Merge pull request #1 from PaddlePaddle/develop

update-2020-7-17

ppocr/postprocess/lanms/.gitignore

+adaptor.so

ppocr/postprocess/lanms/.ycm_extra_conf.py

+#!/usr/bin/env python
+#
+# Copyright (C) 2014  Google Inc.
+#
+# This file is part of YouCompleteMe.
+#
+# YouCompleteMe 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 3 of the License, or
+# (at your option) any later version.
+#
+# YouCompleteMe 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 YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import sys
+import glob
+import ycm_core
+
+# These are the compilation flags that will be used in case there's no
+# compilation database set (by default, one is not set).
+# CHANGE THIS LIST OF FLAGS. YES, THIS IS THE DROID YOU HAVE BEEN LOOKING FOR.
+sys.path.append(os.path.dirname(__file__))
+
+
+BASE_DIR = os.path.dirname(os.path.realpath(__file__))
+
+from plumbum.cmd import python_config
+
+
+flags = [
+    '-Wall',
+    '-Wextra',
+    '-Wnon-virtual-dtor',
+    '-Winvalid-pch',
+    '-Wno-unused-local-typedefs',
+    '-std=c++11',
+    '-x', 'c++',
+    '-Iinclude',
+] + python_config('--cflags').split()
+
+
+# Set this to the absolute path to the folder (NOT the file!) containing the
+# compile_commands.json file to use that instead of 'flags'. See here for
+# more details: http://clang.llvm.org/docs/JSONCompilationDatabase.html
+#
+# Most projects will NOT need to set this to anything; you can just change the
+# 'flags' list of compilation flags.
+compilation_database_folder = ''
+
+if os.path.exists( compilation_database_folder ):
+  database = ycm_core.CompilationDatabase( compilation_database_folder )
+else:
+  database = None
+
+SOURCE_EXTENSIONS = [ '.cpp', '.cxx', '.cc', '.c', '.m', '.mm' ]
+
+def DirectoryOfThisScript():
+  return os.path.dirname( os.path.abspath( __file__ ) )
+
+
+def MakeRelativePathsInFlagsAbsolute( flags, working_directory ):
+  if not working_directory:
+    return list( flags )
+  new_flags = []
+  make_next_absolute = False
+  path_flags = [ '-isystem', '-I', '-iquote', '--sysroot=' ]
+  for flag in flags:
+    new_flag = flag
+
+    if make_next_absolute:
+      make_next_absolute = False
+      if not flag.startswith( '/' ):
+        new_flag = os.path.join( working_directory, flag )
+
+    for path_flag in path_flags:
+      if flag == path_flag:
+        make_next_absolute = True
+        break
+
+      if flag.startswith( path_flag ):
+        path = flag[ len( path_flag ): ]
+        new_flag = path_flag + os.path.join( working_directory, path )
+        break
+
+    if new_flag:
+      new_flags.append( new_flag )
+  return new_flags
+
+
+def IsHeaderFile( filename ):
+  extension = os.path.splitext( filename )[ 1 ]
+  return extension in [ '.h', '.hxx', '.hpp', '.hh' ]
+
+
+def GetCompilationInfoForFile( filename ):
+  # The compilation_commands.json file generated by CMake does not have entries
+  # for header files. So we do our best by asking the db for flags for a
+  # corresponding source file, if any. If one exists, the flags for that file
+  # should be good enough.
+  if IsHeaderFile( filename ):
+    basename = os.path.splitext( filename )[ 0 ]
+    for extension in SOURCE_EXTENSIONS:
+      replacement_file = basename + extension
+      if os.path.exists( replacement_file ):
+        compilation_info = database.GetCompilationInfoForFile(
+          replacement_file )
+        if compilation_info.compiler_flags_:
+          return compilation_info
+    return None
+  return database.GetCompilationInfoForFile( filename )
+
+
+# This is the entry point; this function is called by ycmd to produce flags for
+# a file.
+def FlagsForFile( filename, **kwargs ):
+  if database:
+    # Bear in mind that compilation_info.compiler_flags_ does NOT return a
+    # python list, but a "list-like" StringVec object
+    compilation_info = GetCompilationInfoForFile( filename )
+    if not compilation_info:
+      return None
+
+    final_flags = MakeRelativePathsInFlagsAbsolute(
+      compilation_info.compiler_flags_,
+      compilation_info.compiler_working_dir_ )
+  else:
+    relative_to = DirectoryOfThisScript()
+    final_flags = MakeRelativePathsInFlagsAbsolute( flags, relative_to )
+
+  return {
+    'flags': final_flags,
+    'do_cache': True
+  }
+

ppocr/postprocess/lanms/Makefile

+CXXFLAGS = -I include  -std=c++11 -O3 $(shell python3-config --cflags)
+LDFLAGS = $(shell python3-config --ldflags)
+
+DEPS = lanms.h $(shell find include -xtype f)
+CXX_SOURCES = adaptor.cpp include/clipper/clipper.cpp
+
+LIB_SO = adaptor.so
+
+$(LIB_SO): $(CXX_SOURCES) $(DEPS)
+	$(CXX) -o $@ $(CXXFLAGS) $(LDFLAGS) $(CXX_SOURCES) --shared -fPIC
+
+clean:
+	rm -rf $(LIB_SO)

ppocr/postprocess/lanms/__init__.py

+import subprocess
+import os
+import numpy as np
+
+BASE_DIR = os.path.dirname(os.path.realpath(__file__))
+
+if subprocess.call(['make', '-C', BASE_DIR]) != 0:  # return value
+    raise RuntimeError('Cannot compile lanms: {}'.format(BASE_DIR))
+
+
+def merge_quadrangle_n9(polys, thres=0.3, precision=10000):
+    from .adaptor import merge_quadrangle_n9 as nms_impl
+    if len(polys) == 0:
+        return np.array([], dtype='float32')
+    p = polys.copy()
+    p[:,:8] *= precision
+    ret = np.array(nms_impl(p, thres), dtype='float32')
+    ret[:,:8] /= precision
+    return ret
+

ppocr/postprocess/lanms/__main__.py

+import numpy as np
+
+
+from . import merge_quadrangle_n9
+
+if __name__ == '__main__':
+    # unit square with confidence 1
+    q = np.array([0, 0, 0, 1, 1, 1, 1, 0, 1], dtype='float32')
+
+    print(merge_quadrangle_n9(np.array([q, q + 0.1, q + 2])))

ppocr/postprocess/lanms/adaptor.cpp

+#include "pybind11/pybind11.h"
+#include "pybind11/numpy.h"
+#include "pybind11/stl.h"
+#include "pybind11/stl_bind.h"
+
+#include "lanms.h"
+
+namespace py = pybind11;
+
+
+namespace lanms_adaptor {
+
+	std::vector<std::vector<float>> polys2floats(const std::vector<lanms::Polygon> &polys) {
+		std::vector<std::vector<float>> ret;
+		for (size_t i = 0; i < polys.size(); i ++) {
+			auto &p = polys[i];
+			auto &poly = p.poly;
+			ret.emplace_back(std::vector<float>{
+					float(poly[0].X), float(poly[0].Y),
+					float(poly[1].X), float(poly[1].Y),
+					float(poly[2].X), float(poly[2].Y),
+					float(poly[3].X), float(poly[3].Y),
+					float(p.score),
+					});
+		}
+
+		return ret;
+	}
+
+
+	/**
+	 *
+	 * \param quad_n9 an n-by-9 numpy array, where first 8 numbers denote the
+	 *		quadrangle, and the last one is the score
+	 * \param iou_threshold two quadrangles with iou score above this threshold
+	 *		will be merged
+	 *
+	 * \return an n-by-9 numpy array, the merged quadrangles
+	 */
+	std::vector<std::vector<float>> merge_quadrangle_n9(
+			py::array_t<float, py::array::c_style | py::array::forcecast> quad_n9,
+			float iou_threshold) {
+		auto pbuf = quad_n9.request();
+		if (pbuf.ndim != 2 || pbuf.shape[1] != 9)
+			throw std::runtime_error("quadrangles must have a shape of (n, 9)");
+		auto n = pbuf.shape[0];
+		auto ptr = static_cast<float *>(pbuf.ptr);
+		return polys2floats(lanms::merge_quadrangle_n9(ptr, n, iou_threshold));
+	}
+
+}
+
+PYBIND11_PLUGIN(adaptor) {
+	py::module m("adaptor", "NMS");
+
+	m.def("merge_quadrangle_n9", &lanms_adaptor::merge_quadrangle_n9,
+			"merge quadrangels");
+
+	return m.ptr();
+}
+

ppocr/postprocess/lanms/include/clipper/clipper.cpp

+/*******************************************************************************
+*                                                                              *
+* Author    :  Angus Johnson                                                   *
+* Version   :  6.4.0                                                           *
+* Date      :  2 July 2015                                                     *
+* Website   :  http://www.angusj.com                                           *
+* Copyright :  Angus Johnson 2010-2015                                         *
+*                                                                              *
+* License:                                                                     *
+* Use, modification & distribution is subject to Boost Software License Ver 1. *
+* http://www.boost.org/LICENSE_1_0.txt                                         *
+*                                                                              *
+* Attributions:                                                                *
+* The code in this library is an extension of Bala Vatti's clipping algorithm: *
+* "A generic solution to polygon clipping"                                     *
+* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.             *
+* http://portal.acm.org/citation.cfm?id=129906                                 *
+*                                                                              *
+* Computer graphics and geometric modeling: implementation and algorithms      *
+* By Max K. Agoston                                                            *
+* Springer; 1 edition (January 4, 2005)                                        *
+* http://books.google.com/books?q=vatti+clipping+agoston                       *
+*                                                                              *
+* See also:                                                                    *
+* "Polygon Offsetting by Computing Winding Numbers"                            *
+* Paper no. DETC2005-85513 pp. 565-575                                         *
+* ASME 2005 International Design Engineering Technical Conferences             *
+* and Computers and Information in Engineering Conference (IDETC/CIE2005)      *
+* September 24-28, 2005 , Long Beach, California, USA                          *
+* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf              *
+*                                                                              *
+*******************************************************************************/
+
+/*******************************************************************************
+*                                                                              *
+* This is a translation of the Delphi Clipper library and the naming style     *
+* used has retained a Delphi flavour.                                          *
+*                                                                              *
+*******************************************************************************/
+
+#include "clipper.hpp"
+#include <cmath>
+#include <vector>
+#include <algorithm>
+#include <stdexcept>
+#include <cstring>
+#include <cstdlib>
+#include <ostream>
+#include <functional>
+
+namespace ClipperLib {
+
+static double const pi = 3.141592653589793238;
+static double const two_pi = pi *2;
+static double const def_arc_tolerance = 0.25;
+
+enum Direction { dRightToLeft, dLeftToRight };
+
+static int const Unassigned = -1;  //edge not currently 'owning' a solution
+static int const Skip = -2;        //edge that would otherwise close a path
+
+#define HORIZONTAL (-1.0E+40)
+#define TOLERANCE (1.0e-20)
+#define NEAR_ZERO(val) (((val) > -TOLERANCE) && ((val) < TOLERANCE))
+
+struct TEdge {
+  IntPoint Bot;
+  IntPoint Curr; //current (updated for every new scanbeam)
+  IntPoint Top;
+  double Dx;
+  PolyType PolyTyp;
+  EdgeSide Side; //side only refers to current side of solution poly
+  int WindDelta; //1 or -1 depending on winding direction
+  int WindCnt;
+  int WindCnt2; //winding count of the opposite polytype
+  int OutIdx;
+  TEdge *Next;
+  TEdge *Prev;
+  TEdge *NextInLML;
+  TEdge *NextInAEL;
+  TEdge *PrevInAEL;
+  TEdge *NextInSEL;
+  TEdge *PrevInSEL;
+};
+
+struct IntersectNode {
+  TEdge          *Edge1;
+  TEdge          *Edge2;
+  IntPoint        Pt;
+};
+
+struct LocalMinimum {
+  cInt          Y;
+  TEdge        *LeftBound;
+  TEdge        *RightBound;
+};
+
+struct OutPt;
+
+//OutRec: contains a path in the clipping solution. Edges in the AEL will
+//carry a pointer to an OutRec when they are part of the clipping solution.
+struct OutRec {
+  int       Idx;
+  bool      IsHole;
+  bool      IsOpen;
+  OutRec   *FirstLeft;  //see comments in clipper.pas
+  PolyNode *PolyNd;
+  OutPt    *Pts;
+  OutPt    *BottomPt;
+};
+
+struct OutPt {
+  int       Idx;
+  IntPoint  Pt;
+  OutPt    *Next;
+  OutPt    *Prev;
+};
+
+struct Join {
+  OutPt    *OutPt1;
+  OutPt    *OutPt2;
+  IntPoint  OffPt;
+};
+
+struct LocMinSorter
+{
+  inline bool operator()(const LocalMinimum& locMin1, const LocalMinimum& locMin2)
+  {
+    return locMin2.Y < locMin1.Y;
+  }
+};
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+inline cInt Round(double val)
+{
+  if ((val < 0)) return static_cast<cInt>(val - 0.5); 
+  else return static_cast<cInt>(val + 0.5);
+}
+//------------------------------------------------------------------------------
+
+inline cInt Abs(cInt val)
+{
+  return val < 0 ? -val : val;
+}
+
+//------------------------------------------------------------------------------
+// PolyTree methods ...
+//------------------------------------------------------------------------------
+
+void PolyTree::Clear()
+{
+    for (PolyNodes::size_type i = 0; i < AllNodes.size(); ++i)
+      delete AllNodes[i];
+    AllNodes.resize(0); 
+    Childs.resize(0);
+}
+//------------------------------------------------------------------------------
+
+PolyNode* PolyTree::GetFirst() const
+{
+  if (!Childs.empty())
+      return Childs[0];
+  else
+      return 0;
+}
+//------------------------------------------------------------------------------
+
+int PolyTree::Total() const
+{
+  int result = (int)AllNodes.size();
+  //with negative offsets, ignore the hidden outer polygon ...
+  if (result > 0 && Childs[0] != AllNodes[0]) result--;
+  return result;
+}
+
+//------------------------------------------------------------------------------
+// PolyNode methods ...
+//------------------------------------------------------------------------------
+
+PolyNode::PolyNode(): Childs(), Parent(0), Index(0), m_IsOpen(false)
+{
+}
+//------------------------------------------------------------------------------
+
+int PolyNode::ChildCount() const
+{
+  return (int)Childs.size();
+}
+//------------------------------------------------------------------------------
+
+void PolyNode::AddChild(PolyNode& child)
+{
+  unsigned cnt = (unsigned)Childs.size();
+  Childs.push_back(&child);
+  child.Parent = this;
+  child.Index = cnt;
+}
+//------------------------------------------------------------------------------
+
+PolyNode* PolyNode::GetNext() const
+{ 
+  if (!Childs.empty()) 
+      return Childs[0]; 
+  else
+      return GetNextSiblingUp();    
+}  
+//------------------------------------------------------------------------------
+
+PolyNode* PolyNode::GetNextSiblingUp() const
+{ 
+  if (!Parent) //protects against PolyTree.GetNextSiblingUp()
+      return 0;
+  else if (Index == Parent->Childs.size() - 1)
+      return Parent->GetNextSiblingUp();
+  else
+      return Parent->Childs[Index + 1];
+}  
+//------------------------------------------------------------------------------
+
+bool PolyNode::IsHole() const
+{ 
+  bool result = true;
+  PolyNode* node = Parent;
+  while (node)
+  {
+      result = !result;
+      node = node->Parent;
+  }
+  return result;
+}  
+//------------------------------------------------------------------------------
+
+bool PolyNode::IsOpen() const
+{ 
+  return m_IsOpen;
+}  
+//------------------------------------------------------------------------------
+
+#ifndef use_int32
+
+//------------------------------------------------------------------------------
+// Int128 class (enables safe math on signed 64bit integers)
+// eg Int128 val1((long64)9223372036854775807); //ie 2^63 -1
+//    Int128 val2((long64)9223372036854775807);
+//    Int128 val3 = val1 * val2;
+//    val3.AsString => "85070591730234615847396907784232501249" (8.5e+37)
+//------------------------------------------------------------------------------
+
+class Int128
+{
+  public:
+    ulong64 lo;
+    long64 hi;
+
+    Int128(long64 _lo = 0)
+    {
+      lo = (ulong64)_lo;   
+      if (_lo < 0)  hi = -1; else hi = 0; 
+    }
+
+
+    Int128(const Int128 &val): lo(val.lo), hi(val.hi){}
+
+    Int128(const long64& _hi, const ulong64& _lo): lo(_lo), hi(_hi){}
+    
+    Int128& operator = (const long64 &val)
+    {
+      lo = (ulong64)val;
+      if (val < 0) hi = -1; else hi = 0;
+      return *this;
+    }
+
+    bool operator == (const Int128 &val) const
+      {return (hi == val.hi && lo == val.lo);}
+
+    bool operator != (const Int128 &val) const
+      { return !(*this == val);}
+
+    bool operator > (const Int128 &val) const
+    {
+      if (hi != val.hi)
+        return hi > val.hi;
+      else
+        return lo > val.lo;
+    }
+
+    bool operator < (const Int128 &val) const
+    {
+      if (hi != val.hi)
+        return hi < val.hi;
+      else
+        return lo < val.lo;
+    }
+
+    bool operator >= (const Int128 &val) const
+      { return !(*this < val);}
+
+    bool operator <= (const Int128 &val) const
+      { return !(*this > val);}
+
+    Int128& operator += (const Int128 &rhs)
+    {
+      hi += rhs.hi;
+      lo += rhs.lo;
+      if (lo < rhs.lo) hi++;
+      return *this;
+    }
+
+    Int128 operator + (const Int128 &rhs) const
+    {
+      Int128 result(*this);
+      result+= rhs;
+      return result;
+    }
+
+    Int128& operator -= (const Int128 &rhs)
+    {
+      *this += -rhs;
+      return *this;
+    }
+
+    Int128 operator - (const Int128 &rhs) const
+    {
+      Int128 result(*this);
+      result -= rhs;
+      return result;
+    }
+
+    Int128 operator-() const //unary negation
+    {
+      if (lo == 0)
+        return Int128(-hi, 0);
+      else
+        return Int128(~hi, ~lo + 1);
+    }
+
+    operator double() const
+    {
+      const double shift64 = 18446744073709551616.0; //2^64
+      if (hi < 0)
+      {
+        if (lo == 0) return (double)hi * shift64;
+        else return -(double)(~lo + ~hi * shift64);
+      }
+      else
+        return (double)(lo + hi * shift64);
+    }
+
+};
+//------------------------------------------------------------------------------
+
+Int128 Int128Mul (long64 lhs, long64 rhs)
+{
+  bool negate = (lhs < 0) != (rhs < 0);
+
+  if (lhs < 0) lhs = -lhs;
+  ulong64 int1Hi = ulong64(lhs) >> 32;
+  ulong64 int1Lo = ulong64(lhs & 0xFFFFFFFF);
+
+  if (rhs < 0) rhs = -rhs;
+  ulong64 int2Hi = ulong64(rhs) >> 32;
+  ulong64 int2Lo = ulong64(rhs & 0xFFFFFFFF);
+
+  //nb: see comments in clipper.pas
+  ulong64 a = int1Hi * int2Hi;
+  ulong64 b = int1Lo * int2Lo;
+  ulong64 c = int1Hi * int2Lo + int1Lo * int2Hi;
+
+  Int128 tmp;
+  tmp.hi = long64(a + (c >> 32));
+  tmp.lo = long64(c << 32);
+  tmp.lo += long64(b);
+  if (tmp.lo < b) tmp.hi++;
+  if (negate) tmp = -tmp;
+  return tmp;
+};
+#endif
+
+//------------------------------------------------------------------------------
+// Miscellaneous global functions
+//------------------------------------------------------------------------------
+
+bool Orientation(const Path &poly)
+{
+    return Area(poly) >= 0;
+}
+//------------------------------------------------------------------------------
+
+double Area(const Path &poly)
+{
+  int size = (int)poly.size();
+  if (size < 3) return 0;
+
+  double a = 0;
+  for (int i = 0, j = size -1; i < size; ++i)
+  {
+    a += ((double)poly[j].X + poly[i].X) * ((double)poly[j].Y - poly[i].Y);
+    j = i;
+  }
+  return -a * 0.5;
+}
+//------------------------------------------------------------------------------
+
+double Area(const OutPt *op)
+{
+  const OutPt *startOp = op;
+  if (!op) return 0;
+  double a = 0;
+  do {
+    a +=  (double)(op->Prev->Pt.X + op->Pt.X) * (double)(op->Prev->Pt.Y - op->Pt.Y);
+    op = op->Next;
+  } while (op != startOp);
+  return a * 0.5;
+}
+//------------------------------------------------------------------------------
+
+double Area(const OutRec &outRec)
+{
+  return Area(outRec.Pts);
+}
+//------------------------------------------------------------------------------
+
+bool PointIsVertex(const IntPoint &Pt, OutPt *pp)
+{
+  OutPt *pp2 = pp;
+  do
+  {
+    if (pp2->Pt == Pt) return true;
+    pp2 = pp2->Next;
+  }
+  while (pp2 != pp);
+  return false;
+}
+//------------------------------------------------------------------------------
+
+//See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
+//http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
+int PointInPolygon(const IntPoint &pt, const Path &path)
+{
+  //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+  int result = 0;
+  size_t cnt = path.size();
+  if (cnt < 3) return 0;
+  IntPoint ip = path[0];
+  for(size_t i = 1; i <= cnt; ++i)
+  {
+    IntPoint ipNext = (i == cnt ? path[0] : path[i]);
+    if (ipNext.Y == pt.Y)
+    {
+        if ((ipNext.X == pt.X) || (ip.Y == pt.Y && 
+          ((ipNext.X > pt.X) == (ip.X < pt.X)))) return -1;
+    }
+    if ((ip.Y < pt.Y) != (ipNext.Y < pt.Y))
+    {
+      if (ip.X >= pt.X)
+      {
+        if (ipNext.X > pt.X) result = 1 - result;
+        else
+        {
+          double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) - 
+            (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
+          if (!d) return -1;
+          if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
+        }
+      } else
+      {
+        if (ipNext.X > pt.X)
+        {
+          double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) - 
+            (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
+          if (!d) return -1;
+          if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
+        }
+      }
+    }
+    ip = ipNext;
+  } 
+  return result;
+}
+//------------------------------------------------------------------------------
+
+int PointInPolygon (const IntPoint &pt, OutPt *op)
+{
+  //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+  int result = 0;
+  OutPt* startOp = op;
+  for(;;)
+  {
+    if (op->Next->Pt.Y == pt.Y)
+    {
+        if ((op->Next->Pt.X == pt.X) || (op->Pt.Y == pt.Y && 
+          ((op->Next->Pt.X > pt.X) == (op->Pt.X < pt.X)))) return -1;
+    }
+    if ((op->Pt.Y < pt.Y) != (op->Next->Pt.Y < pt.Y))
+    {
+      if (op->Pt.X >= pt.X)
+      {
+        if (op->Next->Pt.X > pt.X) result = 1 - result;
+        else
+        {
+          double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) - 
+            (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
+          if (!d) return -1;
+          if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
+        }
+      } else
+      {
+        if (op->Next->Pt.X > pt.X)
+        {
+          double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) - 
+            (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
+          if (!d) return -1;
+          if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
+        }
+      }
+    } 
+    op = op->Next;
+    if (startOp == op) break;
+  } 
+  return result;
+}
+//------------------------------------------------------------------------------
+
+bool Poly2ContainsPoly1(OutPt *OutPt1, OutPt *OutPt2)
+{
+  OutPt* op = OutPt1;
+  do
+  {
+    //nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
+    int res = PointInPolygon(op->Pt, OutPt2);
+    if (res >= 0) return res > 0;
+    op = op->Next; 
+  }
+  while (op != OutPt1);
+  return true; 
+}
+//----------------------------------------------------------------------
+
+bool SlopesEqual(const TEdge &e1, const TEdge &e2, bool UseFullInt64Range)
+{
+#ifndef use_int32
+  if (UseFullInt64Range)
+    return Int128Mul(e1.Top.Y - e1.Bot.Y, e2.Top.X - e2.Bot.X) == 
+    Int128Mul(e1.Top.X - e1.Bot.X, e2.Top.Y - e2.Bot.Y);
+  else 
+#endif
+    return (e1.Top.Y - e1.Bot.Y) * (e2.Top.X - e2.Bot.X) == 
+    (e1.Top.X - e1.Bot.X) * (e2.Top.Y - e2.Bot.Y);
+}
+//------------------------------------------------------------------------------
+
+bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
+  const IntPoint pt3, bool UseFullInt64Range)
+{
+#ifndef use_int32
+  if (UseFullInt64Range)
+    return Int128Mul(pt1.Y-pt2.Y, pt2.X-pt3.X) == Int128Mul(pt1.X-pt2.X, pt2.Y-pt3.Y);
+  else 
+#endif
+    return (pt1.Y-pt2.Y)*(pt2.X-pt3.X) == (pt1.X-pt2.X)*(pt2.Y-pt3.Y);
+}
+//------------------------------------------------------------------------------
+
+bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
+  const IntPoint pt3, const IntPoint pt4, bool UseFullInt64Range)
+{
+#ifndef use_int32
+  if (UseFullInt64Range)
+    return Int128Mul(pt1.Y-pt2.Y, pt3.X-pt4.X) == Int128Mul(pt1.X-pt2.X, pt3.Y-pt4.Y);
+  else 
+#endif
+    return (pt1.Y-pt2.Y)*(pt3.X-pt4.X) == (pt1.X-pt2.X)*(pt3.Y-pt4.Y);
+}
+//------------------------------------------------------------------------------
+
+inline bool IsHorizontal(TEdge &e)
+{
+  return e.Dx == HORIZONTAL;
+}
+//------------------------------------------------------------------------------
+
+inline double GetDx(const IntPoint pt1, const IntPoint pt2)
+{
+  return (pt1.Y == pt2.Y) ?
+    HORIZONTAL : (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y);
+}
+//---------------------------------------------------------------------------
+
+inline void SetDx(TEdge &e)
+{
+  cInt dy  = (e.Top.Y - e.Bot.Y);
+  if (dy == 0) e.Dx = HORIZONTAL;
+  else e.Dx = (double)(e.Top.X - e.Bot.X) / dy;
+}
+//---------------------------------------------------------------------------
+
+inline void SwapSides(TEdge &Edge1, TEdge &Edge2)
+{
+  EdgeSide Side =  Edge1.Side;
+  Edge1.Side = Edge2.Side;
+  Edge2.Side = Side;
+}
+//------------------------------------------------------------------------------
+
+inline void SwapPolyIndexes(TEdge &Edge1, TEdge &Edge2)
+{
+  int OutIdx =  Edge1.OutIdx;
+  Edge1.OutIdx = Edge2.OutIdx;
+  Edge2.OutIdx = OutIdx;
+}
+//------------------------------------------------------------------------------
+
+inline cInt TopX(TEdge &edge, const cInt currentY)
+{
+  return ( currentY == edge.Top.Y ) ?
+    edge.Top.X : edge.Bot.X + Round(edge.Dx *(currentY - edge.Bot.Y));
+}
+//------------------------------------------------------------------------------
+
+void IntersectPoint(TEdge &Edge1, TEdge &Edge2, IntPoint &ip)
+{
+#ifdef use_xyz  
+  ip.Z = 0;
+#endif
+
+  double b1, b2;
+  if (Edge1.Dx == Edge2.Dx)
+  {
+    ip.Y = Edge1.Curr.Y;
+    ip.X = TopX(Edge1, ip.Y);
+    return;
+  }
+  else if (Edge1.Dx == 0)
+  {
+    ip.X = Edge1.Bot.X;
+    if (IsHorizontal(Edge2))
+      ip.Y = Edge2.Bot.Y;
+    else
+    {
+      b2 = Edge2.Bot.Y - (Edge2.Bot.X / Edge2.Dx);
+      ip.Y = Round(ip.X / Edge2.Dx + b2);
+    }
+  }
+  else if (Edge2.Dx == 0)
+  {
+    ip.X = Edge2.Bot.X;
+    if (IsHorizontal(Edge1))
+      ip.Y = Edge1.Bot.Y;
+    else
+    {
+      b1 = Edge1.Bot.Y - (Edge1.Bot.X / Edge1.Dx);
+      ip.Y = Round(ip.X / Edge1.Dx + b1);
+    }
+  } 
+  else 
+  {
+    b1 = Edge1.Bot.X - Edge1.Bot.Y * Edge1.Dx;
+    b2 = Edge2.Bot.X - Edge2.Bot.Y * Edge2.Dx;
+    double q = (b2-b1) / (Edge1.Dx - Edge2.Dx);
+    ip.Y = Round(q);
+    if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
+      ip.X = Round(Edge1.Dx * q + b1);
+    else 
+      ip.X = Round(Edge2.Dx * q + b2);
+  }
+
+  if (ip.Y < Edge1.Top.Y || ip.Y < Edge2.Top.Y) 
+  {
+    if (Edge1.Top.Y > Edge2.Top.Y)
+      ip.Y = Edge1.Top.Y;
+    else
+      ip.Y = Edge2.Top.Y;
+    if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
+      ip.X = TopX(Edge1, ip.Y);
+    else
+      ip.X = TopX(Edge2, ip.Y);
+  } 
+  //finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
+  if (ip.Y > Edge1.Curr.Y)
+  {
+    ip.Y = Edge1.Curr.Y;
+    //use the more vertical edge to derive X ...
+    if (std::fabs(Edge1.Dx) > std::fabs(Edge2.Dx))
+      ip.X = TopX(Edge2, ip.Y); else
+      ip.X = TopX(Edge1, ip.Y);
+  }
+}
+//------------------------------------------------------------------------------
+
+void ReversePolyPtLinks(OutPt *pp)
+{
+  if (!pp) return;
+  OutPt *pp1, *pp2;
+  pp1 = pp;
+  do {
+  pp2 = pp1->Next;
+  pp1->Next = pp1->Prev;
+  pp1->Prev = pp2;
+  pp1 = pp2;
+  } while( pp1 != pp );
+}
+//------------------------------------------------------------------------------
+
+void DisposeOutPts(OutPt*& pp)
+{
+  if (pp == 0) return;
+    pp->Prev->Next = 0;
+  while( pp )
+  {
+    OutPt *tmpPp = pp;
+    pp = pp->Next;
+    delete tmpPp;
+  }
+}
+//------------------------------------------------------------------------------
+
+inline void InitEdge(TEdge* e, TEdge* eNext, TEdge* ePrev, const IntPoint& Pt)
+{
+  std::memset(e, 0, sizeof(TEdge));
+  e->Next = eNext;
+  e->Prev = ePrev;
+  e->Curr = Pt;
+  e->OutIdx = Unassigned;
+}
+//------------------------------------------------------------------------------
+
+void InitEdge2(TEdge& e, PolyType Pt)
+{
+  if (e.Curr.Y >= e.Next->Curr.Y)
+  {
+    e.Bot = e.Curr;
+    e.Top = e.Next->Curr;
+  } else
+  {
+    e.Top = e.Curr;
+    e.Bot = e.Next->Curr;
+  }
+  SetDx(e);
+  e.PolyTyp = Pt;
+}
+//------------------------------------------------------------------------------
+
+TEdge* RemoveEdge(TEdge* e)
+{
+  //removes e from double_linked_list (but without removing from memory)
+  e->Prev->Next = e->Next;
+  e->Next->Prev = e->Prev;
+  TEdge* result = e->Next;
+  e->Prev = 0; //flag as removed (see ClipperBase.Clear)
+  return result;
+}
+//------------------------------------------------------------------------------
+
+inline void ReverseHorizontal(TEdge &e)
+{
+  //swap horizontal edges' Top and Bottom x's so they follow the natural
+  //progression of the bounds - ie so their xbots will align with the
+  //adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
+  std::swap(e.Top.X, e.Bot.X);
+#ifdef use_xyz  
+  std::swap(e.Top.Z, e.Bot.Z);
+#endif
+}
+//------------------------------------------------------------------------------
+
+void SwapPoints(IntPoint &pt1, IntPoint &pt2)
+{
+  IntPoint tmp = pt1;
+  pt1 = pt2;
+  pt2 = tmp;
+}
+//------------------------------------------------------------------------------
+
+bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a,
+  IntPoint pt2b, IntPoint &pt1, IntPoint &pt2)
+{
+  //precondition: segments are Collinear.
+  if (Abs(pt1a.X - pt1b.X) > Abs(pt1a.Y - pt1b.Y))
+  {
+    if (pt1a.X > pt1b.X) SwapPoints(pt1a, pt1b);
+    if (pt2a.X > pt2b.X) SwapPoints(pt2a, pt2b);
+    if (pt1a.X > pt2a.X) pt1 = pt1a; else pt1 = pt2a;
+    if (pt1b.X < pt2b.X) pt2 = pt1b; else pt2 = pt2b;
+    return pt1.X < pt2.X;
+  } else
+  {
+    if (pt1a.Y < pt1b.Y) SwapPoints(pt1a, pt1b);
+    if (pt2a.Y < pt2b.Y) SwapPoints(pt2a, pt2b);
+    if (pt1a.Y < pt2a.Y) pt1 = pt1a; else pt1 = pt2a;
+    if (pt1b.Y > pt2b.Y) pt2 = pt1b; else pt2 = pt2b;
+    return pt1.Y > pt2.Y;
+  }
+}
+//------------------------------------------------------------------------------
+
+bool FirstIsBottomPt(const OutPt* btmPt1, const OutPt* btmPt2)
+{
+  OutPt *p = btmPt1->Prev;
+  while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Prev;
+  double dx1p = std::fabs(GetDx(btmPt1->Pt, p->Pt));
+  p = btmPt1->Next;
+  while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Next;
+  double dx1n = std::fabs(GetDx(btmPt1->Pt, p->Pt));
+
+  p = btmPt2->Prev;
+  while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Prev;
+  double dx2p = std::fabs(GetDx(btmPt2->Pt, p->Pt));
+  p = btmPt2->Next;
+  while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Next;
+  double dx2n = std::fabs(GetDx(btmPt2->Pt, p->Pt));
+
+  if (std::max(dx1p, dx1n) == std::max(dx2p, dx2n) &&
+    std::min(dx1p, dx1n) == std::min(dx2p, dx2n))
+      return Area(btmPt1) > 0; //if otherwise identical use orientation
+  else
+    return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
+}
+//------------------------------------------------------------------------------
+
+OutPt* GetBottomPt(OutPt *pp)
+{
+  OutPt* dups = 0;
+  OutPt* p = pp->Next;
+  while (p != pp)
+  {
+    if (p->Pt.Y > pp->Pt.Y)
+    {
+      pp = p;
+      dups = 0;
+    }
+    else if (p->Pt.Y == pp->Pt.Y && p->Pt.X <= pp->Pt.X)
+    {
+      if (p->Pt.X < pp->Pt.X)
+      {
+        dups = 0;
+        pp = p;
+      } else
+      {
+        if (p->Next != pp && p->Prev != pp) dups = p;
+      }
+    }
+    p = p->Next;
+  }
+  if (dups)
+  {
+    //there appears to be at least 2 vertices at BottomPt so ...
+    while (dups != p)
+    {
+      if (!FirstIsBottomPt(p, dups)) pp = dups;
+      dups = dups->Next;
+      while (dups->Pt != pp->Pt) dups = dups->Next;
+    }
+  }
+  return pp;
+}
+//------------------------------------------------------------------------------
+
+bool Pt2IsBetweenPt1AndPt3(const IntPoint pt1,
+  const IntPoint pt2, const IntPoint pt3)
+{
+  if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2))
+    return false;
+  else if (pt1.X != pt3.X)
+    return (pt2.X > pt1.X) == (pt2.X < pt3.X);
+  else
+    return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y);
+}
+//------------------------------------------------------------------------------
+
+bool HorzSegmentsOverlap(cInt seg1a, cInt seg1b, cInt seg2a, cInt seg2b)
+{
+  if (seg1a > seg1b) std::swap(seg1a, seg1b);
+  if (seg2a > seg2b) std::swap(seg2a, seg2b);
+  return (seg1a < seg2b) && (seg2a < seg1b);
+}
+
+//------------------------------------------------------------------------------
+// ClipperBase class methods ...
+//------------------------------------------------------------------------------
+
+ClipperBase::ClipperBase() //constructor
+{
+  m_CurrentLM = m_MinimaList.begin(); //begin() == end() here
+  m_UseFullRange = false;
+}
+//------------------------------------------------------------------------------
+
+ClipperBase::~ClipperBase() //destructor
+{
+  Clear();
+}
+//------------------------------------------------------------------------------
+
+void RangeTest(const IntPoint& Pt, bool& useFullRange)
+{
+  if (useFullRange)
+  {
+    if (Pt.X > hiRange || Pt.Y > hiRange || -Pt.X > hiRange || -Pt.Y > hiRange) 
+      throw clipperException("Coordinate outside allowed range");
+  }
+  else if (Pt.X > loRange|| Pt.Y > loRange || -Pt.X > loRange || -Pt.Y > loRange) 
+  {
+    useFullRange = true;
+    RangeTest(Pt, useFullRange);
+  }
+}
+//------------------------------------------------------------------------------
+
+TEdge* FindNextLocMin(TEdge* E)
+{
+  for (;;)
+  {
+    while (E->Bot != E->Prev->Bot || E->Curr == E->Top) E = E->Next;
+    if (!IsHorizontal(*E) && !IsHorizontal(*E->Prev)) break;
+    while (IsHorizontal(*E->Prev)) E = E->Prev;
+    TEdge* E2 = E;
+    while (IsHorizontal(*E)) E = E->Next;
+    if (E->Top.Y == E->Prev->Bot.Y) continue; //ie just an intermediate horz.
+    if (E2->Prev->Bot.X < E->Bot.X) E = E2;
+    break;
+  }
+  return E;
+}
+//------------------------------------------------------------------------------
+
+TEdge* ClipperBase::ProcessBound(TEdge* E, bool NextIsForward)
+{
+  TEdge *Result = E;
+  TEdge *Horz = 0;
+
+  if (E->OutIdx == Skip)
+  {
+    //if edges still remain in the current bound beyond the skip edge then
+    //create another LocMin and call ProcessBound once more
+    if (NextIsForward)
+    {
+      while (E->Top.Y == E->Next->Bot.Y) E = E->Next;
+      //don't include top horizontals when parsing a bound a second time,
+      //they will be contained in the opposite bound ...
+      while (E != Result && IsHorizontal(*E)) E = E->Prev;
+    }
+    else
+    {
+      while (E->Top.Y == E->Prev->Bot.Y) E = E->Prev;
+      while (E != Result && IsHorizontal(*E)) E = E->Next;
+    }
+
+    if (E == Result)
+    {
+      if (NextIsForward) Result = E->Next;
+      else Result = E->Prev;
+    }
+    else
+    {
+      //there are more edges in the bound beyond result starting with E
+      if (NextIsForward)
+        E = Result->Next;
+      else
+        E = Result->Prev;
+      MinimaList::value_type locMin;
+      locMin.Y = E->Bot.Y;
+      locMin.LeftBound = 0;
+      locMin.RightBound = E;
+      E->WindDelta = 0;
+      Result = ProcessBound(E, NextIsForward);
+      m_MinimaList.push_back(locMin);
+    }
+    return Result;
+  }
+
+  TEdge *EStart;
+
+  if (IsHorizontal(*E))
+  {
+    //We need to be careful with open paths because this may not be a
+    //true local minima (ie E may be following a skip edge).
+    //Also, consecutive horz. edges may start heading left before going right.
+    if (NextIsForward) 
+      EStart = E->Prev;
+    else 
+      EStart = E->Next;
+    if (IsHorizontal(*EStart)) //ie an adjoining horizontal skip edge
+      {
+        if (EStart->Bot.X != E->Bot.X && EStart->Top.X != E->Bot.X)
+          ReverseHorizontal(*E);
+      }
+      else if (EStart->Bot.X != E->Bot.X)
+        ReverseHorizontal(*E);
+  }
+  
+  EStart = E;
+  if (NextIsForward)
+  {
+    while (Result->Top.Y == Result->Next->Bot.Y && Result->Next->OutIdx != Skip)
+      Result = Result->Next;
+    if (IsHorizontal(*Result) && Result->Next->OutIdx != Skip)
+    {
+      //nb: at the top of a bound, horizontals are added to the bound
+      //only when the preceding edge attaches to the horizontal's left vertex
+      //unless a Skip edge is encountered when that becomes the top divide
+      Horz = Result;
+      while (IsHorizontal(*Horz->Prev)) Horz = Horz->Prev;
+      if (Horz->Prev->Top.X > Result->Next->Top.X) Result = Horz->Prev;
+    }
+    while (E != Result) 
+    {
+      E->NextInLML = E->Next;
+      if (IsHorizontal(*E) && E != EStart &&
+        E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
+      E = E->Next;
+    }
+    if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Prev->Top.X) 
+      ReverseHorizontal(*E);
+    Result = Result->Next; //move to the edge just beyond current bound
+  } else
+  {
+    while (Result->Top.Y == Result->Prev->Bot.Y && Result->Prev->OutIdx != Skip) 
+      Result = Result->Prev;
+    if (IsHorizontal(*Result) && Result->Prev->OutIdx != Skip)
+    {
+      Horz = Result;
+      while (IsHorizontal(*Horz->Next)) Horz = Horz->Next;
+      if (Horz->Next->Top.X == Result->Prev->Top.X ||
+          Horz->Next->Top.X > Result->Prev->Top.X) Result = Horz->Next;
+    }
+
+    while (E != Result)
+    {
+      E->NextInLML = E->Prev;
+      if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X) 
+        ReverseHorizontal(*E);
+      E = E->Prev;
+    }
+    if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X) 
+      ReverseHorizontal(*E);
+    Result = Result->Prev; //move to the edge just beyond current bound
+  }
+
+  return Result;
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::AddPath(const Path &pg, PolyType PolyTyp, bool Closed)
+{
+#ifdef use_lines
+  if (!Closed && PolyTyp == ptClip)
+    throw clipperException("AddPath: Open paths must be subject.");
+#else
+  if (!Closed)
+    throw clipperException("AddPath: Open paths have been disabled.");
+#endif
+
+  int highI = (int)pg.size() -1;
+  if (Closed) while (highI > 0 && (pg[highI] == pg[0])) --highI;
+  while (highI > 0 && (pg[highI] == pg[highI -1])) --highI;
+  if ((Closed && highI < 2) || (!Closed && highI < 1)) return false;
+
+  //create a new edge array ...
+  TEdge *edges = new TEdge [highI +1];
+
+  bool IsFlat = true;
+  //1. Basic (first) edge initialization ...
+  try
+  {
+    edges[1].Curr = pg[1];
+    RangeTest(pg[0], m_UseFullRange);
+    RangeTest(pg[highI], m_UseFullRange);
+    InitEdge(&edges[0], &edges[1], &edges[highI], pg[0]);
+    InitEdge(&edges[highI], &edges[0], &edges[highI-1], pg[highI]);
+    for (int i = highI - 1; i >= 1; --i)
+    {
+      RangeTest(pg[i], m_UseFullRange);
+      InitEdge(&edges[i], &edges[i+1], &edges[i-1], pg[i]);
+    }
+  }
+  catch(...)
+  {
+    delete [] edges;
+    throw; //range test fails
+  }
+  TEdge *eStart = &edges[0];
+
+  //2. Remove duplicate vertices, and (when closed) collinear edges ...
+  TEdge *E = eStart, *eLoopStop = eStart;
+  for (;;)
+  {
+    //nb: allows matching start and end points when not Closed ...
+    if (E->Curr == E->Next->Curr && (Closed || E->Next != eStart))
+    {
+      if (E == E->Next) break;
+      if (E == eStart) eStart = E->Next;
+      E = RemoveEdge(E);
+      eLoopStop = E;
+      continue;
+    }
+    if (E->Prev == E->Next) 
+      break; //only two vertices
+    else if (Closed &&
+      SlopesEqual(E->Prev->Curr, E->Curr, E->Next->Curr, m_UseFullRange) && 
+      (!m_PreserveCollinear ||
+      !Pt2IsBetweenPt1AndPt3(E->Prev->Curr, E->Curr, E->Next->Curr)))
+    {
+      //Collinear edges are allowed for open paths but in closed paths
+      //the default is to merge adjacent collinear edges into a single edge.
+      //However, if the PreserveCollinear property is enabled, only overlapping
+      //collinear edges (ie spikes) will be removed from closed paths.
+      if (E == eStart) eStart = E->Next;
+      E = RemoveEdge(E);
+      E = E->Prev;
+      eLoopStop = E;
+      continue;
+    }
+    E = E->Next;
+    if ((E == eLoopStop) || (!Closed && E->Next == eStart)) break;
+  }
+
+  if ((!Closed && (E == E->Next)) || (Closed && (E->Prev == E->Next)))
+  {
+    delete [] edges;
+    return false;
+  }
+
+  if (!Closed)
+  { 
+    m_HasOpenPaths = true;
+    eStart->Prev->OutIdx = Skip;
+  }
+
+  //3. Do second stage of edge initialization ...
+  E = eStart;
+  do
+  {
+    InitEdge2(*E, PolyTyp);
+    E = E->Next;
+    if (IsFlat && E->Curr.Y != eStart->Curr.Y) IsFlat = false;
+  }
+  while (E != eStart);
+
+  //4. Finally, add edge bounds to LocalMinima list ...
+
+  //Totally flat paths must be handled differently when adding them
+  //to LocalMinima list to avoid endless loops etc ...
+  if (IsFlat) 
+  {
+    if (Closed) 
+    {
+      delete [] edges;
+      return false;
+    }
+    E->Prev->OutIdx = Skip;
+    MinimaList::value_type locMin;
+    locMin.Y = E->Bot.Y;
+    locMin.LeftBound = 0;
+    locMin.RightBound = E;
+    locMin.RightBound->Side = esRight;
+    locMin.RightBound->WindDelta = 0;
+    for (;;)
+    {
+      if (E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
+      if (E->Next->OutIdx == Skip) break;
+      E->NextInLML = E->Next;
+      E = E->Next;
+    }
+    m_MinimaList.push_back(locMin);
+    m_edges.push_back(edges);
+	  return true;
+  }
+
+  m_edges.push_back(edges);
+  bool leftBoundIsForward;
+  TEdge* EMin = 0;
+
+  //workaround to avoid an endless loop in the while loop below when
+  //open paths have matching start and end points ...
+  if (E->Prev->Bot == E->Prev->Top) E = E->Next;
+
+  for (;;)
+  {
+    E = FindNextLocMin(E);
+    if (E == EMin) break;
+    else if (!EMin) EMin = E;
+
+    //E and E.Prev now share a local minima (left aligned if horizontal).
+    //Compare their slopes to find which starts which bound ...
+    MinimaList::value_type locMin;
+    locMin.Y = E->Bot.Y;
+    if (E->Dx < E->Prev->Dx) 
+    {
+      locMin.LeftBound = E->Prev;
+      locMin.RightBound = E;
+      leftBoundIsForward = false; //Q.nextInLML = Q.prev
+    } else
+    {
+      locMin.LeftBound = E;
+      locMin.RightBound = E->Prev;
+      leftBoundIsForward = true; //Q.nextInLML = Q.next
+    }
+
+    if (!Closed) locMin.LeftBound->WindDelta = 0;
+    else if (locMin.LeftBound->Next == locMin.RightBound)
+      locMin.LeftBound->WindDelta = -1;
+    else locMin.LeftBound->WindDelta = 1;
+    locMin.RightBound->WindDelta = -locMin.LeftBound->WindDelta;
+
+    E = ProcessBound(locMin.LeftBound, leftBoundIsForward);
+    if (E->OutIdx == Skip) E = ProcessBound(E, leftBoundIsForward);
+
+    TEdge* E2 = ProcessBound(locMin.RightBound, !leftBoundIsForward);
+    if (E2->OutIdx == Skip) E2 = ProcessBound(E2, !leftBoundIsForward);
+
+    if (locMin.LeftBound->OutIdx == Skip)
+      locMin.LeftBound = 0;
+    else if (locMin.RightBound->OutIdx == Skip)
+      locMin.RightBound = 0;
+    m_MinimaList.push_back(locMin);
+    if (!leftBoundIsForward) E = E2;
+  }
+  return true;
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed)
+{
+  bool result = false;
+  for (Paths::size_type i = 0; i < ppg.size(); ++i)
+    if (AddPath(ppg[i], PolyTyp, Closed)) result = true;
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::Clear()
+{
+  DisposeLocalMinimaList();
+  for (EdgeList::size_type i = 0; i < m_edges.size(); ++i)
+  {
+    TEdge* edges = m_edges[i];
+    delete [] edges;
+  }
+  m_edges.clear();
+  m_UseFullRange = false;
+  m_HasOpenPaths = false;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::Reset()
+{
+  m_CurrentLM = m_MinimaList.begin();
+  if (m_CurrentLM == m_MinimaList.end()) return; //ie nothing to process
+  std::sort(m_MinimaList.begin(), m_MinimaList.end(), LocMinSorter());
+
+  m_Scanbeam = ScanbeamList(); //clears/resets priority_queue
+  //reset all edges ...
+  for (MinimaList::iterator lm = m_MinimaList.begin(); lm != m_MinimaList.end(); ++lm)
+  {
+    InsertScanbeam(lm->Y);
+    TEdge* e = lm->LeftBound;
+    if (e)
+    {
+      e->Curr = e->Bot;
+      e->Side = esLeft;
+      e->OutIdx = Unassigned;
+    }
+
+    e = lm->RightBound;
+    if (e)
+    {
+      e->Curr = e->Bot;
+      e->Side = esRight;
+      e->OutIdx = Unassigned;
+    }
+  }
+  m_ActiveEdges = 0;
+  m_CurrentLM = m_MinimaList.begin();
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::DisposeLocalMinimaList()
+{
+  m_MinimaList.clear();
+  m_CurrentLM = m_MinimaList.begin();
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::PopLocalMinima(cInt Y, const LocalMinimum *&locMin)
+{
+  if (m_CurrentLM == m_MinimaList.end() || (*m_CurrentLM).Y != Y) return false;
+  locMin = &(*m_CurrentLM);
+  ++m_CurrentLM;
+  return true;
+}
+//------------------------------------------------------------------------------
+
+IntRect ClipperBase::GetBounds()
+{
+  IntRect result;
+  MinimaList::iterator lm = m_MinimaList.begin();
+  if (lm == m_MinimaList.end())
+  {
+    result.left = result.top = result.right = result.bottom = 0;
+    return result;
+  }
+  result.left = lm->LeftBound->Bot.X;
+  result.top = lm->LeftBound->Bot.Y;
+  result.right = lm->LeftBound->Bot.X;
+  result.bottom = lm->LeftBound->Bot.Y;
+  while (lm != m_MinimaList.end())
+  {
+    //todo - needs fixing for open paths
+    result.bottom = std::max(result.bottom, lm->LeftBound->Bot.Y);
+    TEdge* e = lm->LeftBound;
+    for (;;) {
+      TEdge* bottomE = e;
+      while (e->NextInLML)
+      {
+        if (e->Bot.X < result.left) result.left = e->Bot.X;
+        if (e->Bot.X > result.right) result.right = e->Bot.X;
+        e = e->NextInLML;
+      }
+      result.left = std::min(result.left, e->Bot.X);
+      result.right = std::max(result.right, e->Bot.X);
+      result.left = std::min(result.left, e->Top.X);
+      result.right = std::max(result.right, e->Top.X);
+      result.top = std::min(result.top, e->Top.Y);
+      if (bottomE == lm->LeftBound) e = lm->RightBound;
+      else break;
+    }
+    ++lm;
+  }
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::InsertScanbeam(const cInt Y)
+{
+  m_Scanbeam.push(Y);
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::PopScanbeam(cInt &Y)
+{
+  if (m_Scanbeam.empty()) return false;
+  Y = m_Scanbeam.top();
+  m_Scanbeam.pop();
+  while (!m_Scanbeam.empty() && Y == m_Scanbeam.top()) { m_Scanbeam.pop(); } // Pop duplicates.
+  return true;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::DisposeAllOutRecs(){
+  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+    DisposeOutRec(i);
+  m_PolyOuts.clear();
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::DisposeOutRec(PolyOutList::size_type index)
+{
+  OutRec *outRec = m_PolyOuts[index];
+  if (outRec->Pts) DisposeOutPts(outRec->Pts);
+  delete outRec;
+  m_PolyOuts[index] = 0;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::DeleteFromAEL(TEdge *e)
+{
+  TEdge* AelPrev = e->PrevInAEL;
+  TEdge* AelNext = e->NextInAEL;
+  if (!AelPrev &&  !AelNext && (e != m_ActiveEdges)) return; //already deleted
+  if (AelPrev) AelPrev->NextInAEL = AelNext;
+  else m_ActiveEdges = AelNext;
+  if (AelNext) AelNext->PrevInAEL = AelPrev;
+  e->NextInAEL = 0;
+  e->PrevInAEL = 0;
+}
+//------------------------------------------------------------------------------
+
+OutRec* ClipperBase::CreateOutRec()
+{
+  OutRec* result = new OutRec;
+  result->IsHole = false;
+  result->IsOpen = false;
+  result->FirstLeft = 0;
+  result->Pts = 0;
+  result->BottomPt = 0;
+  result->PolyNd = 0;
+  m_PolyOuts.push_back(result);
+  result->Idx = (int)m_PolyOuts.size() - 1;
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::SwapPositionsInAEL(TEdge *Edge1, TEdge *Edge2)
+{
+  //check that one or other edge hasn't already been removed from AEL ...
+  if (Edge1->NextInAEL == Edge1->PrevInAEL ||
+    Edge2->NextInAEL == Edge2->PrevInAEL) return;
+
+  if (Edge1->NextInAEL == Edge2)
+  {
+    TEdge* Next = Edge2->NextInAEL;
+    if (Next) Next->PrevInAEL = Edge1;
+    TEdge* Prev = Edge1->PrevInAEL;
+    if (Prev) Prev->NextInAEL = Edge2;
+    Edge2->PrevInAEL = Prev;
+    Edge2->NextInAEL = Edge1;
+    Edge1->PrevInAEL = Edge2;
+    Edge1->NextInAEL = Next;
+  }
+  else if (Edge2->NextInAEL == Edge1)
+  {
+    TEdge* Next = Edge1->NextInAEL;
+    if (Next) Next->PrevInAEL = Edge2;
+    TEdge* Prev = Edge2->PrevInAEL;
+    if (Prev) Prev->NextInAEL = Edge1;
+    Edge1->PrevInAEL = Prev;
+    Edge1->NextInAEL = Edge2;
+    Edge2->PrevInAEL = Edge1;
+    Edge2->NextInAEL = Next;
+  }
+  else
+  {
+    TEdge* Next = Edge1->NextInAEL;
+    TEdge* Prev = Edge1->PrevInAEL;
+    Edge1->NextInAEL = Edge2->NextInAEL;
+    if (Edge1->NextInAEL) Edge1->NextInAEL->PrevInAEL = Edge1;
+    Edge1->PrevInAEL = Edge2->PrevInAEL;
+    if (Edge1->PrevInAEL) Edge1->PrevInAEL->NextInAEL = Edge1;
+    Edge2->NextInAEL = Next;
+    if (Edge2->NextInAEL) Edge2->NextInAEL->PrevInAEL = Edge2;
+    Edge2->PrevInAEL = Prev;
+    if (Edge2->PrevInAEL) Edge2->PrevInAEL->NextInAEL = Edge2;
+  }
+
+  if (!Edge1->PrevInAEL) m_ActiveEdges = Edge1;
+  else if (!Edge2->PrevInAEL) m_ActiveEdges = Edge2;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::UpdateEdgeIntoAEL(TEdge *&e)
+{
+  if (!e->NextInLML) 
+    throw clipperException("UpdateEdgeIntoAEL: invalid call");
+
+  e->NextInLML->OutIdx = e->OutIdx;
+  TEdge* AelPrev = e->PrevInAEL;
+  TEdge* AelNext = e->NextInAEL;
+  if (AelPrev) AelPrev->NextInAEL = e->NextInLML;
+  else m_ActiveEdges = e->NextInLML;
+  if (AelNext) AelNext->PrevInAEL = e->NextInLML;
+  e->NextInLML->Side = e->Side;
+  e->NextInLML->WindDelta = e->WindDelta;
+  e->NextInLML->WindCnt = e->WindCnt;
+  e->NextInLML->WindCnt2 = e->WindCnt2;
+  e = e->NextInLML;
+  e->Curr = e->Bot;
+  e->PrevInAEL = AelPrev;
+  e->NextInAEL = AelNext;
+  if (!IsHorizontal(*e)) InsertScanbeam(e->Top.Y);
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::LocalMinimaPending()
+{
+  return (m_CurrentLM != m_MinimaList.end());
+}
+
+//------------------------------------------------------------------------------
+// TClipper methods ...
+//------------------------------------------------------------------------------
+
+Clipper::Clipper(int initOptions) : ClipperBase() //constructor
+{
+  m_ExecuteLocked = false;
+  m_UseFullRange = false;
+  m_ReverseOutput = ((initOptions & ioReverseSolution) != 0);
+  m_StrictSimple = ((initOptions & ioStrictlySimple) != 0);
+  m_PreserveCollinear = ((initOptions & ioPreserveCollinear) != 0);
+  m_HasOpenPaths = false;
+#ifdef use_xyz  
+  m_ZFill = 0;
+#endif
+}
+//------------------------------------------------------------------------------
+
+#ifdef use_xyz  
+void Clipper::ZFillFunction(ZFillCallback zFillFunc)
+{  
+  m_ZFill = zFillFunc;
+}
+//------------------------------------------------------------------------------
+#endif
+
+bool Clipper::Execute(ClipType clipType, Paths &solution, PolyFillType fillType)
+{
+    return Execute(clipType, solution, fillType, fillType);
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::Execute(ClipType clipType, PolyTree &polytree, PolyFillType fillType)
+{
+    return Execute(clipType, polytree, fillType, fillType);
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::Execute(ClipType clipType, Paths &solution,
+    PolyFillType subjFillType, PolyFillType clipFillType)
+{
+  if( m_ExecuteLocked ) return false;
+  if (m_HasOpenPaths)
+    throw clipperException("Error: PolyTree struct is needed for open path clipping.");
+  m_ExecuteLocked = true;
+  solution.resize(0);
+  m_SubjFillType = subjFillType;
+  m_ClipFillType = clipFillType;
+  m_ClipType = clipType;
+  m_UsingPolyTree = false;
+  bool succeeded = ExecuteInternal();
+  if (succeeded) BuildResult(solution);
+  DisposeAllOutRecs();
+  m_ExecuteLocked = false;
+  return succeeded;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::Execute(ClipType clipType, PolyTree& polytree,
+    PolyFillType subjFillType, PolyFillType clipFillType)
+{
+  if( m_ExecuteLocked ) return false;
+  m_ExecuteLocked = true;
+  m_SubjFillType = subjFillType;
+  m_ClipFillType = clipFillType;
+  m_ClipType = clipType;
+  m_UsingPolyTree = true;
+  bool succeeded = ExecuteInternal();
+  if (succeeded) BuildResult2(polytree);
+  DisposeAllOutRecs();
+  m_ExecuteLocked = false;
+  return succeeded;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::FixHoleLinkage(OutRec &outrec)
+{
+  //skip OutRecs that (a) contain outermost polygons or
+  //(b) already have the correct owner/child linkage ...
+  if (!outrec.FirstLeft ||                
+      (outrec.IsHole != outrec.FirstLeft->IsHole &&
+      outrec.FirstLeft->Pts)) return;
+
+  OutRec* orfl = outrec.FirstLeft;
+  while (orfl && ((orfl->IsHole == outrec.IsHole) || !orfl->Pts))
+      orfl = orfl->FirstLeft;
+  outrec.FirstLeft = orfl;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::ExecuteInternal()
+{
+  bool succeeded = true;
+  try {
+    Reset();
+    m_Maxima = MaximaList();
+    m_SortedEdges = 0;
+
+    succeeded = true;
+    cInt botY, topY;
+    if (!PopScanbeam(botY)) return false;
+    InsertLocalMinimaIntoAEL(botY);
+    while (PopScanbeam(topY) || LocalMinimaPending())
+    {
+      ProcessHorizontals();
+	    ClearGhostJoins();
+      if (!ProcessIntersections(topY))
+      {
+        succeeded = false;
+        break;
+      }
+      ProcessEdgesAtTopOfScanbeam(topY);
+      botY = topY;
+      InsertLocalMinimaIntoAEL(botY);
+    }
+  }
+  catch(...) 
+  {
+    succeeded = false;
+  }
+
+  if (succeeded)
+  {
+    //fix orientations ...
+    for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+    {
+      OutRec *outRec = m_PolyOuts[i];
+      if (!outRec->Pts || outRec->IsOpen) continue;
+      if ((outRec->IsHole ^ m_ReverseOutput) == (Area(*outRec) > 0))
+        ReversePolyPtLinks(outRec->Pts);
+    }
+
+    if (!m_Joins.empty()) JoinCommonEdges();
+
+    //unfortunately FixupOutPolygon() must be done after JoinCommonEdges()
+    for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+    {
+      OutRec *outRec = m_PolyOuts[i];
+      if (!outRec->Pts) continue;
+      if (outRec->IsOpen)
+        FixupOutPolyline(*outRec);
+      else
+        FixupOutPolygon(*outRec);
+    }
+
+    if (m_StrictSimple) DoSimplePolygons();
+  }
+
+  ClearJoins();
+  ClearGhostJoins();
+  return succeeded;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::SetWindingCount(TEdge &edge)
+{
+  TEdge *e = edge.PrevInAEL;
+  //find the edge of the same polytype that immediately preceeds 'edge' in AEL
+  while (e  && ((e->PolyTyp != edge.PolyTyp) || (e->WindDelta == 0))) e = e->PrevInAEL;
+  if (!e)
+  {
+    if (edge.WindDelta == 0)
+    {
+      PolyFillType pft = (edge.PolyTyp == ptSubject ? m_SubjFillType : m_ClipFillType);
+      edge.WindCnt = (pft == pftNegative ? -1 : 1);
+    }
+    else
+      edge.WindCnt = edge.WindDelta;
+    edge.WindCnt2 = 0;
+    e = m_ActiveEdges; //ie get ready to calc WindCnt2
+  }   
+  else if (edge.WindDelta == 0 && m_ClipType != ctUnion)
+  {
+    edge.WindCnt = 1;
+    edge.WindCnt2 = e->WindCnt2;
+    e = e->NextInAEL; //ie get ready to calc WindCnt2
+  }
+  else if (IsEvenOddFillType(edge))
+  {
+    //EvenOdd filling ...
+    if (edge.WindDelta == 0)
+    {
+      //are we inside a subj polygon ...
+      bool Inside = true;
+      TEdge *e2 = e->PrevInAEL;
+      while (e2)
+      {
+        if (e2->PolyTyp == e->PolyTyp && e2->WindDelta != 0) 
+          Inside = !Inside;
+        e2 = e2->PrevInAEL;
+      }
+      edge.WindCnt = (Inside ? 0 : 1);
+    }
+    else
+    {
+      edge.WindCnt = edge.WindDelta;
+    }
+    edge.WindCnt2 = e->WindCnt2;
+    e = e->NextInAEL; //ie get ready to calc WindCnt2
+  } 
+  else
+  {
+    //nonZero, Positive or Negative filling ...
+    if (e->WindCnt * e->WindDelta < 0)
+    {
+      //prev edge is 'decreasing' WindCount (WC) toward zero
+      //so we're outside the previous polygon ...
+      if (Abs(e->WindCnt) > 1)
+      {
+        //outside prev poly but still inside another.
+        //when reversing direction of prev poly use the same WC 
+        if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
+        //otherwise continue to 'decrease' WC ...
+        else edge.WindCnt = e->WindCnt + edge.WindDelta;
+      } 
+      else
+        //now outside all polys of same polytype so set own WC ...
+        edge.WindCnt = (edge.WindDelta == 0 ? 1 : edge.WindDelta);
+    } else
+    {
+      //prev edge is 'increasing' WindCount (WC) away from zero
+      //so we're inside the previous polygon ...
+      if (edge.WindDelta == 0) 
+        edge.WindCnt = (e->WindCnt < 0 ? e->WindCnt - 1 : e->WindCnt + 1);
+      //if wind direction is reversing prev then use same WC
+      else if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
+      //otherwise add to WC ...
+      else edge.WindCnt = e->WindCnt + edge.WindDelta;
+    }
+    edge.WindCnt2 = e->WindCnt2;
+    e = e->NextInAEL; //ie get ready to calc WindCnt2
+  }
+
+  //update WindCnt2 ...
+  if (IsEvenOddAltFillType(edge))
+  {
+    //EvenOdd filling ...
+    while (e != &edge)
+    {
+      if (e->WindDelta != 0)
+        edge.WindCnt2 = (edge.WindCnt2 == 0 ? 1 : 0);
+      e = e->NextInAEL;
+    }
+  } else
+  {
+    //nonZero, Positive or Negative filling ...
+    while ( e != &edge )
+    {
+      edge.WindCnt2 += e->WindDelta;
+      e = e->NextInAEL;
+    }
+  }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsEvenOddFillType(const TEdge& edge) const
+{
+  if (edge.PolyTyp == ptSubject)
+    return m_SubjFillType == pftEvenOdd; else
+    return m_ClipFillType == pftEvenOdd;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsEvenOddAltFillType(const TEdge& edge) const
+{
+  if (edge.PolyTyp == ptSubject)
+    return m_ClipFillType == pftEvenOdd; else
+    return m_SubjFillType == pftEvenOdd;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsContributing(const TEdge& edge) const
+{
+  PolyFillType pft, pft2;
+  if (edge.PolyTyp == ptSubject)
+  {
+    pft = m_SubjFillType;
+    pft2 = m_ClipFillType;
+  } else
+  {
+    pft = m_ClipFillType;
+    pft2 = m_SubjFillType;
+  }
+
+  switch(pft)
+  {
+    case pftEvenOdd: 
+      //return false if a subj line has been flagged as inside a subj polygon
+      if (edge.WindDelta == 0 && edge.WindCnt != 1) return false;
+      break;
+    case pftNonZero:
+      if (Abs(edge.WindCnt) != 1) return false;
+      break;
+    case pftPositive: 
+      if (edge.WindCnt != 1) return false;
+      break;
+    default: //pftNegative
+      if (edge.WindCnt != -1) return false;
+  }
+
+  switch(m_ClipType)
+  {
+    case ctIntersection:
+      switch(pft2)
+      {
+        case pftEvenOdd: 
+        case pftNonZero: 
+          return (edge.WindCnt2 != 0);
+        case pftPositive: 
+          return (edge.WindCnt2 > 0);
+        default: 
+          return (edge.WindCnt2 < 0);
+      }
+      break;
+    case ctUnion:
+      switch(pft2)
+      {
+        case pftEvenOdd: 
+        case pftNonZero: 
+          return (edge.WindCnt2 == 0);
+        case pftPositive: 
+          return (edge.WindCnt2 <= 0);
+        default: 
+          return (edge.WindCnt2 >= 0);
+      }
+      break;
+    case ctDifference:
+      if (edge.PolyTyp == ptSubject)
+        switch(pft2)
+        {
+          case pftEvenOdd: 
+          case pftNonZero: 
+            return (edge.WindCnt2 == 0);
+          case pftPositive: 
+            return (edge.WindCnt2 <= 0);
+          default: 
+            return (edge.WindCnt2 >= 0);
+        }
+      else
+        switch(pft2)
+        {
+          case pftEvenOdd: 
+          case pftNonZero: 
+            return (edge.WindCnt2 != 0);
+          case pftPositive: 
+            return (edge.WindCnt2 > 0);
+          default: 
+            return (edge.WindCnt2 < 0);
+        }
+      break;
+    case ctXor:
+      if (edge.WindDelta == 0) //XOr always contributing unless open
+        switch(pft2)
+        {
+          case pftEvenOdd: 
+          case pftNonZero: 
+            return (edge.WindCnt2 == 0);
+          case pftPositive: 
+            return (edge.WindCnt2 <= 0);
+          default: 
+            return (edge.WindCnt2 >= 0);
+        }
+      else 
+        return true;
+      break;
+    default:
+      return true;
+  }
+}
+//------------------------------------------------------------------------------
+
+OutPt* Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
+{
+  OutPt* result;
+  TEdge *e, *prevE;
+  if (IsHorizontal(*e2) || ( e1->Dx > e2->Dx ))
+  {
+    result = AddOutPt(e1, Pt);
+    e2->OutIdx = e1->OutIdx;
+    e1->Side = esLeft;
+    e2->Side = esRight;
+    e = e1;
+    if (e->PrevInAEL == e2)
+      prevE = e2->PrevInAEL; 
+    else
+      prevE = e->PrevInAEL;
+  } else
+  {
+    result = AddOutPt(e2, Pt);
+    e1->OutIdx = e2->OutIdx;
+    e1->Side = esRight;
+    e2->Side = esLeft;
+    e = e2;
+    if (e->PrevInAEL == e1)
+        prevE = e1->PrevInAEL;
+    else
+        prevE = e->PrevInAEL;
+  }
+
+  if (prevE && prevE->OutIdx >= 0)
+  {
+    cInt xPrev = TopX(*prevE, Pt.Y);
+    cInt xE = TopX(*e, Pt.Y);
+    if (xPrev == xE && (e->WindDelta != 0) && (prevE->WindDelta != 0) &&
+      SlopesEqual(IntPoint(xPrev, Pt.Y), prevE->Top, IntPoint(xE, Pt.Y), e->Top, m_UseFullRange))
+    {
+      OutPt* outPt = AddOutPt(prevE, Pt);
+      AddJoin(result, outPt, e->Top);
+    }
+  }
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
+{
+  AddOutPt( e1, Pt );
+  if (e2->WindDelta == 0) AddOutPt(e2, Pt);
+  if( e1->OutIdx == e2->OutIdx )
+  {
+    e1->OutIdx = Unassigned;
+    e2->OutIdx = Unassigned;
+  }
+  else if (e1->OutIdx < e2->OutIdx) 
+    AppendPolygon(e1, e2); 
+  else 
+    AppendPolygon(e2, e1);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddEdgeToSEL(TEdge *edge)
+{
+  //SEL pointers in PEdge are reused to build a list of horizontal edges.
+  //However, we don't need to worry about order with horizontal edge processing.
+  if( !m_SortedEdges )
+  {
+    m_SortedEdges = edge;
+    edge->PrevInSEL = 0;
+    edge->NextInSEL = 0;
+  }
+  else
+  {
+    edge->NextInSEL = m_SortedEdges;
+    edge->PrevInSEL = 0;
+    m_SortedEdges->PrevInSEL = edge;
+    m_SortedEdges = edge;
+  }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::PopEdgeFromSEL(TEdge *&edge)
+{
+  if (!m_SortedEdges) return false;
+  edge = m_SortedEdges;
+  DeleteFromSEL(m_SortedEdges);
+  return true;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::CopyAELToSEL()
+{
+  TEdge* e = m_ActiveEdges;
+  m_SortedEdges = e;
+  while ( e )
+  {
+    e->PrevInSEL = e->PrevInAEL;
+    e->NextInSEL = e->NextInAEL;
+    e = e->NextInAEL;
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddJoin(OutPt *op1, OutPt *op2, const IntPoint OffPt)
+{
+  Join* j = new Join;
+  j->OutPt1 = op1;
+  j->OutPt2 = op2;
+  j->OffPt = OffPt;
+  m_Joins.push_back(j);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ClearJoins()
+{
+  for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+    delete m_Joins[i];
+  m_Joins.resize(0);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ClearGhostJoins()
+{
+  for (JoinList::size_type i = 0; i < m_GhostJoins.size(); i++)
+    delete m_GhostJoins[i];
+  m_GhostJoins.resize(0);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddGhostJoin(OutPt *op, const IntPoint OffPt)
+{
+  Join* j = new Join;
+  j->OutPt1 = op;
+  j->OutPt2 = 0;
+  j->OffPt = OffPt;
+  m_GhostJoins.push_back(j);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::InsertLocalMinimaIntoAEL(const cInt botY)
+{
+  const LocalMinimum *lm;
+  while (PopLocalMinima(botY, lm))
+  {
+    TEdge* lb = lm->LeftBound;
+    TEdge* rb = lm->RightBound;
+    
+    OutPt *Op1 = 0;
+    if (!lb)
+    {
+      //nb: don't insert LB into either AEL or SEL
+      InsertEdgeIntoAEL(rb, 0);
+      SetWindingCount(*rb);
+      if (IsContributing(*rb))
+        Op1 = AddOutPt(rb, rb->Bot); 
+    } 
+    else if (!rb)
+    {
+      InsertEdgeIntoAEL(lb, 0);
+      SetWindingCount(*lb);
+      if (IsContributing(*lb))
+        Op1 = AddOutPt(lb, lb->Bot);
+      InsertScanbeam(lb->Top.Y);
+    }
+    else
+    {
+      InsertEdgeIntoAEL(lb, 0);
+      InsertEdgeIntoAEL(rb, lb);
+      SetWindingCount( *lb );
+      rb->WindCnt = lb->WindCnt;
+      rb->WindCnt2 = lb->WindCnt2;
+      if (IsContributing(*lb))
+        Op1 = AddLocalMinPoly(lb, rb, lb->Bot);      
+      InsertScanbeam(lb->Top.Y);
+    }
+
+     if (rb)
+     {
+		 if (IsHorizontal(*rb))
+		 {
+			 AddEdgeToSEL(rb);
+			 if (rb->NextInLML) 
+				 InsertScanbeam(rb->NextInLML->Top.Y);
+		 }
+		 else InsertScanbeam( rb->Top.Y );
+     }
+
+    if (!lb || !rb) continue;
+
+    //if any output polygons share an edge, they'll need joining later ...
+    if (Op1 && IsHorizontal(*rb) && 
+      m_GhostJoins.size() > 0 && (rb->WindDelta != 0))
+    {
+      for (JoinList::size_type i = 0; i < m_GhostJoins.size(); ++i)
+      {
+        Join* jr = m_GhostJoins[i];
+        //if the horizontal Rb and a 'ghost' horizontal overlap, then convert
+        //the 'ghost' join to a real join ready for later ...
+        if (HorzSegmentsOverlap(jr->OutPt1->Pt.X, jr->OffPt.X, rb->Bot.X, rb->Top.X))
+          AddJoin(jr->OutPt1, Op1, jr->OffPt);
+      }
+    }
+
+    if (lb->OutIdx >= 0 && lb->PrevInAEL && 
+      lb->PrevInAEL->Curr.X == lb->Bot.X &&
+      lb->PrevInAEL->OutIdx >= 0 &&
+      SlopesEqual(lb->PrevInAEL->Bot, lb->PrevInAEL->Top, lb->Curr, lb->Top, m_UseFullRange) &&
+      (lb->WindDelta != 0) && (lb->PrevInAEL->WindDelta != 0))
+    {
+        OutPt *Op2 = AddOutPt(lb->PrevInAEL, lb->Bot);
+        AddJoin(Op1, Op2, lb->Top);
+    }
+
+    if(lb->NextInAEL != rb)
+    {
+
+      if (rb->OutIdx >= 0 && rb->PrevInAEL->OutIdx >= 0 &&
+        SlopesEqual(rb->PrevInAEL->Curr, rb->PrevInAEL->Top, rb->Curr, rb->Top, m_UseFullRange) &&
+        (rb->WindDelta != 0) && (rb->PrevInAEL->WindDelta != 0))
+      {
+          OutPt *Op2 = AddOutPt(rb->PrevInAEL, rb->Bot);
+          AddJoin(Op1, Op2, rb->Top);
+      }
+
+      TEdge* e = lb->NextInAEL;
+      if (e)
+      {
+        while( e != rb )
+        {
+          //nb: For calculating winding counts etc, IntersectEdges() assumes
+          //that param1 will be to the Right of param2 ABOVE the intersection ...
+          IntersectEdges(rb , e , lb->Curr); //order important here
+          e = e->NextInAEL;
+        }
+      }
+    }
+    
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DeleteFromSEL(TEdge *e)
+{
+  TEdge* SelPrev = e->PrevInSEL;
+  TEdge* SelNext = e->NextInSEL;
+  if( !SelPrev &&  !SelNext && (e != m_SortedEdges) ) return; //already deleted
+  if( SelPrev ) SelPrev->NextInSEL = SelNext;
+  else m_SortedEdges = SelNext;
+  if( SelNext ) SelNext->PrevInSEL = SelPrev;
+  e->NextInSEL = 0;
+  e->PrevInSEL = 0;
+}
+//------------------------------------------------------------------------------
+
+#ifdef use_xyz
+void Clipper::SetZ(IntPoint& pt, TEdge& e1, TEdge& e2)
+{
+  if (pt.Z != 0 || !m_ZFill) return;
+  else if (pt == e1.Bot) pt.Z = e1.Bot.Z;
+  else if (pt == e1.Top) pt.Z = e1.Top.Z;
+  else if (pt == e2.Bot) pt.Z = e2.Bot.Z;
+  else if (pt == e2.Top) pt.Z = e2.Top.Z;
+  else (*m_ZFill)(e1.Bot, e1.Top, e2.Bot, e2.Top, pt); 
+}
+//------------------------------------------------------------------------------
+#endif
+
+void Clipper::IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &Pt)
+{
+  bool e1Contributing = ( e1->OutIdx >= 0 );
+  bool e2Contributing = ( e2->OutIdx >= 0 );
+
+#ifdef use_xyz
+        SetZ(Pt, *e1, *e2);
+#endif
+
+#ifdef use_lines
+  //if either edge is on an OPEN path ...
+  if (e1->WindDelta == 0 || e2->WindDelta == 0)
+  {
+    //ignore subject-subject open path intersections UNLESS they
+    //are both open paths, AND they are both 'contributing maximas' ...
+	if (e1->WindDelta == 0 && e2->WindDelta == 0) return;
+
+    //if intersecting a subj line with a subj poly ...
+    else if (e1->PolyTyp == e2->PolyTyp && 
+      e1->WindDelta != e2->WindDelta && m_ClipType == ctUnion)
+    {
+      if (e1->WindDelta == 0)
+      {
+        if (e2Contributing)
+        {
+          AddOutPt(e1, Pt);
+          if (e1Contributing) e1->OutIdx = Unassigned;
+        }
+      }
+      else
+      {
+        if (e1Contributing)
+        {
+          AddOutPt(e2, Pt);
+          if (e2Contributing) e2->OutIdx = Unassigned;
+        }
+      }
+    }
+    else if (e1->PolyTyp != e2->PolyTyp)
+    {
+      //toggle subj open path OutIdx on/off when Abs(clip.WndCnt) == 1 ...
+      if ((e1->WindDelta == 0) && abs(e2->WindCnt) == 1 && 
+        (m_ClipType != ctUnion || e2->WindCnt2 == 0))
+      {
+        AddOutPt(e1, Pt);
+        if (e1Contributing) e1->OutIdx = Unassigned;
+      }
+      else if ((e2->WindDelta == 0) && (abs(e1->WindCnt) == 1) && 
+        (m_ClipType != ctUnion || e1->WindCnt2 == 0))
+      {
+        AddOutPt(e2, Pt);
+        if (e2Contributing) e2->OutIdx = Unassigned;
+      }
+    }
+    return;
+  }
+#endif
+
+  //update winding counts...
+  //assumes that e1 will be to the Right of e2 ABOVE the intersection
+  if ( e1->PolyTyp == e2->PolyTyp )
+  {
+    if ( IsEvenOddFillType( *e1) )
+    {
+      int oldE1WindCnt = e1->WindCnt;
+      e1->WindCnt = e2->WindCnt;
+      e2->WindCnt = oldE1WindCnt;
+    } else
+    {
+      if (e1->WindCnt + e2->WindDelta == 0 ) e1->WindCnt = -e1->WindCnt;
+      else e1->WindCnt += e2->WindDelta;
+      if ( e2->WindCnt - e1->WindDelta == 0 ) e2->WindCnt = -e2->WindCnt;
+      else e2->WindCnt -= e1->WindDelta;
+    }
+  } else
+  {
+    if (!IsEvenOddFillType(*e2)) e1->WindCnt2 += e2->WindDelta;
+    else e1->WindCnt2 = ( e1->WindCnt2 == 0 ) ? 1 : 0;
+    if (!IsEvenOddFillType(*e1)) e2->WindCnt2 -= e1->WindDelta;
+    else e2->WindCnt2 = ( e2->WindCnt2 == 0 ) ? 1 : 0;
+  }
+
+  PolyFillType e1FillType, e2FillType, e1FillType2, e2FillType2;
+  if (e1->PolyTyp == ptSubject)
+  {
+    e1FillType = m_SubjFillType;
+    e1FillType2 = m_ClipFillType;
+  } else
+  {
+    e1FillType = m_ClipFillType;
+    e1FillType2 = m_SubjFillType;
+  }
+  if (e2->PolyTyp == ptSubject)
+  {
+    e2FillType = m_SubjFillType;
+    e2FillType2 = m_ClipFillType;
+  } else
+  {
+    e2FillType = m_ClipFillType;
+    e2FillType2 = m_SubjFillType;
+  }
+
+  cInt e1Wc, e2Wc;
+  switch (e1FillType)
+  {
+    case pftPositive: e1Wc = e1->WindCnt; break;
+    case pftNegative: e1Wc = -e1->WindCnt; break;
+    default: e1Wc = Abs(e1->WindCnt);
+  }
+  switch(e2FillType)
+  {
+    case pftPositive: e2Wc = e2->WindCnt; break;
+    case pftNegative: e2Wc = -e2->WindCnt; break;
+    default: e2Wc = Abs(e2->WindCnt);
+  }
+
+  if ( e1Contributing && e2Contributing )
+  {
+    if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) ||
+      (e1->PolyTyp != e2->PolyTyp && m_ClipType != ctXor) )
+    {
+      AddLocalMaxPoly(e1, e2, Pt); 
+    }
+    else
+    {
+      AddOutPt(e1, Pt);
+      AddOutPt(e2, Pt);
+      SwapSides( *e1 , *e2 );
+      SwapPolyIndexes( *e1 , *e2 );
+    }
+  }
+  else if ( e1Contributing )
+  {
+    if (e2Wc == 0 || e2Wc == 1) 
+    {
+      AddOutPt(e1, Pt);
+      SwapSides(*e1, *e2);
+      SwapPolyIndexes(*e1, *e2);
+    }
+  }
+  else if ( e2Contributing )
+  {
+    if (e1Wc == 0 || e1Wc == 1) 
+    {
+      AddOutPt(e2, Pt);
+      SwapSides(*e1, *e2);
+      SwapPolyIndexes(*e1, *e2);
+    }
+  } 
+  else if ( (e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1))
+  {
+    //neither edge is currently contributing ...
+
+    cInt e1Wc2, e2Wc2;
+    switch (e1FillType2)
+    {
+      case pftPositive: e1Wc2 = e1->WindCnt2; break;
+      case pftNegative : e1Wc2 = -e1->WindCnt2; break;
+      default: e1Wc2 = Abs(e1->WindCnt2);
+    }
+    switch (e2FillType2)
+    {
+      case pftPositive: e2Wc2 = e2->WindCnt2; break;
+      case pftNegative: e2Wc2 = -e2->WindCnt2; break;
+      default: e2Wc2 = Abs(e2->WindCnt2);
+    }
+
+    if (e1->PolyTyp != e2->PolyTyp)
+    {
+      AddLocalMinPoly(e1, e2, Pt);
+    }
+    else if (e1Wc == 1 && e2Wc == 1)
+      switch( m_ClipType ) {
+        case ctIntersection:
+          if (e1Wc2 > 0 && e2Wc2 > 0)
+            AddLocalMinPoly(e1, e2, Pt);
+          break;
+        case ctUnion:
+          if ( e1Wc2 <= 0 && e2Wc2 <= 0 )
+            AddLocalMinPoly(e1, e2, Pt);
+          break;
+        case ctDifference:
+          if (((e1->PolyTyp == ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
+              ((e1->PolyTyp == ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
+                AddLocalMinPoly(e1, e2, Pt);
+          break;
+        case ctXor:
+          AddLocalMinPoly(e1, e2, Pt);
+      }
+    else
+      SwapSides( *e1, *e2 );
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::SetHoleState(TEdge *e, OutRec *outrec)
+{
+  TEdge *e2 = e->PrevInAEL;
+  TEdge *eTmp = 0;
+  while (e2)
+  {
+    if (e2->OutIdx >= 0 && e2->WindDelta != 0)
+    {
+      if (!eTmp) eTmp = e2;
+      else if (eTmp->OutIdx == e2->OutIdx) eTmp = 0;        
+    }
+    e2 = e2->PrevInAEL;
+  }
+  if (!eTmp)
+  {
+    outrec->FirstLeft = 0;
+    outrec->IsHole = false;
+  }
+  else
+  {
+    outrec->FirstLeft = m_PolyOuts[eTmp->OutIdx];
+    outrec->IsHole = !outrec->FirstLeft->IsHole;
+  }
+}
+//------------------------------------------------------------------------------
+
+OutRec* GetLowermostRec(OutRec *outRec1, OutRec *outRec2)
+{
+  //work out which polygon fragment has the correct hole state ...
+  if (!outRec1->BottomPt) 
+    outRec1->BottomPt = GetBottomPt(outRec1->Pts);
+  if (!outRec2->BottomPt) 
+    outRec2->BottomPt = GetBottomPt(outRec2->Pts);
+  OutPt *OutPt1 = outRec1->BottomPt;
+  OutPt *OutPt2 = outRec2->BottomPt;
+  if (OutPt1->Pt.Y > OutPt2->Pt.Y) return outRec1;
+  else if (OutPt1->Pt.Y < OutPt2->Pt.Y) return outRec2;
+  else if (OutPt1->Pt.X < OutPt2->Pt.X) return outRec1;
+  else if (OutPt1->Pt.X > OutPt2->Pt.X) return outRec2;
+  else if (OutPt1->Next == OutPt1) return outRec2;
+  else if (OutPt2->Next == OutPt2) return outRec1;
+  else if (FirstIsBottomPt(OutPt1, OutPt2)) return outRec1;
+  else return outRec2;
+}
+//------------------------------------------------------------------------------
+
+bool OutRec1RightOfOutRec2(OutRec* outRec1, OutRec* outRec2)
+{
+  do
+  {
+    outRec1 = outRec1->FirstLeft;
+    if (outRec1 == outRec2) return true;
+  } while (outRec1);
+  return false;
+}
+//------------------------------------------------------------------------------
+
+OutRec* Clipper::GetOutRec(int Idx)
+{
+  OutRec* outrec = m_PolyOuts[Idx];
+  while (outrec != m_PolyOuts[outrec->Idx])
+    outrec = m_PolyOuts[outrec->Idx];
+  return outrec;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AppendPolygon(TEdge *e1, TEdge *e2)
+{
+  //get the start and ends of both output polygons ...
+  OutRec *outRec1 = m_PolyOuts[e1->OutIdx];
+  OutRec *outRec2 = m_PolyOuts[e2->OutIdx];
+
+  OutRec *holeStateRec;
+  if (OutRec1RightOfOutRec2(outRec1, outRec2))
+    holeStateRec = outRec2;
+  else if (OutRec1RightOfOutRec2(outRec2, outRec1))
+    holeStateRec = outRec1;
+  else 
+    holeStateRec = GetLowermostRec(outRec1, outRec2);
+
+  //get the start and ends of both output polygons and
+  //join e2 poly onto e1 poly and delete pointers to e2 ...
+
+  OutPt* p1_lft = outRec1->Pts;
+  OutPt* p1_rt = p1_lft->Prev;
+  OutPt* p2_lft = outRec2->Pts;
+  OutPt* p2_rt = p2_lft->Prev;
+
+  //join e2 poly onto e1 poly and delete pointers to e2 ...
+  if(  e1->Side == esLeft )
+  {
+    if(  e2->Side == esLeft )
+    {
+      //z y x a b c
+      ReversePolyPtLinks(p2_lft);
+      p2_lft->Next = p1_lft;
+      p1_lft->Prev = p2_lft;
+      p1_rt->Next = p2_rt;
+      p2_rt->Prev = p1_rt;
+      outRec1->Pts = p2_rt;
+    } else
+    {
+      //x y z a b c
+      p2_rt->Next = p1_lft;
+      p1_lft->Prev = p2_rt;
+      p2_lft->Prev = p1_rt;
+      p1_rt->Next = p2_lft;
+      outRec1->Pts = p2_lft;
+    }
+  } else
+  {
+    if(  e2->Side == esRight )
+    {
+      //a b c z y x
+      ReversePolyPtLinks(p2_lft);
+      p1_rt->Next = p2_rt;
+      p2_rt->Prev = p1_rt;
+      p2_lft->Next = p1_lft;
+      p1_lft->Prev = p2_lft;
+    } else
+    {
+      //a b c x y z
+      p1_rt->Next = p2_lft;
+      p2_lft->Prev = p1_rt;
+      p1_lft->Prev = p2_rt;
+      p2_rt->Next = p1_lft;
+    }
+  }
+
+  outRec1->BottomPt = 0;
+  if (holeStateRec == outRec2)
+  {
+    if (outRec2->FirstLeft != outRec1)
+      outRec1->FirstLeft = outRec2->FirstLeft;
+    outRec1->IsHole = outRec2->IsHole;
+  }
+  outRec2->Pts = 0;
+  outRec2->BottomPt = 0;
+  outRec2->FirstLeft = outRec1;
+
+  int OKIdx = e1->OutIdx;
+  int ObsoleteIdx = e2->OutIdx;
+
+  e1->OutIdx = Unassigned; //nb: safe because we only get here via AddLocalMaxPoly
+  e2->OutIdx = Unassigned;
+
+  TEdge* e = m_ActiveEdges;
+  while( e )
+  {
+    if( e->OutIdx == ObsoleteIdx )
+    {
+      e->OutIdx = OKIdx;
+      e->Side = e1->Side;
+      break;
+    }
+    e = e->NextInAEL;
+  }
+
+  outRec2->Idx = outRec1->Idx;
+}
+//------------------------------------------------------------------------------
+
+OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt)
+{
+  if(  e->OutIdx < 0 )
+  {
+    OutRec *outRec = CreateOutRec();
+    outRec->IsOpen = (e->WindDelta == 0);
+    OutPt* newOp = new OutPt;
+    outRec->Pts = newOp;
+    newOp->Idx = outRec->Idx;
+    newOp->Pt = pt;
+    newOp->Next = newOp;
+    newOp->Prev = newOp;
+    if (!outRec->IsOpen)
+      SetHoleState(e, outRec);
+    e->OutIdx = outRec->Idx;
+    return newOp;
+  } else
+  {
+    OutRec *outRec = m_PolyOuts[e->OutIdx];
+    //OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
+    OutPt* op = outRec->Pts;
+
+	bool ToFront = (e->Side == esLeft);
+	if (ToFront && (pt == op->Pt)) return op;
+    else if (!ToFront && (pt == op->Prev->Pt)) return op->Prev;
+
+    OutPt* newOp = new OutPt;
+    newOp->Idx = outRec->Idx;
+    newOp->Pt = pt;
+    newOp->Next = op;
+    newOp->Prev = op->Prev;
+    newOp->Prev->Next = newOp;
+    op->Prev = newOp;
+    if (ToFront) outRec->Pts = newOp;
+    return newOp;
+  }
+}
+//------------------------------------------------------------------------------
+
+OutPt* Clipper::GetLastOutPt(TEdge *e)
+{
+	OutRec *outRec = m_PolyOuts[e->OutIdx];
+	if (e->Side == esLeft)
+		return outRec->Pts;
+	else
+		return outRec->Pts->Prev;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessHorizontals()
+{
+  TEdge* horzEdge;
+  while (PopEdgeFromSEL(horzEdge))
+    ProcessHorizontal(horzEdge);
+}
+//------------------------------------------------------------------------------
+
+inline bool IsMinima(TEdge *e)
+{
+  return e  && (e->Prev->NextInLML != e) && (e->Next->NextInLML != e);
+}
+//------------------------------------------------------------------------------
+
+inline bool IsMaxima(TEdge *e, const cInt Y)
+{
+  return e && e->Top.Y == Y && !e->NextInLML;
+}
+//------------------------------------------------------------------------------
+
+inline bool IsIntermediate(TEdge *e, const cInt Y)
+{
+  return e->Top.Y == Y && e->NextInLML;
+}
+//------------------------------------------------------------------------------
+
+TEdge *GetMaximaPair(TEdge *e)
+{
+  if ((e->Next->Top == e->Top) && !e->Next->NextInLML)
+    return e->Next;
+  else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML)
+    return e->Prev;
+  else return 0;
+}
+//------------------------------------------------------------------------------
+
+TEdge *GetMaximaPairEx(TEdge *e)
+{
+  //as GetMaximaPair() but returns 0 if MaxPair isn't in AEL (unless it's horizontal)
+  TEdge* result = GetMaximaPair(e);
+  if (result && (result->OutIdx == Skip ||
+    (result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result)))) return 0;
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::SwapPositionsInSEL(TEdge *Edge1, TEdge *Edge2)
+{
+  if(  !( Edge1->NextInSEL ) &&  !( Edge1->PrevInSEL ) ) return;
+  if(  !( Edge2->NextInSEL ) &&  !( Edge2->PrevInSEL ) ) return;
+
+  if(  Edge1->NextInSEL == Edge2 )
+  {
+    TEdge* Next = Edge2->NextInSEL;
+    if( Next ) Next->PrevInSEL = Edge1;
+    TEdge* Prev = Edge1->PrevInSEL;
+    if( Prev ) Prev->NextInSEL = Edge2;
+    Edge2->PrevInSEL = Prev;
+    Edge2->NextInSEL = Edge1;
+    Edge1->PrevInSEL = Edge2;
+    Edge1->NextInSEL = Next;
+  }
+  else if(  Edge2->NextInSEL == Edge1 )
+  {
+    TEdge* Next = Edge1->NextInSEL;
+    if( Next ) Next->PrevInSEL = Edge2;
+    TEdge* Prev = Edge2->PrevInSEL;
+    if( Prev ) Prev->NextInSEL = Edge1;
+    Edge1->PrevInSEL = Prev;
+    Edge1->NextInSEL = Edge2;
+    Edge2->PrevInSEL = Edge1;
+    Edge2->NextInSEL = Next;
+  }
+  else
+  {
+    TEdge* Next = Edge1->NextInSEL;
+    TEdge* Prev = Edge1->PrevInSEL;
+    Edge1->NextInSEL = Edge2->NextInSEL;
+    if( Edge1->NextInSEL ) Edge1->NextInSEL->PrevInSEL = Edge1;
+    Edge1->PrevInSEL = Edge2->PrevInSEL;
+    if( Edge1->PrevInSEL ) Edge1->PrevInSEL->NextInSEL = Edge1;
+    Edge2->NextInSEL = Next;
+    if( Edge2->NextInSEL ) Edge2->NextInSEL->PrevInSEL = Edge2;
+    Edge2->PrevInSEL = Prev;
+    if( Edge2->PrevInSEL ) Edge2->PrevInSEL->NextInSEL = Edge2;
+  }
+
+  if( !Edge1->PrevInSEL ) m_SortedEdges = Edge1;
+  else if( !Edge2->PrevInSEL ) m_SortedEdges = Edge2;
+}
+//------------------------------------------------------------------------------
+
+TEdge* GetNextInAEL(TEdge *e, Direction dir)
+{
+  return dir == dLeftToRight ? e->NextInAEL : e->PrevInAEL;
+}
+//------------------------------------------------------------------------------
+
+void GetHorzDirection(TEdge& HorzEdge, Direction& Dir, cInt& Left, cInt& Right)
+{
+  if (HorzEdge.Bot.X < HorzEdge.Top.X)
+  {
+    Left = HorzEdge.Bot.X;
+    Right = HorzEdge.Top.X;
+    Dir = dLeftToRight;
+  } else
+  {
+    Left = HorzEdge.Top.X;
+    Right = HorzEdge.Bot.X;
+    Dir = dRightToLeft;
+  }
+}
+//------------------------------------------------------------------------
+
+/*******************************************************************************
+* Notes: Horizontal edges (HEs) at scanline intersections (ie at the Top or    *
+* Bottom of a scanbeam) are processed as if layered. The order in which HEs    *
+* are processed doesn't matter. HEs intersect with other HE Bot.Xs only [#]    *
+* (or they could intersect with Top.Xs only, ie EITHER Bot.Xs OR Top.Xs),      *
+* and with other non-horizontal edges [*]. Once these intersections are        *
+* processed, intermediate HEs then 'promote' the Edge above (NextInLML) into   *
+* the AEL. These 'promoted' edges may in turn intersect [%] with other HEs.    *
+*******************************************************************************/
+
+void Clipper::ProcessHorizontal(TEdge *horzEdge)
+{
+  Direction dir;
+  cInt horzLeft, horzRight;
+  bool IsOpen = (horzEdge->WindDelta == 0);
+
+  GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
+
+  TEdge* eLastHorz = horzEdge, *eMaxPair = 0;
+  while (eLastHorz->NextInLML && IsHorizontal(*eLastHorz->NextInLML)) 
+    eLastHorz = eLastHorz->NextInLML;
+  if (!eLastHorz->NextInLML)
+    eMaxPair = GetMaximaPair(eLastHorz);
+
+  MaximaList::const_iterator maxIt;
+  MaximaList::const_reverse_iterator maxRit;
+  if (m_Maxima.size() > 0)
+  {
+      //get the first maxima in range (X) ...
+      if (dir == dLeftToRight)
+      {
+          maxIt = m_Maxima.begin();
+          while (maxIt != m_Maxima.end() && *maxIt <= horzEdge->Bot.X) maxIt++;
+          if (maxIt != m_Maxima.end() && *maxIt >= eLastHorz->Top.X)
+              maxIt = m_Maxima.end();
+      }
+      else
+      {
+          maxRit = m_Maxima.rbegin();
+          while (maxRit != m_Maxima.rend() && *maxRit > horzEdge->Bot.X) maxRit++;
+          if (maxRit != m_Maxima.rend() && *maxRit <= eLastHorz->Top.X)
+              maxRit = m_Maxima.rend();
+      }
+  }
+
+  OutPt* op1 = 0;
+
+  for (;;) //loop through consec. horizontal edges
+  {
+		  
+    bool IsLastHorz = (horzEdge == eLastHorz);
+    TEdge* e = GetNextInAEL(horzEdge, dir);
+    while(e)
+    {
+
+        //this code block inserts extra coords into horizontal edges (in output
+        //polygons) whereever maxima touch these horizontal edges. This helps
+        //'simplifying' polygons (ie if the Simplify property is set).
+        if (m_Maxima.size() > 0)
+        {
+            if (dir == dLeftToRight)
+            {
+                while (maxIt != m_Maxima.end() && *maxIt < e->Curr.X) 
+                {
+                  if (horzEdge->OutIdx >= 0 && !IsOpen)
+                    AddOutPt(horzEdge, IntPoint(*maxIt, horzEdge->Bot.Y));
+                  maxIt++;
+                }
+            }
+            else
+            {
+                while (maxRit != m_Maxima.rend() && *maxRit > e->Curr.X)
+                {
+                  if (horzEdge->OutIdx >= 0 && !IsOpen)
+                    AddOutPt(horzEdge, IntPoint(*maxRit, horzEdge->Bot.Y));
+                  maxRit++;
+                }
+            }
+        };
+
+        if ((dir == dLeftToRight && e->Curr.X > horzRight) ||
+			(dir == dRightToLeft && e->Curr.X < horzLeft)) break;
+
+		//Also break if we've got to the end of an intermediate horizontal edge ...
+		//nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
+		if (e->Curr.X == horzEdge->Top.X && horzEdge->NextInLML && 
+			e->Dx < horzEdge->NextInLML->Dx) break;
+
+    if (horzEdge->OutIdx >= 0 && !IsOpen)  //note: may be done multiple times
+		{
+            op1 = AddOutPt(horzEdge, e->Curr);
+			TEdge* eNextHorz = m_SortedEdges;
+			while (eNextHorz)
+			{
+				if (eNextHorz->OutIdx >= 0 &&
+					HorzSegmentsOverlap(horzEdge->Bot.X,
+					horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
+				{
+                    OutPt* op2 = GetLastOutPt(eNextHorz);
+                    AddJoin(op2, op1, eNextHorz->Top);
+				}
+				eNextHorz = eNextHorz->NextInSEL;
+			}
+			AddGhostJoin(op1, horzEdge->Bot);
+		}
+		
+		//OK, so far we're still in range of the horizontal Edge  but make sure
+        //we're at the last of consec. horizontals when matching with eMaxPair
+        if(e == eMaxPair && IsLastHorz)
+        {
+          if (horzEdge->OutIdx >= 0)
+            AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge->Top);
+          DeleteFromAEL(horzEdge);
+          DeleteFromAEL(eMaxPair);
+          return;
+        }
+        
+		if(dir == dLeftToRight)
+        {
+          IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
+          IntersectEdges(horzEdge, e, Pt);
+        }
+        else
+        {
+          IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
+          IntersectEdges( e, horzEdge, Pt);
+        }
+        TEdge* eNext = GetNextInAEL(e, dir);
+        SwapPositionsInAEL( horzEdge, e );
+        e = eNext;
+    } //end while(e)
+
+	//Break out of loop if HorzEdge.NextInLML is not also horizontal ...
+	if (!horzEdge->NextInLML || !IsHorizontal(*horzEdge->NextInLML)) break;
+
+	UpdateEdgeIntoAEL(horzEdge);
+    if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Bot);
+    GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
+
+  } //end for (;;)
+
+  if (horzEdge->OutIdx >= 0 && !op1)
+  {
+      op1 = GetLastOutPt(horzEdge);
+      TEdge* eNextHorz = m_SortedEdges;
+      while (eNextHorz)
+      {
+          if (eNextHorz->OutIdx >= 0 &&
+              HorzSegmentsOverlap(horzEdge->Bot.X,
+              horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
+          {
+              OutPt* op2 = GetLastOutPt(eNextHorz);
+              AddJoin(op2, op1, eNextHorz->Top);
+          }
+          eNextHorz = eNextHorz->NextInSEL;
+      }
+      AddGhostJoin(op1, horzEdge->Top);
+  }
+
+  if (horzEdge->NextInLML)
+  {
+    if(horzEdge->OutIdx >= 0)
+    {
+      op1 = AddOutPt( horzEdge, horzEdge->Top);
+      UpdateEdgeIntoAEL(horzEdge);
+      if (horzEdge->WindDelta == 0) return;
+      //nb: HorzEdge is no longer horizontal here
+      TEdge* ePrev = horzEdge->PrevInAEL;
+      TEdge* eNext = horzEdge->NextInAEL;
+      if (ePrev && ePrev->Curr.X == horzEdge->Bot.X &&
+        ePrev->Curr.Y == horzEdge->Bot.Y && ePrev->WindDelta != 0 &&
+        (ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
+        SlopesEqual(*horzEdge, *ePrev, m_UseFullRange)))
+      {
+        OutPt* op2 = AddOutPt(ePrev, horzEdge->Bot);
+        AddJoin(op1, op2, horzEdge->Top);
+      }
+      else if (eNext && eNext->Curr.X == horzEdge->Bot.X &&
+        eNext->Curr.Y == horzEdge->Bot.Y && eNext->WindDelta != 0 &&
+        eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
+        SlopesEqual(*horzEdge, *eNext, m_UseFullRange))
+      {
+        OutPt* op2 = AddOutPt(eNext, horzEdge->Bot);
+        AddJoin(op1, op2, horzEdge->Top);
+      }
+    }
+    else
+      UpdateEdgeIntoAEL(horzEdge); 
+  }
+  else
+  {
+    if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top);
+    DeleteFromAEL(horzEdge);
+  }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::ProcessIntersections(const cInt topY)
+{
+  if( !m_ActiveEdges ) return true;
+  try {
+    BuildIntersectList(topY);
+    size_t IlSize = m_IntersectList.size();
+    if (IlSize == 0) return true;
+    if (IlSize == 1 || FixupIntersectionOrder()) ProcessIntersectList();
+    else return false;
+  }
+  catch(...) 
+  {
+    m_SortedEdges = 0;
+    DisposeIntersectNodes();
+    throw clipperException("ProcessIntersections error");
+  }
+  m_SortedEdges = 0;
+  return true;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DisposeIntersectNodes()
+{
+  for (size_t i = 0; i < m_IntersectList.size(); ++i )
+    delete m_IntersectList[i];
+  m_IntersectList.clear();
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildIntersectList(const cInt topY)
+{
+  if ( !m_ActiveEdges ) return;
+
+  //prepare for sorting ...
+  TEdge* e = m_ActiveEdges;
+  m_SortedEdges = e;
+  while( e )
+  {
+    e->PrevInSEL = e->PrevInAEL;
+    e->NextInSEL = e->NextInAEL;
+    e->Curr.X = TopX( *e, topY );
+    e = e->NextInAEL;
+  }
+
+  //bubblesort ...
+  bool isModified;
+  do
+  {
+    isModified = false;
+    e = m_SortedEdges;
+    while( e->NextInSEL )
+    {
+      TEdge *eNext = e->NextInSEL;
+      IntPoint Pt;
+      if(e->Curr.X > eNext->Curr.X)
+      {
+        IntersectPoint(*e, *eNext, Pt);
+        if (Pt.Y < topY) Pt = IntPoint(TopX(*e, topY), topY);
+        IntersectNode * newNode = new IntersectNode;
+        newNode->Edge1 = e;
+        newNode->Edge2 = eNext;
+        newNode->Pt = Pt;
+        m_IntersectList.push_back(newNode);
+
+        SwapPositionsInSEL(e, eNext);
+        isModified = true;
+      }
+      else
+        e = eNext;
+    }
+    if( e->PrevInSEL ) e->PrevInSEL->NextInSEL = 0;
+    else break;
+  }
+  while ( isModified );
+  m_SortedEdges = 0; //important
+}
+//------------------------------------------------------------------------------
+
+
+void Clipper::ProcessIntersectList()
+{
+  for (size_t i = 0; i < m_IntersectList.size(); ++i)
+  {
+    IntersectNode* iNode = m_IntersectList[i];
+    {
+      IntersectEdges( iNode->Edge1, iNode->Edge2, iNode->Pt);
+      SwapPositionsInAEL( iNode->Edge1 , iNode->Edge2 );
+    }
+    delete iNode;
+  }
+  m_IntersectList.clear();
+}
+//------------------------------------------------------------------------------
+
+bool IntersectListSort(IntersectNode* node1, IntersectNode* node2)
+{
+  return node2->Pt.Y < node1->Pt.Y;
+}
+//------------------------------------------------------------------------------
+
+inline bool EdgesAdjacent(const IntersectNode &inode)
+{
+  return (inode.Edge1->NextInSEL == inode.Edge2) ||
+    (inode.Edge1->PrevInSEL == inode.Edge2);
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::FixupIntersectionOrder()
+{
+  //pre-condition: intersections are sorted Bottom-most first.
+  //Now it's crucial that intersections are made only between adjacent edges,
+  //so to ensure this the order of intersections may need adjusting ...
+  CopyAELToSEL();
+  std::sort(m_IntersectList.begin(), m_IntersectList.end(), IntersectListSort);
+  size_t cnt = m_IntersectList.size();
+  for (size_t i = 0; i < cnt; ++i) 
+  {
+    if (!EdgesAdjacent(*m_IntersectList[i]))
+    {
+      size_t j = i + 1;
+      while (j < cnt && !EdgesAdjacent(*m_IntersectList[j])) j++;
+      if (j == cnt)  return false;
+      std::swap(m_IntersectList[i], m_IntersectList[j]);
+    }
+    SwapPositionsInSEL(m_IntersectList[i]->Edge1, m_IntersectList[i]->Edge2);
+  }
+  return true;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DoMaxima(TEdge *e)
+{
+  TEdge* eMaxPair = GetMaximaPairEx(e);
+  if (!eMaxPair)
+  {
+    if (e->OutIdx >= 0)
+      AddOutPt(e, e->Top);
+    DeleteFromAEL(e);
+    return;
+  }
+
+  TEdge* eNext = e->NextInAEL;
+  while(eNext && eNext != eMaxPair)
+  {
+    IntersectEdges(e, eNext, e->Top);
+    SwapPositionsInAEL(e, eNext);
+    eNext = e->NextInAEL;
+  }
+
+  if(e->OutIdx == Unassigned && eMaxPair->OutIdx == Unassigned)
+  {
+    DeleteFromAEL(e);
+    DeleteFromAEL(eMaxPair);
+  }
+  else if( e->OutIdx >= 0 && eMaxPair->OutIdx >= 0 )
+  {
+    if (e->OutIdx >= 0) AddLocalMaxPoly(e, eMaxPair, e->Top);
+    DeleteFromAEL(e);
+    DeleteFromAEL(eMaxPair);
+  }
+#ifdef use_lines
+  else if (e->WindDelta == 0)
+  {
+    if (e->OutIdx >= 0) 
+    {
+      AddOutPt(e, e->Top);
+      e->OutIdx = Unassigned;
+    }
+    DeleteFromAEL(e);
+
+    if (eMaxPair->OutIdx >= 0)
+    {
+      AddOutPt(eMaxPair, e->Top);
+      eMaxPair->OutIdx = Unassigned;
+    }
+    DeleteFromAEL(eMaxPair);
+  } 
+#endif
+  else throw clipperException("DoMaxima error");
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessEdgesAtTopOfScanbeam(const cInt topY)
+{
+  TEdge* e = m_ActiveEdges;
+  while( e )
+  {
+    //1. process maxima, treating them as if they're 'bent' horizontal edges,
+    //   but exclude maxima with horizontal edges. nb: e can't be a horizontal.
+    bool IsMaximaEdge = IsMaxima(e, topY);
+
+    if(IsMaximaEdge)
+    {
+      TEdge* eMaxPair = GetMaximaPairEx(e);
+      IsMaximaEdge = (!eMaxPair || !IsHorizontal(*eMaxPair));
+    }
+
+    if(IsMaximaEdge)
+    {
+      if (m_StrictSimple) m_Maxima.push_back(e->Top.X);
+      TEdge* ePrev = e->PrevInAEL;
+      DoMaxima(e);
+      if( !ePrev ) e = m_ActiveEdges;
+      else e = ePrev->NextInAEL;
+    }
+    else
+    {
+      //2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
+      if (IsIntermediate(e, topY) && IsHorizontal(*e->NextInLML))
+      {
+        UpdateEdgeIntoAEL(e);
+        if (e->OutIdx >= 0)
+          AddOutPt(e, e->Bot);
+        AddEdgeToSEL(e);
+      } 
+      else
+      {
+        e->Curr.X = TopX( *e, topY );
+        e->Curr.Y = topY;
+      }
+
+      //When StrictlySimple and 'e' is being touched by another edge, then
+      //make sure both edges have a vertex here ...
+      if (m_StrictSimple)
+      {  
+        TEdge* ePrev = e->PrevInAEL;
+        if ((e->OutIdx >= 0) && (e->WindDelta != 0) && ePrev && (ePrev->OutIdx >= 0) &&
+          (ePrev->Curr.X == e->Curr.X) && (ePrev->WindDelta != 0))
+        {
+          IntPoint pt = e->Curr;
+#ifdef use_xyz
+          SetZ(pt, *ePrev, *e);
+#endif
+          OutPt* op = AddOutPt(ePrev, pt);
+          OutPt* op2 = AddOutPt(e, pt);
+          AddJoin(op, op2, pt); //StrictlySimple (type-3) join
+        }
+      }
+
+      e = e->NextInAEL;
+    }
+  }
+
+  //3. Process horizontals at the Top of the scanbeam ...
+  m_Maxima.sort();
+  ProcessHorizontals();
+  m_Maxima.clear();
+
+  //4. Promote intermediate vertices ...
+  e = m_ActiveEdges;
+  while(e)
+  {
+    if(IsIntermediate(e, topY))
+    {
+      OutPt* op = 0;
+      if( e->OutIdx >= 0 ) 
+        op = AddOutPt(e, e->Top);
+      UpdateEdgeIntoAEL(e);
+
+      //if output polygons share an edge, they'll need joining later ...
+      TEdge* ePrev = e->PrevInAEL;
+      TEdge* eNext = e->NextInAEL;
+      if (ePrev && ePrev->Curr.X == e->Bot.X &&
+        ePrev->Curr.Y == e->Bot.Y && op &&
+        ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
+        SlopesEqual(e->Curr, e->Top, ePrev->Curr, ePrev->Top, m_UseFullRange) &&
+        (e->WindDelta != 0) && (ePrev->WindDelta != 0))
+      {
+        OutPt* op2 = AddOutPt(ePrev, e->Bot);
+        AddJoin(op, op2, e->Top);
+      }
+      else if (eNext && eNext->Curr.X == e->Bot.X &&
+        eNext->Curr.Y == e->Bot.Y && op &&
+        eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
+        SlopesEqual(e->Curr, e->Top, eNext->Curr, eNext->Top, m_UseFullRange) &&
+        (e->WindDelta != 0) && (eNext->WindDelta != 0))
+      {
+        OutPt* op2 = AddOutPt(eNext, e->Bot);
+        AddJoin(op, op2, e->Top);
+      }
+    }
+    e = e->NextInAEL;
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::FixupOutPolyline(OutRec &outrec)
+{
+  OutPt *pp = outrec.Pts;
+  OutPt *lastPP = pp->Prev;
+  while (pp != lastPP)
+  {
+    pp = pp->Next;
+    if (pp->Pt == pp->Prev->Pt)
+    {
+      if (pp == lastPP) lastPP = pp->Prev;
+      OutPt *tmpPP = pp->Prev;
+      tmpPP->Next = pp->Next;
+      pp->Next->Prev = tmpPP;
+      delete pp;
+      pp = tmpPP;
+    }
+  }
+
+  if (pp == pp->Prev)
+  {
+    DisposeOutPts(pp);
+    outrec.Pts = 0;
+    return;
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::FixupOutPolygon(OutRec &outrec)
+{
+    //FixupOutPolygon() - removes duplicate points and simplifies consecutive
+    //parallel edges by removing the middle vertex.
+    OutPt *lastOK = 0;
+    outrec.BottomPt = 0;
+    OutPt *pp = outrec.Pts;
+    bool preserveCol = m_PreserveCollinear || m_StrictSimple;
+
+    for (;;)
+    {
+        if (pp->Prev == pp || pp->Prev == pp->Next)
+        {
+            DisposeOutPts(pp);
+            outrec.Pts = 0;
+            return;
+        }
+
+        //test for duplicate points and collinear edges ...
+        if ((pp->Pt == pp->Next->Pt) || (pp->Pt == pp->Prev->Pt) ||
+            (SlopesEqual(pp->Prev->Pt, pp->Pt, pp->Next->Pt, m_UseFullRange) &&
+            (!preserveCol || !Pt2IsBetweenPt1AndPt3(pp->Prev->Pt, pp->Pt, pp->Next->Pt))))
+        {
+            lastOK = 0;
+            OutPt *tmp = pp;
+            pp->Prev->Next = pp->Next;
+            pp->Next->Prev = pp->Prev;
+            pp = pp->Prev;
+            delete tmp;
+        }
+        else if (pp == lastOK) break;
+        else
+        {
+            if (!lastOK) lastOK = pp;
+            pp = pp->Next;
+        }
+    }
+    outrec.Pts = pp;
+}
+//------------------------------------------------------------------------------
+
+int PointCount(OutPt *Pts)
+{
+    if (!Pts) return 0;
+    int result = 0;
+    OutPt* p = Pts;
+    do
+    {
+        result++;
+        p = p->Next;
+    }
+    while (p != Pts);
+    return result;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildResult(Paths &polys)
+{
+  polys.reserve(m_PolyOuts.size());
+  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+  {
+    if (!m_PolyOuts[i]->Pts) continue;
+    Path pg;
+    OutPt* p = m_PolyOuts[i]->Pts->Prev;
+    int cnt = PointCount(p);
+    if (cnt < 2) continue;
+    pg.reserve(cnt);
+    for (int i = 0; i < cnt; ++i)
+    {
+      pg.push_back(p->Pt);
+      p = p->Prev;
+    }
+    polys.push_back(pg);
+  }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildResult2(PolyTree& polytree)
+{
+    polytree.Clear();
+    polytree.AllNodes.reserve(m_PolyOuts.size());
+    //add each output polygon/contour to polytree ...
+    for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
+    {
+        OutRec* outRec = m_PolyOuts[i];
+        int cnt = PointCount(outRec->Pts);
+        if ((outRec->IsOpen && cnt < 2) || (!outRec->IsOpen && cnt < 3)) continue;
+        FixHoleLinkage(*outRec);
+        PolyNode* pn = new PolyNode();
+        //nb: polytree takes ownership of all the PolyNodes
+        polytree.AllNodes.push_back(pn);
+        outRec->PolyNd = pn;
+        pn->Parent = 0;
+        pn->Index = 0;
+        pn->Contour.reserve(cnt);
+        OutPt *op = outRec->Pts->Prev;
+        for (int j = 0; j < cnt; j++)
+        {
+            pn->Contour.push_back(op->Pt);
+            op = op->Prev;
+        }
+    }
+
+    //fixup PolyNode links etc ...
+    polytree.Childs.reserve(m_PolyOuts.size());
+    for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
+    {
+        OutRec* outRec = m_PolyOuts[i];
+        if (!outRec->PolyNd) continue;
+        if (outRec->IsOpen) 
+        {
+          outRec->PolyNd->m_IsOpen = true;
+          polytree.AddChild(*outRec->PolyNd);
+        }
+        else if (outRec->FirstLeft && outRec->FirstLeft->PolyNd) 
+          outRec->FirstLeft->PolyNd->AddChild(*outRec->PolyNd);
+        else
+          polytree.AddChild(*outRec->PolyNd);
+    }
+}
+//------------------------------------------------------------------------------
+
+void SwapIntersectNodes(IntersectNode &int1, IntersectNode &int2)
+{
+  //just swap the contents (because fIntersectNodes is a single-linked-list)
+  IntersectNode inode = int1; //gets a copy of Int1
+  int1.Edge1 = int2.Edge1;
+  int1.Edge2 = int2.Edge2;
+  int1.Pt = int2.Pt;
+  int2.Edge1 = inode.Edge1;
+  int2.Edge2 = inode.Edge2;
+  int2.Pt = inode.Pt;
+}
+//------------------------------------------------------------------------------
+
+inline bool E2InsertsBeforeE1(TEdge &e1, TEdge &e2)
+{
+  if (e2.Curr.X == e1.Curr.X) 
+  {
+    if (e2.Top.Y > e1.Top.Y)
+      return e2.Top.X < TopX(e1, e2.Top.Y); 
+      else return e1.Top.X > TopX(e2, e1.Top.Y);
+  } 
+  else return e2.Curr.X < e1.Curr.X;
+}
+//------------------------------------------------------------------------------
+
+bool GetOverlap(const cInt a1, const cInt a2, const cInt b1, const cInt b2, 
+    cInt& Left, cInt& Right)
+{
+  if (a1 < a2)
+  {
+    if (b1 < b2) {Left = std::max(a1,b1); Right = std::min(a2,b2);}
+    else {Left = std::max(a1,b2); Right = std::min(a2,b1);}
+  } 
+  else
+  {
+    if (b1 < b2) {Left = std::max(a2,b1); Right = std::min(a1,b2);}
+    else {Left = std::max(a2,b2); Right = std::min(a1,b1);}
+  }
+  return Left < Right;
+}
+//------------------------------------------------------------------------------
+
+inline void UpdateOutPtIdxs(OutRec& outrec)
+{  
+  OutPt* op = outrec.Pts;
+  do
+  {
+    op->Idx = outrec.Idx;
+    op = op->Prev;
+  }
+  while(op != outrec.Pts);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge)
+{
+  if(!m_ActiveEdges)
+  {
+    edge->PrevInAEL = 0;
+    edge->NextInAEL = 0;
+    m_ActiveEdges = edge;
+  }
+  else if(!startEdge && E2InsertsBeforeE1(*m_ActiveEdges, *edge))
+  {
+      edge->PrevInAEL = 0;
+      edge->NextInAEL = m_ActiveEdges;
+      m_ActiveEdges->PrevInAEL = edge;
+      m_ActiveEdges = edge;
+  } 
+  else
+  {
+    if(!startEdge) startEdge = m_ActiveEdges;
+    while(startEdge->NextInAEL  && 
+      !E2InsertsBeforeE1(*startEdge->NextInAEL , *edge))
+        startEdge = startEdge->NextInAEL;
+    edge->NextInAEL = startEdge->NextInAEL;
+    if(startEdge->NextInAEL) startEdge->NextInAEL->PrevInAEL = edge;
+    edge->PrevInAEL = startEdge;
+    startEdge->NextInAEL = edge;
+  }
+}
+//----------------------------------------------------------------------
+
+OutPt* DupOutPt(OutPt* outPt, bool InsertAfter)
+{
+  OutPt* result = new OutPt;
+  result->Pt = outPt->Pt;
+  result->Idx = outPt->Idx;
+  if (InsertAfter)
+  {
+    result->Next = outPt->Next;
+    result->Prev = outPt;
+    outPt->Next->Prev = result;
+    outPt->Next = result;
+  } 
+  else
+  {
+    result->Prev = outPt->Prev;
+    result->Next = outPt;
+    outPt->Prev->Next = result;
+    outPt->Prev = result;
+  }
+  return result;
+}
+//------------------------------------------------------------------------------
+
+bool JoinHorz(OutPt* op1, OutPt* op1b, OutPt* op2, OutPt* op2b,
+  const IntPoint Pt, bool DiscardLeft)
+{
+  Direction Dir1 = (op1->Pt.X > op1b->Pt.X ? dRightToLeft : dLeftToRight);
+  Direction Dir2 = (op2->Pt.X > op2b->Pt.X ? dRightToLeft : dLeftToRight);
+  if (Dir1 == Dir2) return false;
+
+  //When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
+  //want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
+  //So, to facilitate this while inserting Op1b and Op2b ...
+  //when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
+  //otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
+  if (Dir1 == dLeftToRight) 
+  {
+    while (op1->Next->Pt.X <= Pt.X && 
+      op1->Next->Pt.X >= op1->Pt.X && op1->Next->Pt.Y == Pt.Y)  
+        op1 = op1->Next;
+    if (DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
+    op1b = DupOutPt(op1, !DiscardLeft);
+    if (op1b->Pt != Pt) 
+    {
+      op1 = op1b;
+      op1->Pt = Pt;
+      op1b = DupOutPt(op1, !DiscardLeft);
+    }
+  } 
+  else
+  {
+    while (op1->Next->Pt.X >= Pt.X && 
+      op1->Next->Pt.X <= op1->Pt.X && op1->Next->Pt.Y == Pt.Y) 
+        op1 = op1->Next;
+    if (!DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
+    op1b = DupOutPt(op1, DiscardLeft);
+    if (op1b->Pt != Pt)
+    {
+      op1 = op1b;
+      op1->Pt = Pt;
+      op1b = DupOutPt(op1, DiscardLeft);
+    }
+  }
+
+  if (Dir2 == dLeftToRight)
+  {
+    while (op2->Next->Pt.X <= Pt.X && 
+      op2->Next->Pt.X >= op2->Pt.X && op2->Next->Pt.Y == Pt.Y)
+        op2 = op2->Next;
+    if (DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
+    op2b = DupOutPt(op2, !DiscardLeft);
+    if (op2b->Pt != Pt)
+    {
+      op2 = op2b;
+      op2->Pt = Pt;
+      op2b = DupOutPt(op2, !DiscardLeft);
+    };
+  } else
+  {
+    while (op2->Next->Pt.X >= Pt.X && 
+      op2->Next->Pt.X <= op2->Pt.X && op2->Next->Pt.Y == Pt.Y) 
+        op2 = op2->Next;
+    if (!DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
+    op2b = DupOutPt(op2, DiscardLeft);
+    if (op2b->Pt != Pt)
+    {
+      op2 = op2b;
+      op2->Pt = Pt;
+      op2b = DupOutPt(op2, DiscardLeft);
+    };
+  };
+
+  if ((Dir1 == dLeftToRight) == DiscardLeft)
+  {
+    op1->Prev = op2;
+    op2->Next = op1;
+    op1b->Next = op2b;
+    op2b->Prev = op1b;
+  }
+  else
+  {
+    op1->Next = op2;
+    op2->Prev = op1;
+    op1b->Prev = op2b;
+    op2b->Next = op1b;
+  }
+  return true;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2)
+{
+  OutPt *op1 = j->OutPt1, *op1b;
+  OutPt *op2 = j->OutPt2, *op2b;
+
+  //There are 3 kinds of joins for output polygons ...
+  //1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
+  //along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
+  //2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
+  //location at the Bottom of the overlapping segment (& Join.OffPt is above).
+  //3. StrictSimple joins where edges touch but are not collinear and where
+  //Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
+  bool isHorizontal = (j->OutPt1->Pt.Y == j->OffPt.Y);
+
+  if (isHorizontal  && (j->OffPt == j->OutPt1->Pt) &&
+  (j->OffPt == j->OutPt2->Pt))
+  {
+    //Strictly Simple join ...
+    if (outRec1 != outRec2) return false;
+    op1b = j->OutPt1->Next;
+    while (op1b != op1 && (op1b->Pt == j->OffPt)) 
+      op1b = op1b->Next;
+    bool reverse1 = (op1b->Pt.Y > j->OffPt.Y);
+    op2b = j->OutPt2->Next;
+    while (op2b != op2 && (op2b->Pt == j->OffPt)) 
+      op2b = op2b->Next;
+    bool reverse2 = (op2b->Pt.Y > j->OffPt.Y);
+    if (reverse1 == reverse2) return false;
+    if (reverse1)
+    {
+      op1b = DupOutPt(op1, false);
+      op2b = DupOutPt(op2, true);
+      op1->Prev = op2;
+      op2->Next = op1;
+      op1b->Next = op2b;
+      op2b->Prev = op1b;
+      j->OutPt1 = op1;
+      j->OutPt2 = op1b;
+      return true;
+    } else
+    {
+      op1b = DupOutPt(op1, true);
+      op2b = DupOutPt(op2, false);
+      op1->Next = op2;
+      op2->Prev = op1;
+      op1b->Prev = op2b;
+      op2b->Next = op1b;
+      j->OutPt1 = op1;
+      j->OutPt2 = op1b;
+      return true;
+    }
+  } 
+  else if (isHorizontal)
+  {
+    //treat horizontal joins differently to non-horizontal joins since with
+    //them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
+    //may be anywhere along the horizontal edge.
+    op1b = op1;
+    while (op1->Prev->Pt.Y == op1->Pt.Y && op1->Prev != op1b && op1->Prev != op2)
+      op1 = op1->Prev;
+    while (op1b->Next->Pt.Y == op1b->Pt.Y && op1b->Next != op1 && op1b->Next != op2)
+      op1b = op1b->Next;
+    if (op1b->Next == op1 || op1b->Next == op2) return false; //a flat 'polygon'
+
+    op2b = op2;
+    while (op2->Prev->Pt.Y == op2->Pt.Y && op2->Prev != op2b && op2->Prev != op1b)
+      op2 = op2->Prev;
+    while (op2b->Next->Pt.Y == op2b->Pt.Y && op2b->Next != op2 && op2b->Next != op1)
+      op2b = op2b->Next;
+    if (op2b->Next == op2 || op2b->Next == op1) return false; //a flat 'polygon'
+
+    cInt Left, Right;
+    //Op1 --> Op1b & Op2 --> Op2b are the extremites of the horizontal edges
+    if (!GetOverlap(op1->Pt.X, op1b->Pt.X, op2->Pt.X, op2b->Pt.X, Left, Right))
+      return false;
+
+    //DiscardLeftSide: when overlapping edges are joined, a spike will created
+    //which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
+    //on the discard Side as either may still be needed for other joins ...
+    IntPoint Pt;
+    bool DiscardLeftSide;
+    if (op1->Pt.X >= Left && op1->Pt.X <= Right) 
+    {
+      Pt = op1->Pt; DiscardLeftSide = (op1->Pt.X > op1b->Pt.X);
+    } 
+    else if (op2->Pt.X >= Left&& op2->Pt.X <= Right) 
+    {
+      Pt = op2->Pt; DiscardLeftSide = (op2->Pt.X > op2b->Pt.X);
+    } 
+    else if (op1b->Pt.X >= Left && op1b->Pt.X <= Right)
+    {
+      Pt = op1b->Pt; DiscardLeftSide = op1b->Pt.X > op1->Pt.X;
+    } 
+    else
+    {
+      Pt = op2b->Pt; DiscardLeftSide = (op2b->Pt.X > op2->Pt.X);
+    }
+    j->OutPt1 = op1; j->OutPt2 = op2;
+    return JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide);
+  } else
+  {
+    //nb: For non-horizontal joins ...
+    //    1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
+    //    2. Jr.OutPt1.Pt > Jr.OffPt.Y
+
+    //make sure the polygons are correctly oriented ...
+    op1b = op1->Next;
+    while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Next;
+    bool Reverse1 = ((op1b->Pt.Y > op1->Pt.Y) ||
+      !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange));
+    if (Reverse1)
+    {
+      op1b = op1->Prev;
+      while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Prev;
+      if ((op1b->Pt.Y > op1->Pt.Y) ||
+        !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange)) return false;
+    };
+    op2b = op2->Next;
+    while ((op2b->Pt == op2->Pt) && (op2b != op2))op2b = op2b->Next;
+    bool Reverse2 = ((op2b->Pt.Y > op2->Pt.Y) ||
+      !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange));
+    if (Reverse2)
+    {
+      op2b = op2->Prev;
+      while ((op2b->Pt == op2->Pt) && (op2b != op2)) op2b = op2b->Prev;
+      if ((op2b->Pt.Y > op2->Pt.Y) ||
+        !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange)) return false;
+    }
+
+    if ((op1b == op1) || (op2b == op2) || (op1b == op2b) ||
+      ((outRec1 == outRec2) && (Reverse1 == Reverse2))) return false;
+
+    if (Reverse1)
+    {
+      op1b = DupOutPt(op1, false);
+      op2b = DupOutPt(op2, true);
+      op1->Prev = op2;
+      op2->Next = op1;
+      op1b->Next = op2b;
+      op2b->Prev = op1b;
+      j->OutPt1 = op1;
+      j->OutPt2 = op1b;
+      return true;
+    } else
+    {
+      op1b = DupOutPt(op1, true);
+      op2b = DupOutPt(op2, false);
+      op1->Next = op2;
+      op2->Prev = op1;
+      op1b->Prev = op2b;
+      op2b->Next = op1b;
+      j->OutPt1 = op1;
+      j->OutPt2 = op1b;
+      return true;
+    }
+  }
+}
+//----------------------------------------------------------------------
+
+static OutRec* ParseFirstLeft(OutRec* FirstLeft)
+{
+  while (FirstLeft && !FirstLeft->Pts)
+    FirstLeft = FirstLeft->FirstLeft;
+  return FirstLeft;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec)
+{ 
+  //tests if NewOutRec contains the polygon before reassigning FirstLeft
+  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+  {
+    OutRec* outRec = m_PolyOuts[i];
+    OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+    if (outRec->Pts  && firstLeft == OldOutRec)
+    {
+      if (Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts))
+        outRec->FirstLeft = NewOutRec;
+    }
+  }
+}
+//----------------------------------------------------------------------
+
+void Clipper::FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec)
+{
+  //A polygon has split into two such that one is now the inner of the other.
+  //It's possible that these polygons now wrap around other polygons, so check
+  //every polygon that's also contained by OuterOutRec's FirstLeft container
+  //(including 0) to see if they've become inner to the new inner polygon ...
+  OutRec* orfl = OuterOutRec->FirstLeft;
+  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+  {
+    OutRec* outRec = m_PolyOuts[i];
+
+    if (!outRec->Pts || outRec == OuterOutRec || outRec == InnerOutRec)
+      continue;
+    OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+    if (firstLeft != orfl && firstLeft != InnerOutRec && firstLeft != OuterOutRec)
+      continue;
+    if (Poly2ContainsPoly1(outRec->Pts, InnerOutRec->Pts))
+      outRec->FirstLeft = InnerOutRec;
+    else if (Poly2ContainsPoly1(outRec->Pts, OuterOutRec->Pts))
+      outRec->FirstLeft = OuterOutRec;
+    else if (outRec->FirstLeft == InnerOutRec || outRec->FirstLeft == OuterOutRec)
+      outRec->FirstLeft = orfl;
+  }
+}
+//----------------------------------------------------------------------
+void Clipper::FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec)
+{
+  //reassigns FirstLeft WITHOUT testing if NewOutRec contains the polygon
+  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+  {
+    OutRec* outRec = m_PolyOuts[i];
+    OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+    if (outRec->Pts && outRec->FirstLeft == OldOutRec)
+      outRec->FirstLeft = NewOutRec;
+  }
+}
+//----------------------------------------------------------------------
+
+void Clipper::JoinCommonEdges()
+{
+  for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+  {
+    Join* join = m_Joins[i];
+
+    OutRec *outRec1 = GetOutRec(join->OutPt1->Idx);
+    OutRec *outRec2 = GetOutRec(join->OutPt2->Idx);
+
+    if (!outRec1->Pts || !outRec2->Pts) continue;
+    if (outRec1->IsOpen || outRec2->IsOpen) continue;
+
+    //get the polygon fragment with the correct hole state (FirstLeft)
+    //before calling JoinPoints() ...
+    OutRec *holeStateRec;
+    if (outRec1 == outRec2) holeStateRec = outRec1;
+    else if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2;
+    else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1;
+    else holeStateRec = GetLowermostRec(outRec1, outRec2);
+
+    if (!JoinPoints(join, outRec1, outRec2)) continue;
+
+    if (outRec1 == outRec2)
+    {
+      //instead of joining two polygons, we've just created a new one by
+      //splitting one polygon into two.
+      outRec1->Pts = join->OutPt1;
+      outRec1->BottomPt = 0;
+      outRec2 = CreateOutRec();
+      outRec2->Pts = join->OutPt2;
+
+      //update all OutRec2.Pts Idx's ...
+      UpdateOutPtIdxs(*outRec2);
+
+      if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts))
+      {
+        //outRec1 contains outRec2 ...
+        outRec2->IsHole = !outRec1->IsHole;
+        outRec2->FirstLeft = outRec1;
+
+        if (m_UsingPolyTree) FixupFirstLefts2(outRec2, outRec1);
+
+        if ((outRec2->IsHole ^ m_ReverseOutput) == (Area(*outRec2) > 0))
+          ReversePolyPtLinks(outRec2->Pts);
+            
+      } else if (Poly2ContainsPoly1(outRec1->Pts, outRec2->Pts))
+      {
+        //outRec2 contains outRec1 ...
+        outRec2->IsHole = outRec1->IsHole;
+        outRec1->IsHole = !outRec2->IsHole;
+        outRec2->FirstLeft = outRec1->FirstLeft;
+        outRec1->FirstLeft = outRec2;
+
+        if (m_UsingPolyTree) FixupFirstLefts2(outRec1, outRec2);
+
+        if ((outRec1->IsHole ^ m_ReverseOutput) == (Area(*outRec1) > 0))
+          ReversePolyPtLinks(outRec1->Pts);
+      } 
+      else
+      {
+        //the 2 polygons are completely separate ...
+        outRec2->IsHole = outRec1->IsHole;
+        outRec2->FirstLeft = outRec1->FirstLeft;
+
+        //fixup FirstLeft pointers that may need reassigning to OutRec2
+        if (m_UsingPolyTree) FixupFirstLefts1(outRec1, outRec2);
+      }
+     
+    } else
+    {
+      //joined 2 polygons together ...
+
+      outRec2->Pts = 0;
+      outRec2->BottomPt = 0;
+      outRec2->Idx = outRec1->Idx;
+
+      outRec1->IsHole = holeStateRec->IsHole;
+      if (holeStateRec == outRec2) 
+        outRec1->FirstLeft = outRec2->FirstLeft;
+      outRec2->FirstLeft = outRec1;
+
+      if (m_UsingPolyTree) FixupFirstLefts3(outRec2, outRec1);
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// ClipperOffset support functions ...
+//------------------------------------------------------------------------------
+
+DoublePoint GetUnitNormal(const IntPoint &pt1, const IntPoint &pt2)
+{
+  if(pt2.X == pt1.X && pt2.Y == pt1.Y) 
+    return DoublePoint(0, 0);
+
+  double Dx = (double)(pt2.X - pt1.X);
+  double dy = (double)(pt2.Y - pt1.Y);
+  double f = 1 *1.0/ std::sqrt( Dx*Dx + dy*dy );
+  Dx *= f;
+  dy *= f;
+  return DoublePoint(dy, -Dx);
+}
+
+//------------------------------------------------------------------------------
+// ClipperOffset class
+//------------------------------------------------------------------------------
+
+ClipperOffset::ClipperOffset(double miterLimit, double arcTolerance)
+{
+  this->MiterLimit = miterLimit;
+  this->ArcTolerance = arcTolerance;
+  m_lowest.X = -1;
+}
+//------------------------------------------------------------------------------
+
+ClipperOffset::~ClipperOffset()
+{
+  Clear();
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::Clear()
+{
+  for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+    delete m_polyNodes.Childs[i];
+  m_polyNodes.Childs.clear();
+  m_lowest.X = -1;
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::AddPath(const Path& path, JoinType joinType, EndType endType)
+{
+  int highI = (int)path.size() - 1;
+  if (highI < 0) return;
+  PolyNode* newNode = new PolyNode();
+  newNode->m_jointype = joinType;
+  newNode->m_endtype = endType;
+
+  //strip duplicate points from path and also get index to the lowest point ...
+  if (endType == etClosedLine || endType == etClosedPolygon)
+    while (highI > 0 && path[0] == path[highI]) highI--;
+  newNode->Contour.reserve(highI + 1);
+  newNode->Contour.push_back(path[0]);
+  int j = 0, k = 0;
+  for (int i = 1; i <= highI; i++)
+    if (newNode->Contour[j] != path[i])
+    {
+      j++;
+      newNode->Contour.push_back(path[i]);
+      if (path[i].Y > newNode->Contour[k].Y ||
+        (path[i].Y == newNode->Contour[k].Y &&
+        path[i].X < newNode->Contour[k].X)) k = j;
+    }
+  if (endType == etClosedPolygon && j < 2)
+  {
+    delete newNode;
+    return;
+  }
+  m_polyNodes.AddChild(*newNode);
+
+  //if this path's lowest pt is lower than all the others then update m_lowest
+  if (endType != etClosedPolygon) return;
+  if (m_lowest.X < 0)
+    m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
+  else
+  {
+    IntPoint ip = m_polyNodes.Childs[(int)m_lowest.X]->Contour[(int)m_lowest.Y];
+    if (newNode->Contour[k].Y > ip.Y ||
+      (newNode->Contour[k].Y == ip.Y &&
+      newNode->Contour[k].X < ip.X))
+      m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
+  }
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::AddPaths(const Paths& paths, JoinType joinType, EndType endType)
+{
+  for (Paths::size_type i = 0; i < paths.size(); ++i)
+    AddPath(paths[i], joinType, endType);
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::FixOrientations()
+{
+  //fixup orientations of all closed paths if the orientation of the
+  //closed path with the lowermost vertex is wrong ...
+  if (m_lowest.X >= 0 && 
+    !Orientation(m_polyNodes.Childs[(int)m_lowest.X]->Contour))
+  {
+    for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+    {
+      PolyNode& node = *m_polyNodes.Childs[i];
+      if (node.m_endtype == etClosedPolygon ||
+        (node.m_endtype == etClosedLine && Orientation(node.Contour)))
+          ReversePath(node.Contour);
+    }
+  } else
+  {
+    for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+    {
+      PolyNode& node = *m_polyNodes.Childs[i];
+      if (node.m_endtype == etClosedLine && !Orientation(node.Contour))
+        ReversePath(node.Contour);
+    }
+  }
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::Execute(Paths& solution, double delta)
+{
+  solution.clear();
+  FixOrientations();
+  DoOffset(delta);
+  
+  //now clean up 'corners' ...
+  Clipper clpr;
+  clpr.AddPaths(m_destPolys, ptSubject, true);
+  if (delta > 0)
+  {
+    clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
+  }
+  else
+  {
+    IntRect r = clpr.GetBounds();
+    Path outer(4);
+    outer[0] = IntPoint(r.left - 10, r.bottom + 10);
+    outer[1] = IntPoint(r.right + 10, r.bottom + 10);
+    outer[2] = IntPoint(r.right + 10, r.top - 10);
+    outer[3] = IntPoint(r.left - 10, r.top - 10);
+
+    clpr.AddPath(outer, ptSubject, true);
+    clpr.ReverseSolution(true);
+    clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
+    if (solution.size() > 0) solution.erase(solution.begin());
+  }
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::Execute(PolyTree& solution, double delta)
+{
+  solution.Clear();
+  FixOrientations();
+  DoOffset(delta);
+
+  //now clean up 'corners' ...
+  Clipper clpr;
+  clpr.AddPaths(m_destPolys, ptSubject, true);
+  if (delta > 0)
+  {
+    clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
+  }
+  else
+  {
+    IntRect r = clpr.GetBounds();
+    Path outer(4);
+    outer[0] = IntPoint(r.left - 10, r.bottom + 10);
+    outer[1] = IntPoint(r.right + 10, r.bottom + 10);
+    outer[2] = IntPoint(r.right + 10, r.top - 10);
+    outer[3] = IntPoint(r.left - 10, r.top - 10);
+
+    clpr.AddPath(outer, ptSubject, true);
+    clpr.ReverseSolution(true);
+    clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
+    //remove the outer PolyNode rectangle ...
+    if (solution.ChildCount() == 1 && solution.Childs[0]->ChildCount() > 0)
+    {
+      PolyNode* outerNode = solution.Childs[0];
+      solution.Childs.reserve(outerNode->ChildCount());
+      solution.Childs[0] = outerNode->Childs[0];
+      solution.Childs[0]->Parent = outerNode->Parent;
+      for (int i = 1; i < outerNode->ChildCount(); ++i)
+        solution.AddChild(*outerNode->Childs[i]);
+    }
+    else
+      solution.Clear();
+  }
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::DoOffset(double delta)
+{
+  m_destPolys.clear();
+  m_delta = delta;
+
+  //if Zero offset, just copy any CLOSED polygons to m_p and return ...
+  if (NEAR_ZERO(delta)) 
+  {
+    m_destPolys.reserve(m_polyNodes.ChildCount());
+    for (int i = 0; i < m_polyNodes.ChildCount(); i++)
+    {
+      PolyNode& node = *m_polyNodes.Childs[i];
+      if (node.m_endtype == etClosedPolygon)
+        m_destPolys.push_back(node.Contour);
+    }
+    return;
+  }
+
+  //see offset_triginometry3.svg in the documentation folder ...
+  if (MiterLimit > 2) m_miterLim = 2/(MiterLimit * MiterLimit);
+  else m_miterLim = 0.5;
+
+  double y;
+  if (ArcTolerance <= 0.0) y = def_arc_tolerance;
+  else if (ArcTolerance > std::fabs(delta) * def_arc_tolerance) 
+    y = std::fabs(delta) * def_arc_tolerance;
+  else y = ArcTolerance;
+  //see offset_triginometry2.svg in the documentation folder ...
+  double steps = pi / std::acos(1 - y / std::fabs(delta));
+  if (steps > std::fabs(delta) * pi) 
+    steps = std::fabs(delta) * pi;  //ie excessive precision check
+  m_sin = std::sin(two_pi / steps);
+  m_cos = std::cos(two_pi / steps);
+  m_StepsPerRad = steps / two_pi;
+  if (delta < 0.0) m_sin = -m_sin;
+
+  m_destPolys.reserve(m_polyNodes.ChildCount() * 2);
+  for (int i = 0; i < m_polyNodes.ChildCount(); i++)
+  {
+    PolyNode& node = *m_polyNodes.Childs[i];
+    m_srcPoly = node.Contour;
+
+    int len = (int)m_srcPoly.size();
+    if (len == 0 || (delta <= 0 && (len < 3 || node.m_endtype != etClosedPolygon)))
+        continue;
+
+    m_destPoly.clear();
+    if (len == 1)
+    {
+      if (node.m_jointype == jtRound)
+      {
+        double X = 1.0, Y = 0.0;
+        for (cInt j = 1; j <= steps; j++)
+        {
+          m_destPoly.push_back(IntPoint(
+            Round(m_srcPoly[0].X + X * delta),
+            Round(m_srcPoly[0].Y + Y * delta)));
+          double X2 = X;
+          X = X * m_cos - m_sin * Y;
+          Y = X2 * m_sin + Y * m_cos;
+        }
+      }
+      else
+      {
+        double X = -1.0, Y = -1.0;
+        for (int j = 0; j < 4; ++j)
+        {
+          m_destPoly.push_back(IntPoint(
+            Round(m_srcPoly[0].X + X * delta),
+            Round(m_srcPoly[0].Y + Y * delta)));
+          if (X < 0) X = 1;
+          else if (Y < 0) Y = 1;
+          else X = -1;
+        }
+      }
+      m_destPolys.push_back(m_destPoly);
+      continue;
+    }
+    //build m_normals ...
+    m_normals.clear();
+    m_normals.reserve(len);
+    for (int j = 0; j < len - 1; ++j)
+      m_normals.push_back(GetUnitNormal(m_srcPoly[j], m_srcPoly[j + 1]));
+    if (node.m_endtype == etClosedLine || node.m_endtype == etClosedPolygon)
+      m_normals.push_back(GetUnitNormal(m_srcPoly[len - 1], m_srcPoly[0]));
+    else
+      m_normals.push_back(DoublePoint(m_normals[len - 2]));
+
+    if (node.m_endtype == etClosedPolygon)
+    {
+      int k = len - 1;
+      for (int j = 0; j < len; ++j)
+        OffsetPoint(j, k, node.m_jointype);
+      m_destPolys.push_back(m_destPoly);
+    }
+    else if (node.m_endtype == etClosedLine)
+    {
+      int k = len - 1;
+      for (int j = 0; j < len; ++j)
+        OffsetPoint(j, k, node.m_jointype);
+      m_destPolys.push_back(m_destPoly);
+      m_destPoly.clear();
+      //re-build m_normals ...
+      DoublePoint n = m_normals[len -1];
+      for (int j = len - 1; j > 0; j--)
+        m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
+      m_normals[0] = DoublePoint(-n.X, -n.Y);
+      k = 0;
+      for (int j = len - 1; j >= 0; j--)
+        OffsetPoint(j, k, node.m_jointype);
+      m_destPolys.push_back(m_destPoly);
+    }
+    else
+    {
+      int k = 0;
+      for (int j = 1; j < len - 1; ++j)
+        OffsetPoint(j, k, node.m_jointype);
+
+      IntPoint pt1;
+      if (node.m_endtype == etOpenButt)
+      {
+        int j = len - 1;
+        pt1 = IntPoint((cInt)Round(m_srcPoly[j].X + m_normals[j].X *
+          delta), (cInt)Round(m_srcPoly[j].Y + m_normals[j].Y * delta));
+        m_destPoly.push_back(pt1);
+        pt1 = IntPoint((cInt)Round(m_srcPoly[j].X - m_normals[j].X *
+          delta), (cInt)Round(m_srcPoly[j].Y - m_normals[j].Y * delta));
+        m_destPoly.push_back(pt1);
+      }
+      else
+      {
+        int j = len - 1;
+        k = len - 2;
+        m_sinA = 0;
+        m_normals[j] = DoublePoint(-m_normals[j].X, -m_normals[j].Y);
+        if (node.m_endtype == etOpenSquare)
+          DoSquare(j, k);
+        else
+          DoRound(j, k);
+      }
+
+      //re-build m_normals ...
+      for (int j = len - 1; j > 0; j--)
+        m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
+      m_normals[0] = DoublePoint(-m_normals[1].X, -m_normals[1].Y);
+
+      k = len - 1;
+      for (int j = k - 1; j > 0; --j) OffsetPoint(j, k, node.m_jointype);
+
+      if (node.m_endtype == etOpenButt)
+      {
+        pt1 = IntPoint((cInt)Round(m_srcPoly[0].X - m_normals[0].X * delta),
+          (cInt)Round(m_srcPoly[0].Y - m_normals[0].Y * delta));
+        m_destPoly.push_back(pt1);
+        pt1 = IntPoint((cInt)Round(m_srcPoly[0].X + m_normals[0].X * delta),
+          (cInt)Round(m_srcPoly[0].Y + m_normals[0].Y * delta));
+        m_destPoly.push_back(pt1);
+      }
+      else
+      {
+        k = 1;
+        m_sinA = 0;
+        if (node.m_endtype == etOpenSquare)
+          DoSquare(0, 1);
+        else
+          DoRound(0, 1);
+      }
+      m_destPolys.push_back(m_destPoly);
+    }
+  }
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::OffsetPoint(int j, int& k, JoinType jointype)
+{
+  //cross product ...
+  m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y);
+  if (std::fabs(m_sinA * m_delta) < 1.0) 
+  {
+    //dot product ...
+    double cosA = (m_normals[k].X * m_normals[j].X + m_normals[j].Y * m_normals[k].Y ); 
+    if (cosA > 0) // angle => 0 degrees
+    {
+      m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
+        Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
+      return; 
+    }
+    //else angle => 180 degrees   
+  }
+  else if (m_sinA > 1.0) m_sinA = 1.0;
+  else if (m_sinA < -1.0) m_sinA = -1.0;
+
+  if (m_sinA * m_delta < 0)
+  {
+    m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
+      Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
+    m_destPoly.push_back(m_srcPoly[j]);
+    m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
+      Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
+  }
+  else
+    switch (jointype)
+    {
+      case jtMiter:
+        {
+          double r = 1 + (m_normals[j].X * m_normals[k].X +
+            m_normals[j].Y * m_normals[k].Y);
+          if (r >= m_miterLim) DoMiter(j, k, r); else DoSquare(j, k);
+          break;
+        }
+      case jtSquare: DoSquare(j, k); break;
+      case jtRound: DoRound(j, k); break;
+    }
+  k = j;
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::DoSquare(int j, int k)
+{
+  double dx = std::tan(std::atan2(m_sinA,
+      m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y) / 4);
+  m_destPoly.push_back(IntPoint(
+      Round(m_srcPoly[j].X + m_delta * (m_normals[k].X - m_normals[k].Y * dx)),
+      Round(m_srcPoly[j].Y + m_delta * (m_normals[k].Y + m_normals[k].X * dx))));
+  m_destPoly.push_back(IntPoint(
+      Round(m_srcPoly[j].X + m_delta * (m_normals[j].X + m_normals[j].Y * dx)),
+      Round(m_srcPoly[j].Y + m_delta * (m_normals[j].Y - m_normals[j].X * dx))));
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::DoMiter(int j, int k, double r)
+{
+  double q = m_delta / r;
+  m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + (m_normals[k].X + m_normals[j].X) * q),
+      Round(m_srcPoly[j].Y + (m_normals[k].Y + m_normals[j].Y) * q)));
+}
+//------------------------------------------------------------------------------
+
+void ClipperOffset::DoRound(int j, int k)
+{
+  double a = std::atan2(m_sinA,
+  m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y);
+  int steps = std::max((int)Round(m_StepsPerRad * std::fabs(a)), 1);
+
+  double X = m_normals[k].X, Y = m_normals[k].Y, X2;
+  for (int i = 0; i < steps; ++i)
+  {
+    m_destPoly.push_back(IntPoint(
+        Round(m_srcPoly[j].X + X * m_delta),
+        Round(m_srcPoly[j].Y + Y * m_delta)));
+    X2 = X;
+    X = X * m_cos - m_sin * Y;
+    Y = X2 * m_sin + Y * m_cos;
+  }
+  m_destPoly.push_back(IntPoint(
+  Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
+  Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
+}
+
+//------------------------------------------------------------------------------
+// Miscellaneous public functions
+//------------------------------------------------------------------------------
+
+void Clipper::DoSimplePolygons()
+{
+  PolyOutList::size_type i = 0;
+  while (i < m_PolyOuts.size()) 
+  {
+    OutRec* outrec = m_PolyOuts[i++];
+    OutPt* op = outrec->Pts;
+    if (!op || outrec->IsOpen) continue;
+    do //for each Pt in Polygon until duplicate found do ...
+    {
+      OutPt* op2 = op->Next;
+      while (op2 != outrec->Pts) 
+      {
+        if ((op->Pt == op2->Pt) && op2->Next != op && op2->Prev != op) 
+        {
+          //split the polygon into two ...
+          OutPt* op3 = op->Prev;
+          OutPt* op4 = op2->Prev;
+          op->Prev = op4;
+          op4->Next = op;
+          op2->Prev = op3;
+          op3->Next = op2;
+
+          outrec->Pts = op;
+          OutRec* outrec2 = CreateOutRec();
+          outrec2->Pts = op2;
+          UpdateOutPtIdxs(*outrec2);
+          if (Poly2ContainsPoly1(outrec2->Pts, outrec->Pts))
+          {
+            //OutRec2 is contained by OutRec1 ...
+            outrec2->IsHole = !outrec->IsHole;
+            outrec2->FirstLeft = outrec;
+            if (m_UsingPolyTree) FixupFirstLefts2(outrec2, outrec);
+          }
+          else
+            if (Poly2ContainsPoly1(outrec->Pts, outrec2->Pts))
+          {
+            //OutRec1 is contained by OutRec2 ...
+            outrec2->IsHole = outrec->IsHole;
+            outrec->IsHole = !outrec2->IsHole;
+            outrec2->FirstLeft = outrec->FirstLeft;
+            outrec->FirstLeft = outrec2;
+            if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2);
+            }
+            else
+          {
+            //the 2 polygons are separate ...
+            outrec2->IsHole = outrec->IsHole;
+            outrec2->FirstLeft = outrec->FirstLeft;
+            if (m_UsingPolyTree) FixupFirstLefts1(outrec, outrec2);
+            }
+          op2 = op; //ie get ready for the Next iteration
+        }
+        op2 = op2->Next;
+      }
+      op = op->Next;
+    }
+    while (op != outrec->Pts);
+  }
+}
+//------------------------------------------------------------------------------
+
+void ReversePath(Path& p)
+{
+  std::reverse(p.begin(), p.end());
+}
+//------------------------------------------------------------------------------
+
+void ReversePaths(Paths& p)
+{
+  for (Paths::size_type i = 0; i < p.size(); ++i)
+    ReversePath(p[i]);
+}
+//------------------------------------------------------------------------------
+
+void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType)
+{
+  Clipper c;
+  c.StrictlySimple(true);
+  c.AddPath(in_poly, ptSubject, true);
+  c.Execute(ctUnion, out_polys, fillType, fillType);
+}
+//------------------------------------------------------------------------------
+
+void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType)
+{
+  Clipper c;
+  c.StrictlySimple(true);
+  c.AddPaths(in_polys, ptSubject, true);
+  c.Execute(ctUnion, out_polys, fillType, fillType);
+}
+//------------------------------------------------------------------------------
+
+void SimplifyPolygons(Paths &polys, PolyFillType fillType)
+{
+  SimplifyPolygons(polys, polys, fillType);
+}
+//------------------------------------------------------------------------------
+
+inline double DistanceSqrd(const IntPoint& pt1, const IntPoint& pt2)
+{
+  double Dx = ((double)pt1.X - pt2.X);
+  double dy = ((double)pt1.Y - pt2.Y);
+  return (Dx*Dx + dy*dy);
+}
+//------------------------------------------------------------------------------
+
+double DistanceFromLineSqrd(
+  const IntPoint& pt, const IntPoint& ln1, const IntPoint& ln2)
+{
+  //The equation of a line in general form (Ax + By + C = 0)
+  //given 2 points (x,y) & (x,y) is ...
+  //(y - y)x + (x - x)y + (y - y)x - (x - x)y = 0
+  //A = (y - y); B = (x - x); C = (y - y)x - (x - x)y
+  //perpendicular distance of point (x,y) = (Ax + By + C)/Sqrt(A + B)
+  //see http://en.wikipedia.org/wiki/Perpendicular_distance
+  double A = double(ln1.Y - ln2.Y);
+  double B = double(ln2.X - ln1.X);
+  double C = A * ln1.X  + B * ln1.Y;
+  C = A * pt.X + B * pt.Y - C;
+  return (C * C) / (A * A + B * B);
+}
+//---------------------------------------------------------------------------
+
+bool SlopesNearCollinear(const IntPoint& pt1, 
+    const IntPoint& pt2, const IntPoint& pt3, double distSqrd)
+{
+  //this function is more accurate when the point that's geometrically
+  //between the other 2 points is the one that's tested for distance.
+  //ie makes it more likely to pick up 'spikes' ...
+	if (Abs(pt1.X - pt2.X) > Abs(pt1.Y - pt2.Y))
+	{
+    if ((pt1.X > pt2.X) == (pt1.X < pt3.X))
+      return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+    else if ((pt2.X > pt1.X) == (pt2.X < pt3.X))
+      return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+		else
+	    return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+	}
+	else
+	{
+    if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y))
+      return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+    else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y))
+      return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+		else
+      return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+	}
+}
+//------------------------------------------------------------------------------
+
+bool PointsAreClose(IntPoint pt1, IntPoint pt2, double distSqrd)
+{
+    double Dx = (double)pt1.X - pt2.X;
+    double dy = (double)pt1.Y - pt2.Y;
+    return ((Dx * Dx) + (dy * dy) <= distSqrd);
+}
+//------------------------------------------------------------------------------
+
+OutPt* ExcludeOp(OutPt* op)
+{
+  OutPt* result = op->Prev;
+  result->Next = op->Next;
+  op->Next->Prev = result;
+  result->Idx = 0;
+  return result;
+}
+//------------------------------------------------------------------------------
+
+void CleanPolygon(const Path& in_poly, Path& out_poly, double distance)
+{
+  //distance = proximity in units/pixels below which vertices
+  //will be stripped. Default ~= sqrt(2).
+  
+  size_t size = in_poly.size();
+  
+  if (size == 0) 
+  {
+    out_poly.clear();
+    return;
+  }
+
+  OutPt* outPts = new OutPt[size];
+  for (size_t i = 0; i < size; ++i)
+  {
+    outPts[i].Pt = in_poly[i];
+    outPts[i].Next = &outPts[(i + 1) % size];
+    outPts[i].Next->Prev = &outPts[i];
+    outPts[i].Idx = 0;
+  }
+
+  double distSqrd = distance * distance;
+  OutPt* op = &outPts[0];
+  while (op->Idx == 0 && op->Next != op->Prev) 
+  {
+    if (PointsAreClose(op->Pt, op->Prev->Pt, distSqrd))
+    {
+      op = ExcludeOp(op);
+      size--;
+    } 
+    else if (PointsAreClose(op->Prev->Pt, op->Next->Pt, distSqrd))
+    {
+      ExcludeOp(op->Next);
+      op = ExcludeOp(op);
+      size -= 2;
+    }
+    else if (SlopesNearCollinear(op->Prev->Pt, op->Pt, op->Next->Pt, distSqrd))
+    {
+      op = ExcludeOp(op);
+      size--;
+    }
+    else
+    {
+      op->Idx = 1;
+      op = op->Next;
+    }
+  }
+
+  if (size < 3) size = 0;
+  out_poly.resize(size);
+  for (size_t i = 0; i < size; ++i)
+  {
+    out_poly[i] = op->Pt;
+    op = op->Next;
+  }
+  delete [] outPts;
+}
+//------------------------------------------------------------------------------
+
+void CleanPolygon(Path& poly, double distance)
+{
+  CleanPolygon(poly, poly, distance);
+}
+//------------------------------------------------------------------------------
+
+void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance)
+{
+  out_polys.resize(in_polys.size());
+  for (Paths::size_type i = 0; i < in_polys.size(); ++i)
+    CleanPolygon(in_polys[i], out_polys[i], distance);
+}
+//------------------------------------------------------------------------------
+
+void CleanPolygons(Paths& polys, double distance)
+{
+  CleanPolygons(polys, polys, distance);
+}
+//------------------------------------------------------------------------------
+
+void Minkowski(const Path& poly, const Path& path, 
+  Paths& solution, bool isSum, bool isClosed)
+{
+  int delta = (isClosed ? 1 : 0);
+  size_t polyCnt = poly.size();
+  size_t pathCnt = path.size();
+  Paths pp;
+  pp.reserve(pathCnt);
+  if (isSum)
+    for (size_t i = 0; i < pathCnt; ++i)
+    {
+      Path p;
+      p.reserve(polyCnt);
+      for (size_t j = 0; j < poly.size(); ++j)
+        p.push_back(IntPoint(path[i].X + poly[j].X, path[i].Y + poly[j].Y));
+      pp.push_back(p);
+    }
+  else
+    for (size_t i = 0; i < pathCnt; ++i)
+    {
+      Path p;
+      p.reserve(polyCnt);
+      for (size_t j = 0; j < poly.size(); ++j)
+        p.push_back(IntPoint(path[i].X - poly[j].X, path[i].Y - poly[j].Y));
+      pp.push_back(p);
+    }
+
+  solution.clear();
+  solution.reserve((pathCnt + delta) * (polyCnt + 1));
+  for (size_t i = 0; i < pathCnt - 1 + delta; ++i)
+    for (size_t j = 0; j < polyCnt; ++j)
+    {
+      Path quad;
+      quad.reserve(4);
+      quad.push_back(pp[i % pathCnt][j % polyCnt]);
+      quad.push_back(pp[(i + 1) % pathCnt][j % polyCnt]);
+      quad.push_back(pp[(i + 1) % pathCnt][(j + 1) % polyCnt]);
+      quad.push_back(pp[i % pathCnt][(j + 1) % polyCnt]);
+      if (!Orientation(quad)) ReversePath(quad);
+      solution.push_back(quad);
+    }
+}
+//------------------------------------------------------------------------------
+
+void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed)
+{
+  Minkowski(pattern, path, solution, true, pathIsClosed);
+  Clipper c;
+  c.AddPaths(solution, ptSubject, true);
+  c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+}
+//------------------------------------------------------------------------------
+
+void TranslatePath(const Path& input, Path& output, const IntPoint delta)
+{
+  //precondition: input != output
+  output.resize(input.size());
+  for (size_t i = 0; i < input.size(); ++i)
+    output[i] = IntPoint(input[i].X + delta.X, input[i].Y + delta.Y);
+}
+//------------------------------------------------------------------------------
+
+void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed)
+{
+  Clipper c;
+  for (size_t i = 0; i < paths.size(); ++i)
+  {
+    Paths tmp;
+    Minkowski(pattern, paths[i], tmp, true, pathIsClosed);
+    c.AddPaths(tmp, ptSubject, true);
+    if (pathIsClosed)
+    {
+      Path tmp2;
+      TranslatePath(paths[i], tmp2, pattern[0]);
+      c.AddPath(tmp2, ptClip, true);
+    }
+  }
+    c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+}
+//------------------------------------------------------------------------------
+
+void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution)
+{
+  Minkowski(poly1, poly2, solution, false, true);
+  Clipper c;
+  c.AddPaths(solution, ptSubject, true);
+  c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+}
+//------------------------------------------------------------------------------
+
+enum NodeType {ntAny, ntOpen, ntClosed};
+
+void AddPolyNodeToPaths(const PolyNode& polynode, NodeType nodetype, Paths& paths)
+{
+  bool match = true;
+  if (nodetype == ntClosed) match = !polynode.IsOpen();
+  else if (nodetype == ntOpen) return;
+
+  if (!polynode.Contour.empty() && match)
+    paths.push_back(polynode.Contour);
+  for (int i = 0; i < polynode.ChildCount(); ++i)
+    AddPolyNodeToPaths(*polynode.Childs[i], nodetype, paths);
+}
+//------------------------------------------------------------------------------
+
+void PolyTreeToPaths(const PolyTree& polytree, Paths& paths)
+{
+  paths.resize(0); 
+  paths.reserve(polytree.Total());
+  AddPolyNodeToPaths(polytree, ntAny, paths);
+}
+//------------------------------------------------------------------------------
+
+void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths)
+{
+  paths.resize(0); 
+  paths.reserve(polytree.Total());
+  AddPolyNodeToPaths(polytree, ntClosed, paths);
+}
+//------------------------------------------------------------------------------
+
+void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths)
+{
+  paths.resize(0); 
+  paths.reserve(polytree.Total());
+  //Open paths are top level only, so ...
+  for (int i = 0; i < polytree.ChildCount(); ++i)
+    if (polytree.Childs[i]->IsOpen())
+      paths.push_back(polytree.Childs[i]->Contour);
+}
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, const IntPoint &p)
+{
+  s << "(" << p.X << "," << p.Y << ")";
+  return s;
+}
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, const Path &p)
+{
+  if (p.empty()) return s;
+  Path::size_type last = p.size() -1;
+  for (Path::size_type i = 0; i < last; i++)
+    s << "(" << p[i].X << "," << p[i].Y << "), ";
+  s << "(" << p[last].X << "," << p[last].Y << ")\n";
+  return s;
+}
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, const Paths &p)
+{
+  for (Paths::size_type i = 0; i < p.size(); i++)
+    s << p[i];
+  s << "\n";
+  return s;
+}
+//------------------------------------------------------------------------------
+
+} //ClipperLib namespace

ppocr/postprocess/lanms/include/clipper/clipper.hpp

+/*******************************************************************************
+*                                                                              *
+* Author    :  Angus Johnson                                                   *
+* Version   :  6.4.0                                                           *
+* Date      :  2 July 2015                                                     *
+* Website   :  http://www.angusj.com                                           *
+* Copyright :  Angus Johnson 2010-2015                                         *
+*                                                                              *
+* License:                                                                     *
+* Use, modification & distribution is subject to Boost Software License Ver 1. *
+* http://www.boost.org/LICENSE_1_0.txt                                         *
+*                                                                              *
+* Attributions:                                                                *
+* The code in this library is an extension of Bala Vatti's clipping algorithm: *
+* "A generic solution to polygon clipping"                                     *
+* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.             *
+* http://portal.acm.org/citation.cfm?id=129906                                 *
+*                                                                              *
+* Computer graphics and geometric modeling: implementation and algorithms      *
+* By Max K. Agoston                                                            *
+* Springer; 1 edition (January 4, 2005)                                        *
+* http://books.google.com/books?q=vatti+clipping+agoston                       *
+*                                                                              *
+* See also:                                                                    *
+* "Polygon Offsetting by Computing Winding Numbers"                            *
+* Paper no. DETC2005-85513 pp. 565-575                                         *
+* ASME 2005 International Design Engineering Technical Conferences             *
+* and Computers and Information in Engineering Conference (IDETC/CIE2005)      *
+* September 24-28, 2005 , Long Beach, California, USA                          *
+* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf              *
+*                                                                              *
+*******************************************************************************/
+
+#ifndef clipper_hpp
+#define clipper_hpp
+
+#define CLIPPER_VERSION "6.2.6"
+
+//use_int32: When enabled 32bit ints are used instead of 64bit ints. This
+//improve performance but coordinate values are limited to the range +/- 46340
+//#define use_int32
+
+//use_xyz: adds a Z member to IntPoint. Adds a minor cost to perfomance.
+//#define use_xyz
+
+//use_lines: Enables line clipping. Adds a very minor cost to performance.
+#define use_lines
+
+//use_deprecated: Enables temporary support for the obsolete functions
+//#define use_deprecated
+
+#include <vector>
+#include <list>
+#include <set>
+#include <stdexcept>
+#include <cstring>
+#include <cstdlib>
+#include <ostream>
+#include <functional>
+#include <queue>
+
+namespace ClipperLib {
+
+enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };
+enum PolyType { ptSubject, ptClip };
+//By far the most widely used winding rules for polygon filling are
+//EvenOdd & NonZero (GDI, GDI+, XLib, OpenGL, Cairo, AGG, Quartz, SVG, Gr32)
+//Others rules include Positive, Negative and ABS_GTR_EQ_TWO (only in OpenGL)
+//see http://glprogramming.com/red/chapter11.html
+enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative };
+
+#ifdef use_int32
+  typedef int cInt;
+  static cInt const loRange = 0x7FFF;
+  static cInt const hiRange = 0x7FFF;
+#else
+  typedef signed long long cInt;
+  static cInt const loRange = 0x3FFFFFFF;
+  static cInt const hiRange = 0x3FFFFFFFFFFFFFFFLL;
+  typedef signed long long long64;     //used by Int128 class
+  typedef unsigned long long ulong64;
+
+#endif
+
+struct IntPoint {
+  cInt X;
+  cInt Y;
+#ifdef use_xyz
+  cInt Z;
+  IntPoint(cInt x = 0, cInt y = 0, cInt z = 0): X(x), Y(y), Z(z) {};
+#else
+  IntPoint(cInt x = 0, cInt y = 0): X(x), Y(y) {};
+#endif
+
+  friend inline bool operator== (const IntPoint& a, const IntPoint& b)
+  {
+    return a.X == b.X && a.Y == b.Y;
+  }
+  friend inline bool operator!= (const IntPoint& a, const IntPoint& b)
+  {
+    return a.X != b.X  || a.Y != b.Y;
+  }
+};
+//------------------------------------------------------------------------------
+
+typedef std::vector< IntPoint > Path;
+typedef std::vector< Path > Paths;
+
+inline Path& operator <<(Path& poly, const IntPoint& p) {poly.push_back(p); return poly;}
+inline Paths& operator <<(Paths& polys, const Path& p) {polys.push_back(p); return polys;}
+
+std::ostream& operator <<(std::ostream &s, const IntPoint &p);
+std::ostream& operator <<(std::ostream &s, const Path &p);
+std::ostream& operator <<(std::ostream &s, const Paths &p);
+
+struct DoublePoint
+{
+  double X;
+  double Y;
+  DoublePoint(double x = 0, double y = 0) : X(x), Y(y) {}
+  DoublePoint(IntPoint ip) : X((double)ip.X), Y((double)ip.Y) {}
+};
+//------------------------------------------------------------------------------
+
+#ifdef use_xyz
+typedef void (*ZFillCallback)(IntPoint& e1bot, IntPoint& e1top, IntPoint& e2bot, IntPoint& e2top, IntPoint& pt);
+#endif
+
+enum InitOptions {ioReverseSolution = 1, ioStrictlySimple = 2, ioPreserveCollinear = 4};
+enum JoinType {jtSquare, jtRound, jtMiter};
+enum EndType {etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound};
+
+class PolyNode;
+typedef std::vector< PolyNode* > PolyNodes;
+
+class PolyNode
+{
+public:
+    PolyNode();
+    virtual ~PolyNode(){};
+    Path Contour;
+    PolyNodes Childs;
+    PolyNode* Parent;
+    PolyNode* GetNext() const;
+    bool IsHole() const;
+    bool IsOpen() const;
+    int ChildCount() const;
+private:
+    unsigned Index; //node index in Parent.Childs
+    bool m_IsOpen;
+    JoinType m_jointype;
+    EndType m_endtype;
+    PolyNode* GetNextSiblingUp() const;
+    void AddChild(PolyNode& child);
+    friend class Clipper; //to access Index
+    friend class ClipperOffset;
+};
+
+class PolyTree: public PolyNode
+{
+public:
+    ~PolyTree(){Clear();};
+    PolyNode* GetFirst() const;
+    void Clear();
+    int Total() const;
+private:
+    PolyNodes AllNodes;
+    friend class Clipper; //to access AllNodes
+};
+
+bool Orientation(const Path &poly);
+double Area(const Path &poly);
+int PointInPolygon(const IntPoint &pt, const Path &path);
+
+void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
+void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
+void SimplifyPolygons(Paths &polys, PolyFillType fillType = pftEvenOdd);
+
+void CleanPolygon(const Path& in_poly, Path& out_poly, double distance = 1.415);
+void CleanPolygon(Path& poly, double distance = 1.415);
+void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance = 1.415);
+void CleanPolygons(Paths& polys, double distance = 1.415);
+
+void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed);
+void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed);
+void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution);
+
+void PolyTreeToPaths(const PolyTree& polytree, Paths& paths);
+void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths);
+void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths);
+
+void ReversePath(Path& p);
+void ReversePaths(Paths& p);
+
+struct IntRect { cInt left; cInt top; cInt right; cInt bottom; };
+
+//enums that are used internally ...
+enum EdgeSide { esLeft = 1, esRight = 2};
+
+//forward declarations (for stuff used internally) ...
+struct TEdge;
+struct IntersectNode;
+struct LocalMinimum;
+struct OutPt;
+struct OutRec;
+struct Join;
+
+typedef std::vector < OutRec* > PolyOutList;
+typedef std::vector < TEdge* > EdgeList;
+typedef std::vector < Join* > JoinList;
+typedef std::vector < IntersectNode* > IntersectList;
+
+//------------------------------------------------------------------------------
+
+//ClipperBase is the ancestor to the Clipper class. It should not be
+//instantiated directly. This class simply abstracts the conversion of sets of
+//polygon coordinates into edge objects that are stored in a LocalMinima list.
+class ClipperBase
+{
+public:
+  ClipperBase();
+  virtual ~ClipperBase();
+  virtual bool AddPath(const Path &pg, PolyType PolyTyp, bool Closed);
+  bool AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed);
+  virtual void Clear();
+  IntRect GetBounds();
+  bool PreserveCollinear() {return m_PreserveCollinear;};
+  void PreserveCollinear(bool value) {m_PreserveCollinear = value;};
+protected:
+  void DisposeLocalMinimaList();
+  TEdge* AddBoundsToLML(TEdge *e, bool IsClosed);
+  virtual void Reset();
+  TEdge* ProcessBound(TEdge* E, bool IsClockwise);
+  void InsertScanbeam(const cInt Y);
+  bool PopScanbeam(cInt &Y);
+  bool LocalMinimaPending();
+  bool PopLocalMinima(cInt Y, const LocalMinimum *&locMin);
+  OutRec* CreateOutRec();
+  void DisposeAllOutRecs();
+  void DisposeOutRec(PolyOutList::size_type index);
+  void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
+  void DeleteFromAEL(TEdge *e);
+  void UpdateEdgeIntoAEL(TEdge *&e);
+
+  typedef std::vector<LocalMinimum> MinimaList;
+  MinimaList::iterator m_CurrentLM;
+  MinimaList           m_MinimaList;
+
+  bool              m_UseFullRange;
+  EdgeList          m_edges;
+  bool              m_PreserveCollinear;
+  bool              m_HasOpenPaths;
+  PolyOutList       m_PolyOuts;
+  TEdge           *m_ActiveEdges;
+
+  typedef std::priority_queue<cInt> ScanbeamList;
+  ScanbeamList     m_Scanbeam;
+};
+//------------------------------------------------------------------------------
+
+class Clipper : public virtual ClipperBase
+{
+public:
+  Clipper(int initOptions = 0);
+  bool Execute(ClipType clipType,
+      Paths &solution,
+      PolyFillType fillType = pftEvenOdd);
+  bool Execute(ClipType clipType,
+      Paths &solution,
+      PolyFillType subjFillType,
+      PolyFillType clipFillType);
+  bool Execute(ClipType clipType,
+      PolyTree &polytree,
+      PolyFillType fillType = pftEvenOdd);
+  bool Execute(ClipType clipType,
+      PolyTree &polytree,
+      PolyFillType subjFillType,
+      PolyFillType clipFillType);
+  bool ReverseSolution() { return m_ReverseOutput; };
+  void ReverseSolution(bool value) {m_ReverseOutput = value;};
+  bool StrictlySimple() {return m_StrictSimple;};
+  void StrictlySimple(bool value) {m_StrictSimple = value;};
+  //set the callback function for z value filling on intersections (otherwise Z is 0)
+#ifdef use_xyz
+  void ZFillFunction(ZFillCallback zFillFunc);
+#endif
+protected:
+  virtual bool ExecuteInternal();
+private:
+  JoinList         m_Joins;
+  JoinList         m_GhostJoins;
+  IntersectList    m_IntersectList;
+  ClipType         m_ClipType;
+  typedef std::list<cInt> MaximaList;
+  MaximaList       m_Maxima;
+  TEdge           *m_SortedEdges;
+  bool             m_ExecuteLocked;
+  PolyFillType     m_ClipFillType;
+  PolyFillType     m_SubjFillType;
+  bool             m_ReverseOutput;
+  bool             m_UsingPolyTree;
+  bool             m_StrictSimple;
+#ifdef use_xyz
+  ZFillCallback   m_ZFill; //custom callback
+#endif
+  void SetWindingCount(TEdge& edge);
+  bool IsEvenOddFillType(const TEdge& edge) const;
+  bool IsEvenOddAltFillType(const TEdge& edge) const;
+  void InsertLocalMinimaIntoAEL(const cInt botY);
+  void InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge);
+  void AddEdgeToSEL(TEdge *edge);
+  bool PopEdgeFromSEL(TEdge *&edge);
+  void CopyAELToSEL();
+  void DeleteFromSEL(TEdge *e);
+  void SwapPositionsInSEL(TEdge *edge1, TEdge *edge2);
+  bool IsContributing(const TEdge& edge) const;
+  bool IsTopHorz(const cInt XPos);
+  void DoMaxima(TEdge *e);
+  void ProcessHorizontals();
+  void ProcessHorizontal(TEdge *horzEdge);
+  void AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
+  OutPt* AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
+  OutRec* GetOutRec(int idx);
+  void AppendPolygon(TEdge *e1, TEdge *e2);
+  void IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &pt);
+  OutPt* AddOutPt(TEdge *e, const IntPoint &pt);
+  OutPt* GetLastOutPt(TEdge *e);
+  bool ProcessIntersections(const cInt topY);
+  void BuildIntersectList(const cInt topY);
+  void ProcessIntersectList();
+  void ProcessEdgesAtTopOfScanbeam(const cInt topY);
+  void BuildResult(Paths& polys);
+  void BuildResult2(PolyTree& polytree);
+  void SetHoleState(TEdge *e, OutRec *outrec);
+  void DisposeIntersectNodes();
+  bool FixupIntersectionOrder();
+  void FixupOutPolygon(OutRec &outrec);
+  void FixupOutPolyline(OutRec &outrec);
+  bool IsHole(TEdge *e);
+  bool FindOwnerFromSplitRecs(OutRec &outRec, OutRec *&currOrfl);
+  void FixHoleLinkage(OutRec &outrec);
+  void AddJoin(OutPt *op1, OutPt *op2, const IntPoint offPt);
+  void ClearJoins();
+  void ClearGhostJoins();
+  void AddGhostJoin(OutPt *op, const IntPoint offPt);
+  bool JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2);
+  void JoinCommonEdges();
+  void DoSimplePolygons();
+  void FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec);
+  void FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec);
+  void FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec);
+#ifdef use_xyz
+  void SetZ(IntPoint& pt, TEdge& e1, TEdge& e2);
+#endif
+};
+//------------------------------------------------------------------------------
+
+class ClipperOffset
+{
+public:
+  ClipperOffset(double miterLimit = 2.0, double roundPrecision = 0.25);
+  ~ClipperOffset();
+  void AddPath(const Path& path, JoinType joinType, EndType endType);
+  void AddPaths(const Paths& paths, JoinType joinType, EndType endType);
+  void Execute(Paths& solution, double delta);
+  void Execute(PolyTree& solution, double delta);
+  void Clear();
+  double MiterLimit;
+  double ArcTolerance;
+private:
+  Paths m_destPolys;
+  Path m_srcPoly;
+  Path m_destPoly;
+  std::vector<DoublePoint> m_normals;
+  double m_delta, m_sinA, m_sin, m_cos;
+  double m_miterLim, m_StepsPerRad;
+  IntPoint m_lowest;
+  PolyNode m_polyNodes;
+
+  void FixOrientations();
+  void DoOffset(double delta);
+  void OffsetPoint(int j, int& k, JoinType jointype);
+  void DoSquare(int j, int k);
+  void DoMiter(int j, int k, double r);
+  void DoRound(int j, int k);
+};
+//------------------------------------------------------------------------------
+
+class clipperException : public std::exception
+{
+  public:
+    clipperException(const char* description): m_descr(description) {}
+    virtual ~clipperException() throw() {}
+    virtual const char* what() const throw() {return m_descr.c_str();}
+  private:
+    std::string m_descr;
+};
+//------------------------------------------------------------------------------
+
+} //ClipperLib namespace
+
+#endif //clipper_hpp
+
+

ppocr/postprocess/lanms/include/pybind11/attr.h

+/*
+    pybind11/attr.h: Infrastructure for processing custom
+    type and function attributes
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "cast.h"
+
+NAMESPACE_BEGIN(pybind11)
+
+/// \addtogroup annotations
+/// @{
+
+/// Annotation for methods
+struct is_method { handle class_; is_method(const handle &c) : class_(c) { } };
+
+/// Annotation for operators
+struct is_operator { };
+
+/// Annotation for parent scope
+struct scope { handle value; scope(const handle &s) : value(s) { } };
+
+/// Annotation for documentation
+struct doc { const char *value; doc(const char *value) : value(value) { } };
+
+/// Annotation for function names
+struct name { const char *value; name(const char *value) : value(value) { } };
+
+/// Annotation indicating that a function is an overload associated with a given "sibling"
+struct sibling { handle value; sibling(const handle &value) : value(value.ptr()) { } };
+
+/// Annotation indicating that a class derives from another given type
+template <typename T> struct base {
+    PYBIND11_DEPRECATED("base<T>() was deprecated in favor of specifying 'T' as a template argument to class_")
+    base() { }
+};
+
+/// Keep patient alive while nurse lives
+template <size_t Nurse, size_t Patient> struct keep_alive { };
+
+/// Annotation indicating that a class is involved in a multiple inheritance relationship
+struct multiple_inheritance { };
+
+/// Annotation which enables dynamic attributes, i.e. adds `__dict__` to a class
+struct dynamic_attr { };
+
+/// Annotation which enables the buffer protocol for a type
+struct buffer_protocol { };
+
+/// Annotation which requests that a special metaclass is created for a type
+struct metaclass {
+    handle value;
+
+    PYBIND11_DEPRECATED("py::metaclass() is no longer required. It's turned on by default now.")
+    metaclass() {}
+
+    /// Override pybind11's default metaclass
+    explicit metaclass(handle value) : value(value) { }
+};
+
+/// Annotation to mark enums as an arithmetic type
+struct arithmetic { };
+
+/** \rst
+    A call policy which places one or more guard variables (``Ts...``) around the function call.
+
+    For example, this definition:
+
+    .. code-block:: cpp
+
+        m.def("foo", foo, py::call_guard<T>());
+
+    is equivalent to the following pseudocode:
+
+    .. code-block:: cpp
+
+        m.def("foo", [](args...) {
+            T scope_guard;
+            return foo(args...); // forwarded arguments
+        });
+ \endrst */
+template <typename... Ts> struct call_guard;
+
+template <> struct call_guard<> { using type = detail::void_type; };
+
+template <typename T>
+struct call_guard<T> {
+    static_assert(std::is_default_constructible<T>::value,
+                  "The guard type must be default constructible");
+
+    using type = T;
+};
+
+template <typename T, typename... Ts>
+struct call_guard<T, Ts...> {
+    struct type {
+        T guard{}; // Compose multiple guard types with left-to-right default-constructor order
+        typename call_guard<Ts...>::type next{};
+    };
+};
+
+/// @} annotations
+
+NAMESPACE_BEGIN(detail)
+/* Forward declarations */
+enum op_id : int;
+enum op_type : int;
+struct undefined_t;
+template <op_id id, op_type ot, typename L = undefined_t, typename R = undefined_t> struct op_;
+template <typename... Args> struct init;
+template <typename... Args> struct init_alias;
+inline void keep_alive_impl(size_t Nurse, size_t Patient, function_call &call, handle ret);
+
+/// Internal data structure which holds metadata about a keyword argument
+struct argument_record {
+    const char *name;  ///< Argument name
+    const char *descr; ///< Human-readable version of the argument value
+    handle value;      ///< Associated Python object
+    bool convert : 1;  ///< True if the argument is allowed to convert when loading
+    bool none : 1;     ///< True if None is allowed when loading
+
+    argument_record(const char *name, const char *descr, handle value, bool convert, bool none)
+        : name(name), descr(descr), value(value), convert(convert), none(none) { }
+};
+
+/// Internal data structure which holds metadata about a bound function (signature, overloads, etc.)
+struct function_record {
+    function_record()
+        : is_constructor(false), is_stateless(false), is_operator(false),
+          has_args(false), has_kwargs(false), is_method(false) { }
+
+    /// Function name
+    char *name = nullptr; /* why no C++ strings? They generate heavier code.. */
+
+    // User-specified documentation string
+    char *doc = nullptr;
+
+    /// Human-readable version of the function signature
+    char *signature = nullptr;
+
+    /// List of registered keyword arguments
+    std::vector<argument_record> args;
+
+    /// Pointer to lambda function which converts arguments and performs the actual call
+    handle (*impl) (function_call &) = nullptr;
+
+    /// Storage for the wrapped function pointer and captured data, if any
+    void *data[3] = { };
+
+    /// Pointer to custom destructor for 'data' (if needed)
+    void (*free_data) (function_record *ptr) = nullptr;
+
+    /// Return value policy associated with this function
+    return_value_policy policy = return_value_policy::automatic;
+
+    /// True if name == '__init__'
+    bool is_constructor : 1;
+
+    /// True if this is a stateless function pointer
+    bool is_stateless : 1;
+
+    /// True if this is an operator (__add__), etc.
+    bool is_operator : 1;
+
+    /// True if the function has a '*args' argument
+    bool has_args : 1;
+
+    /// True if the function has a '**kwargs' argument
+    bool has_kwargs : 1;
+
+    /// True if this is a method
+    bool is_method : 1;
+
+    /// Number of arguments (including py::args and/or py::kwargs, if present)
+    std::uint16_t nargs;
+
+    /// Python method object
+    PyMethodDef *def = nullptr;
+
+    /// Python handle to the parent scope (a class or a module)
+    handle scope;
+
+    /// Python handle to the sibling function representing an overload chain
+    handle sibling;
+
+    /// Pointer to next overload
+    function_record *next = nullptr;
+};
+
+/// Special data structure which (temporarily) holds metadata about a bound class
+struct type_record {
+    PYBIND11_NOINLINE type_record()
+        : multiple_inheritance(false), dynamic_attr(false), buffer_protocol(false) { }
+
+    /// Handle to the parent scope
+    handle scope;
+
+    /// Name of the class
+    const char *name = nullptr;
+
+    // Pointer to RTTI type_info data structure
+    const std::type_info *type = nullptr;
+
+    /// How large is the underlying C++ type?
+    size_t type_size = 0;
+
+    /// How large is the type's holder?
+    size_t holder_size = 0;
+
+    /// The global operator new can be overridden with a class-specific variant
+    void *(*operator_new)(size_t) = ::operator new;
+
+    /// Function pointer to class_<..>::init_instance
+    void (*init_instance)(instance *, const void *) = nullptr;
+
+    /// Function pointer to class_<..>::dealloc
+    void (*dealloc)(const detail::value_and_holder &) = nullptr;
+
+    /// List of base classes of the newly created type
+    list bases;
+
+    /// Optional docstring
+    const char *doc = nullptr;
+
+    /// Custom metaclass (optional)
+    handle metaclass;
+
+    /// Multiple inheritance marker
+    bool multiple_inheritance : 1;
+
+    /// Does the class manage a __dict__?
+    bool dynamic_attr : 1;
+
+    /// Does the class implement the buffer protocol?
+    bool buffer_protocol : 1;
+
+    /// Is the default (unique_ptr) holder type used?
+    bool default_holder : 1;
+
+    PYBIND11_NOINLINE void add_base(const std::type_info &base, void *(*caster)(void *)) {
+        auto base_info = detail::get_type_info(base, false);
+        if (!base_info) {
+            std::string tname(base.name());
+            detail::clean_type_id(tname);
+            pybind11_fail("generic_type: type \"" + std::string(name) +
+                          "\" referenced unknown base type \"" + tname + "\"");
+        }
+
+        if (default_holder != base_info->default_holder) {
+            std::string tname(base.name());
+            detail::clean_type_id(tname);
+            pybind11_fail("generic_type: type \"" + std::string(name) + "\" " +
+                    (default_holder ? "does not have" : "has") +
+                    " a non-default holder type while its base \"" + tname + "\" " +
+                    (base_info->default_holder ? "does not" : "does"));
+        }
+
+        bases.append((PyObject *) base_info->type);
+
+        if (base_info->type->tp_dictoffset != 0)
+            dynamic_attr = true;
+
+        if (caster)
+            base_info->implicit_casts.emplace_back(type, caster);
+    }
+};
+
+inline function_call::function_call(function_record &f, handle p) :
+        func(f), parent(p) {
+    args.reserve(f.nargs);
+    args_convert.reserve(f.nargs);
+}
+
+/**
+ * Partial template specializations to process custom attributes provided to
+ * cpp_function_ and class_. These are either used to initialize the respective
+ * fields in the type_record and function_record data structures or executed at
+ * runtime to deal with custom call policies (e.g. keep_alive).
+ */
+template <typename T, typename SFINAE = void> struct process_attribute;
+
+template <typename T> struct process_attribute_default {
+    /// Default implementation: do nothing
+    static void init(const T &, function_record *) { }
+    static void init(const T &, type_record *) { }
+    static void precall(function_call &) { }
+    static void postcall(function_call &, handle) { }
+};
+
+/// Process an attribute specifying the function's name
+template <> struct process_attribute<name> : process_attribute_default<name> {
+    static void init(const name &n, function_record *r) { r->name = const_cast<char *>(n.value); }
+};
+
+/// Process an attribute specifying the function's docstring
+template <> struct process_attribute<doc> : process_attribute_default<doc> {
+    static void init(const doc &n, function_record *r) { r->doc = const_cast<char *>(n.value); }
+};
+
+/// Process an attribute specifying the function's docstring (provided as a C-style string)
+template <> struct process_attribute<const char *> : process_attribute_default<const char *> {
+    static void init(const char *d, function_record *r) { r->doc = const_cast<char *>(d); }
+    static void init(const char *d, type_record *r) { r->doc = const_cast<char *>(d); }
+};
+template <> struct process_attribute<char *> : process_attribute<const char *> { };
+
+/// Process an attribute indicating the function's return value policy
+template <> struct process_attribute<return_value_policy> : process_attribute_default<return_value_policy> {
+    static void init(const return_value_policy &p, function_record *r) { r->policy = p; }
+};
+
+/// Process an attribute which indicates that this is an overloaded function associated with a given sibling
+template <> struct process_attribute<sibling> : process_attribute_default<sibling> {
+    static void init(const sibling &s, function_record *r) { r->sibling = s.value; }
+};
+
+/// Process an attribute which indicates that this function is a method
+template <> struct process_attribute<is_method> : process_attribute_default<is_method> {
+    static void init(const is_method &s, function_record *r) { r->is_method = true; r->scope = s.class_; }
+};
+
+/// Process an attribute which indicates the parent scope of a method
+template <> struct process_attribute<scope> : process_attribute_default<scope> {
+    static void init(const scope &s, function_record *r) { r->scope = s.value; }
+};
+
+/// Process an attribute which indicates that this function is an operator
+template <> struct process_attribute<is_operator> : process_attribute_default<is_operator> {
+    static void init(const is_operator &, function_record *r) { r->is_operator = true; }
+};
+
+/// Process a keyword argument attribute (*without* a default value)
+template <> struct process_attribute<arg> : process_attribute_default<arg> {
+    static void init(const arg &a, function_record *r) {
+        if (r->is_method && r->args.empty())
+            r->args.emplace_back("self", nullptr, handle(), true /*convert*/, false /*none not allowed*/);
+        r->args.emplace_back(a.name, nullptr, handle(), !a.flag_noconvert, a.flag_none);
+    }
+};
+
+/// Process a keyword argument attribute (*with* a default value)
+template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
+    static void init(const arg_v &a, function_record *r) {
+        if (r->is_method && r->args.empty())
+            r->args.emplace_back("self", nullptr /*descr*/, handle() /*parent*/, true /*convert*/, false /*none not allowed*/);
+
+        if (!a.value) {
+#if !defined(NDEBUG)
+            std::string descr("'");
+            if (a.name) descr += std::string(a.name) + ": ";
+            descr += a.type + "'";
+            if (r->is_method) {
+                if (r->name)
+                    descr += " in method '" + (std::string) str(r->scope) + "." + (std::string) r->name + "'";
+                else
+                    descr += " in method of '" + (std::string) str(r->scope) + "'";
+            } else if (r->name) {
+                descr += " in function '" + (std::string) r->name + "'";
+            }
+            pybind11_fail("arg(): could not convert default argument "
+                          + descr + " into a Python object (type not registered yet?)");
+#else
+            pybind11_fail("arg(): could not convert default argument "
+                          "into a Python object (type not registered yet?). "
+                          "Compile in debug mode for more information.");
+#endif
+        }
+        r->args.emplace_back(a.name, a.descr, a.value.inc_ref(), !a.flag_noconvert, a.flag_none);
+    }
+};
+
+/// Process a parent class attribute.  Single inheritance only (class_ itself already guarantees that)
+template <typename T>
+struct process_attribute<T, enable_if_t<is_pyobject<T>::value>> : process_attribute_default<handle> {
+    static void init(const handle &h, type_record *r) { r->bases.append(h); }
+};
+
+/// Process a parent class attribute (deprecated, does not support multiple inheritance)
+template <typename T>
+struct process_attribute<base<T>> : process_attribute_default<base<T>> {
+    static void init(const base<T> &, type_record *r) { r->add_base(typeid(T), nullptr); }
+};
+
+/// Process a multiple inheritance attribute
+template <>
+struct process_attribute<multiple_inheritance> : process_attribute_default<multiple_inheritance> {
+    static void init(const multiple_inheritance &, type_record *r) { r->multiple_inheritance = true; }
+};
+
+template <>
+struct process_attribute<dynamic_attr> : process_attribute_default<dynamic_attr> {
+    static void init(const dynamic_attr &, type_record *r) { r->dynamic_attr = true; }
+};
+
+template <>
+struct process_attribute<buffer_protocol> : process_attribute_default<buffer_protocol> {
+    static void init(const buffer_protocol &, type_record *r) { r->buffer_protocol = true; }
+};
+
+template <>
+struct process_attribute<metaclass> : process_attribute_default<metaclass> {
+    static void init(const metaclass &m, type_record *r) { r->metaclass = m.value; }
+};
+
+
+/// Process an 'arithmetic' attribute for enums (does nothing here)
+template <>
+struct process_attribute<arithmetic> : process_attribute_default<arithmetic> {};
+
+template <typename... Ts>
+struct process_attribute<call_guard<Ts...>> : process_attribute_default<call_guard<Ts...>> { };
+
+/**
+ * Process a keep_alive call policy -- invokes keep_alive_impl during the
+ * pre-call handler if both Nurse, Patient != 0 and use the post-call handler
+ * otherwise
+ */
+template <size_t Nurse, size_t Patient> struct process_attribute<keep_alive<Nurse, Patient>> : public process_attribute_default<keep_alive<Nurse, Patient>> {
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
+    static void precall(function_call &call) { keep_alive_impl(Nurse, Patient, call, handle()); }
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
+    static void postcall(function_call &, handle) { }
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
+    static void precall(function_call &) { }
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
+    static void postcall(function_call &call, handle ret) { keep_alive_impl(Nurse, Patient, call, ret); }
+};
+
+/// Recursively iterate over variadic template arguments
+template <typename... Args> struct process_attributes {
+    static void init(const Args&... args, function_record *r) {
+        int unused[] = { 0, (process_attribute<typename std::decay<Args>::type>::init(args, r), 0) ... };
+        ignore_unused(unused);
+    }
+    static void init(const Args&... args, type_record *r) {
+        int unused[] = { 0, (process_attribute<typename std::decay<Args>::type>::init(args, r), 0) ... };
+        ignore_unused(unused);
+    }
+    static void precall(function_call &call) {
+        int unused[] = { 0, (process_attribute<typename std::decay<Args>::type>::precall(call), 0) ... };
+        ignore_unused(unused);
+    }
+    static void postcall(function_call &call, handle fn_ret) {
+        int unused[] = { 0, (process_attribute<typename std::decay<Args>::type>::postcall(call, fn_ret), 0) ... };
+        ignore_unused(unused);
+    }
+};
+
+template <typename T>
+using is_call_guard = is_instantiation<call_guard, T>;
+
+/// Extract the ``type`` from the first `call_guard` in `Extras...` (or `void_type` if none found)
+template <typename... Extra>
+using extract_guard_t = typename exactly_one_t<is_call_guard, call_guard<>, Extra...>::type;
+
+/// Check the number of named arguments at compile time
+template <typename... Extra,
+          size_t named = constexpr_sum(std::is_base_of<arg, Extra>::value...),
+          size_t self  = constexpr_sum(std::is_same<is_method, Extra>::value...)>
+constexpr bool expected_num_args(size_t nargs, bool has_args, bool has_kwargs) {
+    return named == 0 || (self + named + has_args + has_kwargs) == nargs;
+}
+
+NAMESPACE_END(detail)
+NAMESPACE_END(pybind11)

ppocr/postprocess/lanms/include/pybind11/buffer_info.h

+/*
+    pybind11/buffer_info.h: Python buffer object interface
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "common.h"
+
+NAMESPACE_BEGIN(pybind11)
+
+/// Information record describing a Python buffer object
+struct buffer_info {
+    void *ptr = nullptr;          // Pointer to the underlying storage
+    ssize_t itemsize = 0;         // Size of individual items in bytes
+    ssize_t size = 0;             // Total number of entries
+    std::string format;           // For homogeneous buffers, this should be set to format_descriptor<T>::format()
+    ssize_t ndim = 0;             // Number of dimensions
+    std::vector<ssize_t> shape;   // Shape of the tensor (1 entry per dimension)
+    std::vector<ssize_t> strides; // Number of entries between adjacent entries (for each per dimension)
+
+    buffer_info() { }
+
+    buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
+                detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in)
+    : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
+      shape(std::move(shape_in)), strides(std::move(strides_in)) {
+        if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size())
+            pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
+        for (size_t i = 0; i < (size_t) ndim; ++i)
+            size *= shape[i];
+    }
+
+    template <typename T>
+    buffer_info(T *ptr, detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in)
+    : buffer_info(private_ctr_tag(), ptr, sizeof(T), format_descriptor<T>::format(), static_cast<ssize_t>(shape_in->size()), std::move(shape_in), std::move(strides_in)) { }
+
+    buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t size)
+    : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}) { }
+
+    template <typename T>
+    buffer_info(T *ptr, ssize_t size)
+    : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size) { }
+
+    explicit buffer_info(Py_buffer *view, bool ownview = true)
+    : buffer_info(view->buf, view->itemsize, view->format, view->ndim,
+            {view->shape, view->shape + view->ndim}, {view->strides, view->strides + view->ndim}) {
+        this->view = view;
+        this->ownview = ownview;
+    }
+
+    buffer_info(const buffer_info &) = delete;
+    buffer_info& operator=(const buffer_info &) = delete;
+
+    buffer_info(buffer_info &&other) {
+        (*this) = std::move(other);
+    }
+
+    buffer_info& operator=(buffer_info &&rhs) {
+        ptr = rhs.ptr;
+        itemsize = rhs.itemsize;
+        size = rhs.size;
+        format = std::move(rhs.format);
+        ndim = rhs.ndim;
+        shape = std::move(rhs.shape);
+        strides = std::move(rhs.strides);
+        std::swap(view, rhs.view);
+        std::swap(ownview, rhs.ownview);
+        return *this;
+    }
+
+    ~buffer_info() {
+        if (view && ownview) { PyBuffer_Release(view); delete view; }
+    }
+
+private:
+    struct private_ctr_tag { };
+
+    buffer_info(private_ctr_tag, void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
+                detail::any_container<ssize_t> &&shape_in, detail::any_container<ssize_t> &&strides_in)
+    : buffer_info(ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in)) { }
+
+    Py_buffer *view = nullptr;
+    bool ownview = false;
+};
+
+NAMESPACE_BEGIN(detail)
+
+template <typename T, typename SFINAE = void> struct compare_buffer_info {
+    static bool compare(const buffer_info& b) {
+        return b.format == format_descriptor<T>::format() && b.itemsize == (ssize_t) sizeof(T);
+    }
+};
+
+template <typename T> struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
+    static bool compare(const buffer_info& b) {
+        return (size_t) b.itemsize == sizeof(T) && (b.format == format_descriptor<T>::value ||
+            ((sizeof(T) == sizeof(long)) && b.format == (std::is_unsigned<T>::value ? "L" : "l")) ||
+            ((sizeof(T) == sizeof(size_t)) && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
+    }
+};
+
+NAMESPACE_END(detail)
+NAMESPACE_END(pybind11)