[core] Replace clipper and libtess with earcut.hpp

2 files changed, 0 insertions, 5010 deletions

diff --git a/src/clipper/clipper.cpp b/src/clipper/clipper.cpp
deleted file mode 100755
index f5d8cd3c95..0000000000
--- a/src/clipper/clipper.cpp
+++ /dev/null
@@ -1,4612 +0,0 @@
-/*******************************************************************************
-*                                                                              *
-* Author    :  Angus Johnson                                                   *
-* Version   :  6.1.3a                                                          *
-* Date      :  22 January 2014                                                 *
-* Website   :  http://www.angusj.com                                           *
-* Copyright :  Angus Johnson 2010-2014                                         *
-*                                                                              *
-* 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>
-
-#pragma GCC diagnostic ignored "-Wshadow"
-
-namespace ClipperLib {
-
-#ifdef use_int32
-  static cInt const loRange = 46340;
-  static cInt const hiRange = 46340;
-#else
-  static cInt const loRange = 0x3FFFFFFF;
-  static cInt const hiRange = 0x3FFFFFFFFFFFFFFFLL;
-  typedef unsigned long long ulong64;
-#endif
-
-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;
-  IntPoint Top;
-  IntPoint Delta;
-  double Dx;
-  PolyType PolyTyp;
-  EdgeSide Side;
-  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 LocalMinima {
-  cInt          Y;
-  TEdge        *LeftBound;
-  TEdge        *RightBound;
-  LocalMinima  *Next;
-};
-
-struct OutPt;
-
-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;
-};
-
-//------------------------------------------------------------------------------
-//------------------------------------------------------------------------------
-
-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
-{
-  return (int)AllNodes.size();
-}
-
-//------------------------------------------------------------------------------
-// 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((cInt)9223372036854775807); //ie 2^63 -1
-//    Int128 val2((cInt)9223372036854775807);
-//    Int128 val3 = val1 * val2;
-//    val3.AsString => "85070591730234615847396907784232501249" (8.5e+37)
-//------------------------------------------------------------------------------
-
-class Int128
-{
-  public:
-
-    cUInt lo;
-    cInt hi;
-
-    Int128(cInt _lo = 0)
-    {
-      lo = (cUInt)_lo;   
-      if (_lo < 0)  hi = -1; else hi = 0; 
-    }
-
-
-    Int128(const Int128 &val): lo(val.lo), hi(val.hi){}
-
-    Int128(const cInt& _hi, const ulong64& _lo): lo(_lo), hi(_hi){}
-    
-    Int128& operator = (const cInt &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);
-    }
-
-    Int128 operator/ (const Int128 &rhs) const
-    {
-      if (rhs.lo == 0 && rhs.hi == 0)
-        throw "Int128 operator/: divide by zero";
-
-      bool negate = (rhs.hi < 0) != (hi < 0);
-      Int128 dividend = *this;
-      Int128 divisor = rhs;
-      if (dividend.hi < 0) dividend = -dividend;
-      if (divisor.hi < 0) divisor = -divisor;
-
-      if (divisor < dividend)
-      {
-          Int128 result = Int128(0);
-          Int128 cntr = Int128(1);
-          while (divisor.hi >= 0 && !(divisor > dividend))
-          {
-              divisor.hi <<= 1;
-              if ((cInt)divisor.lo < 0) divisor.hi++;
-              divisor.lo <<= 1;
-
-              cntr.hi <<= 1;
-              if ((cInt)cntr.lo < 0) cntr.hi++;
-              cntr.lo <<= 1;
-          }
-          divisor.lo >>= 1;
-          if ((divisor.hi & 1) == 1)
-              divisor.lo |= 0x8000000000000000LL; 
-          divisor.hi = (ulong64)divisor.hi >> 1;
-
-          cntr.lo >>= 1;
-          if ((cntr.hi & 1) == 1)
-              cntr.lo |= 0x8000000000000000LL; 
-          cntr.hi >>= 1;
-
-          while (cntr.hi != 0 || cntr.lo != 0)
-          {
-              if (!(dividend < divisor))
-              {
-                  dividend -= divisor;
-                  result.hi |= cntr.hi;
-                  result.lo |= cntr.lo;
-              }
-              divisor.lo >>= 1;
-              if ((divisor.hi & 1) == 1)
-                  divisor.lo |= 0x8000000000000000LL; 
-              divisor.hi >>= 1;
-
-              cntr.lo >>= 1;
-              if ((cntr.hi & 1) == 1)
-                  cntr.lo |= 0x8000000000000000LL; 
-              cntr.hi >>= 1;
-          }
-          if (negate) result = -result;
-          return result;
-      }
-      else if (rhs.hi == this->hi && rhs.lo == this->lo)
-          return Int128(negate ? -1: 1);
-      else
-          return Int128(0);
-    }
-
-    double AsDouble() const
-    {
-      const double shift64 = 18446744073709551616.0; //2^64
-      if (hi < 0)
-      {
-        cUInt lo_ = ~lo + 1;
-        if (lo_ == 0) return (double)hi * shift64;
-        else return -(double)(lo_ + ~hi * shift64);
-      }
-      else
-        return (double)(lo + hi * shift64);
-    }
-
-};
-//------------------------------------------------------------------------------
-
-Int128 Int128Mul (cInt lhs, cInt 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 = cInt(a + (c >> 32));
-  tmp.lo = cInt(c << 32);
-  tmp.lo += cInt(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 OutRec &outRec)
-{
-  OutPt *op = outRec.Pts;
-  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 != outRec.Pts);
-  return a * 0.5;
-}
-//------------------------------------------------------------------------------
-
-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;
-}
-//------------------------------------------------------------------------------
-
-int PointInPolygon (const IntPoint &pt, const Path &path)
-{
-  //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
-  //http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
-  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
-  //http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
-  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
-  {
-    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.Delta.Y, e2.Delta.X) == Int128Mul(e1.Delta.X, e2.Delta.Y);
-  else 
-#endif
-    return e1.Delta.Y * e2.Delta.X == e1.Delta.X * e2.Delta.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.Delta.Y == 0;
-}
-//------------------------------------------------------------------------------
-
-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)
-{
-  e.Delta.X = (e.Top.X - e.Bot.X);
-  e.Delta.Y = (e.Top.Y - e.Bot.Y);
-
-  if (e.Delta.Y == 0) e.Dx = HORIZONTAL;
-  else e.Dx = (double)(e.Delta.X) / e.Delta.Y;
-}
-//---------------------------------------------------------------------------
-
-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));
-}
-//------------------------------------------------------------------------------
-
-bool IntersectPoint(TEdge &Edge1, TEdge &Edge2,
-  IntPoint &ip, bool UseFullInt64Range)
-{
-#ifdef use_xyz  
-  ip.Z = 0;
-#endif
-  double b1, b2;
-  //nb: with very large coordinate values, it's possible for SlopesEqual() to 
-  //return false but for the edge.Dx value be equal due to double precision rounding.
-  if (SlopesEqual(Edge1, Edge2, UseFullInt64Range) || Edge1.Dx == Edge2.Dx)
-  {
-    if (Edge2.Bot.Y > Edge1.Bot.Y) ip = Edge2.Bot;
-    else ip = Edge1.Bot;
-    return false;
-  }
-  else if (Edge1.Delta.X == 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.Delta.X == 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);
-  } 
-  return true;
-}
-//------------------------------------------------------------------------------
-
-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.]
-  cInt tmp = e.Top.X;
-  e.Top.X = e.Bot.X;
-  e.Bot.X = tmp;
-#ifdef use_xyz  
-  tmp = e.Top.Z;
-  e.Top.Z = e.Bot.Z;
-  e.Bot.Z = tmp;
-#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));
-  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 FindSegment(OutPt* &pp, bool UseFullInt64Range, 
-  IntPoint &pt1, IntPoint &pt2)
-{
-  //OutPt1 & OutPt2 => the overlap segment (if the function returns true)
-  if (!pp) return false;
-  OutPt* pp2 = pp;
-  IntPoint pt1a = pt1, pt2a = pt2;
-  do
-  {
-    if (SlopesEqual(pt1a, pt2a, pp->Pt, pp->Prev->Pt, UseFullInt64Range) &&
-      SlopesEqual(pt1a, pt2a, pp->Pt, UseFullInt64Range) &&
-      GetOverlapSegment(pt1a, pt2a, pp->Pt, pp->Prev->Pt, pt1, pt2))
-        return true;
-    pp = pp->Next;
-  }
-  while (pp != pp2);
-  return false;
-}
-//------------------------------------------------------------------------------
-
-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);
-}
-//------------------------------------------------------------------------------
-
-OutPt* InsertPolyPtBetween(OutPt* p1, OutPt* p2, const IntPoint Pt)
-{
-  if (p1 == p2) throw "JoinError";
-  OutPt* result = new OutPt;
-  result->Pt = Pt;
-  if (p2 == p1->Next)
-  {
-    p1->Next = result;
-    p2->Prev = result;
-    result->Next = p2;
-    result->Prev = p1;
-  } else
-  {
-    p2->Next = result;
-    p1->Prev = result;
-    result->Next = p1;
-    result->Prev = p2;
-  }
-  return result;
-}
-//------------------------------------------------------------------------------
-
-bool HorzSegmentsOverlap(const IntPoint& pt1a, const IntPoint& pt1b, 
-    const IntPoint& pt2a, const IntPoint& pt2b)
-{
-  //precondition: both segments are horizontal
-  if ((pt1a.X > pt2a.X) == (pt1a.X < pt2b.X)) return true;
-  else if ((pt1b.X > pt2a.X) == (pt1b.X < pt2b.X)) return true;
-  else if ((pt2a.X > pt1a.X) == (pt2a.X < pt1b.X)) return true;
-  else if ((pt2b.X > pt1a.X) == (pt2b.X < pt1b.X)) return true;
-  else if ((pt1a.X == pt2a.X) && (pt1b.X == pt2b.X)) return true;
-  else if ((pt1a.X == pt2b.X) && (pt1b.X == pt2a.X)) return true;
-  else return false;
-}
-
-
-//------------------------------------------------------------------------------
-// ClipperBase class methods ...
-//------------------------------------------------------------------------------
-
-ClipperBase::ClipperBase() //constructor
-{
-  m_MinimaList = 0;
-  m_CurrentLM = 0;
-  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 "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 IsClockwise)
-{
-  TEdge *EStart = E, *Result = E;
-  TEdge *Horz = 0;
-  cInt StartX;
-  if (IsHorizontal(*E))
-  {
-    //it's possible for adjacent overlapping horz edges to start heading left
-    //before finishing right, so ...
-    if (IsClockwise) StartX = E->Prev->Bot.X;
-    else StartX = E->Next->Bot.X;
-    if (E->Bot.X != StartX) ReverseHorizontal(*E);
-  }
-  
-  if (Result->OutIdx != Skip)
-  {
-    if (IsClockwise)
-    {
-      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) 
-        {
-          if (!IsClockwise) Result = Horz->Prev;
-        }
-        else 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) 
-        {
-          if (!IsClockwise) Result = Horz->Next;
-        }
-        else if (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
-    }
-  }
-
-  if (Result->OutIdx == Skip) 
-  {
-    //if edges still remain in the current bound beyond the skip edge then
-    //create another LocMin and call ProcessBound once more
-    E = Result;
-    if (IsClockwise)
-    {
-      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 (IsClockwise) Result = E->Next;
-      else Result = E->Prev;
-    } else
-    {
-      //there are more edges in the bound beyond result starting with E
-      if (IsClockwise)
-        E = Result->Next; 
-      else
-        E = Result->Prev;
-      LocalMinima* locMin = new LocalMinima;
-      locMin->Next = 0;
-      locMin->Y = E->Bot.Y;
-      locMin->LeftBound = 0;
-      locMin->RightBound = E;
-      locMin->RightBound->WindDelta = 0;
-      Result = ProcessBound(locMin->RightBound, IsClockwise);
-      InsertLocalMinima(locMin);
-    }
-  }
-  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 (;;)
-  {
-    if ((E->Curr == E->Next->Curr))
-    {
-      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) 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;
-    if (E->Prev->Bot.X < E->Prev->Top.X) ReverseHorizontal(*E->Prev);
-    LocalMinima* locMin = new LocalMinima();
-    locMin->Next = 0;
-    locMin->Y = E->Bot.Y;
-    locMin->LeftBound = 0;
-    locMin->RightBound = E;
-    locMin->RightBound->Side = esRight;
-    locMin->RightBound->WindDelta = 0;
-    while (E->Next->OutIdx != Skip)
-    {
-      E->NextInLML = E->Next;
-      if (E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
-      E = E->Next;
-    }
-    InsertLocalMinima(locMin);
-    m_edges.push_back(edges);
-	  return true;
-  }
-
-  m_edges.push_back(edges);
-  bool clockwise;
-  TEdge* EMin = 0;
-  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 ...
-    LocalMinima* locMin = new LocalMinima;
-    locMin->Next = 0;
-    locMin->Y = E->Bot.Y;
-    if (E->Dx < E->Prev->Dx) 
-    {
-      locMin->LeftBound = E->Prev;
-      locMin->RightBound = E;
-      clockwise = false; //Q.nextInLML = Q.prev
-    } else
-    {
-      locMin->LeftBound = E;
-      locMin->RightBound = E->Prev;
-      clockwise = true; //Q.nextInLML = Q.next
-    }
-    locMin->LeftBound->Side = esLeft;
-    locMin->RightBound->Side = esRight;
-
-    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, clockwise);
-    TEdge* E2 = ProcessBound(locMin->RightBound, !clockwise);
-
-    if (locMin->LeftBound->OutIdx == Skip)
-      locMin->LeftBound = 0;
-    else if (locMin->RightBound->OutIdx == Skip)
-      locMin->RightBound = 0;
-    InsertLocalMinima(locMin);
-    if (!clockwise) 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::InsertLocalMinima(LocalMinima *newLm)
-{
-  if( ! m_MinimaList )
-  {
-    m_MinimaList = newLm;
-  }
-  else if( newLm->Y >= m_MinimaList->Y )
-  {
-    newLm->Next = m_MinimaList;
-    m_MinimaList = newLm;
-  } else
-  {
-    LocalMinima* tmpLm = m_MinimaList;
-    while( tmpLm->Next  && ( newLm->Y < tmpLm->Next->Y ) )
-      tmpLm = tmpLm->Next;
-    newLm->Next = tmpLm->Next;
-    tmpLm->Next = newLm;
-  }
-}
-//------------------------------------------------------------------------------
-
-void ClipperBase::Clear()
-{
-  DisposeLocalMinimaList();
-  for (EdgeList::size_type i = 0; i < m_edges.size(); ++i)
-  {
-    //for each edge array in turn, find the first used edge and 
-    //check for and remove any hiddenPts in each edge in the array.
-    TEdge* edges = m_edges[i];
-    delete [] edges;
-  }
-  m_edges.clear();
-  m_UseFullRange = false;
-  m_HasOpenPaths = false;
-}
-//------------------------------------------------------------------------------
-
-void ClipperBase::Reset()
-{
-  m_CurrentLM = m_MinimaList;
-  if( !m_CurrentLM ) return; //ie nothing to process
-
-  //reset all edges ...
-  LocalMinima* lm = m_MinimaList;
-  while( lm )
-  {
-    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;
-    }
-    lm = lm->Next;
-  }
-}
-//------------------------------------------------------------------------------
-
-void ClipperBase::DisposeLocalMinimaList()
-{
-  while( m_MinimaList )
-  {
-    LocalMinima* tmpLm = m_MinimaList->Next;
-    delete m_MinimaList;
-    m_MinimaList = tmpLm;
-  }
-  m_CurrentLM = 0;
-}
-//------------------------------------------------------------------------------
-
-void ClipperBase::PopLocalMinima()
-{
-  if( ! m_CurrentLM ) return;
-  m_CurrentLM = m_CurrentLM->Next;
-}
-//------------------------------------------------------------------------------
-
-IntRect ClipperBase::GetBounds()
-{
-  IntRect result;
-  LocalMinima* lm = m_MinimaList;
-  if (!lm)
-  {
-    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)
-  {
-    if (lm->LeftBound->Bot.Y > result.bottom)
-      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;
-      }
-      if (e->Bot.X < result.left) result.left = e->Bot.X;
-      if (e->Bot.X > result.right) result.right = e->Bot.X;
-      if (e->Top.X < result.left) result.left = e->Top.X;
-      if (e->Top.X > result.right) result.right = e->Top.X;
-      if (e->Top.Y < result.top) result.top = e->Top.Y;
-
-      if (bottomE == lm->LeftBound) e = lm->RightBound;
-      else break;
-    }
-    lm = lm->Next;
-  }
-  return result;
-}
-
-//------------------------------------------------------------------------------
-// TClipper methods ...
-//------------------------------------------------------------------------------
-
-Clipper::Clipper(int initOptions) : ClipperBase() //constructor
-{
-  m_ActiveEdges = 0;
-  m_SortedEdges = 0;
-  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
-}
-//------------------------------------------------------------------------------
-
-Clipper::~Clipper() //destructor
-{
-  Clear();
-  m_Scanbeam.clear();
-}
-//------------------------------------------------------------------------------
-
-#ifdef use_xyz  
-void Clipper::ZFillFunction(TZFillCallback zFillFunc)
-{  
-  m_ZFill = zFillFunc;
-}
-//------------------------------------------------------------------------------
-#endif
-
-void Clipper::Reset()
-{
-  ClipperBase::Reset();
-  m_Scanbeam.clear();
-  m_ActiveEdges = 0;
-  m_SortedEdges = 0;
-  LocalMinima* lm = m_MinimaList;
-  while (lm)
-  {
-    InsertScanbeam(lm->Y);
-    lm = lm->Next;
-  }
-}
-//------------------------------------------------------------------------------
-
-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 need 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();
-    if (!m_CurrentLM) return false;
-    cInt botY = PopScanbeam();
-    do {
-      InsertLocalMinimaIntoAEL(botY);
-      ClearGhostJoins();
-      ProcessHorizontals(false);
-      if (m_Scanbeam.empty()) break;
-      cInt topY = PopScanbeam();
-      succeeded = ProcessIntersections(botY, topY);
-      if (!succeeded) break;
-      ProcessEdgesAtTopOfScanbeam(topY);
-      botY = topY;
-    } while (!m_Scanbeam.empty() || m_CurrentLM);
-  }
-  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 && !outRec->IsOpen)
-        FixupOutPolygon(*outRec);
-    }
-
-    if (m_StrictSimple) DoSimplePolygons();
-  }
-
-  ClearJoins();
-  ClearGhostJoins();
-  return succeeded;
-}
-//------------------------------------------------------------------------------
-
-void Clipper::InsertScanbeam(const cInt Y)
-{
-  m_Scanbeam.insert(Y);
-}
-//------------------------------------------------------------------------------
-
-cInt Clipper::PopScanbeam()
-{
-  cInt Y = *m_Scanbeam.begin();
-  m_Scanbeam.erase(m_Scanbeam.begin());
-  return Y;
-}
-//------------------------------------------------------------------------------
-
-void Clipper::DisposeAllOutRecs(){
-  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
-    DisposeOutRec(i);
-  m_PolyOuts.clear();
-}
-//------------------------------------------------------------------------------
-
-void Clipper::DisposeOutRec(PolyOutList::size_type index)
-{
-  OutRec *outRec = m_PolyOuts[index];
-  if (outRec->Pts) DisposeOutPts(outRec->Pts);
-  delete outRec;
-  m_PolyOuts[index] = 0;
-}
-//------------------------------------------------------------------------------
-
-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)
-  {
-    edge.WindCnt = (edge.WindDelta == 0 ? 1 : 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 &&
-      (TopX(*prevE, Pt.Y) == TopX(*e, Pt.Y)) &&
-      SlopesEqual(*e, *prevE, m_UseFullRange) &&
-      (e->WindDelta != 0) && (prevE->WindDelta != 0))
-  {
-    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;
-  }
-}
-//------------------------------------------------------------------------------
-
-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)
-{
-  while(  m_CurrentLM  && ( m_CurrentLM->Y == botY ) )
-  {
-    TEdge* lb = m_CurrentLM->LeftBound;
-    TEdge* rb = m_CurrentLM->RightBound;
-    PopLocalMinima();
-    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);
-       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, jr->OffPt, rb->Bot, rb->Top))
-          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, *lb, 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, *rb, 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::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;
-}
-//------------------------------------------------------------------------------
-
-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& e)
-{
-  pt.Z = 0;
-  if (m_ZFill)
-  {
-    //put the 'preferred' point as first parameter ...
-    if (e.OutIdx < 0)
-      (*m_ZFill)(e.Bot, e.Top, pt); //outside a path so presume entering
-    else
-      (*m_ZFill)(e.Top, e.Bot, pt); //inside a path so presume exiting
-  }
-}
-//------------------------------------------------------------------------------
-#endif
-
-void Clipper::IntersectEdges(TEdge *e1, TEdge *e2,
-     const IntPoint &Pt, bool protect)
-{
-  //e1 will be to the Left of e2 BELOW the intersection. Therefore e1 is before
-  //e2 in AEL except when e1 is being inserted at the intersection point ...
-  bool e1stops = !protect &&  !e1->NextInLML &&
-    e1->Top.X == Pt.X && e1->Top.Y == Pt.Y;
-  bool e2stops = !protect &&  !e2->NextInLML &&
-    e2->Top.X == Pt.X && e2->Top.Y == Pt.Y;
-  bool e1Contributing = ( e1->OutIdx >= 0 );
-  bool e2Contributing = ( e2->OutIdx >= 0 );
-
-#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)
-    {
-      if ((e1stops || e2stops) && e1Contributing && e2Contributing)
-        AddLocalMaxPoly(e1, e2, Pt);
-    }
-
-    //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) && std::abs(e2->WindCnt) == 1 &&
-        (m_ClipType != ctUnion || e2->WindCnt2 == 0))
-      {
-        AddOutPt(e1, Pt);
-        if (e1Contributing) e1->OutIdx = Unassigned;
-      }
-      else if ((e2->WindDelta == 0) && (std::abs(e1->WindCnt) == 1) &&
-        (m_ClipType != ctUnion || e1->WindCnt2 == 0))
-      {
-        AddOutPt(e2, Pt);
-        if (e2Contributing) e2->OutIdx = Unassigned;
-      }
-    }
-
-    if (e1stops)
-      if (e1->OutIdx < 0) DeleteFromAEL(e1);
-      else throw clipperException("Error intersecting polylines");
-    if (e2stops) 
-      if (e2->OutIdx < 0) DeleteFromAEL(e2);
-      else throw clipperException("Error intersecting polylines");
-    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 ( e1stops || e2stops || 
-      (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) && !e1stops && !e2stops )
-  {
-    //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 );
-  }
-
-  if(  (e1stops != e2stops) &&
-    ( (e1stops && (e1->OutIdx >= 0)) || (e2stops && (e2->OutIdx >= 0)) ) )
-  {
-    SwapSides( *e1, *e2 );
-    SwapPolyIndexes( *e1, *e2 );
-  }
-
-  //finally, delete any non-contributing maxima edges  ...
-  if( e1stops ) DeleteFromAEL( e1 );
-  if( e2stops ) DeleteFromAEL( e2 );
-}
-//------------------------------------------------------------------------------
-
-void Clipper::SetHoleState(TEdge *e, OutRec *outrec)
-{
-  bool IsHole = false;
-  TEdge *e2 = e->PrevInAEL;
-  while (e2)
-  {
-    if (e2->OutIdx >= 0 && e2->WindDelta != 0)
-    {
-      IsHole = !IsHole;
-      if (! outrec->FirstLeft)
-        outrec->FirstLeft = m_PolyOuts[e2->OutIdx];
-    }
-    e2 = e2->PrevInAEL;
-  }
-  if (IsHole) outrec->IsHole = true;
-}
-//------------------------------------------------------------------------------
-
-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 Param1RightOfParam2(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 (Param1RightOfParam2(outRec1, outRec2)) 
-    holeStateRec = outRec2;
-  else if (Param1RightOfParam2(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;
-
-  EdgeSide Side;
-  //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;
-    }
-    Side = esLeft;
-  } 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;
-    }
-    Side = esRight;
-  }
-
-  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 = Side;
-      break;
-    }
-    e = e->NextInAEL;
-  }
-
-  outRec2->Idx = outRec1->Idx;
-}
-//------------------------------------------------------------------------------
-
-OutRec* Clipper::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;
-}
-//------------------------------------------------------------------------------
-
-OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt)
-{
-  bool ToFront = (e->Side == esLeft);
-  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);
-#ifdef use_xyz
-    if (pt == e->Bot) newOp->Pt = e->Bot;
-    else if (pt == e->Top) newOp->Pt = e->Top;
-    else SetZ(newOp->Pt, *e);
-#endif
-    e->OutIdx = outRec->Idx; //nb: do this after SetZ !
-    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;
-
-    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;
-#ifdef use_xyz
-    if (pt == e->Bot) newOp->Pt = e->Bot;
-    else if (pt == e->Top) newOp->Pt = e->Top;
-    else SetZ(newOp->Pt, *e);
-#endif
-    return newOp;
-  }
-}
-//------------------------------------------------------------------------------
-
-void Clipper::ProcessHorizontals(bool IsTopOfScanbeam)
-{
-  TEdge* horzEdge = m_SortedEdges;
-  while(horzEdge)
-  {
-    DeleteFromSEL(horzEdge);
-    ProcessHorizontal(horzEdge, IsTopOfScanbeam);
-    horzEdge = m_SortedEdges;
-  }
-}
-//------------------------------------------------------------------------------
-
-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)
-{
-  TEdge* result = 0;
-  if ((e->Next->Top == e->Top) && !e->Next->NextInLML)
-    result = e->Next;
-  else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML)
-    result = e->Prev;
-
-  if (result && (result->OutIdx == Skip ||
-    //result is false if both NextInAEL & PrevInAEL are nil & not horizontal ...
-    (result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result))))
-      return 0;
-  return result;
-}
-//------------------------------------------------------------------------------
-
-void Clipper::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 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;
-  }
-}
-//------------------------------------------------------------------------
-
-void Clipper::PrepareHorzJoins(TEdge* horzEdge, bool isTopOfScanbeam)
-{
-  //get the last Op for this horizontal edge
-  //the point may be anywhere along the horizontal ...
-  OutPt* outPt = m_PolyOuts[horzEdge->OutIdx]->Pts;
-  if (horzEdge->Side != esLeft) outPt = outPt->Prev;
-
-  //First, match up overlapping horizontal edges (eg when one polygon's
-  //intermediate horz edge overlaps an intermediate horz edge of another, or
-  //when one polygon sits on top of another) ...
-  //for (JoinList::size_type i = 0; i < m_GhostJoins.size(); ++i)
-  //{
-  //  Join* j = m_GhostJoins[i];
-  //  if (HorzSegmentsOverlap(j->OutPt1->Pt, j->OffPt, horzEdge->Bot, horzEdge->Top))
-  //      AddJoin(j->OutPt1, outPt, j->OffPt);
-  //}
-
-  //Also, since horizontal edges at the top of one SB are often removed from
-  //the AEL before we process the horizontal edges at the bottom of the next,
-  //we need to create 'ghost' Join records of 'contrubuting' horizontals that
-  //we can compare with horizontals at the bottom of the next SB.
-  if (isTopOfScanbeam) 
-  {
-    if (outPt->Pt == horzEdge->Top)
-      AddGhostJoin(outPt, horzEdge->Bot); 
-    else
-      AddGhostJoin(outPt, horzEdge->Top);
-  }
-}
-//------------------------------------------------------------------------------
-
-/*******************************************************************************
-* 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, bool isTopOfScanbeam)
-{
-  Direction dir;
-  cInt horzLeft, horzRight;
-
-  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);
-
-  for (;;)
-  {
-    bool IsLastHorz = (horzEdge == eLastHorz);
-    TEdge* e = GetNextInAEL(horzEdge, dir);
-    while(e)
-    {
-      //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;
-
-      TEdge* eNext = GetNextInAEL(e, dir); //saves eNext for later
-
-      if ((dir == dLeftToRight && e->Curr.X <= horzRight) ||
-        (dir == dRightToLeft && e->Curr.X >= horzLeft))
-      {
-        if (horzEdge->OutIdx >= 0 && horzEdge->WindDelta != 0) 
-          PrepareHorzJoins(horzEdge, isTopOfScanbeam);
-        //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 (dir == dLeftToRight)
-            IntersectEdges(horzEdge, e, e->Top);
-          else
-            IntersectEdges(e, horzEdge, e->Top);
-          if (eMaxPair->OutIdx >= 0) throw clipperException("ProcessHorizontal error");
-          return;
-        }
-        else if(dir == dLeftToRight)
-        {
-          IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
-          IntersectEdges(horzEdge, e, Pt, true);
-        }
-        else
-        {
-          IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
-          IntersectEdges( e, horzEdge, Pt, true);
-        }
-        SwapPositionsInAEL( horzEdge, e );
-      }
-      else if( (dir == dLeftToRight && e->Curr.X >= horzRight) ||
-       (dir == dRightToLeft && e->Curr.X <= horzLeft) ) break;
-      e = eNext;
-    } //end while
-
-    if (horzEdge->OutIdx >= 0 && horzEdge->WindDelta != 0)
-      PrepareHorzJoins(horzEdge, isTopOfScanbeam);
-
-    if (horzEdge->NextInLML && IsHorizontal(*horzEdge->NextInLML))
-    {
-      UpdateEdgeIntoAEL(horzEdge);
-      if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Bot);
-      GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
-    } else
-      break;
-  } //end for (;;)
-
-  if(horzEdge->NextInLML)
-  {
-    if(horzEdge->OutIdx >= 0)
-    {
-      OutPt* 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 (eMaxPair)
-  {
-    if (eMaxPair->OutIdx >= 0)
-    {
-      if (dir == dLeftToRight)
-        IntersectEdges(horzEdge, eMaxPair, horzEdge->Top); 
-      else
-        IntersectEdges(eMaxPair, horzEdge, horzEdge->Top);
-      if (eMaxPair->OutIdx >= 0)
-        throw clipperException("ProcessHorizontal error");
-    } else
-    {
-      DeleteFromAEL(horzEdge);
-      DeleteFromAEL(eMaxPair);
-    }
-  } else
-  {
-    if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top);
-    DeleteFromAEL(horzEdge);
-  }
-}
-//------------------------------------------------------------------------------
-
-void Clipper::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 Clipper::ProcessIntersections(const cInt botY, const cInt topY)
-{
-  if( !m_ActiveEdges ) return true;
-  try {
-    BuildIntersectList(botY, 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 botY, 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)
-      {
-        if (!IntersectPoint(*e, *eNext, Pt, m_UseFullRange) && e->Curr.X > eNext->Curr.X +1)
-          throw clipperException("Intersection error");
-        if (Pt.Y > botY)
-        {
-            Pt.Y = botY;
-            if (std::fabs(e->Dx) > std::fabs(eNext->Dx))
-              Pt.X = TopX(*eNext, botY); else
-              Pt.X = TopX(*e, botY);
-        }
-
-        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, true);
-      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 = GetMaximaPair(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, true);
-    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 )
-  {
-    IntersectEdges( e, eMaxPair, e->Top);
-  }
-#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 = GetMaximaPair(e);
-      IsMaximaEdge = (!eMaxPair || !IsHorizontal(*eMaxPair));
-    }
-
-    if(IsMaximaEdge)
-    {
-      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;
-      }
-
-      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))
-        {
-          OutPt* op = AddOutPt(ePrev, e->Curr);
-          OutPt* op2 = AddOutPt(e, e->Curr);
-          AddJoin(op, op2, e->Curr); //StrictlySimple (type-3) join
-        }
-      }
-
-      e = e->NextInAEL;
-    }
-  }
-
-  //3. Process horizontals at the Top of the scanbeam ...
-  ProcessHorizontals(true);
-
-  //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, *ePrev, 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, *eNext, m_UseFullRange) &&
-        (e->WindDelta != 0) && (eNext->WindDelta != 0))
-      {
-        OutPt* op2 = AddOutPt(eNext, e->Bot);
-        AddJoin(op, op2, e->Top);
-      }
-    }
-    e = e->NextInAEL;
-  }
-}
-//------------------------------------------------------------------------------
-
-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;
-
-  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) &&
-      (!m_PreserveCollinear || 
-      !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 j = 0; j < cnt; ++j)
-    {
-      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 a 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 ...
-    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;
-    }
-  }
-}
-//----------------------------------------------------------------------
-
-void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec)
-{ 
-  
-  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
-  {
-    OutRec* outRec = m_PolyOuts[i];
-    if (outRec->Pts && outRec->FirstLeft == OldOutRec) 
-    {
-      if (Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts))
-        outRec->FirstLeft = NewOutRec;
-    }
-  }
-}
-//----------------------------------------------------------------------
-
-void Clipper::FixupFirstLefts2(OutRec* OldOutRec, OutRec* NewOutRec)
-{ 
-  for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
-  {
-    OutRec* outRec = m_PolyOuts[i];
-    if (outRec->FirstLeft == OldOutRec) outRec->FirstLeft = NewOutRec;
-  }
-}
-//----------------------------------------------------------------------
-
-static OutRec* ParseFirstLeft(OutRec* FirstLeft)
-{
-  while (FirstLeft && !FirstLeft->Pts) 
-    FirstLeft = FirstLeft->FirstLeft;
-  return FirstLeft;
-}
-//------------------------------------------------------------------------------
-
-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;
-
-    //get the polygon fragment with the correct hole state (FirstLeft)
-    //before calling JoinPoints() ...
-    OutRec *holeStateRec;
-    if (outRec1 == outRec2) holeStateRec = outRec1;
-    else if (Param1RightOfParam2(outRec1, outRec2)) holeStateRec = outRec2;
-    else if (Param1RightOfParam2(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);
-
-      //We now need to check every OutRec.FirstLeft pointer. If it points
-      //to OutRec1 it may need to point to OutRec2 instead ...
-      if (m_UsingPolyTree)
-        for (PolyOutList::size_type j = 0; j < m_PolyOuts.size() - 1; j++)
-        {
-          OutRec* oRec = m_PolyOuts[j];
-          if (!oRec->Pts || ParseFirstLeft(oRec->FirstLeft) != outRec1 ||
-            oRec->IsHole == outRec1->IsHole) continue;
-          if (Poly2ContainsPoly1(oRec->Pts, join->OutPt2))
-            oRec->FirstLeft = outRec2;
-        }
-
-      if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts))
-      {
-        //outRec2 is contained by outRec1 ...
-        outRec2->IsHole = !outRec1->IsHole;
-        outRec2->FirstLeft = outRec1;
-
-        //fixup FirstLeft pointers that may need reassigning to 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))
-      {
-        //outRec1 is contained by outRec2 ...
-        outRec2->IsHole = outRec1->IsHole;
-        outRec1->IsHole = !outRec2->IsHole;
-        outRec2->FirstLeft = outRec1->FirstLeft;
-        outRec1->FirstLeft = outRec2;
-
-        //fixup FirstLeft pointers that may need reassigning to OutRec1
-        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;
-
-      //fixup FirstLeft pointers that may need reassigning to OutRec1
-      if (m_UsingPolyTree) FixupFirstLefts2(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) || 
-    (endType != etClosedPolygon && j < 0))
-  {
-    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(0, 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];
-      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)
-{
-  m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y);
-  if (m_sinA < 0.00005 && m_sinA > -0.00005) return;
-  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 = (int)Round(m_StepsPerRad * std::fabs(a));
-
-  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) 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;
-          }
-          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;
-          } else
-          {
-            //the 2 polygons are separate ...
-            outrec2->IsHole = outrec->IsHole;
-            outrec2->FirstLeft = outrec->FirstLeft;
-          }
-          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 (x¹,y¹) & (x²,y²) is ...
-  //(y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0
-  //A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹
-  //perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²)
-  //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)
-{
-  return DistanceFromLineSqrd(pt2, pt1, pt3) < 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)
-{
-  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);
-    }
-
-  Paths quads; 
-  quads.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);
-      quads.push_back(quad);
-    }
-
-  Clipper c;
-  c.AddPaths(quads, ptSubject, true);
-  c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
-}
-//------------------------------------------------------------------------------
-
-void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed)
-{
-  Minkowski(pattern, path, solution, true, pathIsClosed);
-}
-//------------------------------------------------------------------------------
-
-void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, 
-    PolyFillType pathFillType, 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) c.AddPaths(paths, ptClip, true);
-  c.Execute(ctUnion, solution, pathFillType, pathFillType);
-}
-//------------------------------------------------------------------------------
-
-void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution)
-{
-  Minkowski(poly1, poly2, solution, false, true);
-}
-//------------------------------------------------------------------------------
-
-enum NodeType {ntAny, ntOpen, ntClosed};
-
-void AddPolyNodeToPolygons(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)
-    AddPolyNodeToPolygons(*polynode.Childs[i], nodetype, paths);
-}
-//------------------------------------------------------------------------------
-
-void PolyTreeToPaths(const PolyTree& polytree, Paths& paths)
-{
-  paths.resize(0); 
-  paths.reserve(polytree.Total());
-  AddPolyNodeToPolygons(polytree, ntAny, paths);
-}
-//------------------------------------------------------------------------------
-
-void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths)
-{
-  paths.resize(0); 
-  paths.reserve(polytree.Total());
-  AddPolyNodeToPolygons(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;
-}
-//------------------------------------------------------------------------------
-
-#ifdef use_deprecated
-
-void OffsetPaths(const Paths &in_polys, Paths &out_polys,
-  double delta, JoinType jointype, EndType_ endtype, double limit)
-{
-  ClipperOffset co(limit, limit);
-  co.AddPaths(in_polys, jointype, (EndType)endtype); 
-  co.Execute(out_polys, delta);
-}
-//------------------------------------------------------------------------------
-
-#endif
-
-
-} //ClipperLib namespace
diff --git a/src/clipper/clipper.hpp b/src/clipper/clipper.hpp
deleted file mode 100755
index 84870141e7..0000000000
--- a/src/clipper/clipper.hpp
+++ /dev/null
@@ -1,398 +0,0 @@
-/*******************************************************************************
-*                                                                              *
-* Author    :  Angus Johnson                                                   *
-* Version   :  6.1.3a                                                          *
-* Date      :  22 January 2014                                                 *
-* Website   :  http://www.angusj.com                                           *
-* Copyright :  Angus Johnson 2010-2014                                         *
-*                                                                              *
-* 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 "6.1.3"
-
-//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 support for the obsolete OffsetPaths() function
-//which has been replace with the ClipperOffset class.
-#define use_deprecated  
-
-#include <vector>
-#include <set>
-#include <stdexcept>
-#include <cstring>
-#include <cstdlib>
-#include <ostream>
-#include <functional>
-
-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;
-typedef unsigned int cUInt;
-#else
-typedef signed long long cInt;
-typedef unsigned long long cUInt;
-#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 (*TZFillCallback)(IntPoint& z1, IntPoint& z2, IntPoint& pt);
-#endif
-
-enum InitOptions {ioReverseSolution = 1, ioStrictlySimple = 2, ioPreserveCollinear = 4};
-enum JoinType {jtSquare, jtRound, jtMiter};
-enum EndType {etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound};
-#ifdef use_deprecated
-  enum EndType_ {etClosed, etButt = 2, etSquare, etRound};
-#endif
-
-class PolyNode;
-typedef std::vector< PolyNode* > PolyNodes;
-
-class PolyNode 
-{ 
-public:
-    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);
-
-#ifdef use_deprecated
-  void OffsetPaths(const Paths &in_polys, Paths &out_polys,
-    double delta, JoinType jointype, EndType_ endtype, double limit = 0);
-#endif
-
-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, PolyFillType pathFillType, 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 LocalMinima;
-struct Scanbeam;
-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();
-  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);
-  void PopLocalMinima();
-  virtual void Reset();
-  TEdge* ProcessBound(TEdge* E, bool IsClockwise);
-  void InsertLocalMinima(LocalMinima *newLm);
-  void DoMinimaLML(TEdge* E1, TEdge* E2, bool IsClosed);
-  TEdge* DescendToMin(TEdge *&E);
-  void AscendToMax(TEdge *&E, bool Appending, bool IsClosed);
-  LocalMinima      *m_CurrentLM;
-  LocalMinima      *m_MinimaList;
-  bool              m_UseFullRange;
-  EdgeList          m_edges;
-  bool             m_PreserveCollinear;
-  bool             m_HasOpenPaths;
-};
-//------------------------------------------------------------------------------
-
-class Clipper : public virtual ClipperBase
-{
-public:
-  Clipper(int initOptions = 0);
-  ~Clipper();
-  bool Execute(ClipType clipType,
-    Paths &solution,
-    PolyFillType subjFillType = pftEvenOdd,
-    PolyFillType clipFillType = pftEvenOdd);
-  bool Execute(ClipType clipType,
-    PolyTree &polytree,
-    PolyFillType subjFillType = pftEvenOdd,
-    PolyFillType clipFillType = pftEvenOdd);
-  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(TZFillCallback zFillFunc);
-#endif
-protected:
-  void Reset();
-  virtual bool ExecuteInternal();
-private:
-  PolyOutList       m_PolyOuts;
-  JoinList          m_Joins;
-  JoinList          m_GhostJoins;
-  IntersectList     m_IntersectList;
-  ClipType          m_ClipType;
-  std::set< cInt, std::greater<cInt> > m_Scanbeam;
-  TEdge           *m_ActiveEdges;
-  TEdge           *m_SortedEdges;
-  bool             m_ExecuteLocked;
-  PolyFillType     m_ClipFillType;
-  PolyFillType     m_SubjFillType;
-  bool             m_ReverseOutput;
-  bool             m_UsingPolyTree; 
-  bool             m_StrictSimple;
-#ifdef use_xyz
-  TZFillCallback   m_ZFill; //custom callback 
-#endif
-  void SetWindingCount(TEdge& edge);
-  bool IsEvenOddFillType(const TEdge& edge) const;
-  bool IsEvenOddAltFillType(const TEdge& edge) const;
-  void InsertScanbeam(const cInt Y);
-  cInt PopScanbeam();
-  void InsertLocalMinimaIntoAEL(const cInt botY);
-  void InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge);
-  void AddEdgeToSEL(TEdge *edge);
-  void CopyAELToSEL();
-  void DeleteFromSEL(TEdge *e);
-  void DeleteFromAEL(TEdge *e);
-  void UpdateEdgeIntoAEL(TEdge *&e);
-  void SwapPositionsInSEL(TEdge *edge1, TEdge *edge2);
-  bool IsContributing(const TEdge& edge) const;
-  bool IsTopHorz(const cInt XPos);
-  void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
-  void DoMaxima(TEdge *e);
-  void PrepareHorzJoins(TEdge* horzEdge, bool isTopOfScanbeam);
-  void ProcessHorizontals(bool IsTopOfScanbeam);
-  void ProcessHorizontal(TEdge *horzEdge, bool isTopOfScanbeam);
-  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,
-    const IntPoint &pt, bool protect = false);
-  OutRec* CreateOutRec();
-  OutPt* AddOutPt(TEdge *e, const IntPoint &pt);
-  void DisposeAllOutRecs();
-  void DisposeOutRec(PolyOutList::size_type index);
-  bool ProcessIntersections(const cInt botY, const cInt topY);
-  void BuildIntersectList(const cInt botY, 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);
-  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* OldOutRec, OutRec* NewOutRec);
-#ifdef use_xyz
-  void SetZ(IntPoint& pt, TEdge& e);
-#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
-
-