an imaginary 1D grid which starts from
+// the bottom of the bounding box created around the supported model. So
+// the first layer which is usually thicker will be part of the supports
+// not the model geometry. Exception is when the model is not in the air
+// (elevation is zero) and no pad creation was requested. In this case the
+// model geometry starts on the ground level and the initial layer is part
+// of it. In any case, the model and the supports have to be sliced in the
+// same imaginary grid (the height vector argument to TriangleMeshSlicer).
+void SLAPrint::Steps::slice_model(SLAPrintObject &po)
+{   
+    TriangleMesh hollowed_mesh;
+    
+    bool is_hollowing = po.m_config.hollowing_enable.getBool() && po.m_hollowing_data;
+    
+    if (is_hollowing) {
+        hollowed_mesh = po.transformed_mesh();
+        hollowed_mesh.merge(po.m_hollowing_data->interior);
+        hollowed_mesh.require_shared_vertices();
+    }
+    
+    const TriangleMesh &mesh = is_hollowing ? hollowed_mesh : po.transformed_mesh();
+    
+    // We need to prepare the slice index...
+    
+    double  lhd  = m_print->m_objects.front()->m_config.layer_height.getFloat();
+    float   lh   = float(lhd);
+    coord_t lhs  = scaled(lhd);
+    auto && bb3d = mesh.bounding_box();
+    double  minZ = bb3d.min(Z) - po.get_elevation();
+    double  maxZ = bb3d.max(Z);
+    auto    minZf = float(minZ);
+    coord_t minZs = scaled(minZ);
+    coord_t maxZs = scaled(maxZ);
+    
+    po.m_slice_index.clear();
+    
+    size_t cap = size_t(1 + (maxZs - minZs - ilhs) / lhs);
+    po.m_slice_index.reserve(cap);
+    
+    po.m_slice_index.emplace_back(minZs + ilhs, minZf + ilh / 2.f, ilh);
+    
+    for(coord_t h = minZs + ilhs + lhs; h <= maxZs; h += lhs)
+        po.m_slice_index.emplace_back(h, unscaled<float>(h) - lh / 2.f, lh);
+    
+    // Just get the first record that is from the model:
+    auto slindex_it =
+        po.closest_slice_record(po.m_slice_index, float(bb3d.min(Z)));
+    
+    if(slindex_it == po.m_slice_index.end())
+        //TRN To be shown at the status bar on SLA slicing error.
+        throw std::runtime_error(
+            L("Slicing had to be stopped due to an internal error: "
+              "Inconsistent slice index."));
+    
+    po.m_model_height_levels.clear();
+    po.m_model_height_levels.reserve(po.m_slice_index.size());
+    for(auto it = slindex_it; it != po.m_slice_index.end(); ++it)
+        po.m_model_height_levels.emplace_back(it->slice_level());
+    
+    TriangleMeshSlicer slicer(&mesh);
+    
+    po.m_model_slices.clear();
+    float closing_r  = float(po.config().slice_closing_radius.value);
+    auto  thr        = [this]() { m_print->throw_if_canceled(); };
+    auto &slice_grid = po.m_model_height_levels;
+    slicer.slice(slice_grid, closing_r, &po.m_model_slices, thr);
+    
+    sla::DrainHoles drainholes = po.transformed_drainhole_points();
+    cut_drainholes(po.m_model_slices, slice_grid, closing_r, drainholes, thr);
+    
+    auto mit = slindex_it;
+    double doffs = m_print->m_printer_config.absolute_correction.getFloat();
+    coord_t clpr_offs = scaled(doffs);
+    for(size_t id = 0;
+         id < po.m_model_slices.size() && mit != po.m_slice_index.end();
+         id++)
+    {
+        // We apply the printer correction offset here.
+        if(clpr_offs != 0)
+            po.m_model_slices[id] =
+                offset_ex(po.m_model_slices[id], float(clpr_offs));
+        
+        mit->set_model_slice_idx(po, id); ++mit;
+    }
+    
+    if(po.m_config.supports_enable.getBool() || po.m_config.pad_enable.getBool())
+    {
+        po.m_supportdata.reset(new SLAPrintObject::SupportData(mesh));
+    }
+}
+
+// In this step we check the slices, identify island and cover them with
+// support points. Then we sprinkle the rest of the mesh.
+void SLAPrint::Steps::support_points(SLAPrintObject &po)
+{
+    // If supports are disabled, we can skip the model scan.
+    if(!po.m_config.supports_enable.getBool()) return;
+    
+    bool is_hollowing = po.m_config.hollowing_enable.getBool() && po.m_hollowing_data;
+    
+    TriangleMesh hollowed_mesh;
+    if (is_hollowing) {
+        hollowed_mesh = po.transformed_mesh();
+        hollowed_mesh.merge(po.m_hollowing_data->interior);
+        hollowed_mesh.require_shared_vertices();
+    }
+    
+    const TriangleMesh &mesh = is_hollowing ? hollowed_mesh : po.transformed_mesh();
+    
+    if (!po.m_supportdata)
+        po.m_supportdata.reset(new SLAPrintObject::SupportData(mesh));
+    
+    const ModelObject& mo = *po.m_model_object;
+    
+    BOOST_LOG_TRIVIAL(debug) << "Support point count "
+                             << mo.sla_support_points.size();
+    
+    // Unless the user modified the points or we already did the calculation,
+    // we will do the autoplacement. Otherwise we will just blindly copy the
+    // frontend data into the backend cache.
+    if (mo.sla_points_status != sla::PointsStatus::UserModified) {
+        
+        // calculate heights of slices (slices are calculated already)
+        const std::vector<float>& heights = po.m_model_height_levels;
+
+        // Tell the mesh where drain holes are. Although the points are
+        // calculated on slices, the algorithm then raycasts the points
+        // so they actually lie on the mesh.
+        po.m_supportdata->emesh.load_holes(po.transformed_drainhole_points());
+        
+        throw_if_canceled();
+        sla::SupportPointGenerator::Config config;
+        const SLAPrintObjectConfig& cfg = po.config();
+        
+        // the density config value is in percents:
+        config.density_relative = float(cfg.support_points_density_relative / 100.f);
+        config.minimal_distance = float(cfg.support_points_minimal_distance);
+        config.head_diameter    = float(cfg.support_head_front_diameter);
+        
+        // scaling for the sub operations
+        double d = objectstep_scale * OBJ_STEP_LEVELS[slaposSupportPoints] / 100.0;
+        double init = current_status();
+        
+        auto statuscb = [this, d, init](unsigned st)
+        {
+            double current = init + st * d;
+            if(std::round(current_status()) < std::round(current))
+                report_status(current, OBJ_STEP_LABELS(slaposSupportPoints));
+        };
+        
+        // Construction of this object does the calculation.
+        throw_if_canceled();
+        sla::SupportPointGenerator auto_supports(
+            po.m_supportdata->emesh, po.get_model_slices(), heights, config,
+            [this]() { throw_if_canceled(); }, statuscb);
+
+        // Now let's extract the result.
+        const std::vector<sla::SupportPoint>& points = auto_supports.output();
+        throw_if_canceled();
+        po.m_supportdata->pts = points;
+        
+        BOOST_LOG_TRIVIAL(debug) << "Automatic support points: "
+                                 << po.m_supportdata->pts.size();
+        
+        // Using RELOAD_SLA_SUPPORT_POINTS to tell the Plater to pass
+        // the update status to GLGizmoSlaSupports
+        report_status(-1, L("Generating support points"),
+                      SlicingStatus::RELOAD_SLA_SUPPORT_POINTS);
+    } else {
+        // There are either some points on the front-end, or the user
+        // removed them on purpose. No calculation will be done.
+        po.m_supportdata->pts = po.transformed_support_points();
+    }
+
+    // If the zero elevation mode is engaged, we have to filter out all the
+    // points that are on the bottom of the object
+    if (is_zero_elevation(po.config())) {
+        double tolerance = po.config().pad_enable.getBool() ?
+                               po.m_config.pad_wall_thickness.getFloat() :
+                               po.m_config.support_base_height.getFloat();
+
+        remove_bottom_points(po.m_supportdata->pts,
+                             po.m_supportdata->emesh.ground_level(),
+                             tolerance);
+    }
+}
+
+void SLAPrint::Steps::support_tree(SLAPrintObject &po)
+{
+    if(!po.m_supportdata) return;
+    
+    sla::PadConfig pcfg = make_pad_cfg(po.m_config);
+    
+    if (pcfg.embed_object)
+        po.m_supportdata->emesh.ground_level_offset(pcfg.wall_thickness_mm);
+    
+    po.m_supportdata->cfg = make_support_cfg(po.m_config);
+    po.m_supportdata->emesh.load_holes(po.transformed_drainhole_points());
+    
+    // scaling for the sub operations
+    double d = objectstep_scale * OBJ_STEP_LEVELS[slaposSupportTree] / 100.0;
+    double init = current_status();
+    sla::JobController ctl;
+    
+    ctl.statuscb = [this, d, init](unsigned st, const std::string &logmsg) {
+        double current = init + st * d;
+        if (std::round(current_status()) < std::round(current))
+            report_status(current, OBJ_STEP_LABELS(slaposSupportTree),
+                          SlicingStatus::DEFAULT, logmsg);
+    };
+    ctl.stopcondition = [this]() { return canceled(); };
+    ctl.cancelfn = [this]() { throw_if_canceled(); };
+    
+    po.m_supportdata->create_support_tree(ctl);
+    
+    if (!po.m_config.supports_enable.getBool()) return;
+    
+    throw_if_canceled();
+    
+    // Create the unified mesh
+    auto rc = SlicingStatus::RELOAD_SCENE;
+    
+    // This is to prevent "Done." being displayed during merged_mesh()
+    report_status(-1, L("Visualizing supports"));
+    
+    BOOST_LOG_TRIVIAL(debug) << "Processed support point count "
+                             << po.m_supportdata->pts.size();
+    
+    // Check the mesh for later troubleshooting.
+    if(po.support_mesh().empty())
+        BOOST_LOG_TRIVIAL(warning) << "Support mesh is empty";
+    
+    report_status(-1, L("Visualizing supports"), rc);
+}
+
+void SLAPrint::Steps::generate_pad(SLAPrintObject &po) {
+    // this step can only go after the support tree has been created
+    // and before the supports had been sliced. (or the slicing has to be
+    // repeated)
+    
+    if(po.m_config.pad_enable.getBool()) {
+        // Get the distilled pad configuration from the config
+        sla::PadConfig pcfg = make_pad_cfg(po.m_config);
+        
+        ExPolygons bp; // This will store the base plate of the pad.
+        double   pad_h             = pcfg.full_height();
+        const TriangleMesh &trmesh = po.transformed_mesh();
+        
+        if (!po.m_config.supports_enable.getBool() || pcfg.embed_object) {
+            // No support (thus no elevation) or zero elevation mode
+            // we sometimes call it "builtin pad" is enabled so we will
+            // get a sample from the bottom of the mesh and use it for pad
+            // creation.
+            sla::pad_blueprint(trmesh, bp, float(pad_h),
+                               float(po.m_config.layer_height.getFloat()),
+                               [this](){ throw_if_canceled(); });
+        }
+        
+        po.m_supportdata->support_tree_ptr->add_pad(bp, pcfg);
+        auto &pad_mesh = po.m_supportdata->support_tree_ptr->retrieve_mesh(sla::MeshType::Pad);
+        
+        if (!validate_pad(pad_mesh, pcfg))
+            throw std::runtime_error(
+                    L("No pad can be generated for this model with the "
+                      "current configuration"));
+        
+    } else if(po.m_supportdata && po.m_supportdata->support_tree_ptr) {
+        po.m_supportdata->support_tree_ptr->remove_pad();
+    }
+    
+    throw_if_canceled();
+    report_status(-1, L("Visualizing supports"), SlicingStatus::RELOAD_SCENE);
+}
+
+// Slicing the support geometries similarly to the model slicing procedure.
+// If the pad had been added previously (see step "base_pool" than it will
+// be part of the slices)
+void SLAPrint::Steps::slice_supports(SLAPrintObject &po) {
+    auto& sd = po.m_supportdata;
+    
+    if(sd) sd->support_slices.clear();
+    
+    // Don't bother if no supports and no pad is present.
+    if (!po.m_config.supports_enable.getBool() && !po.m_config.pad_enable.getBool())
+        return;
+    
+    if(sd && sd->support_tree_ptr) {
+        auto heights = reserve_vector<float>(po.m_slice_index.size());
+        
+        for(auto& rec : po.m_slice_index) heights.emplace_back(rec.slice_level());
+        
+        sd->support_slices = sd->support_tree_ptr->slice(
+                    heights, float(po.config().slice_closing_radius.value));
+    }
+    
+    double doffs = m_print->m_printer_config.absolute_correction.getFloat();
+    coord_t clpr_offs = scaled(doffs);
+
+    for (size_t i = 0; i < sd->support_slices.size() && i < po.m_slice_index.size(); ++i) {
+        // We apply the printer correction offset here.
+        if (clpr_offs != 0)
+            sd->support_slices[i] = offset_ex(sd->support_slices[i], float(clpr_offs));
+
+        po.m_slice_index[i].set_support_slice_idx(po, i);
+    }
+
+    // Using RELOAD_SLA_PREVIEW to tell the Plater to pass the update
+    // status to the 3D preview to load the SLA slices.
+    report_status(-2, "", SlicingStatus::RELOAD_SLA_PREVIEW);
+}
+
+using ClipperPoint  = ClipperLib::IntPoint;
+using ClipperPolygon = ClipperLib::Polygon; // see clipper_polygon.hpp in libnest2d
+using ClipperPolygons = std::vector<ClipperPolygon>;
+
+static ClipperPolygons polyunion(const ClipperPolygons &subjects)
+{
+    ClipperLib::Clipper clipper;
+    
+    bool closed = true;
+    
+    for(auto& path : subjects) {
+        clipper.AddPath(path.Contour, ClipperLib::ptSubject, closed);
+        clipper.AddPaths(path.Holes, ClipperLib::ptSubject, closed);
+    }
+    
+    auto mode = ClipperLib::pftPositive;
+    
+    return libnest2d::clipper_execute(clipper, ClipperLib::ctUnion, mode, mode);
+}
+
+static ClipperPolygons polydiff(const ClipperPolygons &subjects, const ClipperPolygons& clips)
+{
+    ClipperLib::Clipper clipper;
+    
+    bool closed = true;
+    
+    for(auto& path : subjects) {
+        clipper.AddPath(path.Contour, ClipperLib::ptSubject, closed);
+        clipper.AddPaths(path.Holes, ClipperLib::ptSubject, closed);
+    }
+    
+    for(auto& path : clips) {
+        clipper.AddPath(path.Contour, ClipperLib::ptClip, closed);
+        clipper.AddPaths(path.Holes, ClipperLib::ptClip, closed);
+    }
+    
+    auto mode = ClipperLib::pftPositive;
+    
+    return libnest2d::clipper_execute(clipper, ClipperLib::ctDifference, mode, mode);
+}
+
+// get polygons for all instances in the object
+static ClipperPolygons get_all_polygons(
+    const ExPolygons &                           input_polygons,
+    const std::vector<SLAPrintObject::Instance> &instances,
+    bool                                         is_lefthanded)
+{
+    namespace sl = libnest2d::sl;
+    
+    ClipperPolygons polygons;
+    polygons.reserve(input_polygons.size() * instances.size());
+    
+    for (const ExPolygon& polygon : input_polygons) {
+        if(polygon.contour.empty()) continue;
+        
+        for (size_t i = 0; i < instances.size(); ++i)
+        {
+            ClipperPolygon poly;
+            
+            // We need to reverse if is_lefthanded is true but
+            bool needreverse = is_lefthanded;
+            
+            // should be a move
+            poly.Contour.reserve(polygon.contour.size() + 1);
+            
+            auto& cntr = polygon.contour.points;
+            if(needreverse)
+                for(auto it = cntr.rbegin(); it != cntr.rend(); ++it)
+                    poly.Contour.emplace_back(it->x(), it->y());
+            else
+                for(auto& p : cntr)
+                    poly.Contour.emplace_back(p.x(), p.y());
+            
+            for(auto& h : polygon.holes) {
+                poly.Holes.emplace_back();
+                auto& hole = poly.Holes.back();
+                hole.reserve(h.points.size() + 1);
+                
+                if(needreverse)
+                    for(auto it = h.points.rbegin(); it != h.points.rend(); ++it)
+                        hole.emplace_back(it->x(), it->y());
+                else
+                    for(auto& p : h.points)
+                        hole.emplace_back(p.x(), p.y());
+            }
+            
+            if(is_lefthanded) {
+                for(auto& p : poly.Contour) p.X = -p.X;
+                for(auto& h : poly.Holes) for(auto& p : h) p.X = -p.X;
+            }
+            
+            sl::rotate(poly, double(instances[i].rotation));
+            sl::translate(poly, ClipperPoint{instances[i].shift(X),
+                                             instances[i].shift(Y)});
+            
+            polygons.emplace_back(std::move(poly));
+        }
+    }
+    
+    return polygons;
+}
+
+void SLAPrint::Steps::initialize_printer_input()
+{
+    auto &printer_input = m_print->m_printer_input;
+    
+    // clear the rasterizer input
+    printer_input.clear();
+    
+    size_t mx = 0;
+    for(SLAPrintObject * o : m_print->m_objects) {
+        if(auto m = o->get_slice_index().size() > mx) mx = m;
+    }
+    
+    printer_input.reserve(mx);
+    
+    auto eps = coord_t(SCALED_EPSILON);
+    
+    for(SLAPrintObject * o : m_print->m_objects) {
+        coord_t gndlvl = o->get_slice_index().front().print_level() - ilhs;
+        
+        for(const SliceRecord& slicerecord : o->get_slice_index()) {
+            coord_t lvlid = slicerecord.print_level() - gndlvl;
+            
+            // Neat trick to round the layer levels to the grid.
+            lvlid = eps * (lvlid / eps);
+
+            auto it = std::lower_bound(printer_input.begin(),
+                                       printer_input.end(),
+                                       PrintLayer(lvlid));
+
+            if(it == printer_input.end() || it->level() != lvlid)
+                it = printer_input.insert(it, PrintLayer(lvlid));
+            
+            
+            it->add(slicerecord);
+        }
+    }
+}
+
+// Merging the slices from all the print objects into one slice grid and
+// calculating print statistics from the merge result.
+void SLAPrint::Steps::merge_slices_and_eval_stats() {
+    
+    initialize_printer_input();
+    
+    auto &print_statistics = m_print->m_print_statistics;
+    auto &printer_config   = m_print->m_printer_config;
+    auto &material_config  = m_print->m_material_config;
+    auto &printer_input    = m_print->m_printer_input;
+    
+    print_statistics.clear();
+    
+    // libnest calculates positive area for clockwise polygons, Slic3r is in counter-clockwise
+    auto areafn = [](const ClipperPolygon& poly) { return - libnest2d::sl::area(poly); };
+    
+    const double area_fill = printer_config.area_fill.getFloat()*0.01;// 0.5 (50%);
+    const double fast_tilt = printer_config.fast_tilt_time.getFloat();// 5.0;
+    const double slow_tilt = printer_config.slow_tilt_time.getFloat();// 8.0;
+    
+    const double init_exp_time = material_config.initial_exposure_time.getFloat();
+    const double exp_time      = material_config.exposure_time.getFloat();
+    
+    const int fade_layers_cnt = m_print->m_default_object_config.faded_layers.getInt();// 10 // [3;20]
+    
+    const auto width          = scaled<double>(printer_config.display_width.getFloat());
+    const auto height         = scaled<double>(printer_config.display_height.getFloat());
+    const double display_area = width*height;
+    
+    double supports_volume(0.0);
+    double models_volume(0.0);
+    
+    double estim_time(0.0);
+    
+    size_t slow_layers = 0;
+    size_t fast_layers = 0;
+    
+    const double delta_fade_time = (init_exp_time - exp_time) / (fade_layers_cnt + 1);
+    double fade_layer_time = init_exp_time;
+    
+    sla::ccr::SpinningMutex mutex;
+    using Lock = std::lock_guard<sla::ccr::SpinningMutex>;
+    
+    // Going to parallel:
+    auto printlayerfn = [
+            // functions and read only vars
+            areafn, area_fill, display_area, exp_time, init_exp_time, fast_tilt, slow_tilt, delta_fade_time,
+            
+            // write vars
+            &mutex, &models_volume, &supports_volume, &estim_time, &slow_layers,
+            &fast_layers, &fade_layer_time](PrintLayer& layer, size_t sliced_layer_cnt)
+    {
+        // vector of slice record references
+        auto& slicerecord_references = layer.slices();
+        
+        if(slicerecord_references.empty()) return;
+        
+        // Layer height should match for all object slices for a given level.
+        const auto l_height = double(slicerecord_references.front().get().layer_height());
+        
+        // Calculation of the consumed material
+        
+        ClipperPolygons model_polygons;
+        ClipperPolygons supports_polygons;
+        
+        size_t c = std::accumulate(layer.slices().begin(),
+                                   layer.slices().end(),
+                                   size_t(0),
+                                   [](size_t a, const SliceRecord &sr) {
+            return a + sr.get_slice(soModel).size();
+        });
+        
+        model_polygons.reserve(c);
+        
+        c = std::accumulate(layer.slices().begin(),
+                            layer.slices().end(),
+                            size_t(0),
+                            [](size_t a, const SliceRecord &sr) {
+            return a + sr.get_slice(soModel).size();
+        });
+        
+        supports_polygons.reserve(c);
+        
+        for(const SliceRecord& record : layer.slices()) {
+            const SLAPrintObject *po = record.print_obj();
+            
+            const ExPolygons &modelslices = record.get_slice(soModel);
+            
+            bool is_lefth = record.print_obj()->is_left_handed();
+            if (!modelslices.empty()) {
+                ClipperPolygons v = get_all_polygons(modelslices, po->instances(), is_lefth);
+                for(ClipperPolygon& p_tmp : v) model_polygons.emplace_back(std::move(p_tmp));
+            }
+            
+            const ExPolygons &supportslices = record.get_slice(soSupport);
+            
+            if (!supportslices.empty()) {
+                ClipperPolygons v = get_all_polygons(supportslices, po->instances(), is_lefth);
+                for(ClipperPolygon& p_tmp : v) supports_polygons.emplace_back(std::move(p_tmp));
+            }
+        }
+        
+        model_polygons = polyunion(model_polygons);
+        double layer_model_area = 0;
+        for (const ClipperPolygon& polygon : model_polygons)
+            layer_model_area += areafn(polygon);
+        
+        if (layer_model_area < 0 || layer_model_area > 0) {
+            Lock lck(mutex); models_volume += layer_model_area * l_height;
+        }
+        
+        if(!supports_polygons.empty()) {
+            if(model_polygons.empty()) supports_polygons = polyunion(supports_polygons);
+            else supports_polygons = polydiff(supports_polygons, model_polygons);
+            // allegedly, union of subject is done withing the diff according to the pftPositive polyFillType
+        }
+        
+        double layer_support_area = 0;
+        for (const ClipperPolygon& polygon : supports_polygons)
+            layer_support_area += areafn(polygon);
+        
+        if (layer_support_area < 0 || layer_support_area > 0) {
+            Lock lck(mutex); supports_volume += layer_support_area * l_height;
+        }
+        
+        // Here we can save the expensively calculated polygons for printing
+        ClipperPolygons trslices;
+        trslices.reserve(model_polygons.size() + supports_polygons.size());
+        for(ClipperPolygon& poly : model_polygons) trslices.emplace_back(std::move(poly));
+        for(ClipperPolygon& poly : supports_polygons) trslices.emplace_back(std::move(poly));
+        
+        layer.transformed_slices(polyunion(trslices));
+        
+        // Calculation of the slow and fast layers to the future controlling those values on FW
+        
+        const bool is_fast_layer = (layer_model_area + layer_support_area) <= display_area*area_fill;
+        const double tilt_time = is_fast_layer ? fast_tilt : slow_tilt;
+        
+        { Lock lck(mutex);
+            if (is_fast_layer)
+                fast_layers++;
+            else
+                slow_layers++;
+            
+            
+            // Calculation of the printing time
+            
+            if (sliced_layer_cnt < 3)
+                estim_time += init_exp_time;
+            else if (fade_layer_time > exp_time)
+            {
+                fade_layer_time -= delta_fade_time;
+                estim_time += fade_layer_time;
+            }
+            else
+                estim_time += exp_time;
+            
+            estim_time += tilt_time;
+        }
+    };
+    
+    // sequential version for debugging:
+    // for(size_t i = 0; i < m_printer_input.size(); ++i) printlayerfn(i);
+    sla::ccr::enumerate(printer_input.begin(), printer_input.end(), printlayerfn);
+    
+    auto SCALING2 = SCALING_FACTOR * SCALING_FACTOR;
+    print_statistics.support_used_material = supports_volume * SCALING2;
+    print_statistics.objects_used_material = models_volume  * SCALING2;
+    
+    // Estimated printing time
+    // A layers count o the highest object
+    if (printer_input.size() == 0)
+        print_statistics.estimated_print_time = std::nan("");
+    else
+        print_statistics.estimated_print_time = estim_time;
+    
+    print_statistics.fast_layers_count = fast_layers;
+    print_statistics.slow_layers_count = slow_layers;
+    
+    report_status(-2, "", SlicingStatus::RELOAD_SLA_PREVIEW);
+}
+
+// Rasterizing the model objects, and their supports
+void SLAPrint::Steps::rasterize()
+{
+    if(canceled()) return;
+    
+    auto &print_statistics = m_print->m_print_statistics;
+    auto &printer_input    = m_print->m_printer_input;
+    
+    // Set up the printer, allocate space for all the layers
+    sla::RasterWriter &printer = m_print->init_printer();
+    
+    auto lvlcnt = unsigned(printer_input.size());
+    printer.layers(lvlcnt);
+    
+    // coefficient to map the rasterization state (0-99) to the allocated
+    // portion (slot) of the process state
+    double sd = (100 - max_objstatus) / 100.0;
+    
+    // slot is the portion of 100% that is realted to rasterization
+    unsigned slot = PRINT_STEP_LEVELS[slapsRasterize];
+    
+    // pst: previous state
+    double pst = current_status();
+    
+    double increment = (slot * sd) / printer_input.size();
+    double dstatus = current_status();
+    
+    sla::ccr::SpinningMutex slck;
+    using Lock = std::lock_guard<sla::ccr::SpinningMutex>;
+    
+    // procedure to process one height level. This will run in parallel
+    auto lvlfn =
+        [this, &slck, &printer, increment, &dstatus, &pst]
+        (PrintLayer& printlayer, size_t idx)
+    {
+        if(canceled()) return;
+        auto level_id = unsigned(idx);
+        
+        // Switch to the appropriate layer in the printer
+        printer.begin_layer(level_id);
+        
+        for(const ClipperLib::Polygon& poly : printlayer.transformed_slices())
+            printer.draw_polygon(poly, level_id);
+        
+        // Finish the layer for later saving it.
+        printer.finish_layer(level_id);
+        
+        // Status indication guarded with the spinlock
+        {
+            Lock lck(slck);
+            dstatus += increment;
+            double st = std::round(dstatus);
+            if(st > pst) {
+                report_status(st, PRINT_STEP_LABELS(slapsRasterize));
+                pst = st;
+            }
+        }
+    };
+    
+    // last minute escape
+    if(canceled()) return;
+    
+    // Sequential version (for testing)
+    // for(unsigned l = 0; l < lvlcnt; ++l) lvlfn(l);
+    
+    // Print all the layers in parallel
+    sla::ccr::enumerate(printer_input.begin(), printer_input.end(), lvlfn);
+    
+    // Set statistics values to the printer
+    sla::RasterWriter::PrintStatistics stats;
+    stats.used_material = (print_statistics.objects_used_material +
+                           print_statistics.support_used_material) / 1000;
+    
+    int num_fade = m_print->m_default_object_config.faded_layers.getInt();
+    stats.num_fade = num_fade >= 0 ? size_t(num_fade) : size_t(0);
+    stats.num_fast = print_statistics.fast_layers_count;
+    stats.num_slow = print_statistics.slow_layers_count;
+    stats.estimated_print_time_s = print_statistics.estimated_print_time;
+    
+    printer.set_statistics(stats);
+}
+
+std::string SLAPrint::Steps::label(SLAPrintObjectStep step)
+{
+    return OBJ_STEP_LABELS(step);
+}
+
+std::string SLAPrint::Steps::label(SLAPrintStep step)
+{
+    return PRINT_STEP_LABELS(step);
+}
+
+double SLAPrint::Steps::progressrange(SLAPrintObjectStep step) const
+{
+    return OBJ_STEP_LEVELS[step] * objectstep_scale;
+}
+
+double SLAPrint::Steps::progressrange(SLAPrintStep step) const
+{
+    return PRINT_STEP_LEVELS[step] * (100 - max_objstatus) / 100.0;
+}
+
+void SLAPrint::Steps::execute(SLAPrintObjectStep step, SLAPrintObject &obj)
+{
+    switch(step) {
+    case slaposHollowing: hollow_model(obj); break;
+    case slaposObjectSlice: slice_model(obj); break;
+    case slaposDrillHolesIfHollowed: break;
+    case slaposSupportPoints:  support_points(obj); break;
+    case slaposSupportTree: support_tree(obj); break;
+    case slaposPad: generate_pad(obj); break;
+    case slaposSliceSupports: slice_supports(obj); break;
+    case slaposCount: assert(false);
+    }
+}
+
+void SLAPrint::Steps::execute(SLAPrintStep step)
+{
+    switch (step) {
+    case slapsMergeSlicesAndEval: merge_slices_and_eval_stats(); break;
+    case slapsRasterize: rasterize(); break;
+    case slapsCount: assert(false);
+    }
+}
+
+}

src/libslic3r/SLAPrintSteps.hpp

@@ -0,0 +1,68 @@
+#ifndef SLAPRINTSTEPS_HPP
+#define SLAPRINTSTEPS_HPP
+
+#include <libslic3r/SLAPrint.hpp>
+
+#include <libslic3r/SLA/Hollowing.hpp>
+#include <libslic3r/SLA/SupportTree.hpp>
+
+namespace Slic3r {
+
+class SLAPrint::Steps
+{
+private:
+    SLAPrint *m_print = nullptr;
+    
+public:    
+    // where the per object operations start and end
+    static const constexpr unsigned min_objstatus = 0;   
+    static const constexpr unsigned max_objstatus = 50;
+    
+private:
+    const size_t objcount;
+    
+    // shortcut to initial layer height
+    const double  ilhd;
+    const float   ilh;
+    const coord_t ilhs;
+    
+    // the coefficient that multiplies the per object status values which
+    // are set up for <0, 100>. They need to be scaled into the whole process
+    const double objectstep_scale;
+    
+    template<class...Args> void report_status(Args&&...args)
+    {
+        m_print->m_report_status(*m_print, std::forward<Args>(args)...);
+    }
+    
+    double current_status() const { return m_print->m_report_status.status(); }
+    void throw_if_canceled() const { m_print->throw_if_canceled(); }
+    bool canceled() const { return m_print->canceled(); }
+    void initialize_printer_input();
+    
+public:
+    Steps(SLAPrint *print);
+    
+    void hollow_model(SLAPrintObject &po);
+    void slice_model(SLAPrintObject& po);
+    void support_points(SLAPrintObject& po);
+    void support_tree(SLAPrintObject& po);
+    void generate_pad(SLAPrintObject& po);
+    void slice_supports(SLAPrintObject& po);
+    
+    void merge_slices_and_eval_stats();
+    void rasterize();
+    
+    void execute(SLAPrintObjectStep step, SLAPrintObject &obj);
+    void execute(SLAPrintStep step);
+    
+    static std::string label(SLAPrintObjectStep step);
+    static std::string label(SLAPrintStep step);
+    
+    double progressrange(SLAPrintObjectStep step) const;
+    double progressrange(SLAPrintStep step) const;
+};
+
+}
+
+#endif // SLAPRINTSTEPS_HPP

src/libslic3r/SimplifyMesh.cpp

@@ -0,0 +1,66 @@
+#include "SimplifyMesh.hpp"
+#include "SimplifyMeshImpl.hpp"
+
+namespace SimplifyMesh {
+
+template<> struct vertex_traits<stl_vertex> {
+    using coord_type = float;
+    using compute_type = double;
+    
+    static inline float x(const stl_vertex &v) { return v.x(); }
+    static inline float& x(stl_vertex &v) { return v.x(); }
+    
+    static inline float y(const stl_vertex &v) { return v.y(); }
+    static inline float& y(stl_vertex &v) { return v.y(); }
+    
+    static inline float z(const stl_vertex &v) { return v.z(); }
+    static inline float& z(stl_vertex &v) { return v.z(); }
+};
+
+template<> struct mesh_traits<indexed_triangle_set> {
+    using vertex_t = stl_vertex;
+    static size_t face_count(const indexed_triangle_set &m)
+    {
+        return m.indices.size();
+    }
+    static size_t vertex_count(const indexed_triangle_set &m)
+    {
+        return m.vertices.size();
+    }
+    static vertex_t vertex(const indexed_triangle_set &m, size_t idx)
+    {
+        return m.vertices[idx];
+    }
+    static void vertex(indexed_triangle_set &m, size_t idx, const vertex_t &v)
+    {
+        m.vertices[idx] = v;
+    }
+    static Index3 triangle(const indexed_triangle_set &m, size_t idx)
+    {
+        std::array<size_t, 3> t;
+        for (size_t i = 0; i < 3; ++i) t[i] = size_t(m.indices[idx](int(i)));
+        return t;
+    }
+    static void triangle(indexed_triangle_set &m, size_t fidx, const Index3 &t)
+    {
+        auto &face = m.indices[fidx];
+        face(0) = int(t[0]); face(1) = int(t[1]); face(2) = int(t[2]);
+    }
+    static void update(indexed_triangle_set &m, size_t vc, size_t fc)
+    {
+        m.vertices.resize(vc);
+        m.indices.resize(fc);
+    }
+};
+
+} // namespace SimplifyMesh
+
+namespace Slic3r {
+
+void simplify_mesh(indexed_triangle_set &m)
+{
+    SimplifyMesh::implementation::SimplifiableMesh sm{&m};
+    sm.simplify_mesh_lossless();
+}
+
+}

src/libslic3r/SimplifyMesh.hpp

@@ -0,0 +1,25 @@
+#ifndef MESHSIMPLIFY_HPP
+#define MESHSIMPLIFY_HPP
+
+#include <vector>
+
+#include <libslic3r/TriangleMesh.hpp>
+
+namespace Slic3r {
+
+void simplify_mesh(indexed_triangle_set &);
+
+// TODO: (but this can be done with IGL as well)
+// void simplify_mesh(indexed_triangle_set &, int face_count, float agressiveness = 0.5f);
+
+template<class...Args> void simplify_mesh(TriangleMesh &m, Args &&...a)
+{
+    m.require_shared_vertices();
+    simplify_mesh(m.its, std::forward<Args>(a)...);
+    m = TriangleMesh{m.its};
+    m.require_shared_vertices();
+}
+
+} // namespace Slic3r
+
+#endif // MESHSIMPLIFY_H

src/libslic3r/SimplifyMeshImpl.hpp

@@ -0,0 +1,699 @@
+// ///////////////////////////////////////////
+//
+// Mesh Simplification Tutorial
+//
+// (C) by Sven Forstmann in 2014
+//
+// License : MIT
+// http://opensource.org/licenses/MIT
+//
+// https://github.com/sp4cerat/Fast-Quadric-Mesh-Simplification
+//
+// 5/2016: Chris Rorden created minimal version for OSX/Linux/Windows compile
+// https://github.com/sp4cerat/Fast-Quadric-Mesh-Simplification/
+//
+// libslic3r refactor by tamasmeszaros
+
+#ifndef SIMPLIFYMESHIMPL_HPP
+#define SIMPLIFYMESHIMPL_HPP
+
+#include <vector>
+#include <array>
+#include <type_traits>
+#include <algorithm>
+
+#ifndef NDEBUG
+#include <iostream>
+#endif
+
+namespace SimplifyMesh {
+
+using Bary = std::array<double, 3>;
+using Index3 = std::array<size_t, 3>;
+
+template<class Vertex> struct vertex_traits {
+    using coord_type = typename Vertex::coord_type;
+    using compute_type = coord_type;
+    
+    static coord_type x(const Vertex &v);
+    static coord_type& x(Vertex &v);
+    
+    static coord_type y(const Vertex &v);
+    static coord_type& y(Vertex &v);
+    
+    static coord_type z(const Vertex &v);
+    static coord_type& z(Vertex &v);
+};
+
+template<class Mesh> struct mesh_traits {
+    using vertex_t = typename Mesh::vertex_t;
+    
+    static size_t   face_count(const Mesh &m);
+    static size_t   vertex_count(const Mesh &m);
+    static vertex_t vertex(const Mesh &m, size_t vertex_idx);
+    static void     vertex(Mesh &m, size_t vertex_idx, const vertex_t &v);
+    static Index3   triangle(const Mesh &m, size_t face_idx);
+    static void     triangle(Mesh &m, size_t face_idx, const Index3 &t);
+    static void     update(Mesh &m, size_t vertex_count, size_t face_count);
+};
+
+namespace implementation {
+
+// A shorter C++14 style form of the enable_if metafunction
+template<bool B, class T>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
+// Meta predicates for floating, 'scaled coord' and generic arithmetic types
+template<class T, class O = T>
+using FloatingOnly = enable_if_t<std::is_floating_point<T>::value, O>;
+
+template<class T, class O = T>
+using IntegerOnly = enable_if_t<std::is_integral<T>::value, O>;
+
+template<class T, class O = T>
+using ArithmeticOnly = enable_if_t<std::is_arithmetic<T>::value, O>;
+
+template< class T >
+struct remove_cvref {
+    using type = typename std::remove_cv<
+        typename std::remove_reference<T>::type>::type;
+};
+
+template< class T >
+using remove_cvref_t = typename remove_cvref<T>::type;
+
+struct DOut {
+#ifndef NDEBUG
+    std::ostream& out = std::cout;
+#endif
+};
+
+template<class T>
+inline DOut&& operator<<( DOut&& out, T&& d) {
+#ifndef NDEBUG
+    out.out << d;
+#endif
+    return std::move(out);
+}
+
+inline DOut dout() { return DOut(); }
+
+template<class T> FloatingOnly<T, bool> is_approx(T val, T ref) { return std::abs(val - ref) < 1e-8; }
+template<class T> IntegerOnly <T, bool> is_approx(T val, T ref) { val == ref; }
+
+template<class T, size_t N = 10> class SymetricMatrix {
+public:
+    
+    explicit SymetricMatrix(ArithmeticOnly<T> c = T()) { std::fill(m, m + N, c); }
+    
+    SymetricMatrix(T m11, T m12, T m13, T m14,
+                   T m22, T m23, T m24,
+                   T m33, T m34,
+                   T m44)
+    {
+        m[0] = m11;  m[1] = m12;  m[2] = m13;  m[3] = m14;
+        m[4] = m22;  m[5] = m23;  m[6] = m24;
+        m[7] = m33;  m[8] = m34;
+        m[9] = m44;
+    }
+    
+    // Make plane
+    SymetricMatrix(T a, T b, T c, T d)
+    {
+        m[0] = a * a; m[1] = a * b; m[2] = a * c; m[3] = a * d;
+        m[4] = b * b; m[5] = b * c; m[6] = b * d;
+        m[7] = c * c; m[8] = c * d;
+        m[9] = d * d;
+    }
+    
+    T operator[](int c) const { return m[c]; }
+    
+    // Determinant
+    T det(int a11, int a12, int a13,
+          int a21, int a22, int a23,
+          int a31, int a32, int a33)
+    {
+        T det = m[a11] * m[a22] * m[a33] + m[a13] * m[a21] * m[a32] +
+                m[a12] * m[a23] * m[a31] - m[a13] * m[a22] * m[a31] -
+                m[a11] * m[a23] * m[a32] - m[a12] * m[a21] * m[a33];
+        
+        return det;
+    }
+    
+    const SymetricMatrix operator+(const SymetricMatrix& n) const
+    {
+        return SymetricMatrix(m[0] + n[0], m[1] + n[1], m[2] + n[2], m[3]+n[3],
+                              m[4] + n[4], m[5] + n[5], m[6] + n[6], 
+                              m[7] + n[7], m[8] + n[8],
+                              m[9] + n[9]);
+    }
+    
+    SymetricMatrix& operator+=(const SymetricMatrix& n)
+    {
+        m[0]+=n[0]; m[1]+=n[1]; m[2]+=n[2]; m[3]+=n[3];
+        m[4]+=n[4]; m[5]+=n[5]; m[6]+=n[6]; m[7]+=n[7];
+        m[8]+=n[8]; m[9]+=n[9];
+        
+        return *this;
+    }
+    
+    T m[N];
+};
+
+template<class V> using TCoord = typename vertex_traits<remove_cvref_t<V>>::coord_type;
+template<class V> using TCompute = typename vertex_traits<remove_cvref_t<V>>::compute_type;
+template<class V> inline TCoord<V> x(const V &v) { return vertex_traits<remove_cvref_t<V>>::x(v); }
+template<class V> inline TCoord<V> y(const V &v) { return vertex_traits<remove_cvref_t<V>>::y(v); }
+template<class V> inline TCoord<V> z(const V &v) { return vertex_traits<remove_cvref_t<V>>::z(v); }
+template<class V> inline TCoord<V>& x(V &v) { return vertex_traits<remove_cvref_t<V>>::x(v); }
+template<class V> inline TCoord<V>& y(V &v) { return vertex_traits<remove_cvref_t<V>>::y(v); }
+template<class V> inline TCoord<V>& z(V &v) { return vertex_traits<remove_cvref_t<V>>::z(v); }
+template<class M> using TVertex = typename mesh_traits<remove_cvref_t<M>>::vertex_t;
+template<class Mesh> using TMeshCoord = TCoord<TVertex<Mesh>>;
+
+template<class Vertex> TCompute<Vertex> dot(const Vertex &v1, const Vertex &v2)
+{
+    return TCompute<Vertex>(x(v1)) * x(v2) +
+           TCompute<Vertex>(y(v1)) * y(v2) +
+           TCompute<Vertex>(z(v1)) * z(v2);
+}
+
+template<class Vertex> Vertex cross(const Vertex &a, const Vertex &b)
+{
+    return Vertex{y(a) * z(b) - z(a) * y(b),
+                  z(a) * x(b) - x(a) * z(b),
+                  x(a) * y(b) - y(a) * x(b)};
+}
+
+template<class Vertex> TCompute<Vertex> lengthsq(const Vertex &v)
+{
+    return TCompute<Vertex>(x(v)) * x(v) + TCompute<Vertex>(y(v)) * y(v) +
+           TCompute<Vertex>(z(v)) * z(v);
+}
+
+template<class Vertex> void normalize(Vertex &v)
+{
+    double square = std::sqrt(lengthsq(v));
+    x(v) /= square; y(v) /= square; z(v) /= square;
+}
+
+using Bary = std::array<double, 3>;
+
+template<class Vertex>
+Bary barycentric(const Vertex &p, const Vertex &a, const Vertex &b, const Vertex &c)
+{
+    Vertex v0 = (b - a);
+    Vertex v1 = (c - a);
+    Vertex v2 = (p - a);
+
+    double d00   = dot(v0, v0);
+    double d01   = dot(v0, v1);
+    double d11   = dot(v1, v1);
+    double d20   = dot(v2, v0);
+    double d21   = dot(v2, v1);
+    double denom = d00 * d11 - d01 * d01;
+    double v     = (d11 * d20 - d01 * d21) / denom;
+    double w     = (d00 * d21 - d01 * d20) / denom;
+    double u     = 1.0 - v - w;
+
+    return {u, v, w};
+}
+
+template<class Mesh> class SimplifiableMesh {
+    Mesh *m_mesh;
+
+    using Vertex     = TVertex<Mesh>;
+    using Coord      = TMeshCoord<Mesh>;
+    using HiPrecison = TCompute<TVertex<Mesh>>;
+    using SymMat     = SymetricMatrix<HiPrecison>;
+
+    struct FaceInfo {
+        size_t idx;
+        double err[4] = {0.};
+        bool   deleted = false, dirty = false;
+        Vertex n;
+        explicit FaceInfo(size_t id): idx(id) {}
+    };
+
+    struct VertexInfo {
+        size_t idx;
+        size_t tstart = 0, tcount = 0;
+        bool border = false;
+        SymMat q;
+        explicit VertexInfo(size_t id): idx(id) {}
+    };
+    
+    struct Ref { size_t face; size_t vertex; };
+    
+    std::vector<Ref> m_refs;
+    std::vector<FaceInfo> m_faceinfo;
+    std::vector<VertexInfo> m_vertexinfo;
+    
+    void compact_faces();
+    void compact();
+    
+    size_t mesh_vcount() const { return mesh_traits<Mesh>::vertex_count(*m_mesh); }
+    size_t mesh_facecount() const { return mesh_traits<Mesh>::face_count(*m_mesh); }
+    
+    size_t vcount() const { return m_vertexinfo.size(); }
+    
+    inline Vertex read_vertex(size_t vi) const
+    {
+        return mesh_traits<Mesh>::vertex(*m_mesh, vi);
+    }
+    
+    inline Vertex read_vertex(const VertexInfo &vinf) const
+    {
+        return read_vertex(vinf.idx);
+    }
+    
+    inline void write_vertex(size_t idx, const Vertex &v) const
+    {
+        mesh_traits<Mesh>::vertex(*m_mesh, idx, v);
+    }
+    
+    inline void write_vertex(const VertexInfo &vinf, const Vertex &v) const
+    {
+        write_vertex(vinf.idx, v);
+    }
+    
+    inline Index3 read_triangle(size_t fi) const
+    {
+        return mesh_traits<Mesh>::triangle(*m_mesh, fi);
+    }
+    
+    inline Index3 read_triangle(const FaceInfo &finf) const
+    {
+        return read_triangle(finf.idx);
+    }
+    
+    inline void write_triangle(size_t idx, const Index3 &t)
+    {
+        return mesh_traits<Mesh>::triangle(*m_mesh, idx, t);
+    }
+    
+    inline void write_triangle(const FaceInfo &finf, const Index3 &t)
+    {
+        return write_triangle(finf.idx, t);
+    }    
+    
+    inline std::array<Vertex, 3> triangle_vertices(const Index3 &f) const
+    {
+        std::array<Vertex, 3> p;
+        for (size_t i = 0; i < 3; ++i) p[i] = read_vertex(f[i]);
+        return p;
+    }
+
+    // Error between vertex and Quadric    
+    static double vertex_error(const SymMat &q, const Vertex &v)
+    {
+        Coord _x = x(v) , _y = y(v), _z = z(v);
+        return q[0] * _x * _x + 2 * q[1] * _x * _y + 2 * q[2] * _x * _z +
+               2 * q[3] * _x + q[4] * _y * _y + 2 * q[5] * _y * _z +
+               2 * q[6] * _y + q[7] * _z * _z + 2 * q[8] * _z + q[9];
+    }
+    
+    // Error for one edge    
+    double calculate_error(size_t id_v1, size_t id_v2, Vertex &p_result);
+    
+    void calculate_error(FaceInfo &fi)
+    {
+        Vertex p;
+        Index3 t = read_triangle(fi);
+        for (size_t j = 0; j < 3; ++j)
+            fi.err[j] = calculate_error(t[j], t[(j + 1) % 3], p);
+        
+        fi.err[3] = std::min(fi.err[0], std::min(fi.err[1], fi.err[2]));
+    }
+    
+    void update_mesh(int iteration);
+    
+    // Update triangle connections and edge error after a edge is collapsed
+    void update_triangles(size_t i, VertexInfo &vi, std::vector<bool> &deleted, int &deleted_triangles);
+    
+    // Check if a triangle flips when this edge is removed
+    bool flipped(const Vertex &p, size_t i0, size_t i1, VertexInfo &v0, VertexInfo &v1, std::vector<bool> &deleted);
+    
+public:
+    
+    explicit SimplifiableMesh(Mesh *m) : m_mesh{m}
+    {
+        static_assert(
+            std::is_arithmetic<Coord>::value,
+            "Coordinate type of mesh has to be an arithmetic type!");
+        
+        m_faceinfo.reserve(mesh_traits<Mesh>::face_count(*m));
+        m_vertexinfo.reserve(mesh_traits<Mesh>::vertex_count(*m));
+        for (size_t i = 0; i < mesh_facecount(); ++i) m_faceinfo.emplace_back(i);
+        for (size_t i = 0; i < mesh_vcount(); ++i) m_vertexinfo.emplace_back(i);
+        
+    }
+    
+    void simplify_mesh_lossless();
+};
+
+
+template<class Mesh> void SimplifiableMesh<Mesh>::compact_faces()
+{
+    auto it = std::remove_if(m_faceinfo.begin(), m_faceinfo.end(),
+                             [](const FaceInfo &inf) { return inf.deleted; });
+    
+    m_faceinfo.erase(it, m_faceinfo.end());
+}
+
+template<class M> void SimplifiableMesh<M>::compact()
+{   
+    for (auto &vi : m_vertexinfo) vi.tcount = 0;
+    
+    compact_faces();
+    
+    for (FaceInfo &fi : m_faceinfo)
+        for (size_t vidx : read_triangle(fi)) m_vertexinfo[vidx].tcount = 1;
+    
+    size_t dst = 0;
+    for (VertexInfo &vi : m_vertexinfo) {
+        if (vi.tcount) {
+            vi.tstart = dst;
+            write_vertex(dst++, read_vertex(vi)); 
+        }
+    }
+    
+    size_t vertex_count = dst;
+    
+    dst = 0;
+    for (const FaceInfo &fi : m_faceinfo) {
+        Index3 t = read_triangle(fi);
+        for (size_t &idx : t) idx = m_vertexinfo[idx].tstart;
+        write_triangle(dst++, t);
+    }
+    
+    mesh_traits<M>::update(*m_mesh, vertex_count, m_faceinfo.size());
+}
+
+template<class Mesh>
+double SimplifiableMesh<Mesh>::calculate_error(size_t id_v1, size_t id_v2, Vertex &p_result)
+{
+    // compute interpolated vertex
+    
+    SymMat q = m_vertexinfo[id_v1].q + m_vertexinfo[id_v2].q;
+    
+    bool border = m_vertexinfo[id_v1].border & m_vertexinfo[id_v2].border;
+    double     error = 0;
+    HiPrecison det   = q.det(0, 1, 2, 1, 4, 5, 2, 5, 7);
+    
+    if (!is_approx(det, HiPrecison(0)) && !border)
+    {
+        // q_delta is invertible
+        x(p_result) = Coord(-1) / det * q.det(1, 2, 3, 4, 5, 6, 5, 7, 8);	// vx = A41/det(q_delta)
+        y(p_result) = Coord( 1) / det * q.det(0, 2, 3, 1, 5, 6, 2, 7, 8);	// vy = A42/det(q_delta)
+        z(p_result) = Coord(-1) / det * q.det(0, 1, 3, 1, 4, 6, 2, 5, 8);	// vz = A43/det(q_delta)
+        
+        error = vertex_error(q, p_result);
+    } else {
+        // det = 0 -> try to find best result
+        Vertex p1     = read_vertex(id_v1);
+        Vertex p2     = read_vertex(id_v2);
+        Vertex p3     = (p1 + p2) / 2;
+        double error1 = vertex_error(q, p1);
+        double error2 = vertex_error(q, p2);
+        double error3 = vertex_error(q, p3);
+        error         = std::min(error1, std::min(error2, error3));
+
+        if (is_approx(error1, error)) p_result = p1;
+        if (is_approx(error2, error)) p_result = p2;
+        if (is_approx(error3, error)) p_result = p3;
+    }
+
+    return error;
+}
+
+template<class Mesh> void SimplifiableMesh<Mesh>::update_mesh(int iteration)
+{
+    if (iteration > 0) compact_faces();
+    
+    assert(mesh_vcount() == m_vertexinfo.size());
+        
+    //
+    // Init Quadrics by Plane & Edge Errors
+    //
+    // required at the beginning ( iteration == 0 )
+    // recomputing during the simplification is not required,
+    // but mostly improves the result for closed meshes
+    //
+    if (iteration == 0) {
+                
+        for (VertexInfo &vinf : m_vertexinfo) vinf.q = SymMat{};
+        for (FaceInfo   &finf : m_faceinfo) {
+            Index3 t = read_triangle(finf);
+            std::array<Vertex, 3> p = triangle_vertices(t);
+            Vertex                n = cross(Vertex(p[1] - p[0]), Vertex(p[2] - p[0]));
+            normalize(n);
+            finf.n = n;
+            
+            for (size_t fi : t)
+                m_vertexinfo[fi].q += SymMat(x(n), y(n), z(n), -dot(n, p[0]));
+            
+            calculate_error(finf);
+        }
+    }
+    
+    // Init Reference ID list
+    for (VertexInfo &vi : m_vertexinfo) { vi.tstart = 0; vi.tcount = 0; }
+    
+    for (FaceInfo &fi : m_faceinfo)
+        for (size_t vidx : read_triangle(fi))
+            m_vertexinfo[vidx].tcount++;
+    
+    size_t tstart = 0;
+    for (VertexInfo &vi : m_vertexinfo) {
+        vi.tstart = tstart;
+        tstart += vi.tcount;
+        vi.tcount = 0;
+    }
+    
+    // Write References
+    m_refs.resize(m_faceinfo.size() * 3);
+    for (size_t i = 0; i < m_faceinfo.size(); ++i) {
+        const FaceInfo &fi = m_faceinfo[i];
+        Index3 t = read_triangle(fi);
+        for (size_t j = 0; j < 3; ++j) {
+            VertexInfo &vi = m_vertexinfo[t[j]];
+            
+            assert(vi.tstart + vi.tcount < m_refs.size());
+            
+            Ref &ref = m_refs[vi.tstart + vi.tcount];
+            ref.face = i;
+            ref.vertex = j;
+            vi.tcount++;
+        }
+    }
+    
+    // Identify boundary : vertices[].border=0,1
+    if (iteration == 0) {
+        for (VertexInfo &vi: m_vertexinfo) vi.border = false;
+        
+        std::vector<size_t> vcount, vids;
+        
+        for (VertexInfo &vi: m_vertexinfo) {
+            vcount.clear();
+            vids.clear();
+            
+            for(size_t j = 0; j < vi.tcount; ++j) {
+                assert(vi.tstart + j < m_refs.size());
+                FaceInfo &fi = m_faceinfo[m_refs[vi.tstart + j].face];
+                Index3 t = read_triangle(fi);
+                
+                for (size_t fid : t) {
+                    size_t ofs=0;
+                    while (ofs < vcount.size())
+                    {
+                        if (vids[ofs] == fid) break;
+                        ofs++;
+                    }
+                    if (ofs == vcount.size())
+                    {
+                        vcount.emplace_back(1);
+                        vids.emplace_back(fid);
+                    }
+                    else
+                        vcount[ofs]++;
+                }
+            }
+            
+            for (size_t j = 0; j < vcount.size(); ++j)
+                if(vcount[j] == 1) m_vertexinfo[vids[j]].border = true;
+        }
+    }
+}
+
+template<class Mesh>
+void SimplifiableMesh<Mesh>::update_triangles(size_t             i0,
+                                              VertexInfo &       vi,
+                                              std::vector<bool> &deleted,
+                                              int &deleted_triangles)
+{
+    Vertex p;
+    for (size_t k = 0; k < vi.tcount; ++k) {
+        assert(vi.tstart + k < m_refs.size());
+        
+        Ref &r = m_refs[vi.tstart + k];
+        FaceInfo &fi = m_faceinfo[r.face];
+        
+        if (fi.deleted) continue;
+        
+        if (deleted[k]) {
+            fi.deleted = true;
+            deleted_triangles++;
+            continue;
+        }
+        
+        Index3 t = read_triangle(fi);
+        t[r.vertex] = i0;
+        write_triangle(fi, t);
+        
+        fi.dirty  = true;
+        fi.err[0] = calculate_error(t[0], t[1], p);
+        fi.err[1] = calculate_error(t[1], t[2], p);
+        fi.err[2] = calculate_error(t[2], t[0], p);
+        fi.err[3] = std::min(fi.err[0], std::min(fi.err[1], fi.err[2]));
+        m_refs.emplace_back(r);
+    }
+}
+
+template<class Mesh>
+bool SimplifiableMesh<Mesh>::flipped(const Vertex &    p,
+                                     size_t            /*i0*/,
+                                     size_t            i1,
+                                     VertexInfo &      v0,
+                                     VertexInfo &      /*v1*/,
+                                     std::vector<bool> &deleted)
+{
+    for (size_t k = 0; k < v0.tcount; ++k) {
+        size_t ridx = v0.tstart + k;
+        assert(ridx < m_refs.size());
+        
+        FaceInfo &fi = m_faceinfo[m_refs[ridx].face];
+        if (fi.deleted) continue;
+        
+        Index3 t = read_triangle(fi);
+        int s = m_refs[ridx].vertex;
+        size_t id1 = t[(s+1) % 3];
+        size_t id2 = t[(s+2) % 3];
+
+        if(id1 == i1 || id2 == i1) // delete ?
+        {
+            deleted[k] = true;
+            continue;
+        }
+        
+        Vertex d1 = read_vertex(id1) - p;
+        normalize(d1);
+        Vertex d2 = read_vertex(id2) - p;
+        normalize(d2);
+        
+        if (std::abs(dot(d1, d2)) > 0.999) return true;
+        
+        Vertex n = cross(d1, d2);
+        normalize(n);
+        
+        deleted[k] = false;
+        if (dot(n, fi.n) < 0.2) return true;
+    }
+    
+    return false;
+}
+
+template<class Mesh>
+void SimplifiableMesh<Mesh>::simplify_mesh_lossless()
+{
+    // init
+    for (FaceInfo &fi : m_faceinfo) fi.deleted = false;
+    
+    // main iteration loop
+    int deleted_triangles=0;
+    std::vector<bool> deleted0, deleted1;
+    
+    for (int iteration = 0; iteration < 9999; iteration ++) {
+        // update mesh constantly
+        update_mesh(iteration);
+        
+        // clear dirty flag
+        for (FaceInfo &fi : m_faceinfo) fi.dirty = false;
+        
+        //
+        // All triangles with edges below the threshold will be removed
+        //
+        // The following numbers works well for most models.
+        // If it does not, try to adjust the 3 parameters
+        //
+        double threshold = std::numeric_limits<double>::epsilon(); //1.0E-3 EPS; // Really? (tm)
+        
+        dout() << "lossless iteration " << iteration << "\n";
+        
+        for (FaceInfo &fi : m_faceinfo) {
+            if (fi.err[3] > threshold || fi.deleted || fi.dirty) continue;
+            
+            for (size_t j = 0; j < 3; ++j) {
+                if (fi.err[j] > threshold) continue;
+                
+                Index3 t = read_triangle(fi);
+                size_t i0 = t[j];
+                VertexInfo &v0 = m_vertexinfo[i0];
+                
+                size_t i1 = t[(j + 1) % 3];
+                VertexInfo &v1 = m_vertexinfo[i1];
+
+                // Border check
+                if(v0.border != v1.border) continue;
+
+                // Compute vertex to collapse to
+                Vertex p;
+                calculate_error(i0, i1, p);
+
+                deleted0.resize(v0.tcount); // normals temporarily
+                deleted1.resize(v1.tcount); // normals temporarily
+
+                // don't remove if flipped
+                if (flipped(p, i0, i1, v0, v1, deleted0)) continue;
+                if (flipped(p, i1, i0, v1, v0, deleted1)) continue;
+
+                // not flipped, so remove edge
+                write_vertex(v0, p);
+                v0.q = v1.q + v0.q;
+                size_t tstart = m_refs.size();
+
+                update_triangles(i0, v0, deleted0, deleted_triangles);
+                update_triangles(i0, v1, deleted1, deleted_triangles);
+                
+                assert(m_refs.size() >= tstart);
+                
+                size_t tcount = m_refs.size() - tstart;
+
+                if(tcount <= v0.tcount)
+                {
+                    // save ram
+                    if (tcount) {
+                        auto from = m_refs.begin() + tstart, to = from + tcount;
+                        std::copy(from, to, m_refs.begin() + v0.tstart);
+                    }
+                }
+                else
+                    // append
+                    v0.tstart = tstart;
+
+                v0.tcount = tcount;
+                break;
+            }
+        }
+        
+        if (deleted_triangles <= 0) break;
+        deleted_triangles = 0;
+    }
+    
+    compact();
+}
+
+} // namespace implementation
+} // namespace SimplifyMesh
+
+#endif // SIMPLIFYMESHIMPL_HPP

src/libslic3r/TriangleMesh.cpp

@@ -70,6 +70,34 @@ TriangleMesh::TriangleMesh(const Pointf3s &points, const std::vector<Vec3crd>& f
     stl_get_size(&stl);
 }
 
+TriangleMesh::TriangleMesh(const indexed_triangle_set &M)
+{
+    stl.stats.type = inmemory;
+    
+    // count facets and allocate memory
+    stl.stats.number_of_facets = uint32_t(M.indices.size());
+    stl.stats.original_num_facets = int(stl.stats.number_of_facets);
+    stl_allocate(&stl);
+    
+    for (uint32_t i = 0; i < stl.stats.number_of_facets; ++ i) {
+        stl_facet facet;
+        facet.vertex[0] = M.vertices[size_t(M.indices[i](0))];
+        facet.vertex[1] = M.vertices[size_t(M.indices[i](1))];
+        facet.vertex[2] = M.vertices[size_t(M.indices[i](2))];
+        facet.extra[0] = 0;
+        facet.extra[1] = 0;
+        
+        stl_normal normal;
+        stl_calculate_normal(normal, &facet);
+        stl_normalize_vector(normal);
+        facet.normal = normal;
+        
+        stl.facet_start[i] = facet;
+    }
+    
+    stl_get_size(&stl);
+}
+
 // #define SLIC3R_TRACE_REPAIR
 
 void TriangleMesh::repair(bool update_shared_vertices)

src/libslic3r/TriangleMesh.hpp

@@ -23,6 +23,7 @@ class TriangleMesh
 public:
     TriangleMesh() : repaired(false) {}
     TriangleMesh(const Pointf3s &points, const std::vector<Vec3crd> &facets);
+    explicit TriangleMesh(const indexed_triangle_set &M);
 	void clear() { this->stl.clear(); this->its.clear(); this->repaired = false; }
     bool ReadSTLFile(const char* input_file) { return stl_open(&stl, input_file); }
     bool write_ascii(const char* output_file) { return stl_write_ascii(&this->stl, output_file, ""); }

src/libslic3r/libslic3r.h

@@ -230,6 +230,22 @@ static inline bool is_approx(Number value, Number test_value)
     return std::fabs(double(value) - double(test_value)) < double(EPSILON);
 }
 
+template<class...Args>
+std::string string_printf(const char *const fmt, Args &&...args)
+{
+    static const size_t INITIAL_LEN = 1024;
+    std::vector<char> buffer(INITIAL_LEN, '\0');
+    
+    int bufflen = snprintf(buffer.data(), INITIAL_LEN - 1, fmt, std::forward<Args>(args)...);
+    
+    if (bufflen >= int(INITIAL_LEN)) {
+        buffer.resize(size_t(bufflen) + 1);
+        snprintf(buffer.data(), buffer.size(), fmt, std::forward<Args>(args)...);
+    }
+    
+    return std::string(buffer.begin(), buffer.begin() + bufflen);
+}
+
 } // namespace Slic3r
 
 #endif

src/slic3r/CMakeLists.txt

@@ -47,6 +47,8 @@ set(SLIC3R_GUI_SOURCES
     GUI/Gizmos/GLGizmoFlatten.hpp
     GUI/Gizmos/GLGizmoCut.cpp
     GUI/Gizmos/GLGizmoCut.hpp
+    GUI/Gizmos/GLGizmoHollow.cpp
+    GUI/Gizmos/GLGizmoHollow.hpp
     GUI/GLSelectionRectangle.cpp
     GUI/GLSelectionRectangle.hpp
     GUI/GLTexture.hpp
@@ -140,6 +142,7 @@ set(SLIC3R_GUI_SOURCES
     GUI/ProgressStatusBar.cpp
     GUI/PrintHostDialogs.cpp
     GUI/PrintHostDialogs.hpp
+    GUI/Job.hpp
     GUI/Mouse3DController.cpp
     GUI/Mouse3DController.hpp
     GUI/DoubleSlider.cpp

src/slic3r/GUI/GLCanvas3D.cpp

@@ -1438,14 +1438,14 @@ int GLCanvas3D::check_volumes_outside_state() const
 
 void GLCanvas3D::toggle_sla_auxiliaries_visibility(bool visible, const ModelObject* mo, int instance_idx)
 {
+    m_render_sla_auxiliaries = visible;
+
     for (GLVolume* vol : m_volumes.volumes) {
         if ((mo == nullptr || m_model->objects[vol->composite_id.object_id] == mo)
         && (instance_idx == -1 || vol->composite_id.instance_id == instance_idx)
         && vol->composite_id.volume_id < 0)
             vol->is_active = visible;
     }
-
-    m_render_sla_auxiliaries = visible;
 }
 
 void GLCanvas3D::toggle_model_objects_visibility(bool visible, const ModelObject* mo, int instance_idx)
@@ -6061,6 +6061,8 @@ void GLCanvas3D::_load_sla_shells()
             unsigned int initial_volumes_count = (unsigned int)m_volumes.volumes.size();
             for (const SLAPrintObject::Instance& instance : obj->instances()) {
                 add_volume(*obj, 0, instance, obj->transformed_mesh(), GLVolume::MODEL_COLOR[0], true);
+                if (! obj->hollowed_interior_mesh().empty())
+                    add_volume(*obj, -int(slaposHollowing), instance, obj->hollowed_interior_mesh(), GLVolume::MODEL_COLOR[0], false);
                 // Set the extruder_id and volume_id to achieve the same color as in the 3D scene when
                 // through the update_volumes_colors_by_extruder() call.
                 m_volumes.volumes.back()->extruder_id = obj->model_object()->volumes.front()->extruder_id();

src/slic3r/GUI/GLCanvas3D.hpp

@@ -499,6 +499,7 @@ public:
     void set_color_by(const std::string& value);
 
     const Camera& get_camera() const { return m_camera; }
+    const Shader& get_shader() const { return m_shader; }
     Camera& get_camera() { return m_camera; }
 
     BoundingBoxf3 volumes_bounding_box() const;

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -103,6 +103,7 @@ ObjectList::ObjectList(wxWindow* parent) :
         // ptSLA
         CATEGORY_ICON[L("Supports")]                 = create_scaled_bitmap(nullptr, "support"/*"sla_supports"*/);
         CATEGORY_ICON[L("Pad")]                      = create_scaled_bitmap(nullptr, "pad");
+        CATEGORY_ICON[L("Hollowing")]                = create_scaled_bitmap(nullptr, "hollowing");
     }
 
     // create control

src/slic3r/GUI/Gizmos/GLGizmoBase.cpp

@@ -135,7 +135,7 @@ void GLGizmoBase::Grabber::render_face(float half_size) const
 }
 
 
-GLGizmoBase::GLGizmoBase(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id)
+GLGizmoBase::GLGizmoBase(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id, CommonGizmosData* common_data_ptr)
     : m_parent(parent)
     , m_group_id(-1)
     , m_state(Off)
@@ -146,6 +146,7 @@ GLGizmoBase::GLGizmoBase(GLCanvas3D& parent, const std::string& icon_filename, u
     , m_dragging(false)
     , m_imgui(wxGetApp().imgui())
     , m_first_input_window_render(true)
+    , m_c(common_data_ptr)
 {
     ::memcpy((void*)m_base_color, (const void*)DEFAULT_BASE_COLOR, 4 * sizeof(float));
     ::memcpy((void*)m_drag_color, (const void*)DEFAULT_DRAG_COLOR, 4 * sizeof(float));

src/slic3r/GUI/Gizmos/GLGizmoBase.hpp

@@ -30,7 +30,7 @@ static const float CONSTRAINED_COLOR[4] = { 0.5f, 0.5f, 0.5f, 1.0f };
 
 
 class ImGuiWrapper;
-
+class CommonGizmosData;
 
 class GLGizmoBase
 {
@@ -99,9 +99,13 @@ protected:
     mutable std::vector<Grabber> m_grabbers;
     ImGuiWrapper* m_imgui;
     bool m_first_input_window_render;
+    CommonGizmosData* m_c = nullptr;
 
 public:
-    GLGizmoBase(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id);
+    GLGizmoBase(GLCanvas3D& parent,
+                const std::string& icon_filename,
+                unsigned int sprite_id,
+                CommonGizmosData* common_data = nullptr);
     virtual ~GLGizmoBase() {}
 
     bool init() { return on_init(); }
@@ -179,6 +183,34 @@ protected:
 // were not interpolated by alpha blending or multi sampling.
 extern unsigned char picking_checksum_alpha_channel(unsigned char red, unsigned char green, unsigned char blue);
 
+class MeshRaycaster;
+class MeshClipper;
+
+class CommonGizmosData {
+public:
+    const TriangleMesh* mesh() const {
+        return (! m_mesh ? nullptr : (m_cavity_mesh ? m_cavity_mesh.get() : m_mesh));
+    }
+
+
+
+    ModelObject* m_model_object = nullptr;
+    const TriangleMesh* m_mesh;
+    std::unique_ptr<MeshRaycaster> m_mesh_raycaster;
+    std::unique_ptr<MeshClipper> m_object_clipper;
+    std::unique_ptr<MeshClipper> m_supports_clipper;
+
+    std::unique_ptr<TriangleMesh> m_cavity_mesh;
+    std::unique_ptr<GLVolume> m_volume_with_cavity;
+
+    int m_active_instance = -1;
+    float m_active_instance_bb_radius = 0;
+    ObjectID m_model_object_id = 0;
+    int m_print_object_idx = -1;
+    int m_print_objects_count = -1;
+    int m_old_timestamp = -1;
+};
+
 } // namespace GUI
 } // namespace Slic3r
 

src/slic3r/GUI/Gizmos/GLGizmoHollow.hpp

@@ -0,0 +1,131 @@
+#ifndef slic3r_GLGizmoHollow_hpp_
+#define slic3r_GLGizmoHollow_hpp_
+
+#include "GLGizmoBase.hpp"
+#include "slic3r/GUI/GLSelectionRectangle.hpp"
+
+#include <libslic3r/SLA/Hollowing.hpp>
+#include <wx/dialog.h>
+
+#include <cereal/types/vector.hpp>
+
+
+namespace Slic3r {
+namespace GUI {
+
+class ClippingPlane;
+class MeshClipper;
+class MeshRaycaster;
+enum class SLAGizmoEventType : unsigned char;
+
+class GLGizmoHollow : public GLGizmoBase
+{
+private:
+    mutable double m_z_shift = 0.;
+    bool unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, Vec3f>& pos_and_normal);
+
+    const float HoleStickOutLength = 1.f;
+
+    GLUquadricObj* m_quadric;
+
+
+public:
+    GLGizmoHollow(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id, CommonGizmosData* cd);
+    ~GLGizmoHollow() override;
+    void set_sla_support_data(ModelObject* model_object, const Selection& selection);
+    bool gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_position, bool shift_down, bool alt_down, bool control_down);
+    void delete_selected_points();
+    ClippingPlane get_sla_clipping_plane() const;
+    
+    
+    std::pair<const TriangleMesh *, sla::HollowingConfig> get_hollowing_parameters() const;
+    void update_mesh_raycaster(std::unique_ptr<MeshRaycaster> &&rc);
+    void update_hollowed_mesh(std::unique_ptr<TriangleMesh> &&mesh);
+
+    bool is_selection_rectangle_dragging() const { return m_selection_rectangle.is_dragging(); }
+
+private:
+    bool on_init() override;
+    void on_update(const UpdateData& data) override;
+    void on_render() const override;
+    void on_render_for_picking() const override;
+
+    void render_points(const Selection& selection, bool picking = false) const;
+    void render_clipping_plane(const Selection& selection) const;
+    void render_hollowed_mesh() const;
+    bool is_mesh_update_necessary() const;
+    void update_mesh();
+    void hollow_mesh();
+    bool unsaved_changes() const;
+
+    bool  m_show_supports = true;
+    float m_new_hole_radius = 2.f;        // Size of a new hole.
+    float m_new_hole_height = 5.f;
+    mutable std::vector<bool> m_selected; // which holes are currently selected
+
+    bool m_enable_hollowing = true;
+
+    // Stashes to keep data for undo redo. Is taken after the editing
+    // is done, the data are updated continuously.
+    float m_offset_stash = 3.0f;
+    float m_quality_stash = 0.5f;
+    float m_closing_d_stash = 2.f;
+    Vec3f m_hole_before_drag = Vec3f::Zero();
+
+
+    sla::DrainHoles m_holes_stash;
+
+
+    
+    float m_clipping_plane_distance = 0.f;
+    std::unique_ptr<ClippingPlane> m_clipping_plane;
+    
+    // This map holds all translated description texts, so they can be easily referenced during layout calculations
+    // etc. When language changes, GUI is recreated and this class constructed again, so the change takes effect.
+    std::map<std::string, wxString> m_desc;
+
+    GLSelectionRectangle m_selection_rectangle;
+
+    bool m_wait_for_up_event = false;
+    bool m_selection_empty = true;
+    EState m_old_state = Off; // to be able to see that the gizmo has just been closed (see on_set_state)
+
+    std::vector<std::pair<const ConfigOption*, const ConfigOptionDef*>> get_config_options(const std::vector<std::string>& keys) const;
+    bool is_mesh_point_clipped(const Vec3d& point) const;
+
+    // Methods that do the model_object and editing cache synchronization,
+    // editing mode selection, etc:
+    enum {
+        AllPoints = -2,
+        NoPoints,
+    };
+    void select_point(int i);
+    void unselect_point(int i);
+    void reload_cache();
+    void update_clipping_plane(bool keep_normal = false) const;
+
+protected:
+    void on_set_state() override;
+    void on_set_hover_id() override
+
+    {
+        if (int(m_c->m_model_object->sla_drain_holes.size()) <= m_hover_id)
+            m_hover_id = -1;
+    }
+    void on_start_dragging() override;
+    void on_stop_dragging() override;
+    void on_render_input_window(float x, float y, float bottom_limit) override;
+
+    std::string on_get_name() const override;
+    bool on_is_activable() const override;
+    bool on_is_selectable() const override;
+    void on_load(cereal::BinaryInputArchive& ar) override;
+    void on_save(cereal::BinaryOutputArchive& ar) const override;
+};
+
+
+
+} // namespace GUI
+} // namespace Slic3r
+
+#endif // slic3r_GLGizmoHollow_hpp_

src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp

@@ -22,8 +22,8 @@
 namespace Slic3r {
 namespace GUI {
 
-GLGizmoSlaSupports::GLGizmoSlaSupports(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id)
+GLGizmoSlaSupports::GLGizmoSlaSupports(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id, CommonGizmosData* cd)
-    : GLGizmoBase(parent, icon_filename, sprite_id)
+    : GLGizmoBase(parent, icon_filename, sprite_id, cd)
     , m_quadric(nullptr)
     , m_its(nullptr)
 {
@@ -64,23 +64,35 @@ bool GLGizmoSlaSupports::on_init()
 void GLGizmoSlaSupports::set_sla_support_data(ModelObject* model_object, const Selection& selection)
 {
     if (! model_object || selection.is_empty()) {
-        m_model_object = nullptr;
+        m_c->m_model_object = nullptr;
         return;
     }
 
-    if (m_model_object != model_object || m_model_object_id != model_object->id()) {
+    bool something_changed = false;
-        m_model_object = model_object;
-        m_print_object_idx = -1;
-    }
 
-    m_active_instance = selection.get_instance_idx();
+    if (m_c->m_model_object != model_object
+     || m_c->m_model_object_id != model_object->id()
+     || m_c->m_active_instance != selection.get_instance_idx()) {
+        m_c->m_model_object = model_object;
+        m_c->m_print_object_idx = -1;
+        m_c->m_active_instance = selection.get_instance_idx();
+        something_changed = true;
+    }
 
     if (model_object && selection.is_from_single_instance())
     {
         // Cache the bb - it's needed for dealing with the clipping plane quite often
         // It could be done inside update_mesh but one has to account for scaling of the instance.
-        //FIXME calling ModelObject::instance_bounding_box() is expensive!
+        if (something_changed) {
-        m_active_instance_bb_radius = m_model_object->instance_bounding_box(m_active_instance).radius();
+            m_c->m_active_instance_bb_radius = m_c->m_model_object->instance_bounding_box(m_c->m_active_instance).radius();
+            if (m_state == On) {
+                m_parent.toggle_model_objects_visibility(false);
+                m_parent.toggle_model_objects_visibility(! m_c->m_cavity_mesh, m_c->m_model_object, m_c->m_active_instance);
+                m_parent.toggle_sla_auxiliaries_visibility(! m_editing_mode, m_c->m_model_object, m_c->m_active_instance);
+            }
+            else
+                m_parent.toggle_model_objects_visibility(true, nullptr, -1);
+        }
 
         if (is_mesh_update_necessary()) {
             update_mesh();
@@ -88,15 +100,8 @@ void GLGizmoSlaSupports::set_sla_support_data(ModelObject* model_object, const S
         }
 
         // If we triggered autogeneration before, check backend and fetch results if they are there
-        if (m_model_object->sla_points_status == sla::PointsStatus::Generating)
+        if (m_c->m_model_object->sla_points_status == sla::PointsStatus::Generating)
             get_data_from_backend();
-
-        if (m_state == On) {
-            m_parent.toggle_model_objects_visibility(false);
-            m_parent.toggle_model_objects_visibility(true, m_model_object, m_active_instance);
-        }
-        else
-            m_parent.toggle_model_objects_visibility(true, nullptr, -1);
     }
 }
 
@@ -106,16 +111,16 @@ void GLGizmoSlaSupports::on_render() const
 {
     const Selection& selection = m_parent.get_selection();
 
-    // If current m_model_object does not match selection, ask GLCanvas3D to turn us off
+    // If current m_c->m_model_object does not match selection, ask GLCanvas3D to turn us off
     if (m_state == On
-     && (m_model_object != selection.get_model()->objects[selection.get_object_idx()]
+     && (m_c->m_model_object != selection.get_model()->objects[selection.get_object_idx()]
-      || m_active_instance != selection.get_instance_idx()
+      || m_c->m_active_instance != selection.get_instance_idx()
-      || m_model_object_id != m_model_object->id())) {
+      || m_c->m_model_object_id != m_c->m_model_object->id())) {
         m_parent.post_event(SimpleEvent(EVT_GLCANVAS_RESETGIZMOS));
         return;
     }
 
-    if (! m_its || ! m_mesh)
+    if (! m_its || ! m_c->m_mesh)
         const_cast<GLGizmoSlaSupports*>(this)->update_mesh();
 
     glsafe(::glEnable(GL_BLEND));
@@ -123,6 +128,8 @@ void GLGizmoSlaSupports::on_render() const
 
     m_z_shift = selection.get_volume(*selection.get_volume_idxs().begin())->get_sla_shift_z();
 
+    render_hollowed_mesh();
+
     if (m_quadric != nullptr && selection.is_from_single_instance())
         render_points(selection, false);
 
@@ -134,9 +141,32 @@ void GLGizmoSlaSupports::on_render() const
 
 
 
+void GLGizmoSlaSupports::render_hollowed_mesh() const
+{
+    if (m_c->m_volume_with_cavity) {
+        m_c->m_volume_with_cavity->set_sla_shift_z(m_z_shift);
+        m_parent.get_shader().start_using();
+
+        GLint current_program_id;
+        glsafe(::glGetIntegerv(GL_CURRENT_PROGRAM, &current_program_id));
+        GLint color_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "uniform_color") : -1;
+        GLint print_box_detection_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_detection") : -1;
+        GLint print_box_worldmatrix_id = (current_program_id > 0) ? ::glGetUniformLocation(current_program_id, "print_box.volume_world_matrix") : -1;
+        glcheck();
+        m_c->m_volume_with_cavity->set_render_color();
+        const Geometry::Transformation& volume_trafo = m_c->m_model_object->volumes.front()->get_transformation();
+        m_c->m_volume_with_cavity->set_volume_transformation(volume_trafo);
+        m_c->m_volume_with_cavity->set_instance_transformation(m_c->m_model_object->instances[size_t(m_c->m_active_instance)]->get_transformation());
+        m_c->m_volume_with_cavity->render(color_id, print_box_detection_id, print_box_worldmatrix_id);
+        m_parent.get_shader().stop_using();
+    }
+}
+
+
+
 void GLGizmoSlaSupports::render_clipping_plane(const Selection& selection) const
 {
-    if (m_clipping_plane_distance == 0.f)
+    if (m_clipping_plane_distance == 0.f || m_c->m_mesh->empty())
         return;
 
     // Get transformation of the instance
@@ -154,66 +184,66 @@ void GLGizmoSlaSupports::render_clipping_plane(const Selection& selection) const
                                     1.));
 
     // Now initialize the TMS for the object, perform the cut and save the result.
-    if (! m_object_clipper) {
+    if (! m_c->m_object_clipper) {
-        m_object_clipper.reset(new MeshClipper);
+        m_c->m_object_clipper.reset(new MeshClipper);
-        m_object_clipper->set_mesh(*m_mesh);
+        m_c->m_object_clipper->set_mesh(*m_c->mesh());
     }
-    m_object_clipper->set_plane(*m_clipping_plane);
+    m_c->m_object_clipper->set_plane(*m_clipping_plane);
-    m_object_clipper->set_transformation(trafo);
+    m_c->m_object_clipper->set_transformation(trafo);
 
 
     // Next, ask the backend if supports are already calculated. If so, we are gonna cut them too.
     // First we need a pointer to the respective SLAPrintObject. The index into objects vector is
     // cached so we don't have todo it on each render. We only search for the po if needed:
-    if (m_print_object_idx < 0 || (int)m_parent.sla_print()->objects().size() != m_print_objects_count) {
+    if (m_c->m_print_object_idx < 0 || (int)m_parent.sla_print()->objects().size() != m_c->m_print_objects_count) {
-        m_print_objects_count = m_parent.sla_print()->objects().size();
+        m_c->m_print_objects_count = m_parent.sla_print()->objects().size();
-        m_print_object_idx = -1;
+        m_c->m_print_object_idx = -1;
         for (const SLAPrintObject* po : m_parent.sla_print()->objects()) {
-            ++m_print_object_idx;
+            ++m_c->m_print_object_idx;
-            if (po->model_object()->id() == m_model_object->id())
+            if (po->model_object()->id() == m_c->m_model_object->id())
                 break;
         }
     }
-    if (m_print_object_idx >= 0) {
+    if (m_c->m_print_object_idx >= 0) {
-        const SLAPrintObject* print_object = m_parent.sla_print()->objects()[m_print_object_idx];
+        const SLAPrintObject* print_object = m_parent.sla_print()->objects()[m_c->m_print_object_idx];
 
-        if (print_object->is_step_done(slaposSupportTree)) {
+        if (print_object->is_step_done(slaposSupportTree) && !print_object->get_mesh(slaposSupportTree).empty()) {
             // If the supports are already calculated, save the timestamp of the respective step
             // so we can later tell they were recalculated.
             size_t timestamp = print_object->step_state_with_timestamp(slaposSupportTree).timestamp;
 
-            if (! m_supports_clipper || (int)timestamp != m_old_timestamp) {
+            if (! m_c->m_supports_clipper || (int)timestamp != m_c->m_old_timestamp) {
                 // The timestamp has changed.
-                m_supports_clipper.reset(new MeshClipper);
+                m_c->m_supports_clipper.reset(new MeshClipper);
                 // The mesh should already have the shared vertices calculated.
-                m_supports_clipper->set_mesh(print_object->support_mesh());
+                m_c->m_supports_clipper->set_mesh(print_object->support_mesh());
-                m_old_timestamp = timestamp;
+                m_c->m_old_timestamp = timestamp;
             }
-            m_supports_clipper->set_plane(*m_clipping_plane);
+            m_c->m_supports_clipper->set_plane(*m_clipping_plane);
-            m_supports_clipper->set_transformation(supports_trafo);
+            m_c->m_supports_clipper->set_transformation(supports_trafo);
         }
         else
             // The supports are not valid. We better dump the cached data.
-            m_supports_clipper.reset();
+            m_c->m_supports_clipper.reset();
     }
 
     // At this point we have the triangulated cuts for both the object and supports - let's render.
-    if (! m_object_clipper->get_triangles().empty()) {
+    if (! m_c->m_object_clipper->get_triangles().empty()) {
 		::glPushMatrix();
         ::glColor3f(1.0f, 0.37f, 0.0f);
         ::glBegin(GL_TRIANGLES);
-        for (const Vec3f& point : m_object_clipper->get_triangles())
+        for (const Vec3f& point : m_c->m_object_clipper->get_triangles())
             ::glVertex3f(point(0), point(1), point(2));
         ::glEnd();
 		::glPopMatrix();
 	}
 
-    if (m_supports_clipper && ! m_supports_clipper->get_triangles().empty() && !m_editing_mode) {
+    if (m_c->m_supports_clipper && ! m_c->m_supports_clipper->get_triangles().empty() && !m_editing_mode) {
         // The supports are hidden in the editing mode, so it makes no sense to render the cuts.
         ::glPushMatrix();
         ::glColor3f(1.0f, 0.f, 0.37f);
         ::glBegin(GL_TRIANGLES);
-        for (const Vec3f& point : m_supports_clipper->get_triangles())
+        for (const Vec3f& point : m_c->m_supports_clipper->get_triangles())
             ::glVertex3f(point(0), point(1), point(2));
         ::glEnd();
 		::glPopMatrix();
@@ -230,6 +260,7 @@ void GLGizmoSlaSupports::on_render_for_picking() const
 
     glsafe(::glEnable(GL_DEPTH_TEST));
     render_points(selection, true);
+    render_hollowed_mesh();
 }
 
 void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking) const
@@ -298,7 +329,7 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
         if (m_editing_mode) {
             // in case the normal is not yet cached, find and cache it
             if (m_editing_cache[i].normal == Vec3f::Zero())
-                m_mesh_raycaster->get_closest_point(m_editing_cache[i].support_point.pos, &m_editing_cache[i].normal);
+                m_c->m_mesh_raycaster->get_closest_point(m_editing_cache[i].support_point.pos, &m_editing_cache[i].normal);
 
             Eigen::Quaterniond q;
             q.setFromTwoVectors(Vec3d{0., 0., 1.}, instance_scaling_matrix_inverse * m_editing_cache[i].normal.cast<double>());
@@ -327,6 +358,44 @@ void GLGizmoSlaSupports::render_points(const Selection& selection, bool picking)
         glsafe(::glMaterialfv(GL_FRONT, GL_EMISSION, render_color_emissive));
     }
 
+    // Now render the drain holes:
+    if (! m_c->m_cavity_mesh) {
+        render_color[0] = 0.7f;
+        render_color[1] = 0.7f;
+        render_color[2] = 0.7f;
+        render_color[3] = 0.7f;
+        glsafe(::glColor4fv(render_color));
+        for (const sla::DrainHole& drain_hole : m_c->m_model_object->sla_drain_holes) {
+            // Inverse matrix of the instance scaling is applied so that the mark does not scale with the object.
+            glsafe(::glPushMatrix());
+            glsafe(::glTranslatef(drain_hole.pos(0), drain_hole.pos(1), drain_hole.pos(2)));
+            glsafe(::glMultMatrixd(instance_scaling_matrix_inverse.data()));
+
+            if (vol->is_left_handed())
+                glFrontFace(GL_CW);
+
+            // Matrices set, we can render the point mark now.
+
+            Eigen::Quaterniond q;
+            q.setFromTwoVectors(Vec3d{0., 0., 1.}, instance_scaling_matrix_inverse * (-drain_hole.normal).cast<double>());
+            Eigen::AngleAxisd aa(q);
+            glsafe(::glRotated(aa.angle() * (180. / M_PI), aa.axis()(0), aa.axis()(1), aa.axis()(2)));
+            glsafe(::glPushMatrix());
+            glsafe(::glTranslated(0., 0., -drain_hole.height));
+            ::gluCylinder(m_quadric, drain_hole.radius, drain_hole.radius, drain_hole.height, 24, 1);
+            glsafe(::glTranslated(0., 0., drain_hole.height));
+            ::gluDisk(m_quadric, 0.0, drain_hole.radius, 24, 1);
+            glsafe(::glTranslated(0., 0., -drain_hole.height));
+            glsafe(::glRotatef(180.f, 1.f, 0.f, 0.f));
+            ::gluDisk(m_quadric, 0.0, drain_hole.radius, 24, 1);
+            glsafe(::glPopMatrix());
+
+            if (vol->is_left_handed())
+                glFrontFace(GL_CCW);
+            glsafe(::glPopMatrix());
+        }
+    }
+
     if (!picking)
         glsafe(::glDisable(GL_LIGHTING));
 
@@ -340,7 +409,7 @@ bool GLGizmoSlaSupports::is_mesh_point_clipped(const Vec3d& point) const
     if (m_clipping_plane_distance == 0.f)
         return false;
 
-    Vec3d transformed_point = m_model_object->instances.front()->get_transformation().get_matrix() * point;
+    Vec3d transformed_point = m_c->m_model_object->instances[m_c->m_active_instance]->get_transformation().get_matrix() * point;
     transformed_point(2) += m_z_shift;
     return m_clipping_plane->is_point_clipped(transformed_point);
 }
@@ -349,39 +418,38 @@ bool GLGizmoSlaSupports::is_mesh_point_clipped(const Vec3d& point) const
 
 bool GLGizmoSlaSupports::is_mesh_update_necessary() const
 {
-    return ((m_state == On) && (m_model_object != nullptr) && !m_model_object->instances.empty())
+    return ((m_state == On) && (m_c->m_model_object != nullptr) && !m_c->m_model_object->instances.empty())
-        && ((m_model_object->id() != m_model_object_id) || m_its == nullptr);
+        && ((m_c->m_model_object->id() != m_c->m_model_object_id) || m_its == nullptr);
 }
 
 
 
 void GLGizmoSlaSupports::update_mesh()
 {
-    if (! m_model_object)
+    if (! m_c->m_model_object)
         return;
 
     wxBusyCursor wait;
     // this way we can use that mesh directly.
     // This mesh does not account for the possible Z up SLA offset.
-    m_mesh = &m_model_object->volumes.front()->mesh();
+    m_c->m_mesh = &m_c->m_model_object->volumes.front()->mesh();
-    m_its = &m_mesh->its;
+    m_its = &m_c->m_mesh->its;
 
     // If this is different mesh than last time or if the AABB tree is uninitialized, recalculate it.
-    if (m_model_object_id != m_model_object->id() || ! m_mesh_raycaster)
+    if (m_c->m_model_object_id != m_c->m_model_object->id() || ! m_c->m_mesh_raycaster)
-        m_mesh_raycaster.reset(new MeshRaycaster(*m_mesh));
+        m_c->m_mesh_raycaster.reset(new MeshRaycaster(*m_c->mesh()));
 
-    m_model_object_id = m_model_object->id();
+    m_c->m_model_object_id = m_c->m_model_object->id();
     disable_editing_mode();
 }
 
 
-
 // Unprojects the mouse position on the mesh and saves hit point and normal of the facet into pos_and_normal
 // Return false if no intersection was found, true otherwise.
 bool GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, Vec3f>& pos_and_normal)
 {
     // if the gizmo doesn't have the V, F structures for igl, calculate them first:
-    if (! m_mesh_raycaster)
+    if (! m_c->m_mesh_raycaster)
         update_mesh();
 
     const Camera& camera = m_parent.get_camera();
@@ -393,12 +461,27 @@ bool GLGizmoSlaSupports::unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec
     // The raycaster query
     Vec3f hit;
     Vec3f normal;
-    if (m_mesh_raycaster->unproject_on_mesh(mouse_pos, trafo.get_matrix(), camera, hit, normal, m_clipping_plane.get())) {
+    if (m_c->m_mesh_raycaster->unproject_on_mesh(mouse_pos, trafo.get_matrix(), camera, hit, normal, m_clipping_plane.get())) {
+        // Check whether the hit is in a hole
+        bool in_hole = false;
+        // In case the hollowed and drilled mesh is available, we can allow
+        // placing points in holes, because they should never end up
+        // on surface that's been drilled away.
+        if (! m_c->m_cavity_mesh) {
+            for (const sla::DrainHole& hole : m_c->m_model_object->sla_drain_holes) {
+                if (hole.is_inside(hit)) {
+                    in_hole = true;
+                    break;
+                }
+            }
+        }
+        if (! in_hole) {
             // Return both the point and the facet normal.
             pos_and_normal = std::make_pair(hit, normal);
             return true;
         }
-    else
+    }
+
     return false;
 }
 
@@ -459,7 +542,7 @@ bool GLGizmoSlaSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
             GLSelectionRectangle::EState rectangle_status = m_selection_rectangle.get_state();
 
             // First collect positions of all the points in world coordinates.
-            Geometry::Transformation trafo = m_model_object->instances[m_active_instance]->get_transformation();
+            Geometry::Transformation trafo = m_c->m_model_object->instances[m_c->m_active_instance]->get_transformation();
             trafo.set_offset(trafo.get_offset() + Vec3d(0., 0., m_z_shift));
             std::vector<Vec3d> points;
             for (unsigned int i=0; i<m_editing_cache.size(); ++i)
@@ -472,7 +555,7 @@ bool GLGizmoSlaSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
                 points_inside.push_back(points[idx].cast<float>());
 
             // Only select/deselect points that are actually visible
-            for (size_t idx :  m_mesh_raycaster->get_unobscured_idxs(trafo, m_parent.get_camera(), points_inside, m_clipping_plane.get()))
+            for (size_t idx :  m_c->m_mesh_raycaster->get_unobscured_idxs(trafo, m_parent.get_camera(), points_inside, m_clipping_plane.get()))
             {
                 if (rectangle_status == GLSelectionRectangle::Deselect)
                     unselect_point(points_idxs[idx]);
@@ -610,10 +693,10 @@ std::vector<const ConfigOption*> GLGizmoSlaSupports::get_config_options(const st
 {
     std::vector<const ConfigOption*> out;
 
-    if (!m_model_object)
+    if (!m_c->m_model_object)
         return out;
 
-    const DynamicPrintConfig& object_cfg = m_model_object->config;
+    const DynamicPrintConfig& object_cfg = m_c->m_model_object->config;
     const DynamicPrintConfig& print_cfg = wxGetApp().preset_bundle->sla_prints.get_edited_preset().config;
     std::unique_ptr<DynamicPrintConfig> default_cfg = nullptr;
 
@@ -636,7 +719,7 @@ std::vector<const ConfigOption*> GLGizmoSlaSupports::get_config_options(const st
 
 ClippingPlane GLGizmoSlaSupports::get_sla_clipping_plane() const
 {
-    if (!m_model_object || m_state == Off || m_clipping_plane_distance == 0.f)
+    if (!m_c->m_model_object || m_state == Off || m_clipping_plane_distance == 0.f)
         return ClippingPlane::ClipsNothing();
     else
         return ClippingPlane(-m_clipping_plane->get_normal(), m_clipping_plane->get_data()[3]);
@@ -665,7 +748,7 @@ void GLGizmoSlaSupports::find_intersecting_facets(const igl::AABB<Eigen::MatrixX
 
 void GLGizmoSlaSupports::make_line_segments() const
 {
-    TriangleMeshSlicer tms(&m_model_object->volumes.front()->mesh);
+    TriangleMeshSlicer tms(&m_c->m_model_object->volumes.front()->mesh);
     Vec3f normal(0.f, 1.f, 1.f);
     double d = 0.;
 
@@ -689,7 +772,7 @@ void GLGizmoSlaSupports::on_render_input_window(float x, float y, float bottom_l
     static float last_y = 0.0f;
     static float last_h = 0.0f;
 
-    if (!m_model_object)
+    if (! m_c->m_model_object)
         return;
 
     bool first_run = true; // This is a hack to redraw the button when all points are removed,
@@ -728,7 +811,6 @@ RENDER_AGAIN:
     float window_width = minimal_slider_width + std::max(std::max(settings_sliders_left, clipping_slider_left), diameter_slider_left);
     window_width = std::max(std::max(window_width, buttons_width_approx), lock_supports_width_approx);
 
-
     bool force_refresh = false;
     bool remove_selected = false;
     bool remove_all = false;
@@ -827,15 +909,15 @@ RENDER_AGAIN:
             m_density_stash = density;
         }
         if (slider_edited) {
-            m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = minimal_point_distance;
+            m_c->m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = minimal_point_distance;
-            m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)density;
+            m_c->m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)density;
         }
         if (slider_released) {
-            m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = m_minimal_point_distance_stash;
+            m_c->m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = m_minimal_point_distance_stash;
-            m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)m_density_stash;
+            m_c->m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)m_density_stash;
             Plater::TakeSnapshot snapshot(wxGetApp().plater(), _(L("Support parameter change")));
-            m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = minimal_point_distance;
+            m_c->m_model_object->config.opt<ConfigOptionFloat>("support_points_minimal_distance", true)->value = minimal_point_distance;
-            m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)density;
+            m_c->m_model_object->config.opt<ConfigOptionInt>("support_points_density_relative", true)->value = (int)density;
             wxGetApp().obj_list()->update_and_show_object_settings_item();
         }
 
@@ -853,10 +935,10 @@ RENDER_AGAIN:
         m_imgui->disabled_end();
 
         // m_imgui->text("");
-        // m_imgui->text(m_model_object->sla_points_status == sla::PointsStatus::NoPoints ? _(L("No points  (will be autogenerated)")) :
+        // m_imgui->text(m_c->m_model_object->sla_points_status == sla::PointsStatus::NoPoints ? _(L("No points  (will be autogenerated)")) :
-        //              (m_model_object->sla_points_status == sla::PointsStatus::AutoGenerated ? _(L("Autogenerated points (no modifications)")) :
+        //              (m_c->m_model_object->sla_points_status == sla::PointsStatus::AutoGenerated ? _(L("Autogenerated points (no modifications)")) :
-        //              (m_model_object->sla_points_status == sla::PointsStatus::UserModified ? _(L("User-modified points")) :
+        //              (m_c->m_model_object->sla_points_status == sla::PointsStatus::UserModified ? _(L("User-modified points")) :
-        //              (m_model_object->sla_points_status == sla::PointsStatus::Generating ? _(L("Generation in progress...")) : "UNKNOWN STATUS"))));
+        //              (m_c->m_model_object->sla_points_status == sla::PointsStatus::Generating ? _(L("Generation in progress...")) : "UNKNOWN STATUS"))));
     }
 
 
@@ -890,12 +972,6 @@ RENDER_AGAIN:
 
     m_imgui->end();
 
-    if (m_editing_mode != m_old_editing_state) { // user toggled between editing/non-editing mode
-        m_parent.toggle_sla_auxiliaries_visibility(!m_editing_mode, m_model_object, m_active_instance);
-        force_refresh = true;
-    }
-    m_old_editing_state = m_editing_mode;
-
     if (remove_selected || remove_all) {
         force_refresh = false;
         m_parent.set_as_dirty();
@@ -952,12 +1028,12 @@ std::string GLGizmoSlaSupports::on_get_name() const
 
 void GLGizmoSlaSupports::on_set_state()
 {
-    // m_model_object pointer can be invalid (for instance because of undo/redo action),
+    // m_c->m_model_object pointer can be invalid (for instance because of undo/redo action),
     // we should recover it from the object id
-    m_model_object = nullptr;
+    m_c->m_model_object = nullptr;
     for (const auto mo : wxGetApp().model().objects) {
-        if (mo->id() == m_model_object_id) {
+        if (mo->id() == m_c->m_model_object_id) {
-            m_model_object = mo;
+            m_c->m_model_object = mo;
             break;
         }
     }
@@ -971,19 +1047,20 @@ void GLGizmoSlaSupports::on_set_state()
             update_mesh();
 
         // we'll now reload support points:
-        if (m_model_object)
+        if (m_c->m_model_object)
             reload_cache();
 
         m_parent.toggle_model_objects_visibility(false);
-        if (m_model_object)
+        if (m_c->m_model_object && ! m_c->m_cavity_mesh)
-            m_parent.toggle_model_objects_visibility(true, m_model_object, m_active_instance);
+            m_parent.toggle_model_objects_visibility(true, m_c->m_model_object, m_c->m_active_instance);
+        m_parent.toggle_sla_auxiliaries_visibility(! m_editing_mode, m_c->m_model_object, m_c->m_active_instance);
 
         // Set default head diameter from config.
         const DynamicPrintConfig& cfg = wxGetApp().preset_bundle->sla_prints.get_edited_preset().config;
         m_new_point_head_diameter = static_cast<const ConfigOptionFloat*>(cfg.option("support_head_front_diameter"))->value;
     }
     if (m_state == Off && m_old_state != Off) { // the gizmo was just turned Off
-        bool will_ask = m_model_object && m_editing_mode && unsaved_changes();
+        bool will_ask = m_c->m_model_object && m_editing_mode && unsaved_changes();
         if (will_ask) {
             wxGetApp().CallAfter([this]() {
                 // Following is called through CallAfter, because otherwise there was a problem
@@ -1005,11 +1082,12 @@ void GLGizmoSlaSupports::on_set_state()
             m_parent.toggle_model_objects_visibility(true);
             m_normal_cache.clear();
             m_clipping_plane_distance = 0.f;
+            update_clipping_plane();
             // Release clippers and the AABB raycaster.
             m_its = nullptr;
-            m_object_clipper.reset();
+            m_c->m_object_clipper.reset();
-            m_supports_clipper.reset();
+            m_c->m_supports_clipper.reset();
-            m_mesh_raycaster.reset();
+            m_c->m_mesh_raycaster.reset();
         }
     }
     m_old_state = m_state;
@@ -1051,7 +1129,7 @@ void GLGizmoSlaSupports::on_load(cereal::BinaryInputArchive& ar)
 {
     ar(m_clipping_plane_distance,
        *m_clipping_plane,
-       m_model_object_id,
+       m_c->m_model_object_id,
        m_new_point_head_diameter,
        m_normal_cache,
        m_editing_cache,
@@ -1065,7 +1143,7 @@ void GLGizmoSlaSupports::on_save(cereal::BinaryOutputArchive& ar) const
 {
     ar(m_clipping_plane_distance,
        *m_clipping_plane,
-       m_model_object_id,
+       m_c->m_model_object_id,
        m_new_point_head_diameter,
        m_normal_cache,
        m_editing_cache,
@@ -1143,9 +1221,9 @@ void GLGizmoSlaSupports::editing_mode_apply_changes()
         for (const CacheEntry& ce : m_editing_cache)
             m_normal_cache.push_back(ce.support_point);
 
-        m_model_object->sla_points_status = sla::PointsStatus::UserModified;
+        m_c->m_model_object->sla_points_status = sla::PointsStatus::UserModified;
-        m_model_object->sla_support_points.clear();
+        m_c->m_model_object->sla_support_points.clear();
-        m_model_object->sla_support_points = m_normal_cache;
+        m_c->m_model_object->sla_support_points = m_normal_cache;
 
         reslice_SLA_supports();
     }
@@ -1156,10 +1234,10 @@ void GLGizmoSlaSupports::editing_mode_apply_changes()
 void GLGizmoSlaSupports::reload_cache()
 {
     m_normal_cache.clear();
-    if (m_model_object->sla_points_status == sla::PointsStatus::AutoGenerated || m_model_object->sla_points_status == sla::PointsStatus::Generating)
+    if (m_c->m_model_object->sla_points_status == sla::PointsStatus::AutoGenerated || m_c->m_model_object->sla_points_status == sla::PointsStatus::Generating)
         get_data_from_backend();
     else
-        for (const sla::SupportPoint& point : m_model_object->sla_support_points)
+        for (const sla::SupportPoint& point : m_c->m_model_object->sla_support_points)
             m_normal_cache.emplace_back(point);
 }
 
@@ -1168,7 +1246,7 @@ bool GLGizmoSlaSupports::has_backend_supports() const
 {
     // find SlaPrintObject with this ID
     for (const SLAPrintObject* po : m_parent.sla_print()->objects()) {
-        if (po->model_object()->id() == m_model_object->id())
+        if (po->model_object()->id() == m_c->m_model_object->id())
         	return po->is_step_done(slaposSupportPoints);
     }
     return false;
@@ -1176,7 +1254,7 @@ bool GLGizmoSlaSupports::has_backend_supports() const
 
 void GLGizmoSlaSupports::reslice_SLA_supports(bool postpone_error_messages) const
 {
-    wxGetApp().CallAfter([this, postpone_error_messages]() { wxGetApp().plater()->reslice_SLA_supports(*m_model_object, postpone_error_messages); });
+    wxGetApp().CallAfter([this, postpone_error_messages]() { wxGetApp().plater()->reslice_SLA_supports(*m_c->m_model_object, postpone_error_messages); });
 }
 
 void GLGizmoSlaSupports::get_data_from_backend()
@@ -1186,14 +1264,14 @@ void GLGizmoSlaSupports::get_data_from_backend()
 
     // find the respective SLAPrintObject, we need a pointer to it
     for (const SLAPrintObject* po : m_parent.sla_print()->objects()) {
-        if (po->model_object()->id() == m_model_object->id()) {
+        if (po->model_object()->id() == m_c->m_model_object->id()) {
             m_normal_cache.clear();
             const std::vector<sla::SupportPoint>& points = po->get_support_points();
             auto mat = po->trafo().inverse().cast<float>();
             for (unsigned int i=0; i<points.size();++i)
                 m_normal_cache.emplace_back(sla::SupportPoint(mat * points[i].pos, points[i].head_front_radius, points[i].is_new_island));
 
-            m_model_object->sla_points_status = sla::PointsStatus::AutoGenerated;
+            m_c->m_model_object->sla_points_status = sla::PointsStatus::AutoGenerated;
             break;
         }
     }
@@ -1210,10 +1288,10 @@ void GLGizmoSlaSupports::auto_generate()
                         _(L("Are you sure you want to do it?")) + "\n",
                         _(L("Warning")), wxICON_WARNING | wxYES | wxNO);
 
-    if (m_model_object->sla_points_status != sla::PointsStatus::UserModified || m_normal_cache.empty() || dlg.ShowModal() == wxID_YES) {
+    if (m_c->m_model_object->sla_points_status != sla::PointsStatus::UserModified || m_normal_cache.empty() || dlg.ShowModal() == wxID_YES) {
         Plater::TakeSnapshot snapshot(wxGetApp().plater(), _(L("Autogenerate support points")));
         wxGetApp().CallAfter([this]() { reslice_SLA_supports(); });
-        m_model_object->sla_points_status = sla::PointsStatus::Generating;
+        m_c->m_model_object->sla_points_status = sla::PointsStatus::Generating;
     }
 }
 
@@ -1227,6 +1305,9 @@ void GLGizmoSlaSupports::switch_to_editing_mode()
     for (const sla::SupportPoint& sp : m_normal_cache)
         m_editing_cache.emplace_back(sp);
     select_point(NoPoints);
+
+    m_parent.toggle_sla_auxiliaries_visibility(false, m_c->m_model_object, m_c->m_active_instance);
+    m_parent.set_as_dirty();
 }
 
 
@@ -1235,6 +1316,8 @@ void GLGizmoSlaSupports::disable_editing_mode()
     if (m_editing_mode) {
         m_editing_mode = false;
         wxGetApp().plater()->leave_gizmos_stack();
+        m_parent.toggle_sla_auxiliaries_visibility(true, m_c->m_model_object, m_c->m_active_instance);
+        m_parent.set_as_dirty();
     }
 }
 
@@ -1258,9 +1341,9 @@ void GLGizmoSlaSupports::update_clipping_plane(bool keep_normal) const
     Vec3d normal = (keep_normal && m_clipping_plane->get_normal() != Vec3d::Zero() ?
                         m_clipping_plane->get_normal() : -m_parent.get_camera().get_dir_forward());
 
-    const Vec3d& center = m_model_object->instances[m_active_instance]->get_offset() + Vec3d(0., 0., m_z_shift);
+    const Vec3d& center = m_c->m_model_object->instances[m_c->m_active_instance]->get_offset() + Vec3d(0., 0., m_z_shift);
     float dist = normal.dot(center);
-    *m_clipping_plane = ClippingPlane(normal, (dist - (-m_active_instance_bb_radius) - m_clipping_plane_distance * 2*m_active_instance_bb_radius));
+    *m_clipping_plane = ClippingPlane(normal, (dist - (-m_c->m_active_instance_bb_radius) - m_clipping_plane_distance * 2*m_c->m_active_instance_bb_radius));
     m_parent.set_as_dirty();
 }
 

src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp

@@ -4,7 +4,7 @@
 #include "GLGizmoBase.hpp"
 #include "slic3r/GUI/GLSelectionRectangle.hpp"
 
-#include "libslic3r/SLA/SLACommon.hpp"
+#include "libslic3r/SLA/Common.hpp"
 #include <wx/dialog.h>
 
 #include <cereal/types/vector.hpp>
@@ -21,10 +21,10 @@ enum class SLAGizmoEventType : unsigned char;
 class GLGizmoSlaSupports : public GLGizmoBase
 {
 private:
-    ModelObject* m_model_object = nullptr;
+    //ModelObject* m_model_object = nullptr;
-    ObjectID m_model_object_id = 0;
+    //ObjectID m_model_object_id = 0;
-    int m_active_instance = -1;
+    //int m_active_instance = -1;
-    float m_active_instance_bb_radius; // to cache the bb
+    //float m_active_instance_bb_radius; // to cache the bb
     mutable double m_z_shift = 0.f;
     bool unproject_on_mesh(const Vec2d& mouse_pos, std::pair<Vec3f, Vec3f>& pos_and_normal);
 
@@ -34,15 +34,12 @@ private:
     typedef Eigen::Map<const Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXfUnaligned;
     typedef Eigen::Map<const Eigen::Matrix<int, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXiUnaligned;
 
-    std::unique_ptr<MeshRaycaster> m_mesh_raycaster;
+    //std::unique_ptr<MeshRaycaster> m_mesh_raycaster;
-    const TriangleMesh* m_mesh;
+    //const TriangleMesh* m_mesh;
     const indexed_triangle_set* m_its;
-    mutable const TriangleMesh* m_supports_mesh;
+    //mutable int m_old_timestamp = -1;
-    mutable std::vector<Vec2f> m_triangles;
+    //mutable int m_print_object_idx = -1;
-    mutable std::vector<Vec2f> m_supports_triangles;
+    //mutable int m_print_objects_count = -1;
-    mutable int m_old_timestamp = -1;
-    mutable int m_print_object_idx = -1;
-    mutable int m_print_objects_count = -1;
 
     class CacheEntry {
     public:
@@ -72,7 +69,7 @@ private:
     };
 
 public:
-    GLGizmoSlaSupports(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id);
+    GLGizmoSlaSupports(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id, CommonGizmosData* cd);
     ~GLGizmoSlaSupports() override;
     void set_sla_support_data(ModelObject* model_object, const Selection& selection);
     bool gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_position, bool shift_down, bool alt_down, bool control_down);
@@ -93,13 +90,13 @@ private:
     //void render_selection_rectangle() const;
     void render_points(const Selection& selection, bool picking = false) const;
     void render_clipping_plane(const Selection& selection) const;
+    void render_hollowed_mesh() const;
     bool is_mesh_update_necessary() const;
     void update_mesh();
     bool unsaved_changes() const;
 
     bool m_lock_unique_islands = false;
     bool m_editing_mode = false;            // Is editing mode active?
-    bool m_old_editing_state = false;       // To keep track of whether the user toggled between the modes (needed for imgui refreshes).
     float m_new_point_head_diameter;        // Size of a new point.
     CacheEntry m_point_before_drag;         // undo/redo - so we know what state was edited
     float m_old_point_head_diameter = 0.;   // the same
@@ -121,11 +118,12 @@ private:
     bool m_selection_empty = true;
     EState m_old_state = Off; // to be able to see that the gizmo has just been closed (see on_set_state)
 
-    mutable std::unique_ptr<MeshClipper> m_object_clipper;
+    //mutable std::unique_ptr<MeshClipper> m_object_clipper;
-    mutable std::unique_ptr<MeshClipper> m_supports_clipper;
+    //mutable std::unique_ptr<MeshClipper> m_supports_clipper;
 
     std::vector<const ConfigOption*> get_config_options(const std::vector<std::string>& keys) const;
     bool is_mesh_point_clipped(const Vec3d& point) const;
+    bool is_point_in_hole(const Vec3f& pt) const;
     //void find_intersecting_facets(const igl::AABB<Eigen::MatrixXf, 3>* aabb, const Vec3f& normal, double offset, std::vector<unsigned int>& out) const;
 
     // Methods that do the model_object and editing cache synchronization,

src/slic3r/GUI/Gizmos/GLGizmos.hpp

@@ -32,5 +32,6 @@ enum class SLAGizmoEventType : unsigned char {
 #include "slic3r/GUI/Gizmos/GLGizmoFlatten.hpp"
 #include "slic3r/GUI/Gizmos/GLGizmoSlaSupports.hpp"
 #include "slic3r/GUI/Gizmos/GLGizmoCut.hpp"
+#include "slic3r/GUI/Gizmos/GLGizmoHollow.hpp"
 
 #endif //slic3r_GLGizmos_hpp_

src/slic3r/GUI/Gizmos/GLGizmosManager.cpp

@@ -83,12 +83,16 @@ bool GLGizmosManager::init()
             return false;
     }
 
+    m_common_gizmos_data.reset(new CommonGizmosData());
+
+    // Order of gizmos in the vector must match order in EType!
     m_gizmos.emplace_back(new GLGizmoMove3D(m_parent, "move.svg", 0));
     m_gizmos.emplace_back(new GLGizmoScale3D(m_parent, "scale.svg", 1));
     m_gizmos.emplace_back(new GLGizmoRotate3D(m_parent, "rotate.svg", 2));
     m_gizmos.emplace_back(new GLGizmoFlatten(m_parent, "place.svg", 3));
     m_gizmos.emplace_back(new GLGizmoCut(m_parent, "cut.svg", 4));
-    m_gizmos.emplace_back(new GLGizmoSlaSupports(m_parent, "sla_supports.svg", 5));
+    m_gizmos.emplace_back(new GLGizmoHollow(m_parent, "hollow.svg", 5, m_common_gizmos_data.get()));
+    m_gizmos.emplace_back(new GLGizmoSlaSupports(m_parent, "sla_supports.svg", 6, m_common_gizmos_data.get()));
 
     for (auto& gizmo : m_gizmos) {
         if (! gizmo->init()) {
@@ -345,6 +349,7 @@ void GLGizmosManager::set_sla_support_data(ModelObject* model_object)
         return;
 
     dynamic_cast<GLGizmoSlaSupports*>(m_gizmos[SlaSupports].get())->set_sla_support_data(model_object, m_parent.get_selection());
+    dynamic_cast<GLGizmoHollow*>(m_gizmos[Hollow].get())->set_sla_support_data(model_object, m_parent.get_selection());
 }
 
 // Returns true if the gizmo used the event to do something, false otherwise.
@@ -353,15 +358,22 @@ bool GLGizmosManager::gizmo_event(SLAGizmoEventType action, const Vec2d& mouse_p
     if (!m_enabled || m_gizmos.empty())
         return false;
 
+    if (m_current == SlaSupports)
         return dynamic_cast<GLGizmoSlaSupports*>(m_gizmos[SlaSupports].get())->gizmo_event(action, mouse_position, shift_down, alt_down, control_down);
+    if (m_current == Hollow)
+        return dynamic_cast<GLGizmoHollow*>(m_gizmos[Hollow].get())->gizmo_event(action, mouse_position, shift_down, alt_down, control_down);
+    return false;
 }
 
 ClippingPlane GLGizmosManager::get_sla_clipping_plane() const
 {
-    if (!m_enabled || m_current != SlaSupports || m_gizmos.empty())
+    if (!m_enabled || (m_current != SlaSupports && m_current != Hollow) || m_gizmos.empty())
         return ClippingPlane::ClipsNothing();
 
+    if (m_current == SlaSupports)
         return dynamic_cast<GLGizmoSlaSupports*>(m_gizmos[SlaSupports].get())->get_sla_clipping_plane();
+    else
+        return dynamic_cast<GLGizmoHollow*>(m_gizmos[Hollow].get())->get_sla_clipping_plane();
 }
 
 bool GLGizmosManager::wants_reslice_supports_on_undo() const
@@ -401,7 +413,7 @@ bool GLGizmosManager::on_mouse_wheel(wxMouseEvent& evt)
 {
     bool processed = false;
 
-    if (m_current == SlaSupports) {
+    if (m_current == SlaSupports || m_current == Hollow) {
         float rot = (float)evt.GetWheelRotation() / (float)evt.GetWheelDelta();
         if (gizmo_event((rot > 0.f ? SLAGizmoEventType::MouseWheelUp : SLAGizmoEventType::MouseWheelDown), Vec2d::Zero(), evt.ShiftDown(), evt.AltDown(), evt.ControlDown()))
             processed = true;
@@ -459,7 +471,7 @@ bool GLGizmosManager::on_mouse(wxMouseEvent& evt)
 
         if (evt.LeftDown())
         {
-            if ((m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::LeftDown, mouse_pos, evt.ShiftDown(), evt.AltDown(), evt.ControlDown()))
+            if ((m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::LeftDown, mouse_pos, evt.ShiftDown(), evt.AltDown(), evt.ControlDown()))
                 // the gizmo got the event and took some action, there is no need to do anything more
                 processed = true;
             else if (!selection.is_empty() && grabber_contains_mouse()) {
@@ -477,17 +489,17 @@ bool GLGizmosManager::on_mouse(wxMouseEvent& evt)
                 processed = true;
             }
         }
-        else if (evt.RightDown() && (selected_object_idx != -1) && (m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::RightDown))
+        else if (evt.RightDown() && (selected_object_idx != -1) && (m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::RightDown))
         {
             // we need to set the following right up as processed to avoid showing the context menu if the user release the mouse over the object
             pending_right_up = true;
             // event was taken care of by the SlaSupports gizmo
             processed = true;
         }
-        else if (evt.Dragging() && (m_parent.get_move_volume_id() != -1) && (m_current == SlaSupports))
+        else if (evt.Dragging() && (m_parent.get_move_volume_id() != -1) && (m_current == SlaSupports || m_current == Hollow))
                         // don't allow dragging objects with the Sla gizmo on
             processed = true;
-        else if (evt.Dragging() && (m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::Dragging, mouse_pos, evt.ShiftDown(), evt.AltDown(), evt.ControlDown()))
+        else if (evt.Dragging() && (m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::Dragging, mouse_pos, evt.ShiftDown(), evt.AltDown(), evt.ControlDown()))
         {
             // the gizmo got the event and took some action, no need to do anything more here
             m_parent.set_as_dirty();
@@ -563,7 +575,7 @@ bool GLGizmosManager::on_mouse(wxMouseEvent& evt)
 
             processed = true;
         }
-        else if (evt.LeftUp() && (m_current == SlaSupports) && !m_parent.is_mouse_dragging())
+        else if (evt.LeftUp() && (m_current == SlaSupports || m_current == Hollow) && !m_parent.is_mouse_dragging())
         {
             // in case SLA gizmo is selected, we just pass the LeftUp event and stop processing - neither
             // object moving or selecting is suppressed in that case
@@ -628,7 +640,7 @@ bool GLGizmosManager::on_char(wxKeyEvent& evt)
 #endif /* __APPLE__ */
         {
             // Sla gizmo selects all support points
-            if ((m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::SelectAll))
+            if ((m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::SelectAll))
                 processed = true;
 
             break;
@@ -662,7 +674,7 @@ bool GLGizmosManager::on_char(wxKeyEvent& evt)
         case 'r' :
         case 'R' :
         {
-            if ((m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::ResetClippingPlane))
+            if ((m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::ResetClippingPlane))
                 processed = true;
 
             break;
@@ -674,7 +686,7 @@ bool GLGizmosManager::on_char(wxKeyEvent& evt)
         case WXK_DELETE:
 #endif /* __APPLE__ */
         {
-            if ((m_current == SlaSupports) && gizmo_event(SLAGizmoEventType::Delete))
+            if ((m_current == SlaSupports || m_current == Hollow) && gizmo_event(SLAGizmoEventType::Delete))
                 processed = true;
 
             break;
@@ -736,20 +748,31 @@ bool GLGizmosManager::on_key(wxKeyEvent& evt)
 
     if (evt.GetEventType() == wxEVT_KEY_UP)
     {
-        if (m_current == SlaSupports)
+        if (m_current == SlaSupports || m_current == Hollow)
         {
+            bool is_editing = true;
+            bool is_rectangle_dragging = false;
+
+            if (m_current == SlaSupports) {
                 GLGizmoSlaSupports* gizmo = dynamic_cast<GLGizmoSlaSupports*>(get_current());
+                is_editing = gizmo->is_in_editing_mode();
+                is_rectangle_dragging = gizmo->is_selection_rectangle_dragging();
+            }
+            else {
+                GLGizmoHollow* gizmo = dynamic_cast<GLGizmoHollow*>(get_current());
+                is_rectangle_dragging = gizmo->is_selection_rectangle_dragging();
+            }
 
             if (keyCode == WXK_SHIFT)
             {
                 // shift has been just released - SLA gizmo might want to close rectangular selection.
-                if (gizmo_event(SLAGizmoEventType::ShiftUp) || (gizmo->is_in_editing_mode() && gizmo->is_selection_rectangle_dragging()))
+                if (gizmo_event(SLAGizmoEventType::ShiftUp) || (is_editing && is_rectangle_dragging))
                     processed = true;
             }
             else if (keyCode == WXK_ALT)
             {
                 // alt has been just released - SLA gizmo might want to close rectangular selection.
-                if (gizmo_event(SLAGizmoEventType::AltUp) || (gizmo->is_in_editing_mode() && gizmo->is_selection_rectangle_dragging()))
+                if (gizmo_event(SLAGizmoEventType::AltUp) || (is_editing && is_rectangle_dragging))
                     processed = true;
             }
         }

src/slic3r/GUI/Gizmos/GLGizmosManager.hpp

@@ -54,11 +54,13 @@ public:
 
     enum EType : unsigned char
     {
+        // Order must match index in m_gizmos!
         Move,
         Scale,
         Rotate,
         Flatten,
         Cut,
+        Hollow,
         SlaSupports,
         Undefined
     };
@@ -111,6 +113,7 @@ private:
     MouseCapture m_mouse_capture;
     std::string m_tooltip;
     bool m_serializing;
+    std::unique_ptr<CommonGizmosData> m_common_gizmos_data;
 
 public:
     explicit GLGizmosManager(GLCanvas3D& parent);
@@ -168,6 +171,7 @@ public:
     void update_data();
 
     EType get_current_type() const { return m_current; }
+    GLGizmoBase* get_current() const;
 
     bool is_running() const;
     bool handle_shortcut(int key);
@@ -216,8 +220,6 @@ private:
     float get_scaled_total_height() const;
     float get_scaled_total_width() const;
 
-    GLGizmoBase* get_current() const;
-
     bool generate_icons_texture() const;
 
     void update_on_off_state(const Vec2d& mouse_pos);

src/slic3r/GUI/Job.hpp

@@ -0,0 +1,155 @@
+#ifndef JOB_HPP
+#define JOB_HPP
+
+#include <atomic>
+
+#include <slic3r/Utils/Thread.hpp>
+#include <slic3r/GUI/I18N.hpp>
+#include <slic3r/GUI/ProgressIndicator.hpp>
+
+#include <wx/event.h>
+
+#include <boost/thread.hpp>
+
+namespace Slic3r { namespace GUI {
+
+// A class to handle UI jobs like arranging and optimizing rotation.
+// These are not instant jobs, the user has to be informed about their
+// state in the status progress indicator. On the other hand they are
+// separated from the background slicing process. Ideally, these jobs should
+// run when the background process is not running.
+//
+// TODO: A mechanism would be useful for blocking the plater interactions:
+// objects would be frozen for the user. In case of arrange, an animation
+// could be shown, or with the optimize orientations, partial results
+// could be displayed.
+class Job : public wxEvtHandler
+{
+    int               m_range = 100;
+    boost::thread     m_thread;
+    std::atomic<bool> m_running{false}, m_canceled{false};
+    bool              m_finalized = false;
+    std::shared_ptr<ProgressIndicator> m_progress;
+    
+    void run()
+    {
+        m_running.store(true);
+        process();
+        m_running.store(false);
+        
+        // ensure to call the last status to finalize the job
+        update_status(status_range(), "");
+    }
+    
+protected:
+    // status range for a particular job
+    virtual int status_range() const { return 100; }
+    
+    // status update, to be used from the work thread (process() method)
+    void update_status(int st, const wxString &msg = "")
+    {
+        auto evt = new wxThreadEvent();
+        evt->SetInt(st);
+        evt->SetString(msg);
+        wxQueueEvent(this, evt);
+    }
+    
+    bool        was_canceled() const { return m_canceled.load(); }
+    
+    // Launched just before start(), a job can use it to prepare internals
+    virtual void prepare() {}
+    
+    // Launched when the job is finished. It refreshes the 3Dscene by def.
+    virtual void finalize() { m_finalized = true; }
+    
+    
+public:
+    Job(std::shared_ptr<ProgressIndicator> pri) : m_progress(pri)
+    {
+        Bind(wxEVT_THREAD, [this](const wxThreadEvent &evt) {
+            auto msg = evt.GetString();
+            if (!msg.empty())
+                m_progress->set_status_text(msg.ToUTF8().data());
+            
+            if (m_finalized) return;
+            
+            m_progress->set_progress(evt.GetInt());
+            if (evt.GetInt() == status_range()) {
+                // set back the original range and cancel callback
+                m_progress->set_range(m_range);
+                m_progress->set_cancel_callback();
+                wxEndBusyCursor();
+                
+                finalize();
+                
+                // dont do finalization again for the same process
+                m_finalized = true;
+            }
+        });
+    }
+    
+    bool is_finalized() const { return m_finalized; }
+    
+    Job(const Job &) = delete;
+    Job(Job &&)      = delete;
+    Job &operator=(const Job &) = delete;
+    Job &operator=(Job &&) = delete;
+    
+    virtual void process() = 0;
+    
+    void start()
+    { // Start the job. No effect if the job is already running
+        if (!m_running.load()) {
+            prepare();
+            
+            // Save the current status indicatior range and push the new one
+            m_range = m_progress->get_range();
+            m_progress->set_range(status_range());
+            
+            // init cancellation flag and set the cancel callback
+            m_canceled.store(false);
+            m_progress->set_cancel_callback(
+                [this]() { m_canceled.store(true); });
+            
+            m_finalized = false;
+            
+            // Changing cursor to busy
+            wxBeginBusyCursor();
+            
+            try { // Execute the job
+                m_thread = create_thread([this] { this->run(); });
+            } catch (std::exception &) {
+                update_status(status_range(),
+                              _(L("ERROR: not enough resources to "
+                                  "execute a new job.")));
+            }
+            
+            // The state changes will be undone when the process hits the
+            // last status value, in the status update handler (see ctor)
+        }
+    }
+    
+    // To wait for the running job and join the threads. False is
+    // returned if the timeout has been reached and the job is still
+    // running. Call cancel() before this fn if you want to explicitly
+    // end the job.
+    bool join(int timeout_ms = 0)
+    {
+        if (!m_thread.joinable()) return true;
+        
+        if (timeout_ms <= 0)
+            m_thread.join();
+        else if (!m_thread.try_join_for(boost::chrono::milliseconds(timeout_ms)))
+            return false;
+        
+        return true;
+    }
+    
+    bool is_running() const { return m_running.load(); }
+    void cancel() { m_canceled.store(true); }
+};
+
+}
+}
+
+#endif // JOB_HPP

src/slic3r/GUI/MainFrame.cpp

@@ -58,7 +58,8 @@ DPIFrame(NULL, wxID_ANY, "", wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_S
 #endif // _WIN32
 
 	// initialize status bar
-	m_statusbar.reset(new ProgressStatusBar(this));
+	m_statusbar = std::make_shared<ProgressStatusBar>(this);
+    m_statusbar->set_font(GUI::wxGetApp().normal_font());
 	m_statusbar->embed(this);
     m_statusbar->set_status_text(_(L("Version")) + " " +
 		SLIC3R_VERSION +

src/slic3r/GUI/MainFrame.hpp

@@ -135,7 +135,7 @@ public:
     Plater*             m_plater { nullptr };
     wxNotebook*         m_tabpanel { nullptr };
     wxProgressDialog*   m_progress_dialog { nullptr };
-    std::unique_ptr<ProgressStatusBar>  m_statusbar;
+    std::shared_ptr<ProgressStatusBar>  m_statusbar;
 };
 
 } // GUI

src/slic3r/GUI/MeshUtils.cpp

@@ -5,10 +5,6 @@
 
 #include "slic3r/GUI/Camera.hpp"
 
-// There is an L function in igl that would be overridden by our localization macro.
-#undef L
-#include <igl/AABB.h>
-
 #include <GL/glew.h>
 
 
@@ -99,57 +95,6 @@ void MeshClipper::recalculate_triangles()
 }
 
 
-class MeshRaycaster::AABBWrapper {
-public:
-    AABBWrapper(const TriangleMesh* mesh);
-    ~AABBWrapper() { m_AABB.deinit(); }
-
-    typedef Eigen::Map<const Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXfUnaligned;
-    typedef Eigen::Map<const Eigen::Matrix<int, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::DontAlign>> MapMatrixXiUnaligned;
-    igl::AABB<MapMatrixXfUnaligned, 3> m_AABB;
-
-    Vec3f get_hit_pos(const igl::Hit& hit) const;
-    Vec3f get_hit_normal(const igl::Hit& hit) const;
-
-private:
-    const TriangleMesh* m_mesh;
-};
-
-MeshRaycaster::AABBWrapper::AABBWrapper(const TriangleMesh* mesh)
-    : m_mesh(mesh)
-{
-    m_AABB.init(
-        MapMatrixXfUnaligned(m_mesh->its.vertices.front().data(), m_mesh->its.vertices.size(), 3),
-        MapMatrixXiUnaligned(m_mesh->its.indices.front().data(), m_mesh->its.indices.size(), 3));
-}
-
-
-MeshRaycaster::MeshRaycaster(const TriangleMesh& mesh)
-    : m_AABB_wrapper(new AABBWrapper(&mesh)), m_mesh(&mesh)
-{
-}
-
-// Define the default destructor here. This is needed for the PIMPL with
-// unique_ptr to work, the AABBWrapper is complete here.
-MeshRaycaster::~MeshRaycaster() = default;
-
-Vec3f MeshRaycaster::AABBWrapper::get_hit_pos(const igl::Hit& hit) const
-{
-    const stl_triangle_vertex_indices& indices = m_mesh->its.indices[hit.id];
-    return Vec3f((1-hit.u-hit.v) * m_mesh->its.vertices[indices(0)]
-               + hit.u           * m_mesh->its.vertices[indices(1)]
-               + hit.v           * m_mesh->its.vertices[indices(2)]);
-}
-
-
-Vec3f MeshRaycaster::AABBWrapper::get_hit_normal(const igl::Hit& hit) const
-{
-    const stl_triangle_vertex_indices& indices = m_mesh->its.indices[hit.id];
-    Vec3f a(m_mesh->its.vertices[indices(1)] - m_mesh->its.vertices[indices(0)]);
-    Vec3f b(m_mesh->its.vertices[indices(2)] - m_mesh->its.vertices[indices(0)]);
-    return Vec3f(a.cross(b));
-}
-
 
 bool MeshRaycaster::unproject_on_mesh(const Vec2d& mouse_pos, const Transform3d& trafo, const Camera& camera,
                                       Vec3f& position, Vec3f& normal, const ClippingPlane* clipping_plane) const
@@ -163,27 +108,20 @@ bool MeshRaycaster::unproject_on_mesh(const Vec2d& mouse_pos, const Transform3d&
     ::gluUnProject(mouse_pos(0), viewport[3] - mouse_pos(1), 0., model_mat.data(), proj_mat.data(), viewport.data(), &pt1(0), &pt1(1), &pt1(2));
     ::gluUnProject(mouse_pos(0), viewport[3] - mouse_pos(1), 1., model_mat.data(), proj_mat.data(), viewport.data(), &pt2(0), &pt2(1), &pt2(2));
 
-    std::vector<igl::Hit> hits;
-
     Transform3d inv = trafo.inverse();
-
     pt1 = inv * pt1;
     pt2 = inv * pt2;
 
-    if (! m_AABB_wrapper->m_AABB.intersect_ray(
+    std::vector<sla::EigenMesh3D::hit_result> hits = m_emesh.query_ray_hits(pt1, pt2-pt1);
-        AABBWrapper::MapMatrixXfUnaligned(m_mesh->its.vertices.front().data(), m_mesh->its.vertices.size(), 3),
+    if (hits.empty())
-        AABBWrapper::MapMatrixXiUnaligned(m_mesh->its.indices.front().data(), m_mesh->its.indices.size(), 3),
-        pt1.cast<float>(), (pt2-pt1).cast<float>(), hits))
         return false; // no intersection found
 
-    std::sort(hits.begin(), hits.end(), [](const igl::Hit& a, const igl::Hit& b) { return a.t < b.t; });
-
     unsigned i = 0;
 
     // Remove points that are obscured or cut by the clipping plane
     if (clipping_plane) {
         for (i=0; i<hits.size(); ++i)
-            if (! clipping_plane->is_point_clipped(trafo * m_AABB_wrapper->get_hit_pos(hits[i]).cast<double>()))
+            if (! clipping_plane->is_point_clipped(trafo * hits[i].position()))
                 break;
 
         if (i==hits.size() || (hits.size()-i) % 2 != 0) {
@@ -194,8 +132,8 @@ bool MeshRaycaster::unproject_on_mesh(const Vec2d& mouse_pos, const Transform3d&
     }
 
     // Now stuff the points in the provided vector and calculate normals if asked about them:
-    position = m_AABB_wrapper->get_hit_pos(hits[i]);
+    position = hits[i].position().cast<float>();
-    normal = m_AABB_wrapper->get_hit_normal(hits[i]);
+    normal = hits[i].normal().cast<float>();
     return true;
 }
 
@@ -219,24 +157,21 @@ std::vector<unsigned> MeshRaycaster::get_unobscured_idxs(const Geometry::Transfo
 
         bool is_obscured = false;
         // Cast a ray in the direction of the camera and look for intersection with the mesh:
-        std::vector<igl::Hit> hits;
+        std::vector<sla::EigenMesh3D::hit_result> hits;
         // Offset the start of the ray by EPSILON to account for numerical inaccuracies.
-        if (m_AABB_wrapper->m_AABB.intersect_ray(
+        hits = m_emesh.query_ray_hits((inverse_trafo * pt + direction_to_camera_mesh * EPSILON).cast<double>(),
-                AABBWrapper::MapMatrixXfUnaligned(m_mesh->its.vertices.front().data(), m_mesh->its.vertices.size(), 3),
+                                      direction_to_camera.cast<double>());
-                AABBWrapper::MapMatrixXiUnaligned(m_mesh->its.indices.front().data(), m_mesh->its.indices.size(), 3),
-                inverse_trafo * pt + direction_to_camera_mesh * EPSILON, direction_to_camera_mesh, hits)) {
 
-            std::sort(hits.begin(), hits.end(), [](const igl::Hit& h1, const igl::Hit& h2) { return h1.t < h2.t; });
 
+        if (! hits.empty()) {
             // If the closest hit facet normal points in the same direction as the ray,
             // we are looking through the mesh and should therefore discard the point:
-            if (m_AABB_wrapper->get_hit_normal(hits.front()).dot(direction_to_camera_mesh) > 0.f)
+            if (hits.front().normal().dot(direction_to_camera_mesh.cast<double>()) > 0)
                 is_obscured = true;
 
             // Eradicate all hits that the caller wants to ignore
             for (unsigned j=0; j<hits.size(); ++j) {
-                const igl::Hit& hit = hits[j];
+                if (clipping_plane && clipping_plane->is_point_clipped(trafo.get_matrix() * hits[j].position())) {
-                if (clipping_plane && clipping_plane->is_point_clipped(trafo.get_matrix() * m_AABB_wrapper->get_hit_pos(hit).cast<double>())) {
                     hits.erase(hits.begin()+j);
                     --j;
                 }
@@ -257,17 +192,15 @@ std::vector<unsigned> MeshRaycaster::get_unobscured_idxs(const Geometry::Transfo
 Vec3f MeshRaycaster::get_closest_point(const Vec3f& point, Vec3f* normal) const
 {
     int idx = 0;
-    Eigen::Matrix<float, 1, 3> closest_point;
+    Vec3d closest_point;
-    m_AABB_wrapper->m_AABB.squared_distance(
+    m_emesh.squared_distance(point.cast<double>(), idx, closest_point);
-        AABBWrapper::MapMatrixXfUnaligned(m_mesh->its.vertices.front().data(), m_mesh->its.vertices.size(), 3),
-        AABBWrapper::MapMatrixXiUnaligned(m_mesh->its.indices.front().data(), m_mesh->its.indices.size(), 3),
-        point, idx, closest_point);
     if (normal) {
-        igl::Hit imag_hit;
+        auto indices = m_emesh.F().row(idx);
-        imag_hit.id = idx;
+        Vec3d a(m_emesh.V().row(indices(1)) - m_emesh.V().row(indices(0)));
-        *normal = m_AABB_wrapper->get_hit_normal(imag_hit);
+        Vec3d b(m_emesh.V().row(indices(2)) - m_emesh.V().row(indices(0)));
+        *normal = Vec3f(a.cross(b).cast<float>());
     }
-    return closest_point;
+    return closest_point.cast<float>();
 }
 
 

src/slic3r/GUI/MeshUtils.hpp

@@ -3,6 +3,7 @@
 
 #include "libslic3r/Point.hpp"
 #include "libslic3r/Geometry.hpp"
+#include "libslic3r/SLA/EigenMesh3D.hpp"
 
 
 #include <cfloat>
@@ -46,7 +47,7 @@ public:
     bool operator!=(const ClippingPlane& cp) const { return ! (*this==cp); }
 
     double distance(const Vec3d& pt) const {
-        assert(is_approx(get_normal().norm(), 1.));
+        // FIXME: this fails: assert(is_approx(get_normal().norm(), 1.));
         return (-get_normal().dot(pt) + m_data[3]);
     }
 
@@ -104,11 +105,11 @@ private:
 // whether certain points are visible or obscured by the mesh etc.
 class MeshRaycaster {
 public:
-    // The class saves a const* to the mesh, called is responsible
+    // The class makes a copy of the mesh as EigenMesh3D.
-    // for making sure it does not get invalid.
+    // The pointer can be invalidated after constructor returns.
-    MeshRaycaster(const TriangleMesh& mesh);
+    MeshRaycaster(const TriangleMesh& mesh)
-
+        : m_emesh(mesh)
-    ~MeshRaycaster();
+    {}
 
     // Given a mouse position, this returns true in case it is on the mesh.
     bool unproject_on_mesh(
@@ -136,10 +137,7 @@ public:
     Vec3f get_closest_point(const Vec3f& point, Vec3f* normal = nullptr) const;
 
 private:
-    // PIMPL wrapper around igl::AABB so I don't have to include the header-only IGL here
+    sla::EigenMesh3D m_emesh;
-    class AABBWrapper;
-    std::unique_ptr<AABBWrapper> m_AABB_wrapper;
-    const TriangleMesh* m_mesh = nullptr;
 };
 
     

src/slic3r/GUI/Plater.cpp

@@ -39,11 +39,13 @@
 #include "libslic3r/GCode/ThumbnailData.hpp"
 #endif // ENABLE_THUMBNAIL_GENERATOR
 #include "libslic3r/Model.hpp"
+#include "libslic3r/SLA/Hollowing.hpp"
+#include "libslic3r/SLA/Rotfinder.hpp"
+#include "libslic3r/SLA/SupportPoint.hpp"
 #include "libslic3r/Polygon.hpp"
 #include "libslic3r/Print.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/SLAPrint.hpp"
-#include "libslic3r/SLA/SLARotfinder.hpp"
 #include "libslic3r/Utils.hpp"
 
 //#include "libslic3r/ClipperUtils.hpp"
@@ -70,6 +72,7 @@
 #include "Camera.hpp"
 #include "Mouse3DController.hpp"
 #include "Tab.hpp"
+#include "Job.hpp"
 #include "PresetBundle.hpp"
 #include "BackgroundSlicingProcess.hpp"
 #include "ProgressStatusBar.hpp"
@@ -1503,144 +1506,39 @@ struct Plater::priv
     // objects would be frozen for the user. In case of arrange, an animation
     // could be shown, or with the optimize orientations, partial results
     // could be displayed.
-    class Job : public wxEvtHandler
+    class PlaterJob: public Job
     {
-        int               m_range = 100;
+        priv *m_plater;
-        boost::thread     m_thread;
-        priv *            m_plater = nullptr;
-        std::atomic<bool> m_running{false}, m_canceled{false};
-        bool              m_finalized = false;
-
-        void run()
-        {
-            m_running.store(true);
-            process();
-            m_running.store(false);
-
-            // ensure to call the last status to finalize the job
-            update_status(status_range(), "");
-        }
-
     protected:
-        // status range for a particular job
-        virtual int status_range() const { return 100; }
-
-        // status update, to be used from the work thread (process() method)
-        void update_status(int st, const wxString &msg = "")
-        {
-            auto evt = new wxThreadEvent();
-            evt->SetInt(st);
-            evt->SetString(msg);
-            wxQueueEvent(this, evt);
-        }
 
         priv &      plater() { return *m_plater; }
         const priv &plater() const { return *m_plater; }
-        bool        was_canceled() const { return m_canceled.load(); }
-
-        // Launched just before start(), a job can use it to prepare internals
-        virtual void prepare() {}
 
         // Launched when the job is finished. It refreshes the 3Dscene by def.
-        virtual void finalize()
+        void finalize() override
         {
             // Do a full refresh of scene tree, including regenerating
             // all the GLVolumes. FIXME The update function shall just
             // reload the modified matrices.
-            if (!was_canceled())
+            if (!Job::was_canceled())
                 plater().update(unsigned(UpdateParams::FORCE_FULL_SCREEN_REFRESH));
+            
+            Job::finalize();
         }
 
     public:
-        Job(priv *_plater) : m_plater(_plater)
+        PlaterJob(priv *_plater)
-        {
+            : Job(_plater->statusbar()), m_plater(_plater)
-            Bind(wxEVT_THREAD, [this](const wxThreadEvent &evt) {
+        {}
-                auto msg = evt.GetString();
-                if (!msg.empty())
-                    plater().statusbar()->set_status_text(msg);
-
-                if (m_finalized) return;
-
-                plater().statusbar()->set_progress(evt.GetInt());
-                if (evt.GetInt() == status_range()) {
-                    // set back the original range and cancel callback
-                    plater().statusbar()->set_range(m_range);
-                    plater().statusbar()->set_cancel_callback();
-                    wxEndBusyCursor();
-
-                    finalize();
-
-                    // dont do finalization again for the same process
-                    m_finalized = true;
-                }
-            });
-        }
-
-        Job(const Job &) = delete;
-        Job(Job &&)      = delete;
-        Job &operator=(const Job &) = delete;
-        Job &operator=(Job &&) = delete;
-
-        virtual void process() = 0;
-
-        void start()
-        { // Start the job. No effect if the job is already running
-            if (!m_running.load()) {
-                prepare();
-
-                // Save the current status indicatior range and push the new one
-                m_range = plater().statusbar()->get_range();
-                plater().statusbar()->set_range(status_range());
-
-                // init cancellation flag and set the cancel callback
-                m_canceled.store(false);
-                plater().statusbar()->set_cancel_callback(
-                    [this]() { m_canceled.store(true); });
-
-                m_finalized = false;
-
-                // Changing cursor to busy
-                wxBeginBusyCursor();
-
-                try { // Execute the job
-                    m_thread = create_thread([this] { this->run(); });
-                } catch (std::exception &) {
-                    update_status(status_range(),
-                                  _(L("ERROR: not enough resources to "
-                                      "execute a new job.")));
-                }
-
-                // The state changes will be undone when the process hits the
-                // last status value, in the status update handler (see ctor)
-            }
-        }
-
-        // To wait for the running job and join the threads. False is
-        // returned if the timeout has been reached and the job is still
-        // running. Call cancel() before this fn if you want to explicitly
-        // end the job.
-        bool join(int timeout_ms = 0)
-        {
-            if (!m_thread.joinable()) return true;
-            
-            if (timeout_ms <= 0)
-                m_thread.join();
-            else if (!m_thread.try_join_for(boost::chrono::milliseconds(timeout_ms)))
-                return false;
-            
-            return true;
-        }
-
-        bool is_running() const { return m_running.load(); }
-        void cancel() { m_canceled.store(true); }
     };
 
     enum class Jobs : size_t {
         Arrange,
-        Rotoptimize
+        Rotoptimize,
+        Hollow
     };
 
-    class ArrangeJob : public Job
+    class ArrangeJob : public PlaterJob
     {
         using ArrangePolygon = arrangement::ArrangePolygon;
         using ArrangePolygons = arrangement::ArrangePolygons;
@@ -1757,7 +1655,7 @@ struct Plater::priv
         }
 
     public:
-        using Job::Job;
+        using PlaterJob::PlaterJob;
 
         int status_range() const override { return int(m_selected.size()); }
 
@@ -1774,13 +1672,30 @@ struct Plater::priv
         }
     };
 
-    class RotoptimizeJob : public Job
+    class RotoptimizeJob : public PlaterJob
     {
     public:
-        using Job::Job;
+        using PlaterJob::PlaterJob;
         void process() override;
     };
 
+    class HollowJob : public PlaterJob
+    {
+    public:
+        using PlaterJob::PlaterJob;
+        void prepare() override;
+        void process() override;
+        void finalize() override;
+    private:
+        GLGizmoHollow * get_gizmo();
+        const GLGizmoHollow * get_gizmo() const;
+        
+        std::unique_ptr<TriangleMesh> m_output_mesh;
+        std::unique_ptr<MeshRaycaster> m_output_raycaster;
+        const TriangleMesh* m_object_mesh = nullptr;
+        sla::HollowingConfig m_cfg;
+    };
+
     // Jobs defined inside the group class will be managed so that only one can
     // run at a time. Also, the background process will be stopped if a job is
     // started.
@@ -1792,6 +1707,7 @@ struct Plater::priv
 
         ArrangeJob arrange_job{m_plater};
         RotoptimizeJob rotoptimize_job{m_plater};
+        HollowJob hollow_job{m_plater};
 
         // To create a new job, just define a new subclass of Job, implement
         // the process and the optional prepare() and finalize() methods
@@ -1799,7 +1715,8 @@ struct Plater::priv
         // if it cannot run concurrently with other jobs in this group
 
         std::vector<std::reference_wrapper<Job>> m_jobs{arrange_job,
-                                                        rotoptimize_job};
+                                                        rotoptimize_job,
+                                                        hollow_job};
 
     public:
         ExclusiveJobGroup(priv *_plater) : m_plater(_plater) {}
@@ -1876,7 +1793,7 @@ struct Plater::priv
 
     void reset_all_gizmos();
     void update_ui_from_settings();
-    ProgressStatusBar* statusbar();
+    std::shared_ptr<ProgressStatusBar> statusbar();
     std::string get_config(const std::string &key) const;
     BoundingBoxf bed_shape_bb() const;
     BoundingBox scaled_bed_shape_bb() const;
@@ -1901,6 +1818,7 @@ struct Plater::priv
     void reset();
     void mirror(Axis axis);
     void arrange();
+    void hollow();
     void sla_optimize_rotation();
     void split_object();
     void split_volume();
@@ -2291,9 +2209,9 @@ void Plater::priv::update_ui_from_settings()
     preview->get_canvas3d()->update_ui_from_settings();
 }
 
-ProgressStatusBar* Plater::priv::statusbar()
+std::shared_ptr<ProgressStatusBar> Plater::priv::statusbar()
 {
-    return main_frame->m_statusbar.get();
+    return main_frame->m_statusbar;
 }
 
 std::string Plater::priv::get_config(const std::string &key) const
@@ -2815,6 +2733,12 @@ void Plater::priv::arrange()
     m_ui_jobs.start(Jobs::Arrange);
 }
 
+void Plater::priv::hollow()
+{
+    this->take_snapshot(_(L("Hollow")));
+    m_ui_jobs.start(Jobs::Hollow);
+}
+
 // This method will find an optimal orientation for the currently selected item
 // Very similar in nature to the arrange method above...
 void Plater::priv::sla_optimize_rotation() {
@@ -2946,6 +2870,68 @@ void Plater::priv::RotoptimizeJob::process()
                                  : _(L("Orientation found.")));
 }
 
+void Plater::priv::HollowJob::prepare()
+{
+    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
+    const GLGizmoHollow* gizmo_hollow = dynamic_cast<const GLGizmoHollow*>(gizmo_manager.get_current());
+    assert(gizmo_hollow);
+    auto hlw_data = gizmo_hollow->get_hollowing_parameters();
+    m_object_mesh = hlw_data.first;
+    m_cfg = hlw_data.second;
+    m_output_mesh.reset();
+}
+
+void Plater::priv::HollowJob::process()
+{
+    sla::JobController ctl;
+    ctl.stopcondition = [this]{ return was_canceled(); };
+    ctl.statuscb = [this](unsigned st, const std::string &s) {
+        if (st < 100) update_status(int(st), s);
+    };
+    
+    std::unique_ptr<TriangleMesh> omesh =
+        sla::generate_interior(*m_object_mesh, m_cfg, ctl);
+    
+    if (omesh && !omesh->empty()) {
+        m_output_mesh.reset(new TriangleMesh{*m_object_mesh});
+        m_output_mesh->merge(*omesh);
+        m_output_mesh->require_shared_vertices();
+        
+        update_status(90, _(L("Indexing hollowed object")));
+        
+        m_output_raycaster.reset(new MeshRaycaster(*m_output_mesh));
+        
+        update_status(100, was_canceled() ? _(L("Hollowing cancelled.")) :
+                                            _(L("Hollowing done.")));
+    } else {
+        update_status(100, _(L("Hollowing failed.")));
+    }
+}
+
+void Plater::priv::HollowJob::finalize()
+{
+    if (auto gizmo = get_gizmo()) {
+        gizmo->update_mesh_raycaster(std::move(m_output_raycaster));
+        gizmo->update_hollowed_mesh(std::move(m_output_mesh));
+    }       
+}
+
+GLGizmoHollow *Plater::priv::HollowJob::get_gizmo()
+{
+    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
+    auto ret = dynamic_cast<GLGizmoHollow*>(gizmo_manager.get_current());
+    assert(ret);
+    return ret;
+}
+
+const GLGizmoHollow *Plater::priv::HollowJob::get_gizmo() const
+{
+    const GLGizmosManager& gizmo_manager = plater().q->canvas3D()->get_gizmos_manager();
+    auto ret = dynamic_cast<const GLGizmoHollow*>(gizmo_manager.get_current());
+    assert(ret);
+    return ret;
+}
+
 void Plater::priv::split_object()
 {
     int obj_idx = get_selected_object_idx();
@@ -5066,6 +5052,11 @@ void Plater::export_toolpaths_to_obj() const
     p->preview->get_canvas3d()->export_toolpaths_to_obj(into_u8(path).c_str());
 }
 
+void Plater::hollow()
+{
+    p->hollow();
+}
+
 void Plater::reslice()
 {
     // Stop arrange and (or) optimize rotation tasks.

src/slic3r/GUI/Plater.hpp

@@ -194,6 +194,7 @@ public:
     void reload_from_disk();
     bool has_toolpaths_to_export() const;
     void export_toolpaths_to_obj() const;
+    void hollow();
     void reslice();
     void reslice_SLA_supports(const ModelObject &object, bool postpone_error_messages = false);
     void changed_object(int obj_idx);

src/slic3r/GUI/Preset.cpp

@@ -505,6 +505,10 @@ const std::vector<std::string>& Preset::sla_print_options()
             "pad_object_connector_stride",
             "pad_object_connector_width",
             "pad_object_connector_penetration",
+            "hollowing_enable",
+            "hollowing_min_thickness",
+            "hollowing_quality",
+            "hollowing_closing_distance",
             "output_filename_format",
             "default_sla_print_profile",
             "compatible_printers",

src/slic3r/GUI/ProgressIndicator.hpp

@@ -11,58 +11,17 @@ namespace Slic3r {
  */
 class ProgressIndicator {
 public:
-    using CancelFn = std::function<void(void)>; // Cancel function signature.
     
-private:
+    /// Cancel callback function type
-    float m_state = .0f, m_max = 1.f, m_step;
+    using CancelFn = std::function<void()>;
-    CancelFn m_cancelfunc = [](){};
     
-public:
+    virtual ~ProgressIndicator() = default;
     
-    inline virtual ~ProgressIndicator() {}
+    virtual void set_range(int range) = 0;
-
+    virtual void set_cancel_callback(CancelFn = CancelFn()) = 0;
-    /// Get the maximum of the progress range.
+    virtual void set_progress(int pr) = 0;
-    float max() const { return m_max; }
+    virtual void set_status_text(const char *) = 0; // utf8 char array
-
+    virtual int  get_range() const = 0;
-    /// Get the current progress state
-    float state() const { return m_state; }
-
-    /// Set the maximum of the progress range
-    virtual void max(float maxval) { m_max = maxval; }
-
-    /// Set the current state of the progress.
-    virtual void state(float val)  { m_state = val; }
-
-    /**
-     * @brief Number of states int the progress. Can be used instead of giving a
-     * maximum value.
-     */
-    virtual void states(unsigned statenum) {
-        m_step = m_max / statenum;
-    }
-
-    /// Message shown on the next status update.
-    virtual void message(const std::string&) = 0;
-
-    /// Title of the operation.
-    virtual void title(const std::string&) = 0;
-
-    /// Formatted message for the next status update. Works just like sprintf.
-    virtual void message_fmt(const std::string& fmt, ...);
-
-    /// Set up a cancel callback for the operation if feasible.
-    virtual void on_cancel(CancelFn func = CancelFn()) { m_cancelfunc = func; }
-
-    /**
-     * Explicitly shut down the progress indicator and call the associated
-     * callback.
-     */
-    virtual void cancel() { m_cancelfunc(); }
-
-    /// Convenience function to call message and status update in one function.
-    void update(float st, const std::string& msg) {
-        message(msg); state(st);
-    }
 };
 
 }

src/slic3r/GUI/ProgressStatusBar.cpp

@@ -15,8 +15,7 @@
 namespace Slic3r {
 
 ProgressStatusBar::ProgressStatusBar(wxWindow *parent, int id)
-    : self{new wxStatusBar(parent ? parent : GUI::wxGetApp().mainframe,
+    : self{new wxStatusBar(parent, id == -1 ? wxID_ANY : id)}
-                           id == -1 ? wxID_ANY : id)}
     , m_prog{new wxGauge(self,
                          wxGA_HORIZONTAL,
                          100,
@@ -32,7 +31,6 @@ ProgressStatusBar::ProgressStatusBar(wxWindow *parent, int id)
     m_prog->Hide();
     m_cancelbutton->Hide();
 
-	self->SetFont(GUI::wxGetApp().normal_font());
     self->SetFieldsCount(3);
     int w[] = {-1, 150, 155};
     self->SetStatusWidths(3, w);
@@ -149,8 +147,7 @@ void ProgressStatusBar::run(int rate)
 
 void ProgressStatusBar::embed(wxFrame *frame)
 {
-    wxFrame* mf = frame ? frame : GUI::wxGetApp().mainframe;
+    if(frame) frame->SetStatusBar(self);
-    if(mf) mf->SetStatusBar(self);
 }
 
 void ProgressStatusBar::set_status_text(const wxString& txt)
@@ -173,6 +170,11 @@ wxString ProgressStatusBar::get_status_text() const
     return self->GetStatusText();
 }
 
+void ProgressStatusBar::set_font(const wxFont &font)
+{
+    self->SetFont(font);
+}
+
 void ProgressStatusBar::show_cancel_button()
 {
     if(m_cancelbutton) m_cancelbutton->Show();

src/slic3r/GUI/ProgressStatusBar.hpp

@@ -6,6 +6,8 @@
 #include <functional>
 #include <string>
 
+#include "ProgressIndicator.hpp"
+
 class wxTimer;
 class wxGauge;
 class wxButton;
@@ -14,6 +16,7 @@ class wxStatusBar;
 class wxWindow;
 class wxFrame;
 class wxString;
+class wxFont;
 
 namespace Slic3r {
 
@@ -22,7 +25,7 @@ namespace Slic3r {
  * of the Slicer main window. It consists of a message area to the left and a
  * progress indication area to the right with an optional cancel button.
  */
-class ProgressStatusBar 
+class ProgressStatusBar : public ProgressIndicator
 {
     wxStatusBar *self;      // we cheat! It should be the base class but: perl!
     wxGauge *m_prog;
@@ -30,30 +33,29 @@ class ProgressStatusBar
     std::unique_ptr<wxTimer> m_timer;
 public:
 
-    /// Cancel callback function type
-    using CancelFn = std::function<void()>;
 
     ProgressStatusBar(wxWindow *parent = nullptr, int id = -1);
-    ~ProgressStatusBar();
+    ~ProgressStatusBar() override;
 
     int         get_progress() const;
     // if the argument is less than 0 it shows the last state or
     // pulses if no state was set before.
-    void        set_progress(int);
+    void        set_progress(int) override;
-    int         get_range() const;
+    int         get_range() const override;
-    void        set_range(int = 100);
+    void        set_range(int = 100) override;
     void        show_progress(bool);
     void        start_busy(int = 100);
     void        stop_busy();
     inline bool is_busy() const { return m_busy; }
-    void        set_cancel_callback(CancelFn = CancelFn());
+    void        set_cancel_callback(CancelFn = CancelFn()) override;
     inline void reset_cancel_callback() { set_cancel_callback(); }
     void        run(int rate);
     void        embed(wxFrame *frame = nullptr);
     void        set_status_text(const wxString& txt);
     void        set_status_text(const std::string& txt);
-    void        set_status_text(const char *txt);
+    void        set_status_text(const char *txt) override;
     wxString    get_status_text() const;
+    void        set_font(const wxFont &font);
 
     // Temporary methods to satisfy Perl side
     void        show_cancel_button();