Add the full source of BambuStudio

using version 1.0.10

src/libnest2d/CMakeLists.txt

@@ -0,0 +1,28 @@
+set(LIBNEST2D_SRCFILES
+    include/libnest2d/libnest2d.hpp
+    include/libnest2d/nester.hpp
+    include/libnest2d/geometry_traits.hpp
+    include/libnest2d/geometry_traits_nfp.hpp
+    include/libnest2d/common.hpp
+    include/libnest2d/optimizer.hpp
+    include/libnest2d/utils/metaloop.hpp
+    include/libnest2d/utils/rotfinder.hpp
+    include/libnest2d/utils/rotcalipers.hpp
+    include/libnest2d/placers/placer_boilerplate.hpp
+    include/libnest2d/placers/bottomleftplacer.hpp
+    include/libnest2d/placers/nfpplacer.hpp
+    include/libnest2d/selections/selection_boilerplate.hpp
+    include/libnest2d/selections/firstfit.hpp
+    include/libnest2d/backends/libslic3r/geometries.hpp
+    include/libnest2d/optimizers/nlopt/nlopt_boilerplate.hpp
+    include/libnest2d/optimizers/nlopt/simplex.hpp
+    include/libnest2d/optimizers/nlopt/subplex.hpp
+    include/libnest2d/optimizers/nlopt/genetic.hpp
+    src/libnest2d.cpp
+    )
+
+add_library(libnest2d STATIC ${LIBNEST2D_SRCFILES})
+
+target_include_directories(libnest2d PUBLIC ${CMAKE_CURRENT_LIST_DIR}/include)
+target_link_libraries(libnest2d PUBLIC NLopt::nlopt TBB::tbb Boost::boost libslic3r)
+target_compile_definitions(libnest2d PUBLIC LIBNEST2D_THREADING_tbb LIBNEST2D_STATIC LIBNEST2D_OPTIMIZER_nlopt LIBNEST2D_GEOMETRIES_libslic3r)

src/libnest2d/LICENSE.txt

@@ -0,0 +1,165 @@
+    GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
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+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
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+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
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+(ten or fewer lines in length), you do both of the following:
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+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
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+  4. Combined Works.
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+  You may convey a Combined Work under terms of your choice that,
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+the following:
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+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
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+
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+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
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+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
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+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
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+Library as you received it specifies that a certain numbered version
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+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
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+permanent authorization for you to choose that version for the
+Library.

src/libnest2d/include/libnest2d/backends/libslic3r/geometries.hpp

@@ -0,0 +1,283 @@
+#ifndef CLIPPER_BACKEND_HPP
+#define CLIPPER_BACKEND_HPP
+
+#include <sstream>
+#include <unordered_map>
+#include <cassert>
+#include <vector>
+#include <iostream>
+
+#include <libnest2d/geometry_traits.hpp>
+#include <libnest2d/geometry_traits_nfp.hpp>
+
+#include <libslic3r/ExPolygon.hpp>
+#include <libslic3r/ClipperUtils.hpp>
+
+namespace Slic3r {
+
+template<class T, class En = void> struct IsVec_ : public std::false_type {};
+
+template<class T> struct IsVec_< Vec<2, T> >: public std::true_type {};
+
+template<class T>
+static constexpr const bool IsVec = IsVec_<libnest2d::remove_cvref_t<T>>::value;
+
+template<class T, class O> using VecOnly = std::enable_if_t<IsVec<T>, O>;
+
+inline Point operator+(const Point& p1, const Point& p2) {
+    Point ret = p1;
+    ret += p2;
+    return ret;
+}
+
+inline Point operator -(const Point& p ) {
+    Point ret = p;
+    ret.x() = -ret.x();
+    ret.y() = -ret.y();
+    return ret;
+}
+
+inline Point operator-(const Point& p1, const Point& p2) {
+    Point ret = p1;
+    ret -= p2;
+    return ret;
+}
+
+inline Point& operator *=(Point& p, const Point& pa ) {
+    p.x() *= pa.x();
+    p.y() *= pa.y();
+    return p;
+}
+
+inline Point operator*(const Point& p1, const Point& p2) {
+    Point ret = p1;
+    ret *= p2;
+    return ret;
+}
+
+} // namespace Slic3r
+
+namespace libnest2d {
+
+template<class T> using Vec = Slic3r::Vec<2, T>;
+
+// Aliases for convinience
+using PointImpl = Slic3r::Point;
+using PathImpl  = Slic3r::Polygon;
+using HoleStore = Slic3r::Polygons;
+using PolygonImpl = Slic3r::ExPolygon;
+
+template<> struct ShapeTag<Slic3r::Vec2crd> { using Type = PointTag; };
+template<> struct ShapeTag<Slic3r::Point>   { using Type = PointTag; };
+
+template<> struct ShapeTag<std::vector<Slic3r::Vec2crd>> { using Type = PathTag; };
+template<> struct ShapeTag<Slic3r::Polygon> { using Type = PathTag; };
+template<> struct ShapeTag<Slic3r::Points>  { using Type = PathTag; };
+template<> struct ShapeTag<Slic3r::ExPolygon> { using Type = PolygonTag; };
+template<> struct ShapeTag<Slic3r::ExPolygons> { using Type = MultiPolygonTag; };
+
+// Type of coordinate units used by Clipper. Enough to specialize for point,
+// the rest of the types will work (Path, Polygon)
+template<> struct CoordType<Slic3r::Point> {
+    using Type = coord_t;
+    static const constexpr coord_t MM_IN_COORDS = 1000000;
+};
+
+template<> struct CoordType<Slic3r::Vec2crd> {
+    using Type = coord_t;
+    static const constexpr coord_t MM_IN_COORDS = 1000000;
+};
+
+// Enough to specialize for path, it will work for multishape and Polygon
+template<> struct PointType<std::vector<Slic3r::Vec2crd>> { using Type = Slic3r::Vec2crd; };
+template<> struct PointType<Slic3r::Polygon> { using Type = Slic3r::Point; };
+template<> struct PointType<Slic3r::Points> { using Type = Slic3r::Point; };
+
+// This is crucial. CountourType refers to itself by default, so we don't have
+// to secialize for clipper Path. ContourType<PathImpl>::Type is PathImpl.
+template<> struct ContourType<Slic3r::ExPolygon> { using Type = Slic3r::Polygon; };
+
+// The holes are contained in Clipper::Paths
+template<> struct HolesContainer<Slic3r::ExPolygon> { using Type = Slic3r::Polygons; };
+
+template<>
+struct OrientationType<Slic3r::Polygon> {
+    static const constexpr Orientation Value = Orientation::COUNTER_CLOCKWISE;
+};
+
+template<>
+struct OrientationType<Slic3r::Points> {
+    static const constexpr Orientation Value = Orientation::COUNTER_CLOCKWISE;
+};
+
+template<>
+struct ClosureType<Slic3r::Polygon> {
+    static const constexpr Closure Value = Closure::OPEN;
+};
+
+template<>
+struct ClosureType<Slic3r::Points> {
+    static const constexpr Closure Value = Closure::OPEN;
+};
+
+template<> struct MultiShape<Slic3r::ExPolygon> { using Type = Slic3r::ExPolygons; };
+template<> struct ContourType<Slic3r::ExPolygons> { using Type = Slic3r::Polygon; };
+
+// Using the libnest2d default area implementation
+#define DISABLE_BOOST_AREA
+
+namespace shapelike {
+
+template<>
+inline void offset(Slic3r::ExPolygon& sh, coord_t distance, const PolygonTag&)
+{
+#define DISABLE_BOOST_OFFSET
+    auto res = Slic3r::offset_ex(sh, distance, Slic3r::ClipperLib::jtSquare);
+    if (!res.empty()) sh = res.front();
+}
+
+template<>
+inline void offset(Slic3r::Polygon& sh, coord_t distance, const PathTag&)
+{
+    auto res = Slic3r::offset(sh, distance, Slic3r::ClipperLib::jtSquare);
+    if (!res.empty()) sh = res.front();
+}
+
+// Tell libnest2d how to make string out of a ClipperPolygon object
+template<> inline std::string toString(const Slic3r::ExPolygon& sh)
+{
+    std::stringstream ss;
+
+    ss << "Contour {\n";
+    for(auto &p : sh.contour.points) {
+        ss << "\t" << p.x() << " " << p.y() << "\n";
+    }
+    ss << "}\n";
+
+    for(auto& h : sh.holes) {
+        ss << "Holes {\n";
+        for(auto p : h.points)  {
+            ss << "\t{\n";
+            ss << "\t\t" << p.x() << " " << p.y() << "\n";
+            ss << "\t}\n";
+        }
+        ss << "}\n";
+    }
+
+    return ss.str();
+}
+
+template<>
+inline Slic3r::ExPolygon create(const Slic3r::Polygon& path, const Slic3r::Polygons& holes)
+{
+    Slic3r::ExPolygon p;
+    p.contour = path;
+    p.holes = holes;
+
+    return p;
+}
+
+template<> inline Slic3r::ExPolygon create(Slic3r::Polygon&& path, Slic3r::Polygons&& holes) {
+    Slic3r::ExPolygon p;
+    p.contour.points.swap(path.points);
+    p.holes.swap(holes);
+
+    return p;
+}
+
+template<>
+inline const THolesContainer<PolygonImpl>& holes(const Slic3r::ExPolygon& sh)
+{
+    return sh.holes;
+}
+
+template<> inline THolesContainer<PolygonImpl>& holes(Slic3r::ExPolygon& sh)
+{
+    return sh.holes;
+}
+
+template<>
+inline Slic3r::Polygon& hole(Slic3r::ExPolygon& sh, unsigned long idx)
+{
+    return sh.holes[idx];
+}
+
+template<>
+inline const Slic3r::Polygon& hole(const Slic3r::ExPolygon& sh, unsigned long idx)
+{
+    return sh.holes[idx];
+}
+
+template<> inline size_t holeCount(const Slic3r::ExPolygon& sh)
+{
+    return sh.holes.size();
+}
+
+template<> inline Slic3r::Polygon& contour(Slic3r::ExPolygon& sh)
+{
+    return sh.contour;
+}
+
+template<>
+inline const Slic3r::Polygon& contour(const Slic3r::ExPolygon& sh)
+{
+    return sh.contour;
+}
+
+template<>
+inline void reserve(Slic3r::Polygon& p, size_t vertex_capacity, const PathTag&)
+{
+    p.points.reserve(vertex_capacity);
+}
+
+template<>
+inline void addVertex(Slic3r::Polygon& sh, const PathTag&, const Slic3r::Point &p)
+{
+    sh.points.emplace_back(p);
+}
+
+#define DISABLE_BOOST_TRANSLATE
+template<>
+inline void translate(Slic3r::ExPolygon& sh, const Slic3r::Point& offs)
+{
+    sh.translate(offs);
+}
+
+#define DISABLE_BOOST_ROTATE
+template<>
+inline void rotate(Slic3r::ExPolygon& sh, const Radians& rads)
+{
+    sh.rotate(rads);
+}
+
+} // namespace shapelike
+
+namespace nfp {
+
+#define DISABLE_BOOST_NFP_MERGE
+template<>
+inline TMultiShape<PolygonImpl> merge(const TMultiShape<PolygonImpl>& shapes)
+{
+    return Slic3r::union_ex(shapes);
+}
+
+} // namespace nfp
+} // namespace libnest2d
+
+#define DISABLE_BOOST_CONVEX_HULL
+
+//#define DISABLE_BOOST_SERIALIZE
+//#define DISABLE_BOOST_UNSERIALIZE
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4244)
+#pragma warning(disable: 4267)
+#endif
+// All other operators and algorithms are implemented with boost
+#include <libnest2d/utils/boost_alg.hpp>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+#endif // CLIPPER_BACKEND_HPP

src/libnest2d/include/libnest2d/common.hpp

@@ -0,0 +1,232 @@
+#ifndef LIBNEST2D_CONFIG_HPP
+#define LIBNEST2D_CONFIG_HPP
+
+#ifndef NDEBUG
+#include <iostream>
+#endif
+
+#include <stdexcept>
+#include <string>
+#include <cmath>
+#include <type_traits>
+#include <limits>
+
+#define MAX_NUM_PLATES 50
+
+#if defined(_MSC_VER) &&  _MSC_VER <= 1800 || __cplusplus < 201103L
+    #define BP2D_NOEXCEPT
+    #define BP2D_CONSTEXPR
+    #define BP2D_COMPILER_MSVC12
+#elif __cplusplus >= 201103L
+    #define BP2D_NOEXCEPT noexcept
+    #define BP2D_CONSTEXPR constexpr
+#endif
+
+/*
+ * Debugging output dout and derr definition
+ */
+//#ifndef NDEBUG
+//#   define dout std::cout
+//#   define derr std::cerr
+//#else
+//#   define dout 0 && std::cout
+//#   define derr 0 && std::cerr
+//#endif
+
+namespace libnest2d {
+
+struct DOut {
+#ifndef NDEBUG
+    std::ostream& out = std::cout;
+#endif
+};
+
+struct DErr {
+#ifndef NDEBUG
+    std::ostream& out = std::cerr;
+#endif
+};
+
+template<class T>
+inline DOut&& operator<<( DOut&& out, T&& d) {
+#ifndef NDEBUG
+    out.out << d;
+#endif
+    return std::move(out);
+}
+
+template<class T>
+inline DErr&& operator<<( DErr&& out, T&& d) {
+#ifndef NDEBUG
+    out.out << d;
+#endif
+    return std::move(out);
+}
+inline DOut dout() { return DOut(); }
+inline DErr derr() { return DErr(); }
+
+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;
+
+template< class T >
+using remove_ref_t = typename std::remove_reference<T>::type;
+
+template<bool B, class T>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
+template<class F, class...Args>
+struct invoke_result {
+    using type = typename std::result_of<F(Args...)>::type;
+};
+
+template<class F, class...Args>
+using invoke_result_t = typename invoke_result<F, Args...>::type;
+
+/**
+ * A useful little tool for triggering static_assert error messages e.g. when
+ * a mandatory template specialization (implementation) is missing.
+ *
+ * \tparam T A template argument that may come from and outer template method.
+ */
+template<class T> struct always_false { enum { value = false }; };
+
+const double BP2D_CONSTEXPR Pi = 3.141592653589793238463; // 2*std::acos(0);
+const double BP2D_CONSTEXPR Pi_2 = 2*Pi;
+
+/**
+ * @brief Only for the Radian and Degrees classes to behave as doubles.
+ */
+class Double {
+protected:
+  double val_;
+public:
+  Double(): val_(double{}) { }
+  Double(double d) : val_(d) { }
+
+  operator double() const BP2D_NOEXCEPT { return val_; }
+  operator double&() BP2D_NOEXCEPT { return val_; }
+};
+
+class Degrees;
+
+/**
+ * @brief Data type representing radians. It supports conversion to degrees.
+ */
+class Radians: public Double {
+    mutable double sin_ = std::nan(""), cos_ = std::nan("");
+public:
+    Radians(double rads = Double() ): Double(rads) {}
+    inline Radians(const Degrees& degs);
+
+    inline operator Degrees();
+    inline double toDegrees();
+
+    inline double sin() const {
+        if(std::isnan(sin_)) {
+            cos_ = std::cos(val_);
+            sin_ = std::sin(val_);
+        }
+        return sin_;
+    }
+
+    inline double cos() const {
+        if(std::isnan(cos_)) {
+            cos_ = std::cos(val_);
+            sin_ = std::sin(val_);
+        }
+        return cos_;
+    }
+};
+
+/**
+ * @brief Data type representing degrees. It supports conversion to radians.
+ */
+class Degrees: public Double {
+public:
+    Degrees(double deg = Double()): Double(deg) {}
+    Degrees(const Radians& rads): Double( rads * 180/Pi ) {}
+    inline double toRadians() { return Radians(*this);}
+};
+
+inline bool operator==(const Degrees& deg, const Radians& rads) {
+    Degrees deg2 = rads;
+    auto diff = std::abs(deg - deg2);
+    return diff < 0.0001;
+}
+
+inline bool operator==(const Radians& rads, const Degrees& deg) {
+    return deg == rads;
+}
+
+inline Radians::operator Degrees() { return *this * 180/Pi; }
+
+inline Radians::Radians(const Degrees &degs): Double( degs * Pi/180) {}
+
+inline double Radians::toDegrees() { return operator Degrees(); }
+
+enum class GeomErr : std::size_t {
+    OFFSET,
+    MERGE,
+    NFP
+};
+
+const std::string ERROR_STR[] = {
+    "Offsetting could not be done! An invalid geometry may have been added.",
+    "Error while merging geometries!",
+    "No fit polygon cannot be calculated."
+};
+
+class GeometryException: public std::exception {
+
+    virtual const std::string& errorstr(GeomErr errcode) const BP2D_NOEXCEPT {
+        return ERROR_STR[static_cast<std::size_t>(errcode)];
+    }
+
+    GeomErr errcode_;
+public:
+
+    GeometryException(GeomErr code): errcode_(code) {}
+
+    GeomErr errcode() const { return errcode_; }
+
+    const char * what() const BP2D_NOEXCEPT override {
+        return errorstr(errcode_).c_str();
+    }
+};
+
+struct ScalarTag {};
+struct BigIntTag {};
+struct RationalTag {};
+
+template<class T> struct _NumTag { 
+    using Type = 
+        enable_if_t<std::is_arithmetic<T>::value, ScalarTag>; 
+};
+
+template<class T> using NumTag = typename _NumTag<remove_cvref_t<T>>::Type;
+
+/// A local version for abs that is garanteed to work with libnest2d types
+template <class T> inline T abs(const T& v, ScalarTag) 
+{ 
+    return std::abs(v); 
+}
+
+template<class T> inline T abs(const T& v) { return abs(v, NumTag<T>()); }
+
+template<class T2, class T1> inline T2 cast(const T1& v, ScalarTag, ScalarTag) 
+{
+    return static_cast<T2>(v);    
+}
+
+template<class T2, class T1> inline T2 cast(const T1& v) { 
+    return cast<T2, T1>(v, NumTag<T1>(), NumTag<T2>());
+}
+
+}
+#endif // LIBNEST2D_CONFIG_HPP

src/libnest2d/include/libnest2d/geometry_traits_nfp.hpp

@@ -0,0 +1,799 @@
+#ifndef GEOMETRIES_NOFITPOLYGON_HPP
+#define GEOMETRIES_NOFITPOLYGON_HPP
+
+#include <algorithm>
+#include <functional>
+#include <vector>
+#include <iterator>
+
+#include <libnest2d/geometry_traits.hpp>
+
+namespace libnest2d {
+
+namespace __nfp {
+// Do not specialize this...
+template<class RawShape, class Unit = TCompute<RawShape>>
+inline bool _vsort(const TPoint<RawShape>& v1, const TPoint<RawShape>& v2)
+{
+    Unit x1 = getX(v1), x2 = getX(v2), y1 = getY(v1), y2 = getY(v2);
+    return y1 == y2 ? x1 < x2 : y1 < y2;
+}
+
+template<class EdgeList, class RawShape, class Vertex = TPoint<RawShape>>
+inline void buildPolygon(const EdgeList& edgelist,
+                         RawShape& rpoly,
+                         Vertex& top_nfp)
+{
+    namespace sl = shapelike;
+
+    auto& rsh = sl::contour(rpoly);
+
+    sl::reserve(rsh, 2 * edgelist.size());
+
+    // Add the two vertices from the first edge into the final polygon.
+    sl::addVertex(rsh, edgelist.front().first());
+    sl::addVertex(rsh, edgelist.front().second());
+
+    // Sorting function for the nfp reference vertex search
+    auto& cmp = _vsort<RawShape>;
+
+    // the reference (rightmost top) vertex so far
+    top_nfp = *std::max_element(sl::cbegin(rsh), sl::cend(rsh), cmp );
+
+    auto tmp = std::next(sl::begin(rsh));
+
+    // Construct final nfp by placing each edge to the end of the previous
+    for(auto eit = std::next(edgelist.begin());
+        eit != edgelist.end();
+        ++eit)
+    {
+        auto d = *tmp - eit->first();
+        Vertex p = eit->second() + d;
+
+        sl::addVertex(rsh, p);
+
+        // Set the new reference vertex
+        if(cmp(top_nfp, p)) top_nfp = p;
+
+        tmp = std::next(tmp);
+    }
+}
+
+template<class Container, class Iterator = typename Container::iterator>
+void advance(Iterator& it, Container& cont, bool direction)
+{
+    int dir = direction ? 1 : -1;
+    if(dir < 0 && it == cont.begin()) it = std::prev(cont.end());
+    else it += dir;
+    if(dir > 0 && it == cont.end()) it = cont.begin();
+}
+
+}
+
+/// A collection of static methods for handling the no fit polygon creation.
+namespace nfp {
+
+const double BP2D_CONSTEXPR TwoPi = 2*Pi;
+
+/// The complexity level of a polygon that an NFP implementation can handle.
+enum class NfpLevel: unsigned {
+    CONVEX_ONLY,
+    ONE_CONVEX,
+    BOTH_CONCAVE,
+    ONE_CONVEX_WITH_HOLES,
+    BOTH_CONCAVE_WITH_HOLES
+};
+
+template<class RawShape>
+using NfpResult = std::pair<RawShape, TPoint<RawShape>>;
+
+template<class RawShape> struct MaxNfpLevel {
+    static const BP2D_CONSTEXPR NfpLevel value = NfpLevel::CONVEX_ONLY;
+};
+
+
+// Shorthand for a pile of polygons
+template<class RawShape>
+using Shapes = TMultiShape<RawShape>;
+
+/**
+ * Merge a bunch of polygons with the specified additional polygon.
+ *
+ * \tparam RawShape the Polygon data type.
+ * \param shc The pile of polygons that will be unified with sh.
+ * \param sh A single polygon to unify with shc.
+ *
+ * \return A set of polygons that is the union of the input polygons. Note that
+ * mostly it will be a set containing only one big polygon but if the input
+ * polygons are disjunct than the resulting set will contain more polygons.
+ */
+template<class RawShapes>
+inline RawShapes merge(const RawShapes& /*shc*/)
+{
+    static_assert(always_false<RawShapes>::value,
+                  "Nfp::merge(shapes, shape) unimplemented!");
+}
+
+/**
+ * Merge a bunch of polygons with the specified additional polygon.
+ *
+ * \tparam RawShape the Polygon data type.
+ * \param shc The pile of polygons that will be unified with sh.
+ * \param sh A single polygon to unify with shc.
+ *
+ * \return A set of polygons that is the union of the input polygons. Note that
+ * mostly it will be a set containing only one big polygon but if the input
+ * polygons are disjunct than the resulting set will contain more polygons.
+ */
+template<class RawShape>
+inline TMultiShape<RawShape> merge(const TMultiShape<RawShape>& shc,
+                                   const RawShape& sh)
+{
+    auto m = nfp::merge(shc);
+    m.emplace_back(sh);
+    return nfp::merge(m);
+}
+
+/**
+ * Get the vertex of the polygon that is at the lowest values (bottom) in the Y
+ * axis and if there are more than one vertices on the same Y coordinate than
+ * the result will be the leftmost (with the highest X coordinate).
+ */
+template<class RawShape>
+inline TPoint<RawShape> leftmostDownVertex(const RawShape& sh)
+{
+
+    // find min x and min y vertex
+    auto it = std::min_element(shapelike::cbegin(sh), shapelike::cend(sh),
+                               __nfp::_vsort<RawShape>);
+
+    return it == shapelike::cend(sh) ? TPoint<RawShape>() : *it;;
+}
+
+/**
+ * Get the vertex of the polygon that is at the highest values (top) in the Y
+ * axis and if there are more than one vertices on the same Y coordinate than
+ * the result will be the rightmost (with the lowest X coordinate).
+ */
+template<class RawShape>
+TPoint<RawShape> rightmostUpVertex(const RawShape& sh)
+{
+
+    // find max x and max y vertex
+    auto it = std::max_element(shapelike::cbegin(sh), shapelike::cend(sh),
+                               __nfp::_vsort<RawShape>);
+
+    return it == shapelike::cend(sh) ? TPoint<RawShape>() : *it;
+}
+
+/**
+ * A method to get a vertex from a polygon that always maintains a relative
+ * position to the coordinate system: It is always the rightmost top vertex.
+ *
+ * This way it does not matter in what order the vertices are stored, the
+ * reference will be always the same for the same polygon.
+ */
+template<class RawShape>
+inline TPoint<RawShape> referenceVertex(const RawShape& sh)
+{
+    return rightmostUpVertex(sh);
+}
+
+/**
+ * The "trivial" Cuninghame-Green implementation of NFP for convex polygons.
+ *
+ * You can use this even if you provide implementations for the more complex
+ * cases (Through specializing the the NfpImpl struct). Currently, no other
+ * cases are covered in the library.
+ *
+ * Complexity should be no more than nlogn (std::sort) in the number of edges
+ * of the input polygons.
+ *
+ * \tparam RawShape the Polygon data type.
+ * \param sh The stationary polygon
+ * \param cother The orbiting polygon
+ * \return Returns a pair of the NFP and its reference vertex of the two input
+ * polygons which have to be strictly convex. The resulting NFP is proven to be
+ * convex as well in this case.
+ *
+ */
+template<class RawShape, class Ratio = double>
+inline NfpResult<RawShape> nfpConvexOnly(const RawShape& sh,
+                                         const RawShape& other)
+{
+    using Vertex = TPoint<RawShape>; using Edge = _Segment<Vertex>;
+    namespace sl = shapelike;
+
+    RawShape rsh;   // Final nfp placeholder
+    Vertex top_nfp;
+    std::vector<Edge> edgelist;
+
+    auto cap = sl::contourVertexCount(sh) + sl::contourVertexCount(other);
+
+    // Reserve the needed memory
+    edgelist.reserve(cap);
+    sl::reserve(rsh, static_cast<unsigned long>(cap));
+    auto add_edge = [&edgelist](const Vertex &v1, const Vertex &v2) {
+        Edge e{v1, v2};
+        if (e.sqlength() > 0)
+            edgelist.emplace_back(e);
+    };
+
+    { // place all edges from sh into edgelist
+        auto first = sl::cbegin(sh);
+        auto next = std::next(first);
+
+        while(next != sl::cend(sh)) {
+            // BBS: some polygons may have duplicate points which is not allowed here (for pcos1, pcos2 calculation)
+            if (*first != *next) add_edge(*(first), *(next));
+            ++first; ++next;
+        }
+
+        if constexpr (ClosureTypeV<RawShape> == Closure::OPEN)
+            add_edge(*sl::rcbegin(sh), *sl::cbegin(sh));
+    }
+
+    { // place all edges from other into edgelist
+        auto first = sl::cbegin(other);
+        auto next = std::next(first);
+
+        while(next != sl::cend(other)) {
+            if (*first != *next) add_edge(*(next), *(first));
+            ++first; ++next;
+        }
+
+        if constexpr (ClosureTypeV<RawShape> == Closure::OPEN)
+            add_edge(*sl::cbegin(other), *sl::rcbegin(other));
+    }
+   
+    std::sort(edgelist.begin(), edgelist.end(),
+              [](const Edge& e1, const Edge& e2)
+    {
+        const Vertex ax(1, 0); // Unit vector for the X axis
+        
+        // get cectors from the edges
+        Vertex p1 = e1.second() - e1.first();
+        Vertex p2 = e2.second() - e2.first();
+
+        // Quadrant mapping array. The quadrant of a vector can be determined
+        // from the dot product of the vector and its perpendicular pair
+        // with the unit vector X axis. The products will carry the values
+        // lcos = dot(p, ax) = l * cos(phi) and
+        // lsin = -dotperp(p, ax) = l * sin(phi) where
+        // l is the length of vector p. From the signs of these values we can
+        // construct an index which has the sign of lcos as MSB and the
+        // sign of lsin as LSB. This index can be used to retrieve the actual
+        // quadrant where vector p resides using the following map:
+        // (+ is 0, - is 1)
+        // cos | sin | decimal | quadrant
+        //  +  |  +  |    0    |    0
+        //  +  |  -  |    1    |    3
+        //  -  |  +  |    2    |    1
+        //  -  |  -  |    3    |    2
+        std::array<int, 4> quadrants {0, 3, 1, 2 };
+
+        std::array<int, 2> q {0, 0}; // Quadrant indices for p1 and p2
+
+        using TDots = std::array<TCompute<Vertex>, 2>;
+        TDots lcos { pl::dot(p1, ax), pl::dot(p2, ax) };
+        TDots lsin { -pl::dotperp(p1, ax), -pl::dotperp(p2, ax) };
+
+        // Construct the quadrant indices for p1 and p2
+        for(size_t i = 0; i < 2; ++i)
+            if(lcos[i] == 0) q[i] = lsin[i] > 0 ? 1 : 3;
+            else if(lsin[i] == 0) q[i] = lcos[i] > 0 ? 0 : 2;
+            else q[i] = quadrants[((lcos[i] < 0) << 1) + (lsin[i] < 0)];
+            
+        if(q[0] == q[1]) { // only bother if p1 and p2 are in the same quadrant
+            auto lsq1 = pl::magnsq(p1);     // squared magnitudes, avoid sqrt
+            auto lsq2 = pl::magnsq(p2);     // squared magnitudes, avoid sqrt
+
+            // We will actually compare l^2 * cos^2(phi) which saturates the
+            // cos function. But with the quadrant info we can get the sign back
+            int sign = q[0] == 1 || q[0] == 2 ? -1 : 1;
+            
+            // If Ratio is an actual rational type, there is no precision loss
+            auto pcos1 = Ratio(lcos[0]) / lsq1 * sign * lcos[0];
+            auto pcos2 = Ratio(lcos[1]) / lsq2 * sign * lcos[1];
+
+            if constexpr (is_clockwise<RawShape>())
+                return q[0] < 2 ? pcos1 < pcos2 : pcos1 > pcos2;
+            else
+                return q[0] < 2 ? pcos1 > pcos2 : pcos1 < pcos2;
+        }
+        
+        // If in different quadrants, compare the quadrant indices only.
+        if constexpr (is_clockwise<RawShape>())
+            return q[0] > q[1];
+        else
+            return q[0] < q[1];
+    });
+
+    __nfp::buildPolygon(edgelist, rsh, top_nfp);
+
+    return {rsh, top_nfp};
+}
+
+template<class RawShape>
+NfpResult<RawShape> nfpSimpleSimple(const RawShape& cstationary,
+                                           const RawShape& cother)
+{
+
+    // Algorithms are from the original algorithm proposed in paper:
+    // https://eprints.soton.ac.uk/36850/1/CORMSIS-05-05.pdf
+
+    // /////////////////////////////////////////////////////////////////////////
+    // Algorithm 1: Obtaining the minkowski sum
+    // /////////////////////////////////////////////////////////////////////////
+
+    // I guess this is not a full minkowski sum of the two input polygons by
+    // definition. This yields a subset that is compatible with the next 2
+    // algorithms.
+
+    using Result = NfpResult<RawShape>;
+    using Vertex = TPoint<RawShape>;
+    using Coord = TCoord<Vertex>;
+    using Edge = _Segment<Vertex>;
+    namespace sl = shapelike;
+    using std::signbit;
+    using std::sort;
+    using std::vector;
+    using std::ref;
+    using std::reference_wrapper;
+
+    // TODO The original algorithms expects the stationary polygon in
+    // counter clockwise and the orbiter in clockwise order.
+    // So for preventing any further complication, I will make the input
+    // the way it should be, than make my way around the orientations.
+
+    // Reverse the stationary contour to counter clockwise
+    auto stcont = sl::contour(cstationary);
+    {
+        std::reverse(sl::begin(stcont), sl::end(stcont));
+        stcont.pop_back();
+        auto it = std::min_element(sl::begin(stcont), sl::end(stcont),
+                               [](const Vertex& v1, const Vertex& v2) {
+            return getY(v1) < getY(v2);
+        });
+        std::rotate(sl::begin(stcont), it, sl::end(stcont));
+        sl::addVertex(stcont, sl::front(stcont));
+    }
+    RawShape stationary;
+    sl::contour(stationary) = stcont;
+
+    // Reverse the orbiter contour to counter clockwise
+    auto orbcont = sl::contour(cother);
+    {
+        std::reverse(orbcont.begin(), orbcont.end());
+
+        // Step 1: Make the orbiter reverse oriented
+
+        orbcont.pop_back();
+        auto it = std::min_element(orbcont.begin(), orbcont.end(),
+                              [](const Vertex& v1, const Vertex& v2) {
+            return getY(v1) < getY(v2);
+        });
+
+        std::rotate(orbcont.begin(), it, orbcont.end());
+        orbcont.emplace_back(orbcont.front());
+
+        for(auto &v : orbcont) v = -v;
+
+    }
+
+    // Copy the orbiter (contour only), we will have to work on it
+    RawShape orbiter;
+    sl::contour(orbiter) = orbcont;
+
+    // An edge with additional data for marking it
+    struct MarkedEdge {
+        Edge e; Radians turn_angle = 0; bool is_turning_point = false;
+        MarkedEdge() = default;
+        MarkedEdge(const Edge& ed, Radians ta, bool tp):
+            e(ed), turn_angle(ta), is_turning_point(tp) {}
+
+        // debug
+        std::string label;
+    };
+
+    // Container for marked edges
+    using EdgeList = vector<MarkedEdge>;
+
+    EdgeList A, B;
+
+    // This is how an edge list is created from the polygons
+    auto fillEdgeList = [](EdgeList& L, const RawShape& ppoly, int dir) {
+        auto& poly = sl::contour(ppoly);
+
+        L.reserve(sl::contourVertexCount(poly));
+
+        if(dir > 0) {
+            auto it = poly.begin();
+            auto nextit = std::next(it);
+
+            double turn_angle = 0;
+            bool is_turn_point = false;
+
+            while(nextit != poly.end()) {
+                L.emplace_back(Edge(*it, *nextit), turn_angle, is_turn_point);
+                it++; nextit++;
+            }
+        } else {
+            auto it = sl::rbegin(poly);
+            auto nextit = std::next(it);
+
+            double turn_angle = 0;
+            bool is_turn_point = false;
+
+            while(nextit != sl::rend(poly)) {
+                L.emplace_back(Edge(*it, *nextit), turn_angle, is_turn_point);
+                it++; nextit++;
+            }
+        }
+
+        auto getTurnAngle = [](const Edge& e1, const Edge& e2) {
+            auto phi = e1.angleToXaxis();
+            auto phi_prev = e2.angleToXaxis();
+            auto turn_angle = phi-phi_prev;
+            if(turn_angle > Pi) turn_angle -= TwoPi;
+            if(turn_angle < -Pi) turn_angle += TwoPi;
+            return turn_angle;
+        };
+
+        auto eit = L.begin();
+        auto enext = std::next(eit);
+
+        eit->turn_angle = getTurnAngle(L.front().e, L.back().e);
+
+        while(enext != L.end()) {
+            enext->turn_angle = getTurnAngle( enext->e, eit->e);
+            eit->is_turning_point =
+                    signbit(enext->turn_angle) != signbit(eit->turn_angle);
+            ++eit; ++enext;
+        }
+
+        L.back().is_turning_point = signbit(L.back().turn_angle) !=
+                                    signbit(L.front().turn_angle);
+
+    };
+
+    // Step 2: Fill the edgelists
+    fillEdgeList(A, stationary, 1);
+    fillEdgeList(B, orbiter, 1);
+
+    int i = 1;
+    for(MarkedEdge& me : A) {
+        std::cout << "a" << i << ":\n\t"
+                  << getX(me.e.first()) << " " << getY(me.e.first()) << "\n\t"
+                  << getX(me.e.second()) << " " << getY(me.e.second()) << "\n\t"
+                  << "Turning point: " << (me.is_turning_point ? "yes" : "no")
+                  << std::endl;
+
+        me.label = "a"; me.label += std::to_string(i);
+        i++;
+    }
+
+    i = 1;
+    for(MarkedEdge& me : B) {
+        std::cout << "b" << i << ":\n\t"
+                  << getX(me.e.first()) << " " << getY(me.e.first()) << "\n\t"
+                  << getX(me.e.second()) << " " << getY(me.e.second()) << "\n\t"
+                  << "Turning point: " << (me.is_turning_point ? "yes" : "no")
+                  << std::endl;
+        me.label = "b"; me.label += std::to_string(i);
+        i++;
+    }
+
+    // A reference to a marked edge that also knows its container
+    struct MarkedEdgeRef {
+        reference_wrapper<MarkedEdge> eref;
+        reference_wrapper<vector<MarkedEdgeRef>> container;
+        Coord dir = 1;  // Direction modifier
+
+        inline Radians angleX() const { return eref.get().e.angleToXaxis(); }
+        inline const Edge& edge() const { return eref.get().e; }
+        inline Edge& edge() { return eref.get().e; }
+        inline bool isTurningPoint() const {
+            return eref.get().is_turning_point;
+        }
+        inline bool isFrom(const vector<MarkedEdgeRef>& cont ) {
+            return &(container.get()) == &cont;
+        }
+        inline bool eq(const MarkedEdgeRef& mr) {
+            return &(eref.get()) == &(mr.eref.get());
+        }
+
+        MarkedEdgeRef(reference_wrapper<MarkedEdge> er,
+                      reference_wrapper<vector<MarkedEdgeRef>> ec):
+            eref(er), container(ec), dir(1) {}
+
+        MarkedEdgeRef(reference_wrapper<MarkedEdge> er,
+                      reference_wrapper<vector<MarkedEdgeRef>> ec,
+                      Coord d):
+            eref(er), container(ec), dir(d) {}
+    };
+
+    using EdgeRefList = vector<MarkedEdgeRef>;
+
+    // Comparing two marked edges
+    auto sortfn = [](const MarkedEdgeRef& e1, const MarkedEdgeRef& e2) {
+        return e1.angleX() < e2.angleX();
+    };
+
+    EdgeRefList Aref, Bref;     // We create containers for the references
+    Aref.reserve(A.size()); Bref.reserve(B.size());
+
+    // Fill reference container for the stationary polygon
+    std::for_each(A.begin(), A.end(), [&Aref](MarkedEdge& me) {
+        Aref.emplace_back( ref(me), ref(Aref) );
+    });
+
+    // Fill reference container for the orbiting polygon
+    std::for_each(B.begin(), B.end(), [&Bref](MarkedEdge& me) {
+        Bref.emplace_back( ref(me), ref(Bref) );
+    });
+
+    auto mink = [sortfn] // the Mink(Q, R, direction) sub-procedure
+            (const EdgeRefList& Q, const EdgeRefList& R, bool positive)
+    {
+
+        // Step 1 "merge sort_list(Q) and sort_list(R) to form merge_list(Q,R)"
+        // Sort the containers of edge references and merge them.
+        // Q could be sorted only once and be reused here but we would still
+        // need to merge it with sorted(R).
+
+        EdgeRefList merged;
+        EdgeRefList S, seq;
+        merged.reserve(Q.size() + R.size());
+
+        merged.insert(merged.end(), R.begin(), R.end());
+        std::stable_sort(merged.begin(), merged.end(), sortfn);
+        merged.insert(merged.end(), Q.begin(), Q.end());
+        std::stable_sort(merged.begin(), merged.end(), sortfn);
+
+        // Step 2 "set i = 1, k = 1, direction = 1, s1 = q1"
+        // we don't use i, instead, q is an iterator into Q. k would be an index
+        // into the merged sequence but we use "it" as an iterator for that
+
+        // here we obtain references for the containers for later comparisons
+        const auto& Rcont = R.begin()->container.get();
+        const auto& Qcont = Q.begin()->container.get();
+
+        // Set the initial direction
+        Coord dir = 1;
+
+        // roughly i = 1 (so q = Q.begin()) and s1 = q1 so S[0] = q;
+        if(positive) {
+            auto q = Q.begin();
+            S.emplace_back(*q);
+
+            // Roughly step 3
+
+            std::cout << "merged size: " << merged.size() << std::endl;
+            auto mit = merged.begin();
+            for(bool finish = false; !finish && q != Q.end();) {
+                ++q; // "Set i = i + 1"
+
+                while(!finish && mit != merged.end()) {
+                    if(mit->isFrom(Rcont)) {
+                        auto s = *mit;
+                        s.dir = dir;
+                        S.emplace_back(s);
+                    }
+
+                    if(mit->eq(*q)) {
+                        S.emplace_back(*q);
+                        if(mit->isTurningPoint()) dir = -dir;
+                        if(q == Q.begin()) finish = true;
+                        break;
+                    }
+
+                    mit += dir;
+    //                __nfp::advance(mit, merged, dir > 0);
+                }
+            }
+        } else {
+            auto q = Q.rbegin();
+            S.emplace_back(*q);
+
+            // Roughly step 3
+
+            std::cout << "merged size: " << merged.size() << std::endl;
+            auto mit = merged.begin();
+            for(bool finish = false; !finish && q != Q.rend();) {
+                ++q; // "Set i = i + 1"
+
+                while(!finish && mit != merged.end()) {
+                    if(mit->isFrom(Rcont)) {
+                        auto s = *mit;
+                        s.dir = dir;
+                        S.emplace_back(s);
+                    }
+
+                    if(mit->eq(*q)) {
+                        S.emplace_back(*q);
+                        S.back().dir = -1;
+                        if(mit->isTurningPoint()) dir = -dir;
+                        if(q == Q.rbegin()) finish = true;
+                        break;
+                    }
+
+                    mit += dir;
+            //                __nfp::advance(mit, merged, dir > 0);
+                }
+            }
+        }
+
+
+        // Step 4:
+
+        // "Let starting edge r1 be in position si in sequence"
+        // whaaat? I guess this means the following:
+        auto it = S.begin();
+        while(!it->eq(*R.begin())) ++it;
+
+        // "Set j = 1, next = 2, direction = 1, seq1 = si"
+        // we don't use j, seq is expanded dynamically.
+        dir = 1;
+        auto next = std::next(R.begin()); seq.emplace_back(*it);
+
+        // Step 5:
+        // "If all si edges have been allocated to seqj" should mean that
+        // we loop until seq has equal size with S
+        auto send = it; //it == S.begin() ? it : std::prev(it);
+        while(it != S.end()) {
+            ++it; if(it == S.end()) it = S.begin();
+            if(it == send) break;
+
+            if(it->isFrom(Qcont)) {
+                seq.emplace_back(*it); // "If si is from Q, j = j + 1, seqj = si"
+
+                // "If si is a turning point in Q,
+                // direction = - direction, next = next + direction"
+                if(it->isTurningPoint()) {
+                    dir = -dir;
+                    next += dir;
+//                    __nfp::advance(next, R, dir > 0);
+                }
+            }
+
+            if(it->eq(*next) /*&& dir == next->dir*/) { // "If si = direction.rnext"
+                // "j = j + 1, seqj = si, next = next + direction"
+                seq.emplace_back(*it);
+                next += dir;
+//                __nfp::advance(next, R, dir > 0);
+            }
+        }
+
+        return seq;
+    };
+
+    std::vector<EdgeRefList> seqlist;
+    seqlist.reserve(Bref.size());
+
+    EdgeRefList Bslope = Bref;  // copy Bref, we will make a slope diagram
+
+    // make the slope diagram of B
+    std::sort(Bslope.begin(), Bslope.end(), sortfn);
+
+    auto slopeit = Bslope.begin(); // search for the first turning point
+    while(!slopeit->isTurningPoint() && slopeit != Bslope.end()) slopeit++;
+
+    if(slopeit == Bslope.end()) {
+        // no turning point means convex polygon.
+        seqlist.emplace_back(mink(Aref, Bref, true));
+    } else {
+        int dir = 1;
+
+        auto firstturn = Bref.begin();
+        while(!firstturn->eq(*slopeit)) ++firstturn;
+
+        assert(firstturn != Bref.end());
+
+        EdgeRefList bgroup; bgroup.reserve(Bref.size());
+        bgroup.emplace_back(*slopeit);
+
+        auto b_it = std::next(firstturn);
+        while(b_it != firstturn) {
+            if(b_it == Bref.end()) b_it = Bref.begin();
+
+            while(!slopeit->eq(*b_it)) {
+                __nfp::advance(slopeit, Bslope, dir > 0);
+            }
+
+            if(!slopeit->isTurningPoint()) {
+                bgroup.emplace_back(*slopeit);
+            } else {
+                if(!bgroup.empty()) {
+                    if(dir > 0) bgroup.emplace_back(*slopeit);
+                    for(auto& me : bgroup) {
+                        std::cout << me.eref.get().label << ", ";
+                    }
+                    std::cout << std::endl;
+                    seqlist.emplace_back(mink(Aref, bgroup, dir == 1 ? true : false));
+                    bgroup.clear();
+                    if(dir < 0) bgroup.emplace_back(*slopeit);
+                } else {
+                    bgroup.emplace_back(*slopeit);
+                }
+
+                dir *= -1;
+            }
+            ++b_it;
+        }
+    }
+
+//    while(it != Bref.end()) // This is step 3 and step 4 in one loop
+//        if(it->isTurningPoint()) {
+//            R = {R.last, it++};
+//            auto seq = mink(Q, R, orientation);
+
+//            // TODO step 6 (should be 5 shouldn't it?): linking edges from A
+//            // I don't get this step
+
+//            seqlist.insert(seqlist.end(), seq.begin(), seq.end());
+//            orientation = !orientation;
+//        } else ++it;
+
+//    if(seqlist.empty()) seqlist = mink(Q, {Bref.begin(), Bref.end()}, true);
+
+    // /////////////////////////////////////////////////////////////////////////
+    // Algorithm 2: breaking Minkowski sums into track line trips
+    // /////////////////////////////////////////////////////////////////////////
+
+
+    // /////////////////////////////////////////////////////////////////////////
+    // Algorithm 3: finding the boundary of the NFP from track line trips
+    // /////////////////////////////////////////////////////////////////////////
+
+
+    for(auto& seq : seqlist) {
+        std::cout << "seqlist size: " << seq.size() << std::endl;
+        for(auto& s : seq) {
+            std::cout << (s.dir > 0 ? "" : "-") << s.eref.get().label << ", ";
+        }
+        std::cout << std::endl;
+    }
+
+    auto& seq = seqlist.front();
+    RawShape rsh;
+    Vertex top_nfp;
+    std::vector<Edge> edgelist; edgelist.reserve(seq.size());
+    for(auto& s : seq) {
+        edgelist.emplace_back(s.eref.get().e);
+    }
+
+    __nfp::buildPolygon(edgelist, rsh, top_nfp);
+
+    return Result(rsh, top_nfp);
+}
+
+// Specializable NFP implementation class. Specialize it if you have a faster
+// or better NFP implementation
+template<class RawShape, NfpLevel nfptype>
+struct NfpImpl {
+    NfpResult<RawShape> operator()(const RawShape& sh, const RawShape& other)
+    {
+        static_assert(nfptype == NfpLevel::CONVEX_ONLY,
+                      "Nfp::noFitPolygon() unimplemented!");
+
+        // Libnest2D has a default implementation for convex polygons and will
+        // use it if feasible.
+        return nfpConvexOnly(sh, other);
+    }
+};
+
+/// Helper function to get the NFP
+template<NfpLevel nfptype, class RawShape>
+inline NfpResult<RawShape> noFitPolygon(const RawShape& sh,
+                                        const RawShape& other)
+{
+    NfpImpl<RawShape, nfptype> nfps;
+    return nfps(sh, other);
+}
+
+}
+
+}
+
+#endif // GEOMETRIES_NOFITPOLYGON_HPP

src/libnest2d/include/libnest2d/libnest2d.hpp

@@ -0,0 +1,144 @@
+#ifndef LIBNEST2D_HPP
+#define LIBNEST2D_HPP
+
+// The type of backend should be set conditionally by the cmake configuriation
+// for now we set it statically to clipper backend
+#ifdef LIBNEST2D_GEOMETRIES_clipper
+#include <libnest2d/backends/clipper/geometries.hpp>
+#endif
+
+#ifdef LIBNEST2D_GEOMETRIES_libslic3r
+#include <libnest2d/backends/libslic3r/geometries.hpp>
+#endif
+
+#ifdef LIBNEST2D_OPTIMIZER_nlopt
+// We include the stock optimizers for local and global optimization
+#include <libnest2d/optimizers/nlopt/subplex.hpp>     // Local subplex for NfpPlacer
+#include <libnest2d/optimizers/nlopt/genetic.hpp>     // Genetic for min. bounding box
+#endif
+
+#include <libnest2d/nester.hpp>
+#include <libnest2d/placers/bottomleftplacer.hpp>
+#include <libnest2d/placers/nfpplacer.hpp>
+#include <libnest2d/selections/firstfit.hpp>
+#include <libnest2d/selections/filler.hpp>
+#include <libnest2d/selections/djd_heuristic.hpp>
+
+namespace libnest2d {
+
+using Point = PointImpl;
+using Coord = TCoord<PointImpl>;
+using Box = _Box<PointImpl>;
+using Segment = _Segment<PointImpl>;
+using Circle = _Circle<PointImpl>;
+using MultiPolygon = TMultiShape<PolygonImpl>; 
+
+using Item = _Item<PolygonImpl>;
+using Rectangle = _Rectangle<PolygonImpl>;
+using PackGroup = _PackGroup<PolygonImpl>;
+
+using FillerSelection = selections::_FillerSelection<PolygonImpl>;
+using FirstFitSelection = selections::_FirstFitSelection<PolygonImpl>;
+using DJDHeuristic  = selections::_DJDHeuristic<PolygonImpl>;
+
+template<class Bin> // Generic placer for arbitrary bin types
+using _NfpPlacer = placers::_NofitPolyPlacer<PolygonImpl, Bin>;
+
+// NfpPlacer is with Box bin
+using NfpPlacer = _NfpPlacer<Box>;
+
+// This supports only box shaped bins
+using BottomLeftPlacer = placers::_BottomLeftPlacer<PolygonImpl>;
+
+#ifdef LIBNEST2D_STATIC
+
+extern template class _Nester<NfpPlacer, FirstFitSelection>;
+extern template class _Nester<BottomLeftPlacer, FirstFitSelection>;
+extern template std::size_t _Nester<NfpPlacer, FirstFitSelection>::execute(
+        std::vector<Item>::iterator, std::vector<Item>::iterator);
+extern template std::size_t _Nester<BottomLeftPlacer, FirstFitSelection>::execute(
+        std::vector<Item>::iterator, std::vector<Item>::iterator);
+
+#endif
+
+template<class Placer = NfpPlacer, class Selector = FirstFitSelection>
+struct NestConfig {
+    typename Placer::Config placer_config;
+    typename Selector::Config selector_config;
+    using Placement = typename Placer::Config;
+    using Selection = typename Selector::Config;
+    
+    NestConfig() = default;
+    NestConfig(const typename Placer::Config &cfg)   : placer_config{cfg} {}
+    NestConfig(const typename Selector::Config &cfg) : selector_config{cfg} {}
+    NestConfig(const typename Placer::Config &  pcfg,
+               const typename Selector::Config &scfg)
+        : placer_config{pcfg}, selector_config{scfg} {}
+};
+
+struct NestControl {
+    ProgressFunction progressfn;
+    StopCondition stopcond = []{ return false; };
+    
+    NestControl() = default;
+    NestControl(ProgressFunction pr) : progressfn{std::move(pr)} {}
+    NestControl(StopCondition sc) : stopcond{std::move(sc)} {}
+    NestControl(ProgressFunction pr, StopCondition sc)
+        : progressfn{std::move(pr)}, stopcond{std::move(sc)}
+    {}
+};
+
+template<class Placer = NfpPlacer,
+         class Selector = FirstFitSelection,
+         class Iterator = std::vector<Item>::iterator>
+std::size_t nest(Iterator from, Iterator to,
+                 const typename Placer::BinType & bin,
+                 Coord dist = 0,
+                 const NestConfig<Placer, Selector> &cfg = {},
+                 NestControl ctl = {})
+{
+    _Nester<Placer, Selector> nester{bin, dist, cfg.placer_config, cfg.selector_config};
+    if(ctl.progressfn) nester.progressIndicator(ctl.progressfn);
+    if(ctl.stopcond) nester.stopCondition(ctl.stopcond);
+    return nester.execute(from, to);
+}
+
+#ifdef LIBNEST2D_STATIC
+
+extern template class _Nester<NfpPlacer, FirstFitSelection>;
+extern template class _Nester<BottomLeftPlacer, FirstFitSelection>;
+extern template std::size_t nest(std::vector<Item>::iterator from,
+                                 std::vector<Item>::iterator to,
+                                 const Box & bin,
+                                 Coord dist,
+                                 const NestConfig<NfpPlacer, FirstFitSelection> &cfg,
+                                 NestControl ctl);
+extern template std::size_t nest(std::vector<Item>::iterator from,
+                                 std::vector<Item>::iterator to,
+                                 const Box & bin,
+                                 Coord dist,
+                                 const NestConfig<BottomLeftPlacer, FirstFitSelection> &cfg,
+                                 NestControl ctl);
+
+#endif
+
+template<class Placer = NfpPlacer,
+         class Selector = FirstFitSelection,
+         class Container = std::vector<Item>>
+std::size_t nest(Container&& cont,
+                 const typename Placer::BinType & bin,
+                 Coord dist = 0,
+                 const NestConfig<Placer, Selector> &cfg = {},
+                 NestControl ctl = {})
+{
+    return nest<Placer, Selector>(cont.begin(), cont.end(), bin, dist, cfg, ctl);
+}
+
+template<class T = double> enable_if_t<std::is_arithmetic<T>::value, TCoord<PointImpl>> mm(T val = T(1)) 
+{
+    return TCoord<PointImpl>(val * CoordType<PointImpl>::MM_IN_COORDS);
+}
+
+}
+
+#endif // LIBNEST2D_HPP

src/libnest2d/include/libnest2d/nester.hpp

@@ -0,0 +1,894 @@
+#ifndef NESTER_HPP
+#define NESTER_HPP
+
+#include <memory>
+#include <vector>
+#include <map>
+#include <array>
+#include <algorithm>
+#include <functional>
+
+#include <libnest2d/geometry_traits.hpp>
+#define LARGE_COST_TO_REJECT 1e7
+
+namespace libnest2d {
+
+    static const constexpr int BIN_ID_UNSET = -1;
+    static const constexpr int BIN_ID_UNFIT = -1;
+
+/**
+ * \brief An item to be placed on a bin.
+ *
+ * It holds a copy of the original shape object but supports move construction
+ * from the shape objects if its an rvalue reference. This way we can construct
+ * the items without the cost of copying a potentially large amount of input.
+ *
+ * The results of some calculations are cached for maintaining fast run times.
+ * For this reason, memory demands are much higher but this should pay off.
+ */
+template<class RawShape>
+class _Item {
+    using Coord = TCoord<TPoint<RawShape>>;
+    using Vertex = TPoint<RawShape>;
+    using Box = _Box<Vertex>;
+
+    using VertexConstIterator = typename TContour<RawShape>::const_iterator;
+
+    // The original shape that gets encapsulated.
+    RawShape sh_;
+
+    // Transformation data
+    Vertex translation_{0, 0};
+    Radians rotation_{0.0};
+    Coord inflation_{0};
+
+    // Info about whether the transformations will have to take place
+    // This is needed because if floating point is used, it is hard to say
+    // that a zero angle is not a rotation because of testing for equality.
+    bool has_rotation_ = false, has_translation_ = false, has_inflation_ = false;
+
+    // For caching the calculations as they can get pretty expensive.
+    mutable RawShape tr_cache_;
+    mutable bool tr_cache_valid_ = false;
+    mutable double area_cache_ = 0;
+    mutable bool area_cache_valid_ = false;
+    mutable RawShape inflate_cache_;
+    mutable bool inflate_cache_valid_ = false;
+
+    enum class Convexity: char {
+        UNCHECKED,
+        C_TRUE,
+        C_FALSE
+    };
+
+    mutable Convexity convexity_ = Convexity::UNCHECKED;
+    mutable VertexConstIterator rmt_;    // rightmost top vertex
+    mutable VertexConstIterator lmb_;    // leftmost bottom vertex
+    mutable bool rmt_valid_ = false, lmb_valid_ = false;
+    mutable struct BBCache {
+        Box bb; bool valid;
+        BBCache(): valid(false) {}
+    } bb_cache_;
+    
+    int binid_{BIN_ID_UNSET}, priority_{0};
+    bool fixed_{false};
+
+public:
+    int itemid_{ 0 };
+    int extrude_id{ 1 };
+    double height{ 0 };
+    double print_temp{ 0 };
+    double bed_temp{ 0 };
+    double vitrify_temp{ 0 };  // vitrify temperature
+    std::string name;
+    //BBS: virtual object to mark unprintable region on heatbed
+    bool is_virt_object{ false };
+    bool is_wipe_tower{ false };
+
+    /// The type of the shape which was handed over as the template argument.
+    using ShapeType = RawShape;
+
+    /**
+     * \brief Iterator type for the outer vertices.
+     *
+     * Only const iterators can be used. The _Item type is not intended to
+     * modify the carried shapes from the outside. The main purpose of this type
+     * is to cache the calculation results from the various operators it
+     * supports. Giving out a non const iterator would make it impossible to
+     * perform correct cache invalidation.
+     */
+    using Iterator = VertexConstIterator;
+
+    /**
+     * @brief Get the orientation of the polygon.
+     *
+     * The orientation have to be specified as a specialization of the
+     * OrientationType struct which has a Value constant.
+     *
+     * @return The orientation type identifier for the _Item type.
+     */
+    static BP2D_CONSTEXPR Orientation orientation() {
+        return OrientationType<TContour<RawShape>>::Value;
+    }
+
+    /**
+     * @brief Constructing an _Item form an existing raw shape. The shape will
+     * be copied into the _Item object.
+     * @param sh The original shape object.
+     */
+    explicit inline _Item(const RawShape& sh): sh_(sh) {}
+
+    /**
+     * @brief Construction of an item by moving the content of the raw shape,
+     * assuming that it supports move semantics.
+     * @param sh The original shape object.
+     */
+    explicit inline _Item(RawShape&& sh): sh_(std::move(sh)) {}
+
+    /**
+     * @brief Create an item from an initializer list.
+     * @param il The initializer list of vertices.
+     */
+    inline _Item(const std::initializer_list< Vertex >& il):
+        sh_(sl::create<RawShape>(il)) {}
+
+    inline _Item(const TContour<RawShape>& contour,
+                 const THolesContainer<RawShape>& holes = {}):
+        sh_(sl::create<RawShape>(contour, holes)) {}
+
+    inline _Item(TContour<RawShape>&& contour,
+                 THolesContainer<RawShape>&& holes):
+        sh_(sl::create<RawShape>(std::move(contour), std::move(holes))) {}
+    
+    inline bool isFixed() const noexcept { return fixed_; }
+    inline void markAsFixedInBin(int binid)
+    {
+        fixed_ = binid >= 0;
+        binid_ = binid;
+    }
+
+    inline void binId(int idx) { binid_ = idx; }
+    inline int binId() const noexcept { return binid_; }
+    
+    inline void priority(int p) { priority_ = p; }
+    inline int priority() const noexcept { return priority_; }
+
+    inline void itemId(int idx) { itemid_ = idx; }
+    inline int itemId() const noexcept { return itemid_; }
+    /**
+     * @brief Convert the polygon to string representation. The format depends
+     * on the implementation of the polygon.
+     * @return
+     */
+    inline std::string toString() const
+    {
+        return sl::toString(sh_);
+    }
+
+    /// Iterator tho the first contour vertex in the polygon.
+    inline Iterator begin() const
+    {
+        return sl::cbegin(sh_);
+    }
+
+    /// Alias to begin()
+    inline Iterator cbegin() const
+    {
+        return sl::cbegin(sh_);
+    }
+
+    /// Iterator to the last contour vertex.
+    inline Iterator end() const
+    {
+        return sl::cend(sh_);
+    }
+
+    /// Alias to end()
+    inline Iterator cend() const
+    {
+        return sl::cend(sh_);
+    }
+
+    /**
+     * @brief Get a copy of an outer vertex within the carried shape.
+     *
+     * Note that the vertex considered here is taken from the original shape
+     * that this item is constructed from. This means that no transformation is
+     * applied to the shape in this call.
+     *
+     * @param idx The index of the requested vertex.
+     * @return A copy of the requested vertex.
+     */
+    inline Vertex vertex(unsigned long idx) const
+    {
+        return sl::vertex(sh_, idx);
+    }
+
+    /**
+     * @brief Modify a vertex.
+     *
+     * Note that this method will invalidate every cached calculation result
+     * including polygon offset and transformations.
+     *
+     * @param idx The index of the requested vertex.
+     * @param v The new vertex data.
+     */
+    inline void setVertex(unsigned long idx, const Vertex& v )
+    {
+        invalidateCache();
+        sl::vertex(sh_, idx) = v;
+    }
+
+    /**
+     * @brief Calculate the shape area.
+     *
+     * The method returns absolute value and does not reflect polygon
+     * orientation. The result is cached, subsequent calls will have very little
+     * cost.
+     * @return The shape area in floating point double precision.
+     */
+    inline double area() const {
+        double ret ;
+        if(area_cache_valid_) ret = area_cache_;
+        else {
+            ret = sl::area(infaltedShape());
+            area_cache_ = ret;
+            area_cache_valid_ = true;
+        }
+        return ret;
+    }
+
+    inline bool isContourConvex() const {
+        bool ret = false;
+
+        switch(convexity_) {
+        case Convexity::UNCHECKED:
+            ret = sl::isConvex(sl::contour(transformedShape()));
+            convexity_ = ret? Convexity::C_TRUE : Convexity::C_FALSE;
+            break;
+        case Convexity::C_TRUE: ret = true; break;
+        case Convexity::C_FALSE:;
+        }
+
+        return ret;
+    }
+
+    inline bool isHoleConvex(unsigned /*holeidx*/) const {
+        return false;
+    }
+
+    inline bool areHolesConvex() const {
+        return false;
+    }
+
+    /// The number of the outer ring vertices.
+    inline size_t vertexCount() const {
+        return sl::contourVertexCount(sh_);
+    }
+
+    inline size_t holeCount() const {
+        return sl::holeCount(sh_);
+    }
+
+    /**
+     * @brief isPointInside
+     * @param p
+     * @return
+     */
+    inline bool isInside(const Vertex& p) const
+    {
+        return sl::isInside(p, transformedShape());
+    }
+
+    inline bool isInside(const _Item& sh) const
+    {
+        return sl::isInside(transformedShape(), sh.transformedShape());
+    }
+
+    inline bool isInside(const RawShape& sh) const
+    {
+        return sl::isInside(transformedShape(), sh);
+    }
+
+    inline bool isInside(const _Box<TPoint<RawShape>>& box) const;
+    inline bool isInside(const _Circle<TPoint<RawShape>>& box) const;
+
+    inline void translate(const Vertex& d) BP2D_NOEXCEPT
+    {
+        translation(translation() + d);
+    }
+
+    inline void rotate(const Radians& rads) BP2D_NOEXCEPT
+    {
+        rotation(rotation() + rads);
+    }
+    
+    inline void inflation(Coord distance) BP2D_NOEXCEPT
+    {
+        inflation_ = distance;
+        has_inflation_ = true;
+        invalidateCache();
+    }
+    
+    inline Coord inflation() const BP2D_NOEXCEPT {
+        return inflation_;
+    }
+    
+    inline void inflate(Coord distance) BP2D_NOEXCEPT
+    {
+        inflation(inflation() + distance);
+    }
+
+    inline Radians rotation() const BP2D_NOEXCEPT
+    {
+        return rotation_;
+    }
+
+    inline TPoint<RawShape> translation() const BP2D_NOEXCEPT
+    {
+        return translation_;
+    }
+
+    inline void rotation(Radians rot) BP2D_NOEXCEPT
+    {
+        if(rotation_ != rot) {
+            rotation_ = rot; has_rotation_ = true; tr_cache_valid_ = false;
+            rmt_valid_ = false; lmb_valid_ = false;
+            bb_cache_.valid = false;
+        }
+    }
+
+    inline void translation(const TPoint<RawShape>& tr) BP2D_NOEXCEPT
+    {
+        if(translation_ != tr) {
+            translation_ = tr; has_translation_ = true; tr_cache_valid_ = false;
+            //bb_cache_.valid = false;
+        }
+    }
+
+    inline const RawShape& transformedShape() const
+    {
+        if(tr_cache_valid_) return tr_cache_;
+
+        RawShape cpy = infaltedShape();
+        if(has_rotation_) sl::rotate(cpy, rotation_);
+        if(has_translation_) sl::translate(cpy, translation_);
+        tr_cache_ = cpy; tr_cache_valid_ = true;
+        rmt_valid_ = false; lmb_valid_ = false;
+
+        return tr_cache_;
+    }
+
+    inline operator RawShape() const
+    {
+        return transformedShape();
+    }
+
+    inline const RawShape& rawShape() const BP2D_NOEXCEPT
+    {
+        return sh_;
+    }
+
+    inline void resetTransformation() BP2D_NOEXCEPT
+    {
+        has_translation_ = false; has_rotation_ = false; has_inflation_ = false;
+        invalidateCache();
+    }
+
+    inline Box boundingBox() const {
+        if(!bb_cache_.valid) {
+            if(!has_rotation_)
+                bb_cache_.bb = sl::boundingBox(infaltedShape());
+            else {
+                // TODO make sure this works
+                auto rotsh = infaltedShape();
+                sl::rotate(rotsh, rotation_);
+                bb_cache_.bb = sl::boundingBox(rotsh);
+            }
+            bb_cache_.valid = true;
+        }
+
+        auto &bb = bb_cache_.bb; auto &tr = translation_;
+        return {bb.minCorner() + tr, bb.maxCorner() + tr };
+    }
+
+    inline Vertex referenceVertex() const {
+        return rightmostTopVertex();
+    }
+
+    inline Vertex rightmostTopVertex() const {
+        if(!rmt_valid_ || !tr_cache_valid_) {  // find max x and max y vertex
+            auto& tsh = transformedShape();
+            rmt_ = std::max_element(sl::cbegin(tsh), sl::cend(tsh), vsort);
+            rmt_valid_ = true;
+        }
+        return *rmt_;
+    }
+
+    inline Vertex leftmostBottomVertex() const {
+        if(!lmb_valid_ || !tr_cache_valid_) {  // find min x and min y vertex
+            auto& tsh = transformedShape();
+            lmb_ = std::min_element(sl::cbegin(tsh), sl::cend(tsh), vsort);
+            lmb_valid_ = true;
+        }
+        return *lmb_;
+    }
+
+    //Static methods:
+
+    inline static bool intersects(const _Item& sh1, const _Item& sh2)
+    {
+        return sl::intersects(sh1.transformedShape(),
+                                     sh2.transformedShape());
+    }
+
+    inline static bool touches(const _Item& sh1, const _Item& sh2)
+    {
+        return sl::touches(sh1.transformedShape(),
+                                  sh2.transformedShape());
+    }
+
+private:
+
+    inline const RawShape& infaltedShape() const {
+        if(has_inflation_ ) {
+            if(inflate_cache_valid_) return inflate_cache_;
+
+            inflate_cache_ = sh_;
+            sl::offset(inflate_cache_, inflation_);
+            inflate_cache_valid_ = true;
+            return inflate_cache_;
+        }
+        return sh_;
+    }
+
+    inline void invalidateCache() const BP2D_NOEXCEPT
+    {
+        tr_cache_valid_ = false;
+        lmb_valid_ = false; rmt_valid_ = false;
+        area_cache_valid_ = false;
+        inflate_cache_valid_ = false;
+        bb_cache_.valid = false;
+        convexity_ = Convexity::UNCHECKED;
+    }
+
+    static inline bool vsort(const Vertex& v1, const Vertex& v2)
+    {
+        TCompute<Vertex> x1 = getX(v1), x2 = getX(v2);
+        TCompute<Vertex> y1 = getY(v1), y2 = getY(v2);
+        return y1 == y2 ? x1 < x2 : y1 < y2;
+    }
+};
+
+template<class Sh> Sh create_rect(TCoord<Sh> width, TCoord<Sh> height)
+{
+    auto sh = sl::create<Sh>(
+        {{0, 0}, {0, height}, {width, height}, {width, 0}});
+
+    if constexpr (ClosureTypeV<Sh> == Closure::CLOSED)
+        sl::addVertex(sh, {0, 0});
+
+    if constexpr (OrientationTypeV<Sh> == Orientation::COUNTER_CLOCKWISE)
+        std::reverse(sl::begin(sh), sl::end(sh));
+
+    return sh;
+}
+
+/**
+ * \brief Subclass of _Item for regular rectangle items.
+ */
+template<class Sh>
+class _Rectangle: public _Item<Sh> {
+    using _Item<Sh>::vertex;
+    using TO = Orientation;
+public:
+
+    using Unit = TCoord<Sh>;
+
+    inline _Rectangle(Unit w, Unit h): _Item<Sh>{create_rect<Sh>(w, h)} {}
+
+    inline Unit width() const BP2D_NOEXCEPT {
+        return getX(vertex(2));
+    }
+
+    inline Unit height() const BP2D_NOEXCEPT {
+        return getY(vertex(2));
+    }
+};
+
+template<class RawShape>
+inline bool _Item<RawShape>::isInside(const _Box<TPoint<RawShape>>& box) const {
+    return sl::isInside(boundingBox(), box);
+}
+
+template<class RawShape> inline bool
+_Item<RawShape>::isInside(const _Circle<TPoint<RawShape>>& circ) const {
+    return sl::isInside(transformedShape(), circ);
+}
+
+template<class RawShape> using _ItemRef = std::reference_wrapper<_Item<RawShape>>;
+template<class RawShape> using _ItemGroup = std::vector<_ItemRef<RawShape>>;
+
+/**
+ * \brief A list of packed item vectors. Each vector represents a bin.
+ */
+template<class RawShape>
+using _PackGroup = std::vector<std::vector<_ItemRef<RawShape>>>;
+
+template<class Iterator>
+struct ConstItemRange {
+    Iterator from;
+    Iterator to;
+    bool valid = false;
+
+    ConstItemRange() = default;
+    ConstItemRange(Iterator f, Iterator t): from(f), to(t), valid(true) {}
+};
+
+template<class Container>
+inline ConstItemRange<typename Container::const_iterator>
+rem(typename Container::const_iterator it, const Container& cont) {
+    return {std::next(it), cont.end()};
+}
+
+/**
+ * \brief A wrapper interface (trait) class for any placement strategy provider.
+ *
+ * If a client wants to use its own placement algorithm, all it has to do is to
+ * specialize this class template and define all the ten methods it has. It can
+ * use the strategies::PlacerBoilerplace class for creating a new placement
+ * strategy where only the constructor and the trypack method has to be provided
+ * and it will work out of the box.
+ */
+template<class PlacementStrategy>
+class PlacementStrategyLike {
+    PlacementStrategy impl_;
+public:
+
+    using RawShape = typename PlacementStrategy::ShapeType;
+
+    /// The item type that the placer works with.
+    using Item = _Item<RawShape>;
+
+    /// The placer's config type. Should be a simple struct but can be anything.
+    using Config = typename PlacementStrategy::Config;
+
+    /**
+     * \brief The type of the bin that the placer works with.
+     *
+     * Can be a box or an arbitrary shape or just a width or height without a
+     * second dimension if an infinite bin is considered.
+     */
+    using BinType = typename PlacementStrategy::BinType;
+
+    /**
+     * \brief Pack result that can be used to accept or discard it. See trypack
+     * method.
+     */
+    using PackResult = typename PlacementStrategy::PackResult;
+
+    using ItemGroup = _ItemGroup<RawShape>;
+    using DefaultIterator = typename ItemGroup::const_iterator;
+
+    /**
+     * @brief Constructor taking the bin and an optional configuration.
+     * @param bin The bin object whose type is defined by the placement strategy.
+     * @param config The configuration for the particular placer.
+     */
+    explicit PlacementStrategyLike(const BinType& bin,
+                                   const Config& config = Config()):
+        impl_(bin)
+    {
+        configure(config);
+    }
+
+    /**
+     * @brief Provide a different configuration for the placer.
+     *
+     * Note that it depends on the particular placer implementation how it
+     * reacts to config changes in the middle of a calculation.
+     *
+     * @param config The configuration object defined by the placement strategy.
+     */
+    inline void configure(const Config& config) { impl_.configure(config); }
+
+    /**
+     * Try to pack an item with a result object that contains the packing
+     * information for later accepting it.
+     *
+     * \param item_store A container of items that are intended to be packed
+     * later. Can be used by the placer to switch tactics. When it's knows that
+     * many items will come a greedy strategy may not be the best.
+     * \param from The iterator to the item from which the packing should start,
+     * including the pointed item
+     * \param count How many items should be packed. If the value is 1, than
+     * just the item pointed to by "from" argument should be packed.
+     */
+    template<class Iter = DefaultIterator>
+    inline PackResult trypack(
+            Item& item,
+            const ConstItemRange<Iter>& remaining = ConstItemRange<Iter>())
+    {
+        return impl_.trypack(item, remaining);
+    }
+
+    /**
+     * @brief A method to accept a previously tried item (or items).
+     *
+     * If the pack result is a failure the method should ignore it.
+     * @param r The result of a previous trypack call.
+     */
+    inline void accept(PackResult& r) { impl_.accept(r); }
+
+    /**
+     * @brief pack Try to pack and immediately accept it on success.
+     *
+     * A default implementation would be to call
+     * { auto&& r = trypack(...); accept(r); return r; } but we should let the
+     * implementor of the placement strategy to harvest any optimizations from
+     * the absence of an intermediate step. The above version can still be used
+     * in the implementation.
+     *
+     * @param item The item to pack.
+     * @return Returns true if the item was packed or false if it could not be
+     * packed.
+     */
+    template<class Range = ConstItemRange<DefaultIterator>>
+    inline PackResult pack(
+            Item& item,
+            const Range& remaining = Range())
+    {
+        return impl_.pack(item, remaining);
+    }
+
+    /**
+     * This method makes possible to "preload" some items into the placer. It
+     * will not move these items but will consider them as already packed.
+     */
+    inline void preload(const ItemGroup& packeditems)
+    {
+        impl_.preload(packeditems);
+    }
+
+    /// Unpack the last element (remove it from the list of packed items).
+    inline void unpackLast() { impl_.unpackLast(); }
+
+    /// Get the bin object.
+    inline const BinType& bin() const { return impl_.bin(); }
+
+    /// Set a new bin object.
+    inline void bin(const BinType& bin) { impl_.bin(bin); }
+
+    /// Get the packed items.
+    inline ItemGroup getItems() { return impl_.getItems(); }
+
+    /// Clear the packed items so a new session can be started.
+    inline void clearItems() { impl_.clearItems(); }
+
+    inline double filledArea() const { return impl_.filledArea(); }
+
+    inline double score() const { return impl_.score(); }
+
+    inline void plateID(int id) { impl_.plateID(id); }
+    inline int plateID() { return impl_.plateID(); }
+
+};
+
+// The progress function will be called with the number of placed items
+using ProgressFunction = std::function<void(unsigned)>;
+using StopCondition = std::function<bool(void)>;
+using UnfitIndicator = std::function<void(std::string)>;
+
+/**
+ * A wrapper interface (trait) class for any selections strategy provider.
+ */
+template<class SelectionStrategy>
+class SelectionStrategyLike {
+    SelectionStrategy impl_;
+public:
+    using RawShape = typename SelectionStrategy::ShapeType;
+    using Item = _Item<RawShape>;
+    using PackGroup = _PackGroup<RawShape>;
+    using Config = typename SelectionStrategy::Config;
+
+
+    /**
+     * @brief Provide a different configuration for the selection strategy.
+     *
+     * Note that it depends on the particular placer implementation how it
+     * reacts to config changes in the middle of a calculation.
+     *
+     * @param config The configuration object defined by the selection strategy.
+     */
+    inline void configure(const Config& config) {
+        impl_.configure(config);
+    }
+
+    /**
+     * @brief A function callback which should be called whenever an item or
+     * a group of items where successfully packed.
+     * @param fn A function callback object taking one unsigned integer as the
+     * number of the remaining items to pack.
+     */
+    void progressIndicator(ProgressFunction fn) { impl_.progressIndicator(fn); }
+
+    //BBS
+    void unfitIndicator(UnfitIndicator fn) { impl_.unfitIndicator(fn); }
+
+    void stopCondition(StopCondition cond) { impl_.stopCondition(cond); }
+
+    /**
+     * \brief A method to start the calculation on the input sequence.
+     *
+     * \tparam TPlacer The only mandatory template parameter is the type of
+     * placer compatible with the PlacementStrategyLike interface.
+     *
+     * \param first, last The first and last iterator if the input sequence. It
+     * can be only an iterator of a type convertible to Item.
+     * \param bin. The shape of the bin. It has to be supported by the placement
+     * strategy.
+     * \param An optional config object for the placer.
+     */
+    template<class TPlacer, class TIterator,
+             class TBin = typename PlacementStrategyLike<TPlacer>::BinType,
+             class PConfig = typename PlacementStrategyLike<TPlacer>::Config>
+    inline void packItems(
+            TIterator first,
+            TIterator last,
+            TBin&& bin,
+            PConfig&& config = PConfig() )
+    {
+        impl_.template packItems<TPlacer>(first, last,
+                                 std::forward<TBin>(bin),
+                                 std::forward<PConfig>(config));
+    }
+
+    /**
+     * @brief Get the items for a particular bin.
+     * @param binIndex The index of the requested bin.
+     * @return Returns a list of all items packed into the requested bin.
+     */
+    inline const PackGroup& getResult() const {
+        return impl_.getResult();
+    }
+
+    inline int lastPackedBinId() const {
+        return impl_.lastPackedBinId();
+    }
+
+    void clear() { impl_.clear(); }
+};
+
+/**
+ * The _Nester is the front-end class for the libnest2d library. It takes the
+ * input items and changes their transformations to be inside the provided bin.
+ */
+template<class PlacementStrategy, class SelectionStrategy >
+class _Nester {
+    using TSel = SelectionStrategyLike<SelectionStrategy>;
+    TSel selector_;
+    
+public:
+    using Item = typename PlacementStrategy::Item;
+    using ShapeType = typename Item::ShapeType;
+    using ItemRef = std::reference_wrapper<Item>;
+    using TPlacer = PlacementStrategyLike<PlacementStrategy>;
+    using BinType = typename TPlacer::BinType;
+    using PlacementConfig = typename TPlacer::Config;
+    using SelectionConfig = typename TSel::Config;
+    using Coord = TCoord<TPoint<typename Item::ShapeType>>;
+    using PackGroup = _PackGroup<typename Item::ShapeType>;
+    using ResultType = PackGroup;
+
+private:
+    BinType bin_;
+    PlacementConfig pconfig_;
+    Coord min_obj_distance_;
+
+    using SItem =  typename SelectionStrategy::Item;
+    using TPItem = remove_cvref_t<Item>;
+    using TSItem = remove_cvref_t<SItem>;
+
+    StopCondition stopfn_;
+
+    template<class It> using TVal = remove_ref_t<typename It::value_type>;
+    
+    template<class It, class Out>
+    using ItemIteratorOnly =
+        enable_if_t<std::is_convertible<TVal<It>&, TPItem&>::value, Out>;
+
+public:
+
+    /**
+     * \brief Constructor taking the bin as the only mandatory parameter.
+     *
+     * \param bin The bin shape that will be used by the placers. The type
+     * of the bin should be one that is supported by the placer type.
+     */
+    template<class TBinType = BinType,
+             class PConf = PlacementConfig,
+             class SConf = SelectionConfig>
+    _Nester(TBinType&& bin, Coord min_obj_distance = 0,
+            const PConf& pconfig = PConf(), const SConf& sconfig = SConf()):
+        bin_(std::forward<TBinType>(bin)),
+        pconfig_(pconfig),
+        min_obj_distance_(min_obj_distance)
+    {
+        static_assert( std::is_same<TPItem, TSItem>::value,
+                       "Incompatible placement and selection strategy!");
+
+        selector_.configure(sconfig);
+    }
+
+    void configure(const PlacementConfig& pconf) { pconfig_ = pconf; }
+    void configure(const SelectionConfig& sconf) { selector_.configure(sconf); }
+    void configure(const PlacementConfig& pconf, const SelectionConfig& sconf)
+    {
+        pconfig_ = pconf;
+        selector_.configure(sconf);
+    }
+    void configure(const SelectionConfig& sconf, const PlacementConfig& pconf)
+    {
+        pconfig_ = pconf;
+        selector_.configure(sconf);
+    }
+
+    /**
+     * \brief Arrange an input sequence of _Item-s.
+     *
+     * To get the result, call the translation(), rotation() and binId()
+     * methods of each item. If only the transformed polygon is needed, call
+     * transformedShape() to get the properly transformed shapes.
+     *
+     * The number of groups in the pack group is the number of bins opened by
+     * the selection algorithm.
+     */
+    template<class It>
+    inline ItemIteratorOnly<It, size_t> execute(It from, It to)
+    {
+        auto infl = static_cast<Coord>(std::ceil(min_obj_distance_/2.0));
+        if(infl > 0) std::for_each(from, to, [infl](Item& item) {
+            item.inflate(infl);
+        });
+        
+        selector_.template packItems<PlacementStrategy>(
+            from, to, bin_, pconfig_);
+        
+        if(min_obj_distance_ > 0) std::for_each(from, to, [infl](Item& item) {
+            item.inflate(-infl);
+        });
+        
+        return selector_.getResult().size();
+    }
+
+    /// Set a progress indicator function object for the selector.
+    inline _Nester& progressIndicator(ProgressFunction func)
+    {
+        selector_.progressIndicator(func); return *this;
+    }
+
+    /// BBS: Set unfit indicator function object for the selector.
+    inline _Nester& unfitIndicator(UnfitIndicator func)
+    {
+        selector_.unfitIndicator(func); return *this;
+    }
+
+    /// Set a predicate to tell when to abort nesting.
+    inline _Nester& stopCondition(StopCondition fn)
+    {
+        stopfn_ = fn; selector_.stopCondition(fn); return *this;
+    }
+
+    inline const PackGroup& lastResult() const
+    {
+        return selector_.getResult();
+    }
+
+    inline int lastPackedBinId() const {
+        return selector_.lastPackedBinId();
+    }
+};
+
+}
+
+#endif // NESTER_HPP

src/libnest2d/include/libnest2d/optimizer.hpp

@@ -0,0 +1,254 @@
+#ifndef OPTIMIZER_HPP
+#define OPTIMIZER_HPP
+
+#include <tuple>
+#include <functional>
+#include <limits>
+
+#include <libnest2d/common.hpp>
+
+namespace libnest2d { namespace opt {
+
+using std::forward;
+using std::tuple;
+using std::make_tuple;
+
+/// A Type trait for upper and lower limit of a numeric type.
+template<class T, class B = void >
+struct limits {
+    inline static T min() { return std::numeric_limits<T>::min(); }
+    inline static T max() { return std::numeric_limits<T>::max(); }
+};
+
+template<class T>
+struct limits<T, enable_if_t<std::numeric_limits<T>::has_infinity, void>> {
+    inline static T min() { return -std::numeric_limits<T>::infinity(); }
+    inline static T max() { return std::numeric_limits<T>::infinity(); }
+};
+
+/// An interval of possible input values for optimization
+template<class T>
+class Bound {
+    T min_;
+    T max_;
+public:
+    Bound(const T& min = limits<T>::min(),
+          const T& max = limits<T>::max()): min_(min), max_(max) {}
+    inline const T min() const BP2D_NOEXCEPT { return min_; }
+    inline const T max() const BP2D_NOEXCEPT { return max_; }
+};
+
+/**
+ * Helper function to make a Bound object with its type deduced automatically.
+ */
+template<class T>
+inline Bound<T> bound(const T& min, const T& max) { return Bound<T>(min, max); }
+
+/**
+ * This is the type of an input tuple for the object function. It holds the
+ * values and their type in each dimension.
+ */
+template<class...Args> using Input = tuple<Args...>;
+
+template<class...Args>
+inline tuple<Args...> initvals(Args...args) { return make_tuple(args...); }
+
+/**
+ * @brief Specific optimization methods for which a default optimizer
+ * implementation can be instantiated.
+ */
+enum class Method {
+    L_SIMPLEX,
+    L_SUBPLEX,
+    G_GENETIC,
+    G_PARTICLE_SWARM
+    //...
+};
+
+/**
+ * @brief Info about result of an optimization. These codes are exactly the same
+ * as the nlopt codes for convinience.
+ */
+enum ResultCodes {
+    FAILURE = -1, /* generic failure code */
+    INVALID_ARGS = -2,
+    OUT_OF_MEMORY = -3,
+    ROUNDOFF_LIMITED = -4,
+    FORCED_STOP = -5,
+    SUCCESS = 1, /* generic success code */
+    STOPVAL_REACHED = 2,
+    FTOL_REACHED = 3,
+    XTOL_REACHED = 4,
+    MAXEVAL_REACHED = 5,
+    MAXTIME_REACHED = 6
+};
+
+/**
+ * \brief A type to hold the complete result of the optimization.
+ */
+template<class...Args>
+struct Result {
+    ResultCodes resultcode;
+    tuple<Args...> optimum;
+    double score;
+};
+
+/**
+ * @brief A type for specifying the stop criteria.
+ */
+struct StopCriteria {
+
+    /// If the absolute value difference between two scores.
+    double absolute_score_difference = std::nan("");
+
+    /// If the relative value difference between two scores.
+    double relative_score_difference = std::nan("");
+
+    /// Stop if this value or better is found.
+    double stop_score = std::nan("");
+
+    /// A predicate that if evaluates to true, the optimization should terminate
+    /// and the best result found prior to termination should be returned.
+    std::function<bool()> stop_condition = [] { return false; };
+
+    /// The max allowed number of iterations.
+    unsigned max_iterations = 0;
+};
+
+/**
+ * \brief The Optimizer base class with CRTP pattern.
+ */
+template<class Subclass>
+class Optimizer {
+protected:
+    enum class OptDir{
+        MIN,
+        MAX
+    } dir_;
+
+    StopCriteria stopcr_;
+
+public:
+
+    inline explicit Optimizer(const StopCriteria& scr = {}): stopcr_(scr) {}
+
+    /**
+     * \brief Optimize for minimum value of the provided objectfunction.
+     * \param objectfunction The function that will be searched for the minimum
+     * return value.
+     * \param initvals A tuple with the initial values for the search
+     * \param bounds A parameter pack with the bounds for each dimension.
+     * \return Returns a Result<Args...> structure.
+     * An example call would be:
+     *     auto result = opt.optimize_min(
+     *           [](tuple<double> x) // object function
+     *           {
+     *               return std::pow(std::get<0>(x), 2);
+     *           },
+     *           make_tuple(-0.5),  // initial value
+     *           {-1.0, 1.0}           // search space bounds
+     *       );
+     */
+    template<class Func, class...Args>
+    inline Result<Args...> optimize_min(Func&& objectfunction,
+                                        Input<Args...> initvals,
+                                        Bound<Args>... bounds)
+    {
+        dir_ = OptDir::MIN;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction), initvals, bounds... );
+    }
+
+    template<class Func, class...Args>
+    inline Result<Args...> optimize_min(Func&& objectfunction,
+                                        Input<Args...> initvals)
+    {
+        dir_ = OptDir::MIN;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction), initvals, Bound<Args>()... );
+    }
+
+    template<class...Args, class Func>
+    inline Result<Args...> optimize_min(Func&& objectfunction)
+    {
+        dir_ = OptDir::MIN;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction),
+                    Input<Args...>(),
+                    Bound<Args>()... );
+    }
+
+    /// Same as optimize_min but optimizes for maximum function value.
+    template<class Func, class...Args>
+    inline Result<Args...> optimize_max(Func&& objectfunction,
+                                        Input<Args...> initvals,
+                                        Bound<Args>... bounds)
+    {
+        dir_ = OptDir::MAX;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction), initvals, bounds... );
+    }
+
+    template<class Func, class...Args>
+    inline Result<Args...> optimize_max(Func&& objectfunction,
+                                        Input<Args...> initvals)
+    {
+        dir_ = OptDir::MAX;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction), initvals, Bound<Args>()... );
+    }
+
+    template<class...Args, class Func>
+    inline Result<Args...> optimize_max(Func&& objectfunction)
+    {
+        dir_ = OptDir::MAX;
+        return static_cast<Subclass*>(this)->template optimize<Func, Args...>(
+                    forward<Func>(objectfunction),
+                    Input<Args...>(),
+                    Bound<Args>()... );
+    }
+
+};
+
+// Just to be able to instantiate an unimplemented method and generate compile
+// error.
+template<class T = void>
+class DummyOptimizer : public Optimizer<DummyOptimizer<T>> {
+    friend class Optimizer<DummyOptimizer<T>>;
+
+public:
+    DummyOptimizer() {
+        static_assert(always_false<T>::value, "Optimizer unimplemented!");
+    }
+
+    DummyOptimizer(const StopCriteria&) {
+        static_assert(always_false<T>::value, "Optimizer unimplemented!");
+    }
+
+    template<class Func, class...Args>
+    Result<Args...> optimize(Func&& /*func*/,
+                             tuple<Args...> /*initvals*/,
+                             Bound<Args>...  /*args*/)
+    {
+        return Result<Args...>();
+    }
+};
+
+// Specializing this struct will tell what kind of optimizer to generate for
+// a given method
+template<Method m> struct OptimizerSubclass { using Type = DummyOptimizer<>; };
+
+/// Optimizer type based on the method provided in parameter m.
+template<Method m> using TOptimizer = typename OptimizerSubclass<m>::Type;
+
+/// Global optimizer with an explicitly specified local method.
+template<Method m>
+inline TOptimizer<m> GlobalOptimizer(Method, const StopCriteria& scr = {})
+{ // Need to be specialized in order to do anything useful.
+    return TOptimizer<m>(scr);
+}
+
+}
+}
+
+#endif // OPTIMIZER_HPP

src/libnest2d/include/libnest2d/optimizers/nlopt/genetic.hpp

@@ -0,0 +1,34 @@
+#ifndef GENETIC_HPP
+#define GENETIC_HPP
+
+#include "nlopt_boilerplate.hpp"
+
+namespace libnest2d { namespace opt {
+
+class GeneticOptimizer: public NloptOptimizer {
+public:
+    inline explicit GeneticOptimizer(const StopCriteria& scr = {}):
+        NloptOptimizer(method2nloptAlg(Method::G_GENETIC), scr) {}
+
+    inline GeneticOptimizer& localMethod(Method m) {
+        localmethod_ = m;
+        return *this;
+    }
+
+    inline void seed(unsigned long val) { nlopt::srand(val); }
+};
+
+template<>
+struct OptimizerSubclass<Method::G_GENETIC> { using Type = GeneticOptimizer; };
+
+template<>
+inline TOptimizer<Method::G_GENETIC> GlobalOptimizer<Method::G_GENETIC>(
+        Method localm, const StopCriteria& scr )
+{
+    return GeneticOptimizer (scr).localMethod(localm);
+}
+
+}
+}
+
+#endif // GENETIC_HPP

src/libnest2d/include/libnest2d/optimizers/nlopt/nlopt_boilerplate.hpp

@@ -0,0 +1,200 @@
+#ifndef NLOPT_BOILERPLATE_HPP
+#define NLOPT_BOILERPLATE_HPP
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4244)
+#pragma warning(disable: 4267)
+#endif
+#include <nlopt.hpp>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+#include <libnest2d/optimizer.hpp>
+#include <cassert>
+#include <libnest2d/utils/metaloop.hpp>
+
+#include <utility>
+
+namespace libnest2d { namespace opt {
+
+inline nlopt::algorithm method2nloptAlg(Method m) {
+
+    switch(m) {
+    case Method::L_SIMPLEX: return nlopt::LN_NELDERMEAD;
+    case Method::L_SUBPLEX: return nlopt::LN_SBPLX;
+    case Method::G_GENETIC: return nlopt::GN_ESCH;
+    default: assert(false); throw(m);
+    }
+}
+
+/**
+ * Optimizer based on NLopt.
+ *
+ * All the optimized types have to be convertible to double.
+ */
+class NloptOptimizer: public Optimizer<NloptOptimizer> {
+protected:
+    nlopt::opt opt_;
+    std::vector<double> lower_bounds_;
+    std::vector<double> upper_bounds_;
+    std::vector<double> initvals_;
+    nlopt::algorithm alg_;
+    Method localmethod_;
+
+    using Base = Optimizer<NloptOptimizer>;
+
+    friend Base;
+
+    // ********************************************************************** */
+
+    // TODO: CHANGE FOR LAMBDAS WHEN WE WILL MOVE TO C++14
+
+    struct BoundsFunc {
+        NloptOptimizer& self;
+        inline explicit BoundsFunc(NloptOptimizer& o): self(o) {}
+
+        template<class T> void operator()(int N, T& bounds)
+        {
+            self.lower_bounds_[N] = bounds.min();
+            self.upper_bounds_[N] = bounds.max();
+        }
+    };
+
+    struct InitValFunc {
+        NloptOptimizer& self;
+        inline explicit InitValFunc(NloptOptimizer& o): self(o) {}
+
+        template<class T> void operator()(int N, T& initval)
+        {
+            self.initvals_[N] = initval;
+        }
+    };
+
+    struct ResultCopyFunc {
+        NloptOptimizer& self;
+        inline explicit ResultCopyFunc(NloptOptimizer& o): self(o) {}
+
+        template<class T> void operator()(int N, T& resultval)
+        {
+            resultval = self.initvals_[N];
+        }
+    };
+
+    struct FunvalCopyFunc {
+        using D = const std::vector<double>;
+        D& params;
+        inline explicit FunvalCopyFunc(D& p): params(p) {}
+
+        template<class T> void operator()(int N, T& resultval)
+        {
+            resultval = params[N];
+        }
+    };
+
+    /* ********************************************************************** */
+
+    template<class Fn, class...Args>
+    static double optfunc(const std::vector<double>& params,
+                          std::vector<double>& /*grad*/,
+                          void *data)
+    {
+        using TData = std::pair<remove_ref_t<Fn>*, NloptOptimizer*>;
+        auto typeddata = static_cast<TData*>(data);
+
+        if(typeddata->second->stopcr_.stop_condition())
+            typeddata->second->opt_.force_stop();
+
+        auto fnptr = typeddata->first;
+        auto funval = std::tuple<Args...>();
+
+        // copy the obtained objectfunction arguments to the funval tuple.
+        metaloop::apply(FunvalCopyFunc(params), funval);
+
+        auto ret = metaloop::callFunWithTuple(*fnptr, funval,
+                                              index_sequence_for<Args...>());
+
+        return ret;
+    }
+
+    template<class Func, class...Args>
+    Result<Args...> optimize(Func&& func,
+                             std::tuple<Args...> initvals,
+                             Bound<Args>... args)
+    {
+        lower_bounds_.resize(sizeof...(Args));
+        upper_bounds_.resize(sizeof...(Args));
+        initvals_.resize(sizeof...(Args));
+
+        opt_ = nlopt::opt(alg_, sizeof...(Args) );
+
+        // Copy the bounds which is obtained as a parameter pack in args into
+        // lower_bounds_ and upper_bounds_
+        metaloop::apply(BoundsFunc(*this), args...);
+
+        opt_.set_lower_bounds(lower_bounds_);
+        opt_.set_upper_bounds(upper_bounds_);
+
+        nlopt::opt localopt;
+        switch(opt_.get_algorithm()) {
+        case nlopt::GN_MLSL:
+        case nlopt::GN_MLSL_LDS:
+            localopt = nlopt::opt(method2nloptAlg(localmethod_),
+                                  sizeof...(Args));
+            localopt.set_lower_bounds(lower_bounds_);
+            localopt.set_upper_bounds(upper_bounds_);
+            opt_.set_local_optimizer(localopt);
+        default: ;
+        }
+
+        double abs_diff = stopcr_.absolute_score_difference;
+        double rel_diff = stopcr_.relative_score_difference;
+        double stopval = stopcr_.stop_score;
+        if(!std::isnan(abs_diff)) opt_.set_ftol_abs(abs_diff);
+        if(!std::isnan(rel_diff)) opt_.set_ftol_rel(rel_diff);
+        if(!std::isnan(stopval))  opt_.set_stopval(stopval);
+
+        if(this->stopcr_.max_iterations > 0)
+            opt_.set_maxeval(this->stopcr_.max_iterations );
+
+        // Take care of the initial values, copy them to initvals_
+        metaloop::apply(InitValFunc(*this), initvals);
+
+        std::pair<remove_ref_t<Func>*, NloptOptimizer*> data =
+                std::make_pair(&func, this);
+
+        switch(dir_) {
+        case OptDir::MIN:
+            opt_.set_min_objective(optfunc<Func, Args...>, &data); break;
+        case OptDir::MAX:
+            opt_.set_max_objective(optfunc<Func, Args...>, &data); break;
+        }
+
+        Result<Args...> result;
+        nlopt::result rescode;
+
+        try {
+            rescode = opt_.optimize(initvals_, result.score);
+            result.resultcode = static_cast<ResultCodes>(rescode);
+        } catch( nlopt::forced_stop& ) {
+            result.resultcode = ResultCodes::FORCED_STOP;
+        }
+
+        metaloop::apply(ResultCopyFunc(*this), result.optimum);
+
+        return result;
+    }
+
+public:
+    inline explicit NloptOptimizer(nlopt::algorithm alg,
+                                   StopCriteria stopcr = {}):
+        Base(stopcr), alg_(alg), localmethod_(Method::L_SIMPLEX) {}
+
+};
+
+}
+}
+
+
+#endif // NLOPT_BOILERPLATE_HPP

src/libnest2d/include/libnest2d/optimizers/nlopt/simplex.hpp

@@ -0,0 +1,20 @@
+#ifndef SIMPLEX_HPP
+#define SIMPLEX_HPP
+
+#include "nlopt_boilerplate.hpp"
+
+namespace libnest2d { namespace opt {
+
+class SimplexOptimizer: public NloptOptimizer {
+public:
+    inline explicit SimplexOptimizer(const StopCriteria& scr = {}):
+        NloptOptimizer(method2nloptAlg(Method::L_SIMPLEX), scr) {}
+};
+
+template<>
+struct OptimizerSubclass<Method::L_SIMPLEX> { using Type = SimplexOptimizer; };
+
+}
+}
+
+#endif // SIMPLEX_HPP

src/libnest2d/include/libnest2d/optimizers/nlopt/subplex.hpp

@@ -0,0 +1,20 @@
+#ifndef SUBPLEX_HPP
+#define SUBPLEX_HPP
+
+#include "nlopt_boilerplate.hpp"
+
+namespace libnest2d { namespace opt {
+
+class SubplexOptimizer: public NloptOptimizer {
+public:
+    inline explicit SubplexOptimizer(const StopCriteria& scr = {}):
+        NloptOptimizer(method2nloptAlg(Method::L_SUBPLEX), scr) {}
+};
+
+template<>
+struct OptimizerSubclass<Method::L_SUBPLEX> { using Type = SubplexOptimizer; };
+
+}
+}
+
+#endif // SUBPLEX_HPP

src/libnest2d/include/libnest2d/parallel.hpp

@@ -0,0 +1,63 @@
+#ifndef LIBNEST2D_PARALLEL_HPP
+#define LIBNEST2D_PARALLEL_HPP
+
+#include <iterator>
+#include <functional>
+#include <future>
+
+#ifdef LIBNEST2D_THREADING_tbb
+#include <tbb/parallel_for.h>
+#endif
+
+#ifdef LIBNEST2D_THREADING_omp
+#include <omp.h>
+#endif
+
+namespace libnest2d { namespace __parallel {
+    
+template<class It> 
+using TIteratorValue = typename std::iterator_traits<It>::value_type;
+
+template<class Iterator>
+inline void enumerate(
+        Iterator from, Iterator to,
+        std::function<void(TIteratorValue<Iterator>, size_t)> fn,
+        std::launch policy = std::launch::deferred | std::launch::async)
+{
+    using TN = size_t;
+    auto iN = to-from;
+    TN N = iN < 0? 0 : TN(iN);
+
+#ifdef LIBNEST2D_THREADING_tbb
+    if((policy & std::launch::async) == std::launch::async) {
+        tbb::parallel_for<TN>(0, N, [from, fn] (TN n) { fn(*(from + n), n); } );
+    } else {
+        for(TN n = 0; n < N; n++) fn(*(from + n), n);
+    }
+#endif
+
+#ifdef LIBNEST2D_THREADING_omp
+    if((policy & std::launch::async) == std::launch::async) {
+        #pragma omp parallel for
+        for(int n = 0; n < int(N); n++) fn(*(from + n), TN(n));
+    }
+    else {
+        for(TN n = 0; n < N; n++) fn(*(from + n), n);
+    }
+#endif
+
+#ifdef LIBNEST2D_THREADING_std
+    std::vector<std::future<void>> rets(N);
+
+    auto it = from;
+    for(TN b = 0; b < N; b++) {
+        rets[b] = std::async(policy, fn, *it++, unsigned(b));
+    }
+
+    for(TN fi = 0; fi < N; ++fi) rets[fi].wait();
+#endif
+}
+
+}}
+
+#endif //LIBNEST2D_PARALLEL_HPP

src/libnest2d/include/libnest2d/placers/bottomleftplacer.hpp

@@ -0,0 +1,434 @@
+#ifndef BOTTOMLEFT_HPP
+#define BOTTOMLEFT_HPP
+
+#include <limits>
+
+#include "placer_boilerplate.hpp"
+
+namespace libnest2d { namespace placers {
+
+template<class T, class = T> struct DefaultEpsilon {};
+
+template<class T>
+struct DefaultEpsilon<T, enable_if_t<std::is_integral<T>::value, T> > {
+    static const T Value = 1;
+};
+
+template<class T>
+struct DefaultEpsilon<T, enable_if_t<std::is_floating_point<T>::value, T> > {
+    static const T Value = 1e-3;
+};
+
+template<class RawShape>
+struct BLConfig {
+    DECLARE_MAIN_TYPES(RawShape);
+
+    Coord min_obj_distance = 0;
+    Coord epsilon = DefaultEpsilon<Coord>::Value;
+    bool allow_rotations = false;
+    //BBS: sort function for selector
+    std::function<bool(_Item<RawShape>& i1, _Item<RawShape>& i2)> sortfunc;
+    //BBS: excluded region for V4 bed
+    std::vector<_Item<RawShape> > m_excluded_regions;
+    _ItemGroup<RawShape> m_excluded_items;
+    std::vector < _Item<RawShape> > m_nonprefered_regions;
+};
+
+template<class RawShape>
+class _BottomLeftPlacer: public PlacerBoilerplate<
+        _BottomLeftPlacer<RawShape>,
+        RawShape, _Box<TPoint<RawShape>>,
+        BLConfig<RawShape> >
+{
+    using Base = PlacerBoilerplate<_BottomLeftPlacer<RawShape>, RawShape,
+                                    _Box<TPoint<RawShape>>, BLConfig<RawShape>>;
+    DECLARE_PLACER(Base)
+
+public:
+
+    explicit _BottomLeftPlacer(const BinType& bin): Base(bin) {}
+
+    template<class Range = ConstItemRange<typename Base::DefaultIter>>
+    PackResult trypack(Item& item,
+                       const Range& = Range())
+    {
+        auto r = _trypack(item);
+        if(!r && Base::config_.allow_rotations) {
+
+            item.rotate(Degrees(90));
+            r =_trypack(item);
+        }
+        return r;
+    }
+
+    enum class Dir {
+        LEFT,
+        DOWN
+    };
+
+    inline RawShape leftPoly(const Item& item) const {
+        return toWallPoly(item, Dir::LEFT);
+    }
+
+    inline RawShape downPoly(const Item& item) const {
+        return toWallPoly(item, Dir::DOWN);
+    }
+
+    inline Coord availableSpaceLeft(const Item& item) {
+        return availableSpace(item, Dir::LEFT);
+    }
+
+    inline Coord availableSpaceDown(const Item& item) {
+        return availableSpace(item, Dir::DOWN);
+    }
+
+    double score() const { return score_; }
+    //BBS
+    void plateID(int id) { plate_id = id; }
+    int plateID() { return plate_id; }
+
+protected:
+    double score_ = 0;
+    int plate_id = 0;   // BBS
+
+    PackResult _trypack(Item& item) {
+
+        // Get initial position for item in the top right corner
+        setInitialPosition(item);
+
+        Coord d = availableSpaceDown(item);
+        auto eps = config_.epsilon;
+        bool can_move = d > eps;
+        bool can_be_packed = can_move;
+        bool left = true;
+
+        while(can_move) {
+            if(left) { // write previous down move and go down
+                item.translate({0, -d+eps});
+                d = availableSpaceLeft(item);
+                can_move = d > eps;
+                left = false;
+            } else { // write previous left move and go down
+                item.translate({-d+eps, 0});
+                d = availableSpaceDown(item);
+                can_move = d > eps;
+                left = true;
+            }
+        }
+
+        if(can_be_packed) {
+            Item trsh(item.transformedShape());
+            for(auto& v : trsh) can_be_packed = can_be_packed &&
+                    getX(v) < bin_.width() &&
+                    getY(v) < bin_.height();
+        }
+
+        return can_be_packed? PackResult(item) : PackResult();
+    }
+
+    void setInitialPosition(Item& item) {
+        auto bb = item.boundingBox();
+
+        Vertex v = { getX(bb.maxCorner()), getY(bb.minCorner()) };
+
+
+        Coord dx = getX(bin_.maxCorner()) - getX(v);
+        Coord dy = getY(bin_.maxCorner()) - getY(v);
+
+        item.translate({dx, dy});
+    }
+
+    template<class C = Coord>
+    static enable_if_t<std::is_floating_point<C>::value, bool>
+    isInTheWayOf( const Item& item,
+                  const Item& other,
+                  const RawShape& scanpoly)
+    {
+        auto tsh = other.transformedShape();
+        return ( sl::intersects(tsh, scanpoly) ||
+                 sl::isInside(tsh, scanpoly) ) &&
+               ( !sl::intersects(tsh, item.rawShape()) &&
+                 !sl::isInside(tsh, item.rawShape()) );
+    }
+
+    template<class C = Coord>
+    static enable_if_t<std::is_integral<C>::value, bool>
+    isInTheWayOf( const Item& item,
+                  const Item& other,
+                  const RawShape& scanpoly)
+    {
+        auto tsh = other.transformedShape();
+
+        bool inters_scanpoly = sl::intersects(tsh, scanpoly) &&
+                !sl::touches(tsh, scanpoly);
+        bool inters_item = sl::intersects(tsh, item.rawShape()) &&
+                !sl::touches(tsh, item.rawShape());
+
+        return ( inters_scanpoly ||
+                 sl::isInside(tsh, scanpoly)) &&
+               ( !inters_item &&
+                 !sl::isInside(tsh, item.rawShape())
+                 );
+    }
+
+    ItemGroup itemsInTheWayOf(const Item& item, const Dir dir) {
+        // Get the left or down polygon, that has the same area as the shadow
+        // of input item reflected to the left or downwards
+        auto&& scanpoly = dir == Dir::LEFT? leftPoly(item) :
+                                            downPoly(item);
+
+        ItemGroup ret;    // packed items 'in the way' of item
+        ret.reserve(items_.size());
+
+        // Predicate to find items that are 'in the way' for left (down) move
+        auto predicate = [&scanpoly, &item](const Item& it) {
+            return isInTheWayOf(item, it, scanpoly);
+        };
+
+        // Get the items that are in the way for the left (or down) movement
+        std::copy_if(items_.begin(), items_.end(),
+                     std::back_inserter(ret), predicate);
+
+        return ret;
+    }
+
+    Coord availableSpace(const Item& _item, const Dir dir) {
+
+        Item item (_item.transformedShape());
+
+
+        std::function<Coord(const Vertex&)> getCoord;
+        std::function< std::pair<Coord, bool>(const Segment&, const Vertex&) >
+            availableDistanceSV;
+
+        std::function< std::pair<Coord, bool>(const Vertex&, const Segment&) >
+            availableDistance;
+
+        if(dir == Dir::LEFT) {
+            getCoord = [](const Vertex& v) { return getX(v); };
+            availableDistance = pointlike::horizontalDistance<Vertex>;
+            availableDistanceSV = [](const Segment& s, const Vertex& v) {
+                auto ret = pointlike::horizontalDistance<Vertex>(v, s);
+                if(ret.second) ret.first = -ret.first;
+                return ret;
+            };
+        }
+        else {
+            getCoord = [](const Vertex& v) { return getY(v); };
+            availableDistance = pointlike::verticalDistance<Vertex>;
+            availableDistanceSV = [](const Segment& s, const Vertex& v) {
+                auto ret = pointlike::verticalDistance<Vertex>(v, s);
+                if(ret.second) ret.first = -ret.first;
+                return ret;
+            };
+        }
+
+        auto&& items_in_the_way = itemsInTheWayOf(item, dir);
+
+        // Comparison function for finding min vertex
+        auto cmp = [&getCoord](const Vertex& v1, const Vertex& v2) {
+            return getCoord(v1) < getCoord(v2);
+        };
+
+        // find minimum left or down coordinate of item
+        auto minvertex_it = std::min_element(item.begin(),
+                                                   item.end(),
+                                                   cmp);
+
+        // Get the initial distance in floating point
+        Coord m = getCoord(*minvertex_it);
+
+        // Check available distance for every vertex of item to the objects
+        // in the way for the nearest intersection
+        if(!items_in_the_way.empty()) { // This is crazy, should be optimized...
+            for(Item& pleft : items_in_the_way) {
+                // For all segments in items_to_left
+
+                assert(pleft.vertexCount() > 0);
+
+                auto trpleft_poly = pleft.transformedShape();
+                auto& trpleft = sl::contour(trpleft_poly);
+                auto first = sl::begin(trpleft);
+                auto next = first + 1;
+                auto endit = sl::end(trpleft);
+
+                while(next != endit) {
+                    Segment seg(*(first++), *(next++));
+                    for(auto& v : item) {   // For all vertices in item
+
+                        auto d = availableDistance(v, seg);
+
+                        if(d.second && d.first < m)  m = d.first;
+                    }
+                }
+            }
+
+            auto first = item.begin();
+            auto next = first + 1;
+            auto endit = item.end();
+
+            // For all edges in item:
+            while(next != endit) {
+                Segment seg(*(first++), *(next++));
+
+                // for all shapes in items_to_left
+                for(Item& sh : items_in_the_way) {
+                    assert(sh.vertexCount() > 0);
+
+                    Item tsh(sh.transformedShape());
+                    for(auto& v : tsh) {   // For all vertices in item
+
+                        auto d = availableDistanceSV(seg, v);
+
+                        if(d.second && d.first < m)  m = d.first;
+                    }
+                }
+            }
+        }
+
+        return m;
+    }
+
+    /**
+     * Implementation of the left (and down) polygon as described by
+     * [López-Camacho et al. 2013]\
+     * (http://www.cs.stir.ac.uk/~goc/papers/EffectiveHueristic2DAOR2013.pdf)
+     * see algorithm 8 for details...
+     */
+    RawShape toWallPoly(const Item& _item, const Dir dir) const {
+        // The variable names reflect the case of left polygon calculation.
+        //
+        // We will iterate through the item's vertices and search for the top
+        // and bottom vertices (or right and left if dir==Dir::DOWN).
+        // Save the relevant vertices and their indices into `bottom` and
+        // `top` vectors. In case of left polygon construction these will
+        // contain the top and bottom polygons which have the same vertical
+        // coordinates (in case there is more of them).
+        //
+        // We get the leftmost (or downmost) vertex from the `bottom` and `top`
+        // vectors and construct the final polygon.
+
+        Item item (_item.transformedShape());
+
+        auto getCoord = [dir](const Vertex& v) {
+            return dir == Dir::LEFT? getY(v) : getX(v);
+        };
+
+        Coord max_y = std::numeric_limits<Coord>::min();
+        Coord min_y = std::numeric_limits<Coord>::max();
+
+        using El = std::pair<size_t, std::reference_wrapper<const Vertex>>;
+
+        std::function<bool(const El&, const El&)> cmp;
+
+        if(dir == Dir::LEFT)
+            cmp = [](const El& e1, const El& e2) {
+                return getX(e1.second.get()) < getX(e2.second.get());
+            };
+        else
+            cmp = [](const El& e1, const El& e2) {
+                return getY(e1.second.get()) < getY(e2.second.get());
+            };
+
+        std::vector< El > top;
+        std::vector< El > bottom;
+
+        size_t idx = 0;
+        for(auto& v : item) { // Find the bottom and top vertices and save them
+            auto vref = std::cref(v);
+            auto vy = getCoord(v);
+
+            if( vy > max_y ) {
+                max_y = vy;
+                top.clear();
+                top.emplace_back(idx, vref);
+            }
+            else if(vy == max_y) { top.emplace_back(idx, vref); }
+
+            if(vy < min_y) {
+                min_y = vy;
+                bottom.clear();
+                bottom.emplace_back(idx, vref);
+            }
+            else if(vy == min_y) { bottom.emplace_back(idx, vref); }
+
+            idx++;
+        }
+
+        // Get the top and bottom leftmost vertices, or the right and left
+        // downmost vertices (if dir == Dir::DOWN)
+        auto topleft_it = std::min_element(top.begin(), top.end(), cmp);
+        auto bottomleft_it =
+                std::min_element(bottom.begin(), bottom.end(), cmp);
+
+        auto& topleft_vertex = topleft_it->second.get();
+        auto& bottomleft_vertex = bottomleft_it->second.get();
+
+        // Start and finish positions for the vertices that will be part of the
+        // new polygon
+        auto start = std::min(topleft_it->first, bottomleft_it->first);
+        auto finish = std::max(topleft_it->first, bottomleft_it->first);
+
+        RawShape ret;
+
+        // the return shape
+        auto& rsh = sl::contour(ret);
+
+        // reserve for all vertices plus 2 for the left horizontal wall, 2 for
+        // the additional vertices for maintaning min object distance
+        sl::reserve(rsh, finish-start+4);
+
+        auto addOthers_ = [&rsh, finish, start, &item](){
+            for(size_t i = start+1; i < finish; i++)
+                sl::addVertex(rsh, item.vertex(i));
+        };
+
+        auto reverseAddOthers_ = [&rsh, finish, start, &item](){
+            for(auto i = finish-1; i > start; i--)
+                sl::addVertex(rsh, item.vertex(static_cast<unsigned long>(i)));
+        };
+
+        auto addOthers = [&addOthers_, &reverseAddOthers_]() {
+            if constexpr (!is_clockwise<RawShape>())
+                addOthers_();
+            else
+                reverseAddOthers_();
+        };
+
+        // Final polygon construction...
+
+        // Clockwise polygon construction
+
+        sl::addVertex(rsh, topleft_vertex);
+
+        if(dir == Dir::LEFT) addOthers();
+        else {
+            sl::addVertex(rsh, {getX(topleft_vertex), 0});
+            sl::addVertex(rsh, {getX(bottomleft_vertex), 0});
+        }
+
+        sl::addVertex(rsh, bottomleft_vertex);
+
+        if(dir == Dir::LEFT) {
+            sl::addVertex(rsh, {0, getY(bottomleft_vertex)});
+            sl::addVertex(rsh, {0, getY(topleft_vertex)});
+        }
+        else addOthers();
+
+
+        // Close the polygon
+        if constexpr (ClosureTypeV<RawShape> == Closure::CLOSED)
+            sl::addVertex(rsh, topleft_vertex);
+
+        if constexpr (!is_clockwise<RawShape>())
+            std::reverse(rsh.begin(), rsh.end());
+
+        return ret;
+    }
+
+};
+
+}
+}
+
+#endif //BOTTOMLEFT_HPP

src/libnest2d/include/libnest2d/placers/placer_boilerplate.hpp

@@ -0,0 +1,140 @@
+#ifndef PLACER_BOILERPLATE_HPP
+#define PLACER_BOILERPLATE_HPP
+
+#include <libnest2d/nester.hpp>
+
+namespace libnest2d { namespace placers {
+
+struct EmptyConfig {};
+
+template<class Subclass, class RawShape, class TBin, class Cfg = EmptyConfig>
+class PlacerBoilerplate {
+    mutable bool farea_valid_ = false;
+    mutable double farea_ = 0.0;
+public:
+    using ShapeType = RawShape;
+    using Item = _Item<RawShape>;
+    using Vertex = TPoint<RawShape>;
+    using Segment = _Segment<Vertex>;
+    using BinType = TBin;
+    using Coord = TCoord<Vertex>;
+    using Config = Cfg;
+    using ItemGroup = _ItemGroup<RawShape>;
+    using DefaultIter = typename ItemGroup::const_iterator;
+
+    class PackResult {
+    public:
+        Item *item_ptr_;
+        Vertex move_;
+        Radians rot_;
+        double overfit_;
+        friend class PlacerBoilerplate;
+        friend Subclass;
+
+        PackResult(Item& item):
+            item_ptr_(&item),
+            move_(item.translation()),
+            rot_(item.rotation()),
+            overfit_(1.0) {}
+
+        PackResult(double overfit = 1.0):
+            item_ptr_(nullptr), overfit_(overfit) {}
+
+    public:
+        operator bool() { return item_ptr_ != nullptr; }
+        double overfit() const { return overfit_; }
+        double score_ = -1;
+        double score() { return score_; }
+        int plate_id = 0;   // BBS
+    };
+
+    inline PlacerBoilerplate(const BinType& bin, unsigned cap = 50): bin_(bin)
+    {
+        items_.reserve(cap);
+    }
+
+    inline const BinType& bin() const BP2D_NOEXCEPT { return bin_; }
+
+    template<class TB> inline void bin(TB&& b) {
+        bin_ = std::forward<BinType>(b);
+    }
+
+    inline void configure(const Config& config) BP2D_NOEXCEPT {
+        config_ = config;
+    }
+
+    template<class Range = ConstItemRange<DefaultIter>>
+    PackResult pack(Item& item, const Range& rem = Range()) {
+        auto&& r = static_cast<Subclass*>(this)->trypack(item, rem);
+        return r;
+    }
+
+    void preload(const ItemGroup& packeditems) {
+        items_.insert(items_.end(), packeditems.begin(), packeditems.end());
+        farea_valid_ = false;
+    }
+
+    void accept(PackResult& r) {
+        if(r) {
+            //r.item_ptr_->translation(r.move_);
+            //r.item_ptr_->rotation(r.rot_);
+            //items_.emplace_back(*(r.item_ptr_));
+            static_cast<Subclass*>(this)->accept(r);
+            farea_valid_ = false;
+        }
+    }
+
+    void unpackLast() {
+        items_.pop_back();
+        farea_valid_ = false;
+    }
+
+    inline const ItemGroup& getItems() const { return items_; }
+
+    inline void clearItems() {
+        items_.clear();
+        farea_valid_ = false;
+    }
+
+    inline double filledArea() const {
+        if(farea_valid_) return farea_;
+        else {
+            farea_ = .0;
+            std::for_each(items_.begin(), items_.end(),
+                          [this] (Item& item) {
+                farea_ += item.area();
+            });
+            farea_valid_ = true;
+        }
+
+        return farea_;
+    }
+
+public:
+
+    BinType bin_;
+    ItemGroup items_;
+    Cfg config_;
+};
+
+
+#define DECLARE_PLACER(Base) \
+using Base::bin_;                 \
+using Base::items_;               \
+using Base::config_;              \
+public:                           \
+using typename Base::ShapeType;   \
+using typename Base::Item;        \
+using typename Base::ItemGroup;   \
+using typename Base::BinType;     \
+using typename Base::Config;      \
+using typename Base::Vertex;      \
+using typename Base::Segment;     \
+using typename Base::PackResult;  \
+using typename Base::Coord;       \
+private:
+
+}
+}
+
+#endif // PLACER_BOILERPLATE_HPP

src/libnest2d/include/libnest2d/selections/djd_heuristic.hpp

@@ -0,0 +1,717 @@
+#ifndef DJD_HEURISTIC_HPP
+#define DJD_HEURISTIC_HPP
+
+#include <list>
+#include <future>
+#include <atomic>
+#include <functional>
+
+#include "selection_boilerplate.hpp"
+
+namespace libnest2d { namespace selections {
+
+/**
+ * Selection heuristic based on [López-Camacho]\
+ * (http://www.cs.stir.ac.uk/~goc/papers/EffectiveHueristic2DAOR2013.pdf)
+ */
+template<class RawShape>
+class _DJDHeuristic: public SelectionBoilerplate<RawShape> {
+    using Base = SelectionBoilerplate<RawShape>;
+
+    class SpinLock {
+        std::atomic_flag& lck_;
+    public:
+
+        inline SpinLock(std::atomic_flag& flg): lck_(flg) {}
+
+        inline void lock() {
+            while(lck_.test_and_set(std::memory_order_acquire)) {}
+        }
+
+        inline void unlock() { lck_.clear(std::memory_order_release); }
+    };
+
+public:
+    using typename Base::Item;
+    using ItemRef = std::reference_wrapper<Item>;
+
+    /**
+     * @brief The Config for DJD heuristic.
+     */
+    struct Config {
+
+        /**
+         * If true, the algorithm will try to place pair and triplets in all
+         * possible order. It will have a hugely negative impact on performance.
+         */
+        bool try_reverse_order = true;
+
+        /**
+         * @brief try_pairs Whether to try pairs of items to pack. It will add
+         * a quadratic component to the complexity.
+         */
+        bool try_pairs = true;
+
+        /**
+         * @brief Whether to try groups of 3 items to pack. This could be very
+         * slow for large number of items (>100) as it adds a cubic component
+         * to the complexity.
+         */
+        bool try_triplets = false;
+
+        /**
+         * The initial fill proportion of the bin area that will be filled before
+         * trying items one by one, or pairs or triplets.
+         *
+         * The initial fill proportion suggested by
+         * [López-Camacho]\
+         * (http://www.cs.stir.ac.uk/~goc/papers/EffectiveHueristic2DAOR2013.pdf)
+         * is one third of the area of bin.
+         */
+        double initial_fill_proportion = 1.0/3.0;
+
+        /**
+         * @brief How much is the acceptable waste incremented at each iteration
+         */
+        double waste_increment = 0.1;
+
+        /**
+         * @brief Allow parallel jobs for filling multiple bins.
+         *
+         * This will decrease the soution quality but can greatly boost up
+         * performance for large number of items.
+         */
+        bool allow_parallel = true;
+
+        /**
+         * @brief Always use parallel processing if the items don't fit into
+         * one bin.
+         */
+        bool force_parallel = false;
+    };
+
+private:
+    using Base::packed_bins_;
+    using ItemGroup = typename Base::ItemGroup;
+
+    using Container = ItemGroup;
+    Container store_;
+    Config config_;
+
+    static const unsigned MAX_ITEMS_SEQUENTIALLY = 30;
+    static const unsigned MAX_VERTICES_SEQUENTIALLY = MAX_ITEMS_SEQUENTIALLY*20;
+
+public:
+
+    inline void configure(const Config& config) {
+        config_ = config;
+    }
+
+    template<class TPlacer, class TIterator,
+             class TBin = typename PlacementStrategyLike<TPlacer>::BinType,
+             class PConfig = typename PlacementStrategyLike<TPlacer>::Config>
+    void packItems( TIterator first,
+                    TIterator last,
+                    const TBin& bin,
+                    PConfig&& pconfig = PConfig() )
+    {
+        using Placer = PlacementStrategyLike<TPlacer>;
+        using ItemList = std::list<ItemRef>;
+
+        const double bin_area = sl::area(bin);
+        const double w = bin_area * config_.waste_increment;
+
+        const double INITIAL_FILL_PROPORTION = config_.initial_fill_proportion;
+        const double INITIAL_FILL_AREA = bin_area*INITIAL_FILL_PROPORTION;
+
+        store_.clear();
+        store_.reserve(last-first);
+
+        // TODO: support preloading
+        packed_bins_.clear();
+
+        std::copy(first, last, std::back_inserter(store_));
+
+        std::sort(store_.begin(), store_.end(), [](Item& i1, Item& i2) {
+            return i1.area() > i2.area();
+        });
+
+        size_t glob_vertex_count = 0;
+        std::for_each(store_.begin(), store_.end(),
+                      [&glob_vertex_count](const Item& item) {
+             glob_vertex_count += item.vertexCount();
+        });
+
+        std::vector<Placer> placers;
+
+        bool try_reverse = config_.try_reverse_order;
+
+        // Will use a subroutine to add a new bin
+        auto addBin = [this, &placers, &bin, &pconfig]()
+        {
+            placers.emplace_back(bin);
+            packed_bins_.emplace_back();
+            placers.back().configure(pconfig);
+        };
+
+        // Types for pairs and triplets
+        using TPair = std::tuple<ItemRef, ItemRef>;
+        using TTriplet = std::tuple<ItemRef, ItemRef, ItemRef>;
+
+
+        // Method for checking a pair whether it was a pack failure.
+        auto check_pair = [](const std::vector<TPair>& wrong_pairs,
+                ItemRef i1, ItemRef i2)
+        {
+            return std::any_of(wrong_pairs.begin(), wrong_pairs.end(),
+                               [&i1, &i2](const TPair& pair)
+            {
+                Item& pi1 = std::get<0>(pair), &pi2 = std::get<1>(pair);
+                Item& ri1 = i1, &ri2 = i2;
+                return (&pi1 == &ri1 && &pi2 == &ri2) ||
+                       (&pi1 == &ri2 && &pi2 == &ri1);
+            });
+        };
+
+        // Method for checking if a triplet was a pack failure
+        auto check_triplet = [](
+                const std::vector<TTriplet>& wrong_triplets,
+                ItemRef i1,
+                ItemRef i2,
+                ItemRef i3)
+        {
+            return std::any_of(wrong_triplets.begin(),
+                               wrong_triplets.end(),
+                               [&i1, &i2, &i3](const TTriplet& tripl)
+            {
+                Item& pi1 = std::get<0>(tripl);
+                Item& pi2 = std::get<1>(tripl);
+                Item& pi3 = std::get<2>(tripl);
+                Item& ri1 = i1, &ri2 = i2, &ri3 = i3;
+                return  (&pi1 == &ri1 && &pi2 == &ri2 && &pi3 == &ri3) ||
+                        (&pi1 == &ri1 && &pi2 == &ri3 && &pi3 == &ri2) ||
+                        (&pi1 == &ri2 && &pi2 == &ri1 && &pi3 == &ri3) ||
+                        (&pi1 == &ri3 && &pi2 == &ri2 && &pi3 == &ri1);
+            });
+        };
+
+        using ItemListIt = typename ItemList::iterator;
+
+        auto largestPiece = [](ItemListIt it, ItemList& not_packed) {
+            return it == not_packed.begin()? std::next(it) : not_packed.begin();
+        };
+
+        auto secondLargestPiece = [&largestPiece](ItemListIt it,
+                ItemList& not_packed) {
+            auto ret = std::next(largestPiece(it, not_packed));
+            return ret == it? std::next(ret) : ret;
+        };
+
+        auto smallestPiece = [](ItemListIt it, ItemList& not_packed) {
+            auto last = std::prev(not_packed.end());
+            return it == last? std::prev(it) : last;
+        };
+
+        auto secondSmallestPiece = [&smallestPiece](ItemListIt it,
+                ItemList& not_packed) {
+            auto ret = std::prev(smallestPiece(it, not_packed));
+            return ret == it? std::prev(ret) : ret;
+        };
+
+        auto tryOneByOne = // Subroutine to try adding items one by one.
+                [&bin_area]
+                (Placer& placer, ItemList& not_packed,
+                double waste,
+                double& free_area,
+                double& filled_area)
+        {
+            double item_area = 0;
+            bool ret = false;
+            auto it = not_packed.begin();
+
+            auto pack = [&placer, &not_packed](ItemListIt it) {
+                return placer.pack(*it, rem(it, not_packed));
+            };
+
+            while(it != not_packed.end() && !ret &&
+                  free_area - (item_area = it->get().area()) <= waste)
+            {
+                if(item_area <= free_area && pack(it) ) {
+                    free_area -= item_area;
+                    filled_area = bin_area - free_area;
+                    ret = true;
+                } else
+                    it++;
+            }
+
+            if(ret) not_packed.erase(it);
+
+            return ret;
+        };
+
+        auto tryGroupsOfTwo = // Try adding groups of two items into the bin.
+                [&bin_area, &check_pair, &largestPiece, &smallestPiece,
+                 try_reverse]
+                (Placer& placer, ItemList& not_packed,
+                double waste,
+                double& free_area,
+                double& filled_area)
+        {
+            double item_area = 0;
+            const auto endit = not_packed.end();
+
+            if(not_packed.size() < 2)
+                return false; // No group of two items
+
+            double largest_area = not_packed.front().get().area();
+            auto itmp = not_packed.begin(); itmp++;
+            double second_largest = itmp->get().area();
+            if( free_area - second_largest - largest_area > waste)
+                return false; // If even the largest two items do not fill
+                // the bin to the desired waste than we can end here.
+
+
+            bool ret = false;
+            auto it = not_packed.begin();
+            auto it2 = it;
+
+            std::vector<TPair> wrong_pairs;
+            using std::placeholders::_1;
+
+            auto trypack = [&placer, &not_packed](ItemListIt it) {
+                return placer.trypack(*it, rem(it, not_packed));
+            };
+
+            while(it != endit && !ret &&
+                  free_area - (item_area = it->get().area()) -
+                  largestPiece(it, not_packed)->get().area() <= waste)
+            {
+                if(item_area + smallestPiece(it, not_packed)->get().area() >
+                        free_area ) { it++; continue; }
+
+                auto pr = trypack(it);
+
+                // First would fit
+                it2 = not_packed.begin();
+                double item2_area = 0;
+                while(it2 != endit && pr && !ret && free_area -
+                      (item2_area = it2->get().area()) - item_area <= waste)
+                {
+                    double area_sum = item_area + item2_area;
+
+                    if(it == it2 || area_sum > free_area ||
+                            check_pair(wrong_pairs, *it, *it2)) {
+                        it2++; continue;
+                    }
+
+                    placer.accept(pr);
+                    auto pr2 = trypack(it2);
+                    if(!pr2) {
+                        placer.unpackLast(); // remove first
+                        if(try_reverse) {
+                            pr2 = trypack(it2);
+                            if(pr2) {
+                                placer.accept(pr2);
+                                auto pr12 = trypack(it);
+                                if(pr12) {
+                                    placer.accept(pr12);
+                                    ret = true;
+                                } else {
+                                    placer.unpackLast();
+                                }
+                            }
+                        }
+                    } else {
+                        placer.accept(pr2); ret = true;
+                    }
+
+                    if(ret)
+                    { // Second fits as well
+                        free_area -= area_sum;
+                        filled_area = bin_area - free_area;
+                    } else {
+                        wrong_pairs.emplace_back(*it, *it2);
+                        it2++;
+                    }
+                }
+
+                if(!ret) it++;
+            }
+
+            if(ret) { not_packed.erase(it); not_packed.erase(it2); }
+
+            return ret;
+        };
+
+        auto tryGroupsOfThree = // Try adding groups of three items.
+                [&bin_area,
+                 &smallestPiece, &largestPiece,
+                 &secondSmallestPiece, &secondLargestPiece,
+                 &check_pair, &check_triplet, try_reverse]
+                (Placer& placer, ItemList& not_packed,
+                double waste,
+                double& free_area,
+                double& filled_area)
+        {
+            auto np_size = not_packed.size();
+            if(np_size < 3) return false;
+
+            auto it = not_packed.begin();           // from
+            const auto endit = not_packed.end();    // to
+            auto it2 = it, it3 = it;
+
+            // Containers for pairs and triplets that were tried before and
+            // do not work.
+            std::vector<TPair> wrong_pairs;
+            std::vector<TTriplet> wrong_triplets;
+
+            auto cap = np_size*np_size / 2 ;
+            wrong_pairs.reserve(cap);
+            wrong_triplets.reserve(cap);
+
+            // Will be true if a succesfull pack can be made.
+            bool ret = false;
+
+            auto area = [](const ItemListIt& it) {
+                return it->get().area();
+            };
+
+            auto trypack = [&placer, &not_packed](ItemListIt it) {
+                return placer.trypack(*it, rem(it, not_packed));
+            };
+
+            auto pack = [&placer, &not_packed](ItemListIt it) {
+                return placer.pack(*it, rem(it, not_packed));
+            };
+
+            while (it != endit && !ret) { // drill down 1st level
+
+                // We need to determine in each iteration the largest, second
+                // largest, smallest and second smallest item in terms of area.
+
+                Item& largest = *largestPiece(it, not_packed);
+                Item& second_largest = *secondLargestPiece(it, not_packed);
+
+                double area_of_two_largest =
+                        largest.area() + second_largest.area();
+
+                // Check if there is enough free area for the item and the two
+                // largest item
+                if(free_area - area(it) - area_of_two_largest > waste)
+                    break;
+
+                // Determine the area of the two smallest item.
+                Item& smallest = *smallestPiece(it, not_packed);
+                Item& second_smallest = *secondSmallestPiece(it, not_packed);
+
+                // Check if there is enough free area for the item and the two
+                // smallest item.
+                double area_of_two_smallest =
+                        smallest.area() + second_smallest.area();
+
+                if(area(it) + area_of_two_smallest > free_area) {
+                    it++; continue;
+                }
+
+                auto pr = trypack(it);
+
+                // Check for free area and try to pack the 1st item...
+                if(!pr) { it++; continue; }
+
+                it2 = not_packed.begin();
+                double rem2_area = free_area - largest.area();
+                double a2_sum = 0;
+
+                while(it2 != endit && !ret &&
+                      rem2_area - (a2_sum = area(it) + area(it2)) <= waste) {
+                    // Drill down level 2
+
+                    if(a2_sum != area(it) + area(it2)) throw -1;
+
+                    if(it == it2 || check_pair(wrong_pairs, *it, *it2)) {
+                        it2++; continue;
+                    }
+
+                    if(a2_sum + smallest.area() > free_area) {
+                        it2++; continue;
+                    }
+
+                    bool can_pack2 = false;
+
+                    placer.accept(pr);
+                    auto pr2 = trypack(it2);
+                    auto pr12 = pr;
+                    if(!pr2) {
+                        placer.unpackLast(); // remove first
+                        if(try_reverse) {
+                            pr2 = trypack(it2);
+                            if(pr2) {
+                                placer.accept(pr2);
+                                pr12 = trypack(it);
+                                if(pr12) can_pack2 = true;
+                                placer.unpackLast();
+                            }
+                        }
+                    } else {
+                        placer.unpackLast();
+                        can_pack2 = true;
+                    }
+
+                    if(!can_pack2) {
+                        wrong_pairs.emplace_back(*it, *it2);
+                        it2++;
+                        continue;
+                    }
+
+                    // Now we have packed a group of 2 items.
+                    // The 'smallest' variable now could be identical with
+                    // it2 but we don't bother with that
+
+                    it3 = not_packed.begin();
+
+                    double a3_sum = 0;
+
+                    while(it3 != endit && !ret &&
+                          free_area - (a3_sum = a2_sum + area(it3)) <= waste) {
+                        // 3rd level
+
+                        if(it3 == it || it3 == it2 ||
+                                check_triplet(wrong_triplets, *it, *it2, *it3))
+                        { it3++; continue; }
+
+                        if(a3_sum > free_area) { it3++; continue; }
+
+                        placer.accept(pr12); placer.accept(pr2);
+                        bool can_pack3 = pack(it3);
+
+                        if(!can_pack3) {
+                            placer.unpackLast();
+                            placer.unpackLast();
+                        }
+
+                        if(!can_pack3 && try_reverse) {
+
+                            std::array<size_t, 3> indices = {0, 1, 2};
+                            std::array<typename ItemList::iterator, 3>
+                                    candidates = {it, it2, it3};
+
+                            auto tryPack = [&placer, &candidates, &pack](
+                                    const decltype(indices)& idx)
+                            {
+                                std::array<bool, 3> packed = {false};
+
+                                for(auto id : idx) packed.at(id) =
+                                        pack(candidates[id]);
+
+                                bool check =
+                                std::all_of(packed.begin(),
+                                            packed.end(),
+                                            [](bool b) { return b; });
+
+                                if(!check) for(bool b : packed) if(b)
+                                        placer.unpackLast();
+
+                                return check;
+                            };
+
+                            while (!can_pack3 && std::next_permutation(
+                                       indices.begin(),
+                                       indices.end())){
+                                can_pack3 = tryPack(indices);
+                            };
+                        }
+
+                        if(can_pack3) {
+                            // finishit
+                            free_area -= a3_sum;
+                            filled_area = bin_area - free_area;
+                            ret = true;
+                        } else {
+                            wrong_triplets.emplace_back(*it, *it2, *it3);
+                            it3++;
+                        }
+
+                    } // 3rd while
+
+                    if(!ret) it2++;
+
+                } // Second while
+
+                if(!ret) it++;
+
+            } // First while
+
+            if(ret) { // If we eventually succeeded, remove all the packed ones.
+                not_packed.erase(it);
+                not_packed.erase(it2);
+                not_packed.erase(it3);
+            }
+
+            return ret;
+        };
+
+        this->template remove_unpackable_items<Placer>(store_, bin, pconfig);
+
+        int acounter = int(store_.size());
+        std::atomic_flag flg = ATOMIC_FLAG_INIT;
+        SpinLock slock(flg);
+
+        auto makeProgress = [this, &acounter, &slock]
+                (Placer& placer, size_t idx, int packednum)
+        {
+
+            packed_bins_[idx] = placer.getItems();
+
+            // TODO here should be a spinlock
+            slock.lock();
+            acounter -= packednum;
+            this->progress_(acounter);
+            slock.unlock();
+        };
+
+        double items_area = 0;
+        for(Item& item : store_) items_area += item.area();
+
+        // Number of bins that will definitely be needed
+        auto bincount_guess = unsigned(std::ceil(items_area / bin_area));
+
+        // Do parallel if feasible
+        bool do_parallel = config_.allow_parallel && bincount_guess > 1 &&
+                ((glob_vertex_count >  MAX_VERTICES_SEQUENTIALLY ||
+                 store_.size() > MAX_ITEMS_SEQUENTIALLY) ||
+                config_.force_parallel);
+
+        if(do_parallel) dout() << "Parallel execution..." << "\n";
+
+        bool do_pairs = config_.try_pairs;
+        bool do_triplets = config_.try_triplets;
+        StopCondition stopcond = this->stopcond_;
+
+        // The DJD heuristic algorithm itself:
+        auto packjob = [INITIAL_FILL_AREA, bin_area, w, do_triplets, do_pairs,
+                        stopcond,
+                        &tryOneByOne,
+                        &tryGroupsOfTwo,
+                        &tryGroupsOfThree,
+                        &makeProgress]
+                        (Placer& placer, ItemList& not_packed, size_t idx)
+        {
+            double filled_area = placer.filledArea();
+            double free_area = bin_area - filled_area;
+            double waste = .0;
+            bool lasttry = false;
+
+            while(!not_packed.empty() && !stopcond()) {
+
+                {// Fill the bin up to INITIAL_FILL_PROPORTION of its capacity
+                    auto it = not_packed.begin();
+
+                    while(it != not_packed.end() && !stopcond() &&
+                          filled_area < INITIAL_FILL_AREA)
+                    {
+                        if(placer.pack(*it, rem(it, not_packed))) {
+                            filled_area += it->get().area();
+                            free_area = bin_area - filled_area;
+                            it = not_packed.erase(it);
+                            makeProgress(placer, idx, 1);
+                        } else it++;
+                    }
+                }
+
+                // try pieces one by one
+                while(tryOneByOne(placer, not_packed, waste, free_area,
+                                  filled_area)) {
+                    waste = 0; lasttry = false;
+                    makeProgress(placer, idx, 1);
+                }
+
+                // try groups of 2 pieces
+                while(do_pairs &&
+                      tryGroupsOfTwo(placer, not_packed, waste, free_area,
+                                     filled_area)) {
+                    waste = 0; lasttry = false;
+                    makeProgress(placer, idx, 2);
+                }
+
+                // try groups of 3 pieces
+                while(do_triplets &&
+                      tryGroupsOfThree(placer, not_packed, waste, free_area,
+                                       filled_area)) {
+                    waste = 0; lasttry = false;
+                    makeProgress(placer, idx, 3);
+                }
+
+                waste += w;
+                if(!lasttry && waste > free_area) lasttry = true;
+                else if(lasttry) break;
+            }
+        };
+
+        size_t idx = 0;
+        ItemList remaining;
+
+        if(do_parallel) {
+            std::vector<ItemList> not_packeds(bincount_guess);
+
+            // Preallocating the bins
+            for(unsigned b = 0; b < bincount_guess; b++) {
+                addBin();
+                ItemList& not_packed = not_packeds[b];
+                for(unsigned idx = b; idx < store_.size(); idx+=bincount_guess) {
+                    not_packed.emplace_back(store_[idx]);
+                }
+            }
+
+            // The parallel job
+            auto job = [&placers, &not_packeds, &packjob](unsigned idx) {
+                Placer& placer = placers[idx];
+                ItemList& not_packed = not_packeds[idx];
+                return packjob(placer, not_packed, idx);
+            };
+
+            // We will create jobs for each bin
+            std::vector<std::future<void>> rets(bincount_guess);
+
+            for(unsigned b = 0; b < bincount_guess; b++) { // launch the jobs
+                rets[b] = std::async(std::launch::async, job, b);
+            }
+
+            for(unsigned fi = 0; fi < rets.size(); ++fi) {
+                rets[fi].wait();
+
+                // Collect remaining items while waiting for the running jobs
+                remaining.merge( not_packeds[fi], [](Item& i1, Item& i2) {
+                    return i1.area() > i2.area();
+                });
+
+            }
+
+            idx = placers.size();
+
+            // Try to put the remaining items into one of the packed bins
+            if(remaining.size() <= placers.size())
+            for(size_t j = 0; j < idx && !remaining.empty(); j++) {
+                packjob(placers[j], remaining, j);
+            }
+
+        } else {
+            remaining = ItemList(store_.begin(), store_.end());
+        }
+
+        while(!remaining.empty()) {
+            addBin();
+            packjob(placers[idx], remaining, idx); idx++;
+        }
+        
+        int binid = 0;
+        for(auto &bin : packed_bins_) {
+            for(Item& itm : bin) itm.binId(binid);
+            binid++;
+        }
+    }
+};
+
+}
+}
+
+#endif // DJD_HEURISTIC_HPP

src/libnest2d/include/libnest2d/selections/filler.hpp

@@ -0,0 +1,87 @@
+#ifndef FILLER_HPP
+#define FILLER_HPP
+
+#include "selection_boilerplate.hpp"
+
+namespace libnest2d { namespace selections {
+
+template<class RawShape>
+class _FillerSelection: public SelectionBoilerplate<RawShape> {
+    using Base = SelectionBoilerplate<RawShape>;
+public:
+    using typename Base::Item;
+    using Config = int; //dummy
+
+private:
+    using Base::packed_bins_;
+    using typename Base::ItemGroup;
+    using Container = ItemGroup;
+    Container store_;
+
+public:
+
+    void configure(const Config& /*config*/) { }
+
+    template<class TPlacer, class TIterator,
+             class TBin = typename PlacementStrategyLike<TPlacer>::BinType,
+             class PConfig = typename PlacementStrategyLike<TPlacer>::Config>
+    void packItems(TIterator first,
+                   TIterator last,
+                   TBin&& bin,
+                   PConfig&& pconfig = PConfig())
+    {
+        using Placer = PlacementStrategyLike<TPlacer>;
+        
+        store_.clear();
+        auto total = last-first;
+        store_.reserve(total);
+
+        // TODO: support preloading
+        packed_bins_.clear();
+
+        packed_bins_.emplace_back();
+
+        auto makeProgress = [this, &total](
+                PlacementStrategyLike<TPlacer>& placer)
+        {
+            packed_bins_.back() = placer.getItems();
+#ifndef NDEBUG
+            packed_bins_.back().insert(packed_bins_.back().end(),
+                                       placer.getDebugItems().begin(),
+                                       placer.getDebugItems().end());
+#endif
+            this->progress_(--total);
+        };
+
+        std::copy(first, last, std::back_inserter(store_));
+
+        auto sortfunc = [](Item& i1, Item& i2) {
+            return i1.area() > i2.area();
+        };
+        
+        this->template remove_unpackable_items<Placer>(store_, bin, pconfig);
+        
+        std::sort(store_.begin(), store_.end(), sortfunc);
+
+        Placer placer(bin);
+        placer.configure(pconfig);
+
+        auto it = store_.begin();
+        while(it != store_.end() && !this->stopcond_()) {
+            if(!placer.pack(*it, {std::next(it), store_.end()}))  {
+                if(packed_bins_.back().empty()) ++it;
+                placer.clearItems();
+                packed_bins_.emplace_back();
+            } else {
+                makeProgress(placer);
+                ++it;
+            }
+        }
+
+    }
+};
+
+}
+}
+
+#endif //BOTTOMLEFT_HPP

src/libnest2d/include/libnest2d/selections/firstfit.hpp

@@ -0,0 +1,179 @@
+#ifndef FIRSTFIT_HPP
+#define FIRSTFIT_HPP
+
+#include "selection_boilerplate.hpp"
+
+namespace libnest2d { namespace selections {
+
+template<class RawShape>
+class _FirstFitSelection: public SelectionBoilerplate<RawShape> {
+    using Base = SelectionBoilerplate<RawShape>;
+public:
+    using typename Base::Item;
+    using Config = int; //dummy
+
+private:
+    using Base::packed_bins_;
+    using typename Base::ItemGroup;
+    using Container = ItemGroup;//typename std::vector<_Item<RawShape>>;
+
+    Container store_;
+
+public:
+
+    void configure(const Config& /*config*/) { }
+
+    template<class TPlacer, class TIterator,
+             class TBin = typename PlacementStrategyLike<TPlacer>::BinType,
+             class PConfig = typename PlacementStrategyLike<TPlacer>::Config>
+    void packItems(TIterator first,
+                   TIterator last,
+                   TBin&& bin,
+                   PConfig&& pconfig = PConfig())
+    {
+
+        using Placer = PlacementStrategyLike<TPlacer>;
+
+        store_.clear();
+        store_.reserve(last-first);
+
+        std::vector<Placer> placers;
+        placers.reserve(last-first);
+        
+        typename Base::PackGroup fixed_bins;
+        std::for_each(first, last, [this, &fixed_bins](Item& itm) {
+            if (itm.isFixed()) {
+                if (itm.binId() < 0) itm.binId(0);
+                auto binidx = size_t(itm.binId());
+
+                while (fixed_bins.size() <= binidx)
+                    fixed_bins.emplace_back();
+
+                fixed_bins[binidx].emplace_back(itm);
+            }
+            else {
+                store_.emplace_back(itm);
+            }
+            });
+
+        std::for_each(pconfig.m_excluded_regions.begin(), pconfig.m_excluded_regions.end(), [this, &pconfig](Item& itm) {
+            pconfig.m_excluded_items.emplace_back(itm);
+            });
+
+        // If the packed_items array is not empty we have to create as many
+        // placers as there are elements in packed bins and preload each item
+        // into the appropriate placer
+        //for(ItemGroup& ig : fixed_bins) {
+        //    placers.emplace_back(bin);
+        //    placers.back().configure(pconfig);
+        //    placers.back().preload(ig);
+        //}
+        
+        std::function<bool(Item& i1, Item& i2)> sortfunc;
+        if (pconfig.sortfunc)
+            sortfunc = pconfig.sortfunc;
+        else {
+            sortfunc = [](Item& i1, Item& i2) {
+                int p1 = i1.priority(), p2 = i2.priority();
+                if (p1 != p2)
+                    return p1 > p2;
+
+                return i1.bed_temp != i2.bed_temp ? (i1.bed_temp > i2.bed_temp) :
+                        (i1.height != i2.height ? (i1.height < i2.height) : (i1.area() > i2.area()));
+            };
+        }
+
+        std::sort(store_.begin(), store_.end(), sortfunc);
+
+        int item_id = 0;
+        auto makeProgress = [this, &item_id](Placer &placer, size_t bin_idx) {
+            packed_bins_[bin_idx] = placer.getItems();
+            this->last_packed_bin_id_ = int(bin_idx);
+            this->progress_(static_cast<unsigned>(item_id));
+        };
+
+        auto& cancelled = this->stopcond_;
+        
+        this->template remove_unpackable_items<Placer>(store_, bin, pconfig);
+
+        for (auto it = store_.begin(); it != store_.end() && !cancelled(); ++it) {
+            // skip unpackable item
+            if (it->get().binId() == BIN_ID_UNFIT)
+                continue;
+            bool was_packed = false;
+            int best_bed_id = -1;
+            int bed_id_firstfit = -1;
+            double score = LARGE_COST_TO_REJECT, best_score = LARGE_COST_TO_REJECT;
+            double score_all_plates = 0, score_all_plates_best = std::numeric_limits<double>::max();
+            typename Placer::PackResult result, result_best, result_firstfit;
+            size_t j = 0;
+            while(!was_packed && !cancelled()) {
+                for(; j < placers.size() && !was_packed && !cancelled(); j++) {
+                    result = placers[j].pack(*it, rem(it, store_));
+                    score = result.score();
+                    score_all_plates = std::accumulate(placers.begin(), placers.begin() + j, score,
+                        [](double sum, const Placer& elem) { return sum + elem.score(); });
+
+                    if(score >= 0 && score < LARGE_COST_TO_REJECT) {
+                        if (bed_id_firstfit == -1) {
+                            bed_id_firstfit = j;
+                            result_firstfit = result;
+                        }
+                        if (score_all_plates < score_all_plates_best) {
+                            best_score = score;
+                            score_all_plates_best = score_all_plates;
+                            best_bed_id = j;
+                            result_best = result;
+                        }
+                    }
+                }
+                if (best_bed_id == MAX_NUM_PLATES) {
+                    // item is not fit because we have tried all possible plates to find a good enough fit
+                    if (bed_id_firstfit == MAX_NUM_PLATES) {
+                        it->get().binId(BIN_ID_UNFIT);
+                        //if (this->unfitindicator_)
+                        //    this->unfitindicator_(it->get().name + " bed_id_firstfit == MAX_NUM_PLATES" + ",best_score=" + std::to_string(best_score));
+                        break;
+                    }
+                    else {
+                        // best bed is invalid, but firstfit bed is OK, use the latter
+                        best_bed_id = bed_id_firstfit;
+                        result_best = result_firstfit;
+                    }
+                }
+
+                if(best_bed_id>=0)
+                {
+                    was_packed = true;
+                    j = best_bed_id;
+                    it->get().binId(int(j));
+                    it->get().itemId(item_id++);
+                    placers[j].accept(result_best);
+                    makeProgress(placers[j], j);
+                }
+
+                if(!was_packed){
+                    //if (this->unfitindicator_)
+                    //    this->unfitindicator_(it->get().name + " ,plate_id=" + std::to_string(j) + ",score=" + std::to_string(score)
+                    //        + ", score_all_plates=" + std::to_string(score_all_plates)
+                    //        + ", overfit=" + std::to_string(result.overfit()));
+
+                    placers.emplace_back(bin);
+                    placers.back().plateID(placers.size() - 1);
+                    placers.back().configure(pconfig);
+                    if (fixed_bins.size() >= placers.size())
+                        placers.back().preload(fixed_bins[placers.size() - 1]);
+                    //placers.back().preload(pconfig.m_excluded_items);
+                    packed_bins_.emplace_back();
+                    j = placers.size() - 1;
+                }
+            }
+        }
+    }
+
+};
+
+}
+}
+
+#endif // FIRSTFIT_HPP

src/libnest2d/include/libnest2d/selections/selection_boilerplate.hpp

@@ -0,0 +1,69 @@
+#ifndef SELECTION_BOILERPLATE_HPP
+#define SELECTION_BOILERPLATE_HPP
+
+#include <atomic>
+#include <libnest2d/nester.hpp>
+
+namespace libnest2d { namespace selections {
+
+template<class RawShape>
+class SelectionBoilerplate {
+public:
+    using ShapeType = RawShape;
+    using Item = _Item<RawShape>;
+    using ItemGroup = _ItemGroup<RawShape>;
+    using PackGroup = _PackGroup<RawShape>;
+
+    inline const PackGroup& getResult() const {
+        return packed_bins_;
+    }
+
+    inline int lastPackedBinId() const { return last_packed_bin_id_; }
+
+    inline void progressIndicator(ProgressFunction fn) { progress_ = fn; }
+
+    inline void stopCondition(StopCondition cond) { stopcond_ = cond; }
+
+    inline void unfitIndicator(UnfitIndicator fn) { unfitindicator_ = fn; }
+
+    inline void clear() { packed_bins_.clear(); }
+
+protected:
+
+    template<class Placer, class Container, class Bin, class PCfg>
+    void remove_unpackable_items(Container &c, const Bin &bin, const PCfg& pcfg)
+    {
+        // Safety test: try to pack each item into an empty bin. If it fails
+        // then it should be removed from the list
+        Placer p{ bin };
+        p.configure(pcfg);
+        //p.preload(pcfg.m_excluded_items);
+        auto it = c.begin();
+        while (it != c.end() && !stopcond_()) {
+
+            // WARNING: The copy of itm needs to be created before Placer.
+            // Placer is working with references and its destructor still
+            // manipulates the item this is why the order of stack creation
+            // matters here.
+            const Item& itm = *it;
+            Item cpy{itm};
+
+            auto result = p.pack(cpy);
+            if (itm.area() <= 0 || !result) {
+                static_cast<Item&>(*it).binId(BIN_ID_UNFIT);
+            }
+            it++;
+        }
+    }
+
+    PackGroup packed_bins_;
+    ProgressFunction progress_ = [](unsigned){};
+    StopCondition stopcond_ = []() { return false; };
+    UnfitIndicator unfitindicator_;
+    int last_packed_bin_id_ = -1;
+};
+
+}
+}
+
+#endif // SELECTION_BOILERPLATE_HPP

src/libnest2d/include/libnest2d/utils/boost_alg.hpp

@@ -0,0 +1,533 @@
+#ifndef BOOST_ALG_HPP
+#define BOOST_ALG_HPP
+
+#ifndef DISABLE_BOOST_SERIALIZE
+    #include <sstream>
+#endif
+
+#ifdef __clang__
+#undef _MSC_EXTENSIONS
+#endif
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4244)
+#pragma warning(disable: 4267)
+#endif
+#include <boost/geometry.hpp>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+// this should be removed to not confuse the compiler
+// #include "../libnest2d.hpp"
+
+namespace bp2d {
+
+using libnest2d::TCoord;
+using libnest2d::PointImpl;
+using Coord = TCoord<PointImpl>;
+using libnest2d::PolygonImpl;
+using libnest2d::PathImpl;
+using libnest2d::Orientation;
+using libnest2d::OrientationType;
+using libnest2d::OrientationTypeV;
+using libnest2d::ClosureType;
+using libnest2d::Closure;
+using libnest2d::ClosureTypeV;
+using libnest2d::getX;
+using libnest2d::getY;
+using libnest2d::setX;
+using libnest2d::setY;
+using Box = libnest2d::_Box<PointImpl>;
+using Segment = libnest2d::_Segment<PointImpl>;
+using Shapes = libnest2d::nfp::Shapes<PolygonImpl>;
+
+}
+
+/**
+ * We have to make all the libnest2d geometry types available to boost. The real
+ * models of the geometries remain the same if a conforming model for libnest2d
+ * was defined by the library client. Boost is used only as an optional
+ * implementer of some algorithms that can be implemented by the model itself
+ * if a faster alternative exists.
+ *
+ * However, boost has its own type traits and we have to define the needed
+ * specializations to be able to use boost::geometry. This can be done with the
+ * already provided model.
+ */
+namespace boost {
+namespace geometry {
+namespace traits {
+
+/* ************************************************************************** */
+/* Point concept adaptaion ************************************************** */
+/* ************************************************************************** */
+
+template<> struct tag<bp2d::PointImpl> {
+    using type = point_tag;
+};
+
+template<> struct coordinate_type<bp2d::PointImpl> {
+    using type = bp2d::Coord;
+};
+
+template<> struct coordinate_system<bp2d::PointImpl> {
+    using type = cs::cartesian;
+};
+
+template<> struct dimension<bp2d::PointImpl>: boost::mpl::int_<2> {};
+
+template<>
+struct access<bp2d::PointImpl, 0 > {
+    static inline bp2d::Coord get(bp2d::PointImpl const& a) {
+        return libnest2d::getX(a);
+    }
+
+    static inline void set(bp2d::PointImpl& a,
+                           bp2d::Coord const& value) {
+        libnest2d::setX(a, value);
+    }
+};
+
+template<>
+struct access<bp2d::PointImpl, 1 > {
+    static inline bp2d::Coord get(bp2d::PointImpl const& a) {
+        return libnest2d::getY(a);
+    }
+
+    static inline void set(bp2d::PointImpl& a,
+                           bp2d::Coord const& value) {
+        libnest2d::setY(a, value);
+    }
+};
+
+
+/* ************************************************************************** */
+/* Box concept adaptaion **************************************************** */
+/* ************************************************************************** */
+
+template<> struct tag<bp2d::Box> {
+    using type = box_tag;
+};
+
+template<> struct point_type<bp2d::Box> {
+    using type = bp2d::PointImpl;
+};
+
+template<> struct indexed_access<bp2d::Box, min_corner, 0> {
+    static inline bp2d::Coord get(bp2d::Box const& box) {
+        return bp2d::getX(box.minCorner());
+    }
+    static inline void set(bp2d::Box &box, bp2d::Coord const& coord) {
+        bp2d::setX(box.minCorner(), coord);
+    }
+};
+
+template<> struct indexed_access<bp2d::Box, min_corner, 1> {
+    static inline bp2d::Coord get(bp2d::Box const& box) {
+        return bp2d::getY(box.minCorner());
+    }
+    static inline void set(bp2d::Box &box, bp2d::Coord const& coord) {
+        bp2d::setY(box.minCorner(), coord);
+    }
+};
+
+template<> struct indexed_access<bp2d::Box, max_corner, 0> {
+    static inline bp2d::Coord get(bp2d::Box const& box) {
+        return bp2d::getX(box.maxCorner());
+    }
+    static inline void set(bp2d::Box &box, bp2d::Coord const& coord) {
+        bp2d::setX(box.maxCorner(), coord);
+    }
+};
+
+template<> struct indexed_access<bp2d::Box, max_corner, 1> {
+    static inline bp2d::Coord get(bp2d::Box const& box) {
+        return bp2d::getY(box.maxCorner());
+    }
+    static inline void set(bp2d::Box &box, bp2d::Coord const& coord) {
+        bp2d::setY(box.maxCorner(), coord);
+    }
+};
+
+/* ************************************************************************** */
+/* Segment concept adaptaion ************************************************ */
+/* ************************************************************************** */
+
+template<> struct tag<bp2d::Segment> {
+    using type = segment_tag;
+};
+
+template<> struct point_type<bp2d::Segment> {
+    using type = bp2d::PointImpl;
+};
+
+template<> struct indexed_access<bp2d::Segment, 0, 0> {
+    static inline bp2d::Coord get(bp2d::Segment const& seg) {
+        return bp2d::getX(seg.first());
+    }
+    static inline void set(bp2d::Segment &seg, bp2d::Coord const& coord) {
+        auto p = seg.first(); bp2d::setX(p, coord); seg.first(p);
+    }
+};
+
+template<> struct indexed_access<bp2d::Segment, 0, 1> {
+    static inline bp2d::Coord get(bp2d::Segment const& seg) {
+        return bp2d::getY(seg.first());
+    }
+    static inline void set(bp2d::Segment &seg, bp2d::Coord const& coord) {
+        auto p = seg.first(); bp2d::setY(p, coord); seg.first(p);
+    }
+};
+
+template<> struct indexed_access<bp2d::Segment, 1, 0> {
+    static inline bp2d::Coord get(bp2d::Segment const& seg) {
+        return bp2d::getX(seg.second());
+    }
+    static inline void set(bp2d::Segment &seg, bp2d::Coord const& coord) {
+        auto p = seg.second();  bp2d::setX(p, coord); seg.second(p);
+    }
+};
+
+template<> struct indexed_access<bp2d::Segment, 1, 1> {
+    static inline bp2d::Coord get(bp2d::Segment const& seg) {
+        return bp2d::getY(seg.second());
+    }
+    static inline void set(bp2d::Segment &seg, bp2d::Coord const& coord) {
+        auto p = seg.second(); bp2d::setY(p, coord); seg.second(p);
+    }
+};
+
+
+/* ************************************************************************** */
+/* Polygon concept adaptation *********************************************** */
+/* ************************************************************************** */
+
+// Connversion between libnest2d::Orientation and order_selector ///////////////
+
+template<bp2d::Orientation> struct ToBoostOrienation {};
+
+template<>
+struct ToBoostOrienation<bp2d::Orientation::CLOCKWISE> {
+    static const order_selector Value = clockwise;
+};
+
+template<>
+struct ToBoostOrienation<bp2d::Orientation::COUNTER_CLOCKWISE> {
+    static const order_selector Value = counterclockwise;
+};
+
+template<bp2d::Closure> struct ToBoostClosure {};
+
+template<> struct ToBoostClosure<bp2d::Closure::OPEN> {
+    static const constexpr closure_selector Value = closure_selector::open;
+};
+
+template<> struct ToBoostClosure<bp2d::Closure::CLOSED> {
+    static const constexpr closure_selector Value = closure_selector::closed;
+};
+
+// Ring implementation /////////////////////////////////////////////////////////
+
+// Boost would refer to ClipperLib::Path (alias bp2d::PolygonImpl) as a ring
+template<> struct tag<bp2d::PathImpl> {
+    using type = ring_tag;
+};
+
+template<> struct point_order<bp2d::PathImpl> {
+    static const order_selector value =
+        ToBoostOrienation<bp2d::OrientationTypeV<bp2d::PathImpl>>::Value;
+};
+
+// All our Paths should be closed for the bin packing application
+template<> struct closure<bp2d::PathImpl> {
+    static const constexpr closure_selector value =
+        ToBoostClosure< bp2d::ClosureTypeV<bp2d::PathImpl> >::Value;
+};
+
+// Polygon implementation //////////////////////////////////////////////////////
+
+template<> struct tag<bp2d::PolygonImpl> {
+    using type = polygon_tag;
+};
+
+template<> struct exterior_ring<bp2d::PolygonImpl> {
+    static inline bp2d::PathImpl& get(bp2d::PolygonImpl& p) {
+        return libnest2d::shapelike::contour(p);
+    }
+
+    static inline bp2d::PathImpl const& get(bp2d::PolygonImpl const& p) {
+        return libnest2d::shapelike::contour(p);
+    }
+};
+
+template<> struct ring_const_type<bp2d::PolygonImpl> {
+    using type = const bp2d::PathImpl&;
+};
+
+template<> struct ring_mutable_type<bp2d::PolygonImpl> {
+    using type = bp2d::PathImpl&;
+};
+
+template<> struct interior_const_type<bp2d::PolygonImpl> {
+   using type = const libnest2d::THolesContainer<bp2d::PolygonImpl>&;
+};
+
+template<> struct interior_mutable_type<bp2d::PolygonImpl> {
+   using type = libnest2d::THolesContainer<bp2d::PolygonImpl>&;
+};
+
+template<>
+struct interior_rings<bp2d::PolygonImpl> {
+
+    static inline libnest2d::THolesContainer<bp2d::PolygonImpl>& get(
+            bp2d::PolygonImpl& p)
+    {
+        return libnest2d::shapelike::holes(p);
+    }
+
+    static inline const libnest2d::THolesContainer<bp2d::PolygonImpl>& get(
+            bp2d::PolygonImpl const& p)
+    {
+        return libnest2d::shapelike::holes(p);
+    }
+};
+
+/* ************************************************************************** */
+/* MultiPolygon concept adaptation ****************************************** */
+/* ************************************************************************** */
+
+template<> struct tag<bp2d::Shapes> {
+    using type = multi_polygon_tag;
+};
+
+}   // traits
+}   // geometry
+
+// This is an addition to the ring implementation of Polygon concept
+template<>
+struct range_value<bp2d::PathImpl> {
+    using type = bp2d::PointImpl;
+};
+
+template<>
+struct range_value<bp2d::Shapes> {
+    using type = bp2d::PolygonImpl;
+};
+
+}   // boost
+
+/* ************************************************************************** */
+/* Algorithms *************************************************************** */
+/* ************************************************************************** */
+
+namespace libnest2d { // Now the algorithms that boost can provide...
+
+//namespace pointlike {
+//template<>
+//inline double distance(const PointImpl& p1, const PointImpl& p2 )
+//{
+//    return boost::geometry::distance(p1, p2);
+//}
+
+//template<>
+//inline double distance(const PointImpl& p, const bp2d::Segment& seg )
+//{
+//    return boost::geometry::distance(p, seg);
+//}
+//}
+
+namespace shapelike {
+// Tell libnest2d how to make string out of a ClipperPolygon object
+template<>
+inline bool intersects(const PathImpl& sh1, const PathImpl& sh2)
+{
+    return boost::geometry::intersects(sh1, sh2);
+}
+
+// Tell libnest2d how to make string out of a ClipperPolygon object
+template<>
+inline bool intersects(const PolygonImpl& sh1, const PolygonImpl& sh2)
+{
+    return boost::geometry::intersects(sh1, sh2);
+}
+
+// Tell libnest2d how to make string out of a ClipperPolygon object
+template<>
+inline bool intersects(const bp2d::Segment& s1, const bp2d::Segment& s2)
+{
+    return boost::geometry::intersects(s1, s2);
+}
+
+#ifndef DISABLE_BOOST_AREA
+template<>
+inline double area(const PolygonImpl& shape, const PolygonTag&)
+{
+    return boost::geometry::area(shape);
+}
+#endif
+
+template<>
+inline bool isInside(const PointImpl& point, const PolygonImpl& shape,
+                     const PointTag&, const PolygonTag&)
+{
+    return boost::geometry::within(point, shape);
+}
+
+template<>
+inline bool isInside(const PolygonImpl& sh1, const PolygonImpl& sh2,
+                     const PolygonTag&, const PolygonTag&)
+{
+    return boost::geometry::within(sh1, sh2);
+}
+
+template<>
+inline bool touches(const PolygonImpl& sh1, const PolygonImpl& sh2)
+{
+    return boost::geometry::touches(sh1, sh2);
+}
+
+template<>
+inline bool touches( const PointImpl& point, const PolygonImpl& shape)
+{
+    return boost::geometry::touches(point, shape);
+}
+
+#ifndef DISABLE_BOOST_BOUNDING_BOX
+
+template<>
+inline bp2d::Box boundingBox(const PathImpl& sh, const PathTag&)
+{
+    bp2d::Box b;
+    boost::geometry::envelope(sh, b);
+    return b;
+}
+
+template<>
+inline bp2d::Box boundingBox<bp2d::Shapes>(const bp2d::Shapes& shapes,
+                                           const MultiPolygonTag&)
+{
+    bp2d::Box b;
+    boost::geometry::envelope(shapes, b);
+    return b;
+}
+#endif
+
+#ifndef DISABLE_BOOST_CONVEX_HULL
+template<>
+inline PathImpl convexHull(const PathImpl& sh, const PathTag&)
+{
+    PathImpl ret;
+    boost::geometry::convex_hull(sh, ret);
+    return ret;
+}
+
+template<>
+inline PolygonImpl convexHull(const TMultiShape<PolygonImpl>& shapes,
+                              const MultiPolygonTag&)
+{
+    PolygonImpl ret;
+    boost::geometry::convex_hull(shapes, ret);
+    return ret;
+}
+#endif
+
+#ifndef DISABLE_BOOST_OFFSET
+template<>
+inline void offset(PolygonImpl& sh, bp2d::Coord distance)
+{
+    PolygonImpl cpy = sh;
+    boost::geometry::buffer(cpy, sh, distance);
+}
+#endif
+
+#ifndef DISABLE_BOOST_SERIALIZE
+template<> inline std::string serialize<libnest2d::Formats::SVG>(
+        const PolygonImpl& sh, double scale, std::string fill, std::string stroke, float stroke_width)
+{
+    std::stringstream ss;
+    std::string style = "fill: "+fill+"; stroke: "+stroke+"; stroke-width: "+std::to_string(stroke_width)+"px; ";
+
+    using namespace boost::geometry;
+    using Pointf = model::point<double, 2, cs::cartesian>;
+    using Polygonf = model::polygon<Pointf>;
+
+    Polygonf::ring_type ring;
+    Polygonf::inner_container_type holes;
+    ring.reserve(shapelike::contourVertexCount(sh));
+
+    for(auto it = shapelike::cbegin(sh); it != shapelike::cend(sh); it++) {
+        auto& v = *it;
+        ring.emplace_back(getX(v)*scale, getY(v)*scale);
+    };
+
+    auto H = shapelike::holes(sh);
+    for(PathImpl& h : H ) {
+        Polygonf::ring_type hf;
+        for(auto it = h.begin(); it != h.end(); it++) {
+            auto& v = *it;
+            hf.emplace_back(getX(v)*scale, getY(v)*scale);
+        };
+        holes.emplace_back(std::move(hf));
+    }
+
+    Polygonf poly;
+    poly.outer() = ring;
+    poly.inners() = holes;
+    auto svg_data = boost::geometry::svg(poly, style);
+
+    ss << svg_data << std::endl;
+
+    return ss.str();
+}
+#endif
+
+#ifndef DISABLE_BOOST_UNSERIALIZE
+template<>
+inline void unserialize<libnest2d::Formats::SVG>(
+        PolygonImpl& sh,
+        const std::string& str)
+{
+}
+#endif
+
+template<> inline std::pair<bool, std::string> isValid(const PolygonImpl& sh)
+{
+    std::string message;
+    bool ret = boost::geometry::is_valid(sh, message);
+
+    return {ret, message};
+}
+}
+
+namespace nfp {
+
+#ifndef DISABLE_BOOST_NFP_MERGE
+
+// Warning: I could not get boost union_ to work. Geometries will overlap.
+template<>
+inline bp2d::Shapes nfp::merge(const bp2d::Shapes& shapes,
+                               const PolygonImpl& sh)
+{
+    bp2d::Shapes retv;
+    boost::geometry::union_(shapes, sh, retv);
+    return retv;
+}
+
+template<>
+inline bp2d::Shapes nfp::merge(const bp2d::Shapes& shapes)
+{
+    bp2d::Shapes retv;
+    boost::geometry::union_(shapes, shapes.back(), retv);
+    return retv;
+}
+#endif
+
+}
+
+
+}
+
+
+
+#endif // BOOST_ALG_HPP

src/libnest2d/include/libnest2d/utils/metaloop.hpp

@@ -0,0 +1,227 @@
+#ifndef METALOOP_HPP
+#define METALOOP_HPP
+
+#include <libnest2d/common.hpp>
+#include <tuple>
+#include <functional>
+
+namespace libnest2d {
+
+/* ************************************************************************** */
+/* C++14 std::index_sequence implementation:                                  */
+/* ************************************************************************** */
+
+/**
+ * \brief C++11 compatible implementation of the index_sequence type from C++14
+ */
+template<size_t...Ints> struct index_sequence {
+    using value_type = size_t;
+    BP2D_CONSTEXPR value_type size() const { return sizeof...(Ints); }
+};
+
+// A Help structure to generate the integer list
+template<size_t...Nseq> struct genSeq;
+
+// Recursive template to generate the list
+template<size_t I, size_t...Nseq> struct genSeq<I, Nseq...> {
+    // Type will contain a genSeq with Nseq appended by one element
+    using Type = typename genSeq< I - 1, I - 1, Nseq...>::Type;
+};
+
+// Terminating recursion
+template <size_t ... Nseq> struct genSeq<0, Nseq...> {
+    // If I is zero, Type will contain index_sequence with the fuly generated
+    // integer list.
+    using Type = index_sequence<Nseq...>;
+};
+
+/// Helper alias to make an index sequence from 0 to N
+template<size_t N> using make_index_sequence = typename genSeq<N>::Type;
+
+/// Helper alias to make an index sequence for a parameter pack
+template<class...Args>
+using index_sequence_for = make_index_sequence<sizeof...(Args)>;
+
+
+/* ************************************************************************** */
+
+namespace opt {
+
+using std::forward;
+using std::tuple;
+using std::get;
+using std::tuple_element;
+
+/**
+ * @brief Helper class to be able to loop over a parameter pack's elements.
+ */
+class metaloop {
+
+// The implementation is based on partial struct template specializations.
+// Basically we need a template type that is callable and takes an integer
+// non-type template parameter which can be used to implement recursive calls.
+//
+// C++11 will not allow the usage of a plain template function that is why we
+// use struct with overloaded call operator. At the same time C++11 prohibits
+// partial template specialization with a non type parameter such as int. We
+// need to wrap that in a type (see metaloop::Int).
+
+/*
+ * A helper alias to create integer values wrapped as a type. It is necessary
+ * because a non type template parameter (such as int) would be prohibited in
+ * a partial specialization. Also for the same reason we have to use a class
+ * _Metaloop instead of a simple function as a functor. A function cannot be
+ * partially specialized in a way that is necessary for this trick.
+ */
+template<int N> using Int = std::integral_constant<int, N>;
+
+/*
+ * Helper class to implement in-place functors.
+ *
+ * We want to be able to use inline functors like a lambda to keep the code
+ * as clear as possible.
+ */
+template<int N, class Fn> class MapFn {
+    Fn&& fn_;
+public:
+
+    // It takes the real functor that can be specified in-place but only
+    // with C++14 because the second parameter's type will depend on the
+    // type of the parameter pack element that is processed. In C++14 we can
+    // specify this second parameter type as auto in the lambda parameter list.
+    inline MapFn(Fn&& fn): fn_(forward<Fn>(fn)) {}
+
+    template<class T> void operator ()(T&& pack_element) {
+        // We provide the index as the first parameter and the pack (or tuple)
+        // element as the second parameter to the functor.
+        fn_(N, forward<T>(pack_element));
+    }
+};
+
+/*
+ * Implementation of the template loop trick.
+ * We create a mechanism for looping over a parameter pack in compile time.
+ * \tparam Idx is the loop index which will be decremented at each recursion.
+ * \tparam Args The parameter pack that will be processed.
+ *
+ */
+template <typename Idx, class...Args>
+class _MetaLoop {};
+
+// Implementation for the first element of Args...
+template <class...Args>
+class _MetaLoop<Int<0>, Args...> {
+public:
+
+    const static BP2D_CONSTEXPR int N = 0;
+    const static BP2D_CONSTEXPR int ARGNUM = sizeof...(Args)-1;
+
+    template<class Tup, class Fn>
+    void run( Tup&& valtup, Fn&& fn) {
+        MapFn<ARGNUM-N, Fn> {forward<Fn>(fn)} (get<ARGNUM-N>(valtup));
+    }
+};
+
+// Implementation for the N-th element of Args...
+template <int N, class...Args>
+class _MetaLoop<Int<N>, Args...> {
+public:
+
+    const static BP2D_CONSTEXPR int ARGNUM = sizeof...(Args)-1;
+
+    template<class Tup, class Fn>
+    void run(Tup&& valtup, Fn&& fn) {
+        MapFn<ARGNUM-N, Fn> {forward<Fn>(fn)} (std::get<ARGNUM-N>(valtup));
+
+        // Recursive call to process the next element of Args
+        _MetaLoop<Int<N-1>, Args...> ().run(forward<Tup>(valtup),
+                                            forward<Fn>(fn));
+    }
+};
+
+/*
+ * Instantiation: We must instantiate the template with the last index because
+ * the generalized version calls the decremented instantiations recursively.
+ * Once the instantiation with the first index is called, the terminating
+ * version of run is called which does not call itself anymore.
+ *
+ * If you are utterly annoyed, at least you have learned a super crazy
+ * functional meta-programming pattern.
+ */
+template<class...Args>
+using MetaLoop = _MetaLoop<Int<sizeof...(Args)-1>, Args...>;
+
+public:
+
+/**
+ * \brief The final usable function template.
+ *
+ * This is similar to what varags was on C but in compile time C++11.
+ * You can call:
+ * apply(<the mapping function>, <arbitrary number of arguments of any type>);
+ * For example:
+ *
+ *      struct mapfunc {
+ *          template<class T> void operator()(int N, T&& element) {
+ *              std::cout << "The value of the parameter "<< N <<": "
+ *                        << element << std::endl;
+ *          }
+ *      };
+ *
+ *      apply(mapfunc(), 'a', 10, 151.545);
+ *
+ * C++14:
+ *      apply([](int N, auto&& element){
+ *          std::cout << "The value of the parameter "<< N <<": "
+ *                        << element << std::endl;
+ *      }, 'a', 10, 151.545);
+ *
+ * This yields the output:
+ * The value of the parameter 0: a
+ * The value of the parameter 1: 10
+ * The value of the parameter 2: 151.545
+ *
+ * As an addition, the function can be called with a tuple as the second
+ * parameter holding the arguments instead of a parameter pack.
+ *
+ */
+template<class...Args, class Fn>
+inline static void apply(Fn&& fn, Args&&...args) {
+    MetaLoop<Args...>().run(tuple<Args&&...>(forward<Args>(args)...),
+                            forward<Fn>(fn));
+}
+
+/// The version of apply with a tuple rvalue reference.
+template<class...Args, class Fn>
+inline static void apply(Fn&& fn, tuple<Args...>&& tup) {
+    MetaLoop<Args...>().run(std::move(tup), forward<Fn>(fn));
+}
+
+/// The version of apply with a tuple lvalue reference.
+template<class...Args, class Fn>
+inline static void apply(Fn&& fn, tuple<Args...>& tup) {
+    MetaLoop<Args...>().run(tup, forward<Fn>(fn));
+}
+
+/// The version of apply with a tuple const reference.
+template<class...Args, class Fn>
+inline static void apply(Fn&& fn, const tuple<Args...>& tup) {
+    MetaLoop<Args...>().run(tup, forward<Fn>(fn));
+}
+
+/**
+ * Call a function with its arguments encapsualted in a tuple.
+ */
+template<class Fn, class Tup, std::size_t...Is>
+inline static auto
+callFunWithTuple(Fn&& fn, Tup&& tup, index_sequence<Is...>) ->
+    decltype(fn(std::get<Is>(tup)...))
+{
+    return fn(std::get<Is>(tup)...);
+}
+
+};
+}
+}
+
+#endif // METALOOP_HPP

src/libnest2d/include/libnest2d/utils/rotcalipers.hpp

@@ -0,0 +1,372 @@
+#ifndef ROTCALIPERS_HPP
+#define ROTCALIPERS_HPP
+
+#include <numeric>
+#include <functional>
+#include <array>
+#include <cmath>
+
+#include <libnest2d/geometry_traits.hpp>
+
+namespace libnest2d {
+
+template<class Pt, class Unit = TCompute<Pt>> class RotatedBox {
+    Pt axis_;
+    Unit bottom_ = Unit(0), right_ = Unit(0);
+public:
+    
+    RotatedBox() = default;
+    RotatedBox(const Pt& axis, Unit b, Unit r):
+        axis_(axis), bottom_(b), right_(r) {}
+    
+    inline long double area() const { 
+        long double asq = pl::magnsq<Pt, long double>(axis_);
+        return cast<long double>(bottom_) * cast<long double>(right_) / asq;
+    }
+    
+    inline long double width() const { 
+        return abs(bottom_) / std::sqrt(pl::magnsq<Pt, long double>(axis_));
+    }
+    
+    inline long double height() const { 
+        return abs(right_) / std::sqrt(pl::magnsq<Pt, long double>(axis_));
+    }
+    
+    inline Unit bottom_extent() const { return bottom_; }
+    inline Unit right_extent() const { return right_;  }
+    inline const Pt& axis() const { return axis_; }
+    
+    inline Radians angleToX() const {
+        double ret = std::atan2(getY(axis_), getX(axis_));
+        auto s = std::signbit(ret);
+        if(s) ret += Pi_2;
+        return -ret;
+    }
+};
+
+template <class Poly, class Pt = TPoint<Poly>, class Unit = TCompute<Pt>> 
+Poly removeCollinearPoints(const Poly& sh, Unit eps = Unit(0))
+{
+    Poly ret; sl::reserve(ret, sl::contourVertexCount(sh));
+    
+    Pt eprev = *sl::cbegin(sh) - *std::prev(sl::cend(sh));
+    
+    auto it  = sl::cbegin(sh);
+    auto itx = std::next(it);
+    if(itx != sl::cend(sh)) while (it != sl::cend(sh))
+    {
+        Pt enext = *itx - *it;
+
+        auto dp = pl::dotperp<Pt, Unit>(eprev, enext);
+        if(abs(dp) > eps) sl::addVertex(ret, *it);
+        
+        eprev = enext;
+        if (++itx == sl::cend(sh)) itx = sl::cbegin(sh);
+        ++it;
+    }
+    
+    return ret;
+}
+
+// The area of the bounding rectangle with the axis dir and support vertices
+template<class Pt, class Unit = TCompute<Pt>, class R = TCompute<Pt>> 
+inline R rectarea(const Pt& w, // the axis
+                  const Pt& vb, const Pt& vr, 
+                  const Pt& vt, const Pt& vl) 
+{
+    Unit a = pl::dot<Pt, Unit>(w, vr - vl); 
+    Unit b = pl::dot<Pt, Unit>(-pl::perp(w), vt - vb);
+    R m = R(a) / pl::magnsq<Pt, Unit>(w);
+    m = m * b;
+    return m;
+};
+
+template<class Pt, 
+         class Unit = TCompute<Pt>,
+         class R = TCompute<Pt>,
+         class It = typename std::vector<Pt>::const_iterator>
+inline R rectarea(const Pt& w, const std::array<It, 4>& rect)
+{
+    return rectarea<Pt, Unit, R>(w, *rect[0], *rect[1], *rect[2], *rect[3]);
+}
+
+template<class Pt, class Unit = TCompute<Pt>, class R = TCompute<Pt>>
+inline R rectarea(const Pt& w, // the axis
+                  const Unit& a,
+                  const Unit& b)
+{
+    R m = R(a) / pl::magnsq<Pt, Unit>(w);
+    m = m * b;
+    return m;
+};
+
+template<class R, class Pt, class Unit>
+inline R rectarea(const RotatedBox<Pt, Unit> &rb)
+{
+    return rectarea<Pt, Unit, R>(rb.axis(), rb.bottom_extent(), rb.right_extent());
+};
+
+// This function is only applicable to counter-clockwise oriented convex
+// polygons where only two points can be collinear witch each other.
+template <class RawShape,
+          class Unit = TCompute<RawShape>,
+          class Ratio = TCompute<RawShape>,
+          class VisitFn>
+void rotcalipers(const RawShape& sh, VisitFn &&visitfn)
+{
+    using Point = TPoint<RawShape>;
+    using Iterator = typename TContour<RawShape>::const_iterator;
+    using pointlike::dot; using pointlike::magnsq; using pointlike::perp;
+
+    // Get the first and the last vertex iterator
+    auto first = sl::cbegin(sh);
+    auto last = std::prev(sl::cend(sh));
+
+    // Check conditions and return undefined box if input is not sane.
+    if(last == first) return;
+    if(getX(*first) == getX(*last) && getY(*first) == getY(*last)) --last;
+    if(last - first < 2) return;
+
+    RawShape shcpy; // empty at this point
+    {
+        Point p = *first, q = *std::next(first), r = *last;
+
+        // Determine orientation from first 3 vertex (should be consistent)
+        Unit d = (Unit(getY(q)) - getY(p)) * (Unit(getX(r)) - getX(p)) -
+                 (Unit(getX(q)) - getX(p)) * (Unit(getY(r)) - getY(p));
+
+        if(d > 0) {
+            // The polygon is clockwise. A flip is needed (for now)
+            sl::reserve(shcpy, last - first);
+            auto it = last; while(it != first) sl::addVertex(shcpy, *it--);
+            sl::addVertex(shcpy, *first);
+            first = sl::cbegin(shcpy); last = std::prev(sl::cend(shcpy));
+        }
+    }
+
+    // Cyclic iterator increment
+    auto inc = [&first, &last](Iterator& it) {
+        if(it == last) it = first; else ++it;
+    };
+
+    // Cyclic previous iterator
+    auto prev = [&first, &last](Iterator it) {
+        return it == first ? last : std::prev(it);
+    };
+
+    // Cyclic next iterator
+    auto next = [&first, &last](Iterator it) {
+        return it == last ? first : std::next(it);
+    };
+
+    // Establish initial (axis aligned) rectangle support verices by determining
+    // polygon extremes:
+
+    auto it = first;
+    Iterator minX = it, maxX = it, minY = it, maxY = it;
+
+    do { // Linear walk through the vertices and save the extreme positions
+
+        Point v = *it, d = v - *minX;
+        if(getX(d) < 0 || (getX(d) == 0 && getY(d) < 0)) minX = it;
+
+        d = v - *maxX;
+        if(getX(d) > 0 || (getX(d) == 0 && getY(d) > 0)) maxX = it;
+
+        d = v - *minY;
+        if(getY(d) < 0 || (getY(d) == 0 && getX(d) > 0)) minY = it;
+
+        d = v - *maxY;
+        if(getY(d) > 0 || (getY(d) == 0 && getX(d) < 0)) maxY = it;
+
+    } while(++it != std::next(last));
+
+    // Update the vertices defining the bounding rectangle. The rectangle with
+    // the smallest rotation is selected and the supporting vertices are
+    // returned in the 'rect' argument.
+    auto update = [&next, &inc]
+        (const Point& w, std::array<Iterator, 4>& rect)
+    {
+        Iterator B = rect[0], Bn = next(B);
+        Iterator R = rect[1], Rn = next(R);
+        Iterator T = rect[2], Tn = next(T);
+        Iterator L = rect[3], Ln = next(L);
+
+        Point b = *Bn - *B, r = *Rn - *R, t = *Tn - *T, l = *Ln - *L;
+        Point pw = perp(w);
+        using Pt = Point;
+
+        Unit dotwpb = dot<Pt, Unit>( w, b), dotwpr = dot<Pt, Unit>(-pw, r);
+        Unit dotwpt = dot<Pt, Unit>(-w, t), dotwpl = dot<Pt, Unit>( pw, l);
+        Unit dw     = magnsq<Pt, Unit>(w);
+
+        std::array<Ratio, 4> angles;
+        angles[0] = (Ratio(dotwpb) / magnsq<Pt, Unit>(b)) * dotwpb;
+        angles[1] = (Ratio(dotwpr) / magnsq<Pt, Unit>(r)) * dotwpr;
+        angles[2] = (Ratio(dotwpt) / magnsq<Pt, Unit>(t)) * dotwpt;
+        angles[3] = (Ratio(dotwpl) / magnsq<Pt, Unit>(l)) * dotwpl;
+
+        using AngleIndex = std::pair<Ratio, size_t>;
+        std::vector<AngleIndex> A; A.reserve(4);
+
+        for (size_t i = 3, j = 0; j < 4; i = j++) {
+            if(rect[i] != rect[j] && angles[i] < dw) {
+                auto iv = std::make_pair(angles[i], i);
+                auto it = std::lower_bound(A.begin(), A.end(), iv,
+                                           [](const AngleIndex& ai,
+                                              const AngleIndex& aj)
+                {
+                    return ai.first > aj.first;
+                });
+
+                A.insert(it, iv);
+            }
+        }
+
+        // The polygon is supposed to be a rectangle.
+        if(A.empty()) return false;
+
+        auto amin = A.front().first;
+        auto imin = A.front().second;
+        for(auto& a : A) if(a.first == amin) inc(rect[a.second]);
+
+        std::rotate(rect.begin(), rect.begin() + imin, rect.end());
+
+        return true;
+    };
+
+    Point w(1, 0);
+    std::array<Iterator, 4> rect = {minY, maxX, maxY, minX};
+
+    {
+        Unit a = dot<Point, Unit>(w, *rect[1] - *rect[3]);
+        Unit b = dot<Point, Unit>(-perp(w), *rect[2] - *rect[0]);
+        if (!visitfn(RotatedBox<Point, Unit>{w, a, b}))
+            return;
+    }
+
+    // An edge might be examined twice in which case the algorithm terminates.
+    size_t c = 0, count = last - first + 1;
+    std::vector<bool> edgemask(count, false);
+
+    while(c++ < count)
+    {
+        // Update the support vertices, if cannot be updated, break the cycle.
+        if(! update(w, rect)) break;
+
+        size_t eidx = size_t(rect[0] - first);
+
+        if(edgemask[eidx]) break;
+        edgemask[eidx] = true;
+
+        // get the unnormalized direction vector
+        w = *rect[0] - *prev(rect[0]);
+
+        Unit a = dot<Point, Unit>(w, *rect[1] - *rect[3]);
+        Unit b = dot<Point, Unit>(-perp(w), *rect[2] - *rect[0]);
+        if (!visitfn(RotatedBox<Point, Unit>{w, a, b}))
+            break;
+    }
+}
+
+// This function is only applicable to counter-clockwise oriented convex
+// polygons where only two points can be collinear witch each other.
+template <class S,
+          class Unit = TCompute<S>,
+          class Ratio = TCompute<S>>
+RotatedBox<TPoint<S>, Unit> minAreaBoundingBox(const S& sh)
+{
+    RotatedBox<TPoint<S>, Unit> minbox;
+    Ratio minarea = std::numeric_limits<Unit>::max();
+    auto minfn = [&minarea, &minbox](const RotatedBox<TPoint<S>, Unit> &rbox){
+        Ratio area = rectarea<Ratio>(rbox);
+        if (area <= minarea)  {
+            minarea = area;
+            minbox = rbox;
+        }
+
+        return true; // continue search
+    };
+
+    rotcalipers<S, Unit, Ratio>(sh, minfn);
+
+    return minbox;
+}
+
+template <class RawShape> Radians minAreaBoundingBoxRotation(const RawShape& sh)
+{
+    return minAreaBoundingBox(sh).angleToX();
+}
+
+// Function to find a rotation for a shape that makes it fit into a box.
+//
+// The method is based on finding a pair of rotations from the rotating calipers
+// algorithm such that the aspect ratio is changing from being smaller than
+// that of the target to being bigger or vice versa. So that the correct
+// AR is somewhere between the obtained pair of angles. Then bisecting that
+// interval is sufficient to find the correct angle.
+//
+// The argument eps is the absolute error limit for the searched angle interval.
+template<class S, class Unit = TCompute<S>, class Ratio = TCompute<S>>
+Radians fitIntoBoxRotation(const S &shape, const _Box<TPoint<S>> &box, Radians eps = 1e-4)
+{
+    constexpr auto get_aspect_r = [](const auto &b) -> double {
+        return double(b.width()) / b.height();
+    };
+
+    auto aspect_r = get_aspect_r(box);
+
+    RotatedBox<TPoint<S>, Unit> prev_rbox;
+    Radians a_from = 0., a_to = 0.;
+    auto visitfn = [&](const RotatedBox<TPoint<S>, Unit> &rbox) {
+        bool lower_prev    = get_aspect_r(prev_rbox) < aspect_r;
+        bool lower_current = get_aspect_r(rbox) < aspect_r;
+
+        if (lower_prev != lower_current) {
+            a_from = prev_rbox.angleToX();
+            a_to   = rbox.angleToX();
+            return false;
+        }
+
+        return true;
+    };
+
+    rotcalipers<S, Unit, Ratio>(shape, visitfn);
+
+    auto rot_shape_bb = [&shape](Radians r) {
+        auto s = shape;
+        sl::rotate(s, r);
+        return sl::boundingBox(s);
+    };
+
+    auto rot_aspect_r = [&rot_shape_bb, &get_aspect_r](Radians r) {
+        return get_aspect_r(rot_shape_bb(r));
+    };
+
+    // Lets bisect the retrieved interval where the correct aspect ratio is.
+    double ar_from = rot_aspect_r(a_from);
+    auto would_fit = [&box](const _Box<TPoint<S>> &b) {
+        return b.width() < box.width() && b.height() < box.height();
+    };
+
+    Radians middle = (a_from + a_to) / 2.;
+    _Box<TPoint<S>> box_middle = rot_shape_bb(middle);
+    while (!would_fit(box_middle) && std::abs(a_to - a_from) > eps)
+    {
+        double ar_middle = get_aspect_r(box_middle);
+        if ((ar_from < aspect_r) != (ar_middle < aspect_r))
+            a_to = middle;
+        else
+            a_from = middle;
+
+        ar_from = rot_aspect_r(a_from);
+        middle = (a_from + a_to) / 2.;
+        box_middle = rot_shape_bb(middle);
+    }
+
+    return middle;
+}
+
+} // namespace libnest2d
+
+#endif // ROTCALIPERS_HPP

src/libnest2d/include/libnest2d/utils/rotfinder.hpp

@@ -0,0 +1,41 @@
+#ifndef ROTFINDER_HPP
+#define ROTFINDER_HPP
+
+#include <libnest2d/libnest2d.hpp>
+#include <libnest2d/optimizer.hpp>
+#include <iterator>
+
+namespace libnest2d {
+
+template<class RawShape>
+Radians findBestRotation(_Item<RawShape>& item) {
+    opt::StopCriteria stopcr;
+    stopcr.absolute_score_difference = 0.01;
+    stopcr.max_iterations = 10000;
+    opt::TOptimizer<opt::Method::G_GENETIC> solver(stopcr);
+
+    auto orig_rot = item.rotation();
+
+    auto result = solver.optimize_min([&item, &orig_rot](Radians rot){
+        item.rotation(orig_rot + rot);
+        auto bb = item.boundingBox();
+        return std::sqrt(bb.height()*bb.width());
+    }, opt::initvals(Radians(0)), opt::bound<Radians>(-Pi/2, Pi/2));
+
+    item.rotation(orig_rot);
+
+    return std::get<0>(result.optimum);
+}
+
+template<class Iterator>
+void findMinimumBoundingBoxRotations(Iterator from, Iterator to) {
+    using V = typename std::iterator_traits<Iterator>::value_type;
+    std::for_each(from, to, [](V& item){
+        Radians rot = findBestRotation(item);
+        item.rotate(rot);
+    });
+}
+
+}
+
+#endif // ROTFINDER_HPP

src/libnest2d/src/libnest2d.cpp

@@ -0,0 +1,26 @@
+#include <libnest2d/libnest2d.hpp>
+
+namespace libnest2d {
+
+template class _Nester<NfpPlacer, FirstFitSelection>;
+template class _Nester<BottomLeftPlacer, FirstFitSelection>;
+
+template std::size_t _Nester<NfpPlacer, FirstFitSelection>::execute(
+        std::vector<Item>::iterator, std::vector<Item>::iterator);
+template std::size_t _Nester<BottomLeftPlacer, FirstFitSelection>::execute(
+        std::vector<Item>::iterator, std::vector<Item>::iterator);
+
+template std::size_t nest(std::vector<Item>::iterator from,
+                          std::vector<Item>::iterator to,
+                          const Box & bin,
+                          Coord dist,
+                          const NestConfig<NfpPlacer, FirstFitSelection> &cfg,
+                          NestControl ctl);
+
+template std::size_t nest(std::vector<Item>::iterator from,
+                          std::vector<Item>::iterator to,
+                          const Box & bin,
+                          Coord dist,
+                          const NestConfig<BottomLeftPlacer, FirstFitSelection> &cfg,
+                          NestControl ctl);
+}

src/libnest2d/tools/benchmark.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) Tamás Mészáros
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef INCLUDE_BENCHMARK_H_
+#define INCLUDE_BENCHMARK_H_
+
+#include <chrono>
+#include <ratio>
+
+/**
+ * A class for doing benchmarks.
+ */
+class Benchmark {
+    typedef std::chrono::high_resolution_clock Clock;
+    typedef Clock::duration Duration;
+    typedef Clock::time_point TimePoint;
+
+    TimePoint t1, t2;
+    Duration d;
+
+    inline double to_sec(Duration d) {
+        return d.count() * double(Duration::period::num) / Duration::period::den;
+    }
+
+public:
+
+    /**
+     *  Measure time from the moment of this call.
+     */
+    void start() {  t1 = Clock::now(); }
+
+    /**
+     *  Measure time to the moment of this call.
+     */
+    void stop() {  t2 = Clock::now(); }
+
+    /**
+     * Get the time elapsed between a start() end a stop() call.
+     * @return Returns the elapsed time in seconds.
+     */
+    double getElapsedSec() {  d = t2 - t1; return to_sec(d); }
+};
+
+
+#endif /* INCLUDE_BENCHMARK_H_ */

src/libnest2d/tools/svgtools.hpp

@@ -0,0 +1,148 @@
+#ifndef SVGTOOLS_HPP
+#define SVGTOOLS_HPP
+
+#include <iostream>
+#include <fstream>
+#include <string>
+
+#include <libnest2d/nester.hpp>
+
+namespace libnest2d { namespace svg {
+
+template<class RawShape>
+class SVGWriter {
+    using Item = _Item<RawShape>;
+    using Coord = TCoord<TPoint<RawShape>>;
+    using Box = _Box<TPoint<RawShape>>;
+    using PackGroup = _PackGroup<RawShape>;
+
+public:
+
+    enum OrigoLocation {
+        TOPLEFT,
+        BOTTOMLEFT
+    };
+
+    struct Config {
+        OrigoLocation origo_location;
+        Coord mm_in_coord_units;
+        double width, height;
+        Config():
+            origo_location(BOTTOMLEFT), mm_in_coord_units(1000000),
+            width(500), height(500) {}
+
+    };
+
+private:
+    Config conf_;
+    std::vector<std::string> svg_layers_;
+    bool finished_ = false;
+public:
+
+    SVGWriter(const Config& conf = Config()):
+        conf_(conf) {}
+
+    void setSize(const Box& box) {
+        conf_.height = static_cast<double>(box.height()) /
+                conf_.mm_in_coord_units;
+        conf_.width = static_cast<double>(box.width()) /
+                conf_.mm_in_coord_units;
+    }
+    
+    void writeShape(RawShape tsh, std::string fill = "none", std::string stroke = "black", float stroke_width = 1) {
+        if(svg_layers_.empty()) addLayer();
+        if(conf_.origo_location == BOTTOMLEFT) {
+            auto d = static_cast<Coord>(
+                std::round(conf_.height*conf_.mm_in_coord_units) );
+
+            auto& contour = shapelike::contour(tsh);
+            for(auto& v : contour) setY(v, -getY(v) + d);
+
+            auto& holes = shapelike::holes(tsh);
+            for(auto& h : holes) for(auto& v : h) setY(v, -getY(v) + d);
+            
+        }
+        currentLayer() +=
+            shapelike::serialize<Formats::SVG>(tsh,
+                                               1.0 / conf_.mm_in_coord_units, fill, stroke, stroke_width) +
+            "\n";
+    }
+
+    void writeItem(const Item& item, std::string fill = "none", std::string stroke = "black", float stroke_width = 1) {
+        writeShape(item.transformedShape(), fill, stroke, stroke_width);
+    }
+
+    void writePackGroup(const PackGroup& result) {
+        for(auto r : result) {
+            addLayer();
+            for(Item& sh : r) {
+                writeItem(sh);
+            }
+            finishLayer();
+        }
+    }
+    
+    template<class ItemIt> void writeItems(ItemIt from, ItemIt to) {
+        auto it = from;
+        PackGroup pg;
+        while(it != to) {
+            if(it->binId() == BIN_ID_UNSET) continue;
+            while(pg.size() <= size_t(it->binId())) pg.emplace_back();
+            pg[it->binId()].emplace_back(*it);
+            ++it;
+        }
+        writePackGroup(pg);
+    }
+
+    void draw_text(float x,float y, const std::string text, const std::string color, int font_size)
+    {
+        char s[500];
+        sprintf(s,
+            "<text x=\"%f\" y=\"%f\" font-family=\"sans-serif\" font-size=\"%dpx\" fill=\"%s\">%s</text>\n",
+            x,y, font_size, color.c_str(), text.c_str());
+        currentLayer() += s;
+    }
+
+    void addLayer() {
+        svg_layers_.emplace_back(header());
+        finished_ = false;
+    }
+
+    void finishLayer() {
+        currentLayer() += "\n</svg>\n";
+        finished_ = true;
+    }
+
+    void save(const std::string& filepath) {
+        size_t lyrc = svg_layers_.size() > 1? 1 : 0;
+        size_t last = svg_layers_.size() > 1? svg_layers_.size() : 0;
+
+        for(auto& lyr : svg_layers_) {
+            std::fstream out(filepath + (lyrc > 0? std::to_string(lyrc) : "") +
+                             ".svg", std::fstream::out);
+            if(out.is_open()) out << lyr;
+            if(lyrc == last && !finished_) out << "\n</svg>\n";
+            out.flush(); out.close(); lyrc++;
+        };
+    }
+
+private:
+
+    std::string& currentLayer() { return svg_layers_.back(); }
+
+    const std::string header() const {
+        std::string svg_header =
+R"raw(<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg height=")raw";
+        svg_header += std::to_string(conf_.height) + "\" width=\"" + std::to_string(conf_.width) + "\" ";
+        svg_header += R"raw(xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">)raw";
+        return svg_header;
+    }
+
+};
+
+}
+}
+
+#endif // SVGTOOLS_HPP