diff --git a/src/Lib/Polygon/clipper.cpp b/src/Lib/Polygon/clipper.cpp
new file mode 100644
index 00000000..62c04ac4
--- /dev/null
+++ b/src/Lib/Polygon/clipper.cpp
@@ -0,0 +1,3206 @@
+/*******************************************************************************
+* *
+* Author : Angus Johnson *
+* Version : 4.5.5 *
+* Date : 6 October 2011 *
+* Website : http://www.angusj.com *
+* Copyright : Angus Johnson 2010-2011 *
+* *
+* 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 *
+* *
+*******************************************************************************/
+
+/*******************************************************************************
+* *
+* 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>
+
+//Workaround for older compilers that don't have std::abs
+#if (__GNUC__ == 2 && __GNUC_MINOR__ <= 97) || (defined(_MSC_VER) && _MSC_VER <= 1500)
+namespace std
+{
+ long long abs(long long x) { return x < 0 ? -x : x; }
+}
+#endif
+
+namespace ClipperLib {
+
+static long64 const loRange = 1518500249; //sqrt(2^63 -1)/2
+static long64 const hiRange = 6521908912666391106LL; //sqrt(2^127 -1)/2
+static double const horizontal = -3.4E+38;
+static double const pi = 3.141592653589793238;
+enum Direction { dRightToLeft, dLeftToRight };
+enum RangeTest { rtLo, rtHi, rtError };
+
+//------------------------------------------------------------------------------
+// Int128 class (enables safe math on signed 64bit integers)
+// eg Int128 val1((long64)9223372036854775807); //ie 2^63 -1
+// Int128 val2((long64)9223372036854775807);
+// Int128 val3 = val1 * val2;
+// val3.AsString => "85070591730234615847396907784232501249" (8.5e+37)
+//------------------------------------------------------------------------------
+
+class Int128
+{
+ public:
+
+ Int128(long64 _lo = 0)
+ {
+ hi = 0;
+ if (_lo < 0) {
+ lo = -_lo;
+ Negate(*this);
+ } else
+ lo = _lo;
+ }
+
+ Int128(const Int128 &val): hi(val.hi), lo(val.lo){}
+
+ long64 operator = (const long64 &val)
+ {
+ hi = 0;
+ lo = std::abs(val);
+ if (val < 0) Negate(*this);
+ return val;
+ }
+
+ 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 true;
+ else if (hi < val.hi) return false;
+ else return ulong64(lo) > ulong64(val.lo);
+ }
+
+ bool operator < (const Int128 &val) const
+ {
+ if (hi < val.hi) return true;
+ else if (hi > val.hi) return false;
+ else return ulong64(lo) < ulong64(val.lo);
+ }
+
+ Int128& operator += (const Int128 &rhs)
+ {
+ hi += rhs.hi;
+ lo += rhs.lo;
+ if (ulong64(lo) < ulong64(rhs.lo)) hi++;
+ return *this;
+ }
+
+ Int128 operator + (const Int128 &rhs) const
+ {
+ Int128 result(*this);
+ result+= rhs;
+ return result;
+ }
+
+ Int128& operator -= (const Int128 &rhs)
+ {
+ Int128 tmp(rhs);
+ Negate(tmp);
+ *this += tmp;
+ return *this;
+ }
+
+ Int128 operator - (const Int128 &rhs) const
+ {
+ Int128 result(*this);
+ result-= rhs;
+ return result;
+ }
+
+ Int128 operator * (const Int128 &rhs) const {
+ if ( !(hi == 0 || hi == -1) || !(rhs.hi == 0 || rhs.hi == -1))
+ throw "Int128 operator*: overflow error";
+ bool negate = (hi < 0) != (rhs.hi < 0);
+
+ Int128 tmp(*this);
+ if (tmp.hi < 0) Negate(tmp);
+ ulong64 int1Hi = ulong64(tmp.lo) >> 32;
+ ulong64 int1Lo = tmp.lo & 0xFFFFFFFF;
+
+ tmp = rhs;
+ if (tmp.hi < 0) Negate(tmp);
+ ulong64 int2Hi = ulong64(tmp.lo) >> 32;
+ ulong64 int2Lo = tmp.lo & 0xFFFFFFFF;
+
+ //nb: see comments in clipper.pas
+ ulong64 a = int1Hi * int2Hi;
+ ulong64 b = int1Lo * int2Lo;
+ ulong64 c = int1Hi * int2Lo + int1Lo * int2Hi;
+
+ tmp.hi = a + (c >> 32);
+ tmp.lo = c << 32;
+ tmp.lo += long64(b);
+ if (ulong64(tmp.lo) < b) tmp.hi++;
+ if (negate) Negate(tmp);
+ return tmp;
+ }
+
+ 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 result(*this), denom(rhs);
+ if (result.hi < 0) Negate(result);
+ if (denom.hi < 0) Negate(denom);
+ if (denom > result) return Int128(0); //result is only a fraction of 1
+ Negate(denom);
+
+ Int128 p(0);
+ for (int i = 0; i < 128; ++i)
+ {
+ p.hi = p.hi << 1;
+ if (p.lo < 0) p.hi++;
+ p.lo = long64(p.lo) << 1;
+ if (result.hi < 0) p.lo++;
+ result.hi = result.hi << 1;
+ if (result.lo < 0) result.hi++;
+ result.lo = long64(result.lo) << 1;
+ Int128 p2(p);
+ p += denom;
+ if (p.hi < 0) p = p2;
+ else result.lo++;
+ }
+ if (negate) Negate(result);
+ return result;
+ }
+
+ double AsDouble() const
+ {
+ const double shift64 = 18446744073709551616.0; //2^64
+ const double bit64 = 9223372036854775808.0;
+ if (hi < 0)
+ {
+ Int128 tmp(*this);
+ Negate(tmp);
+ if (tmp.lo < 0)
+ return (double)tmp.lo - bit64 - tmp.hi * shift64;
+ else
+ return -(double)tmp.lo - tmp.hi * shift64;
+ }
+ else if (lo < 0)
+ return -(double)lo + bit64 + hi * shift64;
+ else
+ return (double)lo + (double)hi * shift64;
+ }
+
+ //for bug testing ...
+ std::string AsString() const
+ {
+ std::string result;
+ unsigned char r = 0;
+ Int128 tmp(0), val(*this);
+ if (hi < 0) Negate(val);
+ result.resize(50);
+ std::string::size_type i = result.size() -1;
+ while (val.hi != 0 || val.lo != 0)
+ {
+ Div10(val, tmp, r);
+ result[i--] = char('0' + r);
+ val = tmp;
+ }
+ if (hi < 0) result[i--] = '-';
+ result.erase(0,i+1);
+ if (result.size() == 0) result = "0";
+ return result;
+ }
+
+private:
+ long64 hi;
+ long64 lo;
+
+ static void Negate(Int128 &val)
+ {
+ if (val.lo == 0)
+ {
+ if( val.hi == 0) return;
+ val.lo = ~val.lo;
+ val.hi = ~val.hi +1;
+ }
+ else
+ {
+ val.lo = ~val.lo +1;
+ val.hi = ~val.hi;
+ }
+ }
+
+ //debugging only ...
+ void Div10(const Int128 val, Int128& result, unsigned char & remainder) const
+ {
+ remainder = 0;
+ result = 0;
+ for (int i = 63; i >= 0; --i)
+ {
+ if ((val.hi & ((long64)1 << i)) != 0)
+ remainder = char((remainder * 2) + 1); else
+ remainder *= char(2);
+ if (remainder >= 10)
+ {
+ result.hi += ((long64)1 << i);
+ remainder -= char(10);
+ }
+ }
+ for (int i = 63; i >= 0; --i)
+ {
+ if ((val.lo & ((long64)1 << i)) != 0)
+ remainder = char((remainder * 2) + 1); else
+ remainder *= char(2);
+ if (remainder >= 10)
+ {
+ result.lo += ((long64)1 << i);
+ remainder -= char(10);
+ }
+ }
+ }
+};
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+inline long64 Abs(long64 val)
+{
+ if ((val < 0)) return -val; else return val;
+}
+//------------------------------------------------------------------------------
+
+RangeTest TestRange(const Polygon &pts)
+{
+ RangeTest result = rtLo;
+ for (Polygon::size_type i = 0; i < pts.size(); ++i)
+ {
+ if (Abs(pts[i].X) > hiRange || Abs(pts[i].Y) > hiRange)
+ return rtError;
+ else if (Abs(pts[i].X) > loRange || Abs(pts[i].Y) > loRange)
+ result = rtHi;
+ }
+ return result;
+}
+//------------------------------------------------------------------------------
+
+bool Orientation(const Polygon &poly)
+{
+ int highI = (int)poly.size() -1;
+ if (highI < 2) return false;
+ bool UseFullInt64Range = false;
+
+ int j = 0, jplus, jminus;
+ for (int i = 0; i <= highI; ++i)
+ {
+ if (std::abs(poly[i].X) > hiRange || std::abs(poly[i].Y) > hiRange)
+ throw "Coordinate exceeds range bounds.";
+ if (std::abs(poly[i].X) > loRange || std::abs(poly[i].Y) > loRange)
+ UseFullInt64Range = true;
+ if (poly[i].Y < poly[j].Y) continue;
+ if ((poly[i].Y > poly[j].Y || poly[i].X < poly[j].X)) j = i;
+ };
+ if (j == highI) jplus = 0;
+ else jplus = j +1;
+ if (j == 0) jminus = highI;
+ else jminus = j -1;
+
+ IntPoint vec1, vec2;
+ //get cross product of vectors of the edges adjacent to highest point ...
+ vec1.X = poly[j].X - poly[jminus].X;
+ vec1.Y = poly[j].Y - poly[jminus].Y;
+ vec2.X = poly[jplus].X - poly[j].X;
+ vec2.Y = poly[jplus].Y - poly[j].Y;
+
+ if (UseFullInt64Range)
+ {
+ Int128 cross = Int128(vec1.X) * Int128(vec2.Y) -
+ Int128(vec2.X) * Int128(vec1.Y);
+ return cross > 0;
+ }
+ else
+ {
+ return (vec1.X * vec2.Y - vec2.X * vec1.Y) > 0;
+ }
+}
+//------------------------------------------------------------------------------
+
+bool Orientation(OutRec *outRec, bool UseFullInt64Range)
+{
+ OutPt *opBottom = outRec->pts, *op = outRec->pts->next;
+ while (op != outRec->pts)
+ {
+ if (op->pt.Y >= opBottom->pt.Y)
+ {
+ if (op->pt.Y > opBottom->pt.Y || op->pt.X < opBottom->pt.X)
+ opBottom = op;
+ }
+ op = op->next;
+ }
+
+ IntPoint vec1, vec2;
+ vec1.X = op->pt.X - op->prev->pt.X;
+ vec1.Y = op->pt.Y - op->prev->pt.Y;
+ vec2.X = op->next->pt.X - op->pt.X;
+ vec2.Y = op->next->pt.Y - op->pt.Y;
+
+ if (UseFullInt64Range)
+ {
+ Int128 cross = Int128(vec1.X) * Int128(vec2.Y) - Int128(vec2.X) * Int128(vec1.Y);
+ return cross > 0;
+ }
+ else
+ {
+ return (vec1.X * vec2.Y - vec2.X * vec1.Y) > 0;
+ }
+}
+//------------------------------------------------------------------------------
+
+int PointCount(OutPt *pts)
+{
+ if (!pts) return 0;
+ int result = 0;
+ OutPt *p = pts;
+ do
+ {
+ result++;
+ p = p->next;
+ }
+ while (p != pts);
+ return result;
+}
+//------------------------------------------------------------------------------
+
+inline bool PointsEqual( const IntPoint &pt1, const IntPoint &pt2)
+{
+ return ( pt1.X == pt2.X && pt1.Y == pt2.Y );
+}
+//------------------------------------------------------------------------------
+
+double Area(const Polygon &poly)
+{
+ int highI = (int)poly.size() -1;
+ if (highI < 2) return 0;
+ bool UseFullInt64Range = false;
+ RangeTest rt = TestRange(poly);
+ switch (rt) {
+ case rtHi:
+ UseFullInt64Range = true;
+ break;
+ case rtError:
+ throw "Coordinate exceeds range bounds.";
+ }
+
+ if (UseFullInt64Range) {
+ Int128 a(0);
+ a = (Int128(poly[highI].X) * Int128(poly[0].Y)) -
+ Int128(poly[0].X) * Int128(poly[highI].Y);
+ for (int i = 0; i < highI; ++i)
+ a += Int128(poly[i].X) * Int128(poly[i+1].Y) -
+ Int128(poly[i+1].X) * Int128(poly[i].Y);
+ return a.AsDouble() / 2;
+ }
+ else
+ {
+ double a;
+ a = (double)poly[highI].X * poly[0].Y - (double)poly[0].X * poly[highI].Y;
+ for (int i = 0; i < highI; ++i)
+ a += (double)poly[i].X * poly[i+1].Y - (double)poly[i+1].X * poly[i].Y;
+ return a/2;
+ }
+}
+//------------------------------------------------------------------------------
+
+bool PointIsVertex(const IntPoint &pt, OutPt *pp)
+{
+ OutPt *pp2 = pp;
+ do
+ {
+ if (PointsEqual(pp2->pt, pt)) return true;
+ pp2 = pp2->next;
+ }
+ while (pp2 != pp);
+ return false;
+}
+//------------------------------------------------------------------------------
+
+bool PointInPolygon(const IntPoint &pt, OutPt *pp, bool UseFullInt64Range)
+{
+ OutPt *pp2 = pp;
+ bool result = false;
+ if (UseFullInt64Range) {
+ do
+ {
+ if ((((pp2->pt.Y <= pt.Y) && (pt.Y < pp2->prev->pt.Y)) ||
+ ((pp2->prev->pt.Y <= pt.Y) && (pt.Y < pp2->pt.Y))) &&
+ Int128(pt.X - pp2->pt.X) < (Int128(pp2->prev->pt.X - pp2->pt.X) *
+ Int128(pt.Y - pp2->pt.Y)) / Int128(pp2->prev->pt.Y - pp2->pt.Y))
+ result = !result;
+ pp2 = pp2->next;
+ }
+ while (pp2 != pp);
+ }
+ else
+ {
+ do
+ {
+ if ((((pp2->pt.Y <= pt.Y) && (pt.Y < pp2->prev->pt.Y)) ||
+ ((pp2->prev->pt.Y <= pt.Y) && (pt.Y < pp2->pt.Y))) &&
+ (pt.X < (pp2->prev->pt.X - pp2->pt.X) * (pt.Y - pp2->pt.Y) /
+ (pp2->prev->pt.Y - pp2->pt.Y) + pp2->pt.X )) result = !result;
+ pp2 = pp2->next;
+ }
+ while (pp2 != pp);
+ }
+ return result;
+}
+//------------------------------------------------------------------------------
+
+bool SlopesEqual(TEdge &e1, TEdge &e2, bool UseFullInt64Range)
+{
+ if (e1.ybot == e1.ytop) return (e2.ybot == e2.ytop);
+ else if (e1.xbot == e1.xtop) return (e2.xbot == e2.xtop);
+ else if (UseFullInt64Range)
+ return Int128(e1.ytop - e1.ybot) * Int128(e2.xtop - e2.xbot) ==
+ Int128(e1.xtop - e1.xbot) * Int128(e2.ytop - e2.ybot);
+ else return (e1.ytop - e1.ybot)*(e2.xtop - e2.xbot) ==
+ (e1.xtop - e1.xbot)*(e2.ytop - e2.ybot);
+}
+//------------------------------------------------------------------------------
+
+bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
+ const IntPoint pt3, bool UseFullInt64Range)
+{
+ if (pt1.Y == pt2.Y) return (pt2.Y == pt3.Y);
+ else if (pt1.X == pt2.X) return (pt2.X == pt3.X);
+ else if (UseFullInt64Range)
+ return Int128(pt1.Y-pt2.Y) * Int128(pt2.X-pt3.X) ==
+ Int128(pt1.X-pt2.X) * Int128(pt2.Y-pt3.Y);
+ else 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)
+{
+ if (pt1.Y == pt2.Y) return (pt3.Y == pt4.Y);
+ else if (pt1.X == pt2.X) return (pt3.X == pt4.X);
+ else if (UseFullInt64Range)
+ return Int128(pt1.Y-pt2.Y) * Int128(pt3.X-pt4.X) ==
+ Int128(pt1.X-pt2.X) * Int128(pt3.Y-pt4.Y);
+ else return (pt1.Y-pt2.Y)*(pt3.X-pt4.X) == (pt1.X-pt2.X)*(pt3.Y-pt4.Y);
+}
+//------------------------------------------------------------------------------
+
+double GetDx(const IntPoint pt1, const IntPoint pt2)
+{
+ if (pt1.Y == pt2.Y) return horizontal;
+ else return
+ (double)(pt2.X - pt1.X) / (double)(pt2.Y - pt1.Y);
+}
+//---------------------------------------------------------------------------
+
+void SetDx(TEdge &e)
+{
+ if (e.ybot == e.ytop) e.dx = horizontal;
+ else e.dx =
+ (double)(e.xtop - e.xbot) / (double)(e.ytop - e.ybot);
+}
+//---------------------------------------------------------------------------
+
+void SwapSides(TEdge &edge1, TEdge &edge2)
+{
+ EdgeSide side = edge1.side;
+ edge1.side = edge2.side;
+ edge2.side = side;
+}
+//------------------------------------------------------------------------------
+
+void SwapPolyIndexes(TEdge &edge1, TEdge &edge2)
+{
+ int outIdx = edge1.outIdx;
+ edge1.outIdx = edge2.outIdx;
+ edge2.outIdx = outIdx;
+}
+//------------------------------------------------------------------------------
+
+inline long64 Round(double val)
+{
+ if ((val < 0)) return static_cast<long64>(val - 0.5);
+ else return static_cast<long64>(val + 0.5);
+}
+//------------------------------------------------------------------------------
+
+long64 TopX(TEdge &edge, const long64 currentY)
+{
+ if( currentY == edge.ytop ) return edge.xtop;
+ return edge.xbot + Round(edge.dx *(currentY - edge.ybot));
+}
+//------------------------------------------------------------------------------
+
+long64 TopX(const IntPoint pt1, const IntPoint pt2, const long64 currentY)
+{
+ //preconditions: pt1.Y <> pt2.Y and pt1.Y > pt2.Y
+ if (currentY >= pt1.Y) return pt1.X;
+ else if (currentY == pt2.Y) return pt2.X;
+ else if (pt1.X == pt2.X) return pt1.X;
+ else
+ {
+ double q = (double)(pt1.X-pt2.X)/(double)(pt1.Y-pt2.Y);
+ return Round(pt1.X + (currentY - pt1.Y) *q);
+ }
+}
+//------------------------------------------------------------------------------
+
+bool IntersectPoint(TEdge &edge1, TEdge &edge2,
+ IntPoint &ip, bool UseFullInt64Range)
+{
+ double b1, b2;
+ if (SlopesEqual(edge1, edge2, UseFullInt64Range)) return false;
+ else if (edge1.dx == 0)
+ {
+ ip.X = edge1.xbot;
+ if (edge2.dx == horizontal)
+ {
+ ip.Y = edge2.ybot;
+ } else
+ {
+ b2 = edge2.ybot - (edge2.xbot/edge2.dx);
+ ip.Y = Round(ip.X/edge2.dx + b2);
+ }
+ }
+ else if (edge2.dx == 0)
+ {
+ ip.X = edge2.xbot;
+ if (edge1.dx == horizontal)
+ {
+ ip.Y = edge1.ybot;
+ } else
+ {
+ b1 = edge1.ybot - (edge1.xbot/edge1.dx);
+ ip.Y = Round(ip.X/edge1.dx + b1);
+ }
+ } else
+ {
+ b1 = edge1.xbot - edge1.ybot * edge1.dx;
+ b2 = edge2.xbot - edge2.ybot * edge2.dx;
+ b2 = (b2-b1)/(edge1.dx - edge2.dx);
+ ip.Y = Round(b2);
+ ip.X = Round(edge1.dx * b2 + b1);
+ }
+
+ return
+ //can be *so close* to the top of one edge that the rounded Y equals one ytop ...
+ (ip.Y == edge1.ytop && ip.Y >= edge2.ytop && edge1.tmpX > edge2.tmpX) ||
+ (ip.Y == edge2.ytop && ip.Y >= edge1.ytop && edge1.tmpX > edge2.tmpX) ||
+ (ip.Y > edge1.ytop && ip.Y > edge2.ytop);
+}
+//------------------------------------------------------------------------------
+
+void ReversePolyPtLinks(OutPt &pp)
+{
+ 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 ;
+ }
+}
+//------------------------------------------------------------------------------
+
+void InitEdge(TEdge *e, TEdge *eNext,
+ TEdge *ePrev, const IntPoint &pt, PolyType polyType)
+{
+ std::memset( e, 0, sizeof( TEdge ));
+
+ e->next = eNext;
+ e->prev = ePrev;
+ e->xcurr = pt.X;
+ e->ycurr = pt.Y;
+ if (e->ycurr >= e->next->ycurr)
+ {
+ e->xbot = e->xcurr;
+ e->ybot = e->ycurr;
+ e->xtop = e->next->xcurr;
+ e->ytop = e->next->ycurr;
+ e->windDelta = 1;
+ } else
+ {
+ e->xtop = e->xcurr;
+ e->ytop = e->ycurr;
+ e->xbot = e->next->xcurr;
+ e->ybot = e->next->ycurr;
+ e->windDelta = -1;
+ }
+ SetDx(*e);
+ e->polyType = polyType;
+ e->outIdx = -1;
+}
+//------------------------------------------------------------------------------
+
+inline void SwapX(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.]
+ e.xcurr = e.xtop;
+ e.xtop = e.xbot;
+ e.xbot = e.xcurr;
+}
+//------------------------------------------------------------------------------
+
+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 colinear.
+ if ( pt1a.Y == pt1b.Y || Abs((pt1a.X - pt1b.X)/(pt1a.Y - pt1b.Y)) > 1 )
+ {
+ 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;
+ }
+}
+//------------------------------------------------------------------------------
+
+OutPt* PolygonBottom(OutPt* pp)
+{
+ OutPt* p = pp->next;
+ OutPt* result = pp;
+ while (p != pp)
+ {
+ if (p->pt.Y > result->pt.Y) result = p;
+ else if (p->pt.Y == result->pt.Y && p->pt.X < result->pt.X) result = p;
+ p = p->next;
+ }
+ return result;
+}
+//------------------------------------------------------------------------------
+
+bool FindSegment(OutPt* &pp, 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, true) &&
+ SlopesEqual(pt1a, pt2a, pp->pt, true) &&
+ GetOverlapSegment(pt1a, pt2a, pp->pt, pp->prev->pt, pt1, pt2))
+ return true;
+ pp = pp->next;
+ }
+ while (pp != pp2);
+ return false;
+}
+//------------------------------------------------------------------------------
+
+bool Pt3IsBetweenPt1AndPt2(const IntPoint pt1,
+ const IntPoint pt2, const IntPoint pt3)
+{
+ if (PointsEqual(pt1, pt3) || PointsEqual(pt2, pt3)) return true;
+ else if (pt1.X != pt2.X) return (pt1.X < pt3.X) == (pt3.X < pt2.X);
+ else return (pt1.Y < pt3.Y) == (pt3.Y < pt2.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;
+}
+
+//------------------------------------------------------------------------------
+// ClipperBase class methods ...
+//------------------------------------------------------------------------------
+
+ClipperBase::ClipperBase() //constructor
+{
+ m_MinimaList = 0;
+ m_CurrentLM = 0;
+ m_UseFullRange = true;
+}
+//------------------------------------------------------------------------------
+
+ClipperBase::~ClipperBase() //destructor
+{
+ Clear();
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::AddPolygon( const Polygon &pg, PolyType polyType)
+{
+ int len = (int)pg.size();
+ if (len < 3) return false;
+ Polygon p(len);
+ p[0] = pg[0];
+ int j = 0;
+
+ long64 maxVal;
+ if (m_UseFullRange) maxVal = hiRange; else maxVal = loRange;
+
+ for (int i = 1; i < len; ++i)
+ {
+ if (Abs(pg[i].X) > maxVal || Abs(pg[i].Y) > maxVal)
+ {
+ if (m_UseFullRange)
+ throw "Coordinate exceeds range bounds";
+ maxVal = hiRange;
+ if (Abs(pg[i].X) > maxVal || Abs(pg[i].Y) > maxVal)
+ throw "Coordinate exceeds range bounds";
+ m_UseFullRange = true;
+ }
+
+ if (PointsEqual(p[j], pg[i])) continue;
+ else if (j > 0 && SlopesEqual(p[j-1], p[j], pg[i], m_UseFullRange))
+ {
+ if (PointsEqual(p[j-1], pg[i])) j--;
+ } else j++;
+ p[j] = pg[i];
+ }
+ if (j < 2) return false;
+
+ len = j+1;
+ for (;;)
+ {
+ //nb: test for point equality before testing slopes ...
+ if (PointsEqual(p[j], p[0])) j--;
+ else if (PointsEqual(p[0], p[1]) ||
+ SlopesEqual(p[j], p[0], p[1], m_UseFullRange))
+ p[0] = p[j--];
+ else if (SlopesEqual(p[j-1], p[j], p[0], m_UseFullRange)) j--;
+ else if (SlopesEqual(p[0], p[1], p[2], m_UseFullRange))
+ {
+ for (int i = 2; i <= j; ++i) p[i-1] = p[i];
+ j--;
+ }
+ //exit loop if nothing is changed or there are too few vertices ...
+ if (j == len-1 || j < 2) break;
+ len = j +1;
+ }
+ if (len < 3) return false;
+
+ //create a new edge array ...
+ TEdge *edges = new TEdge [len];
+ m_edges.push_back(edges);
+
+ //convert vertices to a double-linked-list of edges and initialize ...
+ edges[0].xcurr = p[0].X;
+ edges[0].ycurr = p[0].Y;
+ InitEdge(&edges[len-1], &edges[0], &edges[len-2], p[len-1], polyType);
+ for (int i = len-2; i > 0; --i)
+ InitEdge(&edges[i], &edges[i+1], &edges[i-1], p[i], polyType);
+ InitEdge(&edges[0], &edges[1], &edges[len-1], p[0], polyType);
+
+ //reset xcurr & ycurr and find 'eHighest' (given the Y axis coordinates
+ //increase downward so the 'highest' edge will have the smallest ytop) ...
+ TEdge *e = &edges[0];
+ TEdge *eHighest = e;
+ do
+ {
+ e->xcurr = e->xbot;
+ e->ycurr = e->ybot;
+ if (e->ytop < eHighest->ytop) eHighest = e;
+ e = e->next;
+ }
+ while ( e != &edges[0]);
+
+ //make sure eHighest is positioned so the following loop works safely ...
+ if (eHighest->windDelta > 0) eHighest = eHighest->next;
+ if (eHighest->dx == horizontal) eHighest = eHighest->next;
+
+ //finally insert each local minima ...
+ e = eHighest;
+ do {
+ e = AddBoundsToLML(e);
+ }
+ while( e != eHighest );
+ return true;
+}
+//------------------------------------------------------------------------------
+
+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;
+ }
+}
+//------------------------------------------------------------------------------
+
+TEdge* ClipperBase::AddBoundsToLML(TEdge *e)
+{
+ //Starting at the top of one bound we progress to the bottom where there's
+ //a local minima. We then go to the top of the next bound. These two bounds
+ //form the left and right (or right and left) bounds of the local minima.
+ e->nextInLML = 0;
+ e = e->next;
+ for (;;)
+ {
+ if ( e->dx == horizontal )
+ {
+ //nb: proceed through horizontals when approaching from their right,
+ // but break on horizontal minima if approaching from their left.
+ // This ensures 'local minima' are always on the left of horizontals.
+ if (e->next->ytop < e->ytop && e->next->xbot > e->prev->xbot) break;
+ if (e->xtop != e->prev->xbot) SwapX(*e);
+ e->nextInLML = e->prev;
+ }
+ else if (e->ycurr == e->prev->ycurr) break;
+ else e->nextInLML = e->prev;
+ e = e->next;
+ }
+
+ //e and e.prev are now at a local minima ...
+ LocalMinima* newLm = new LocalMinima;
+ newLm->next = 0;
+ newLm->Y = e->prev->ybot;
+
+ if ( e->dx == horizontal ) //horizontal edges never start a left bound
+ {
+ if (e->xbot != e->prev->xbot) SwapX(*e);
+ newLm->leftBound = e->prev;
+ newLm->rightBound = e;
+ } else if (e->dx < e->prev->dx)
+ {
+ newLm->leftBound = e->prev;
+ newLm->rightBound = e;
+ } else
+ {
+ newLm->leftBound = e;
+ newLm->rightBound = e->prev;
+ }
+ newLm->leftBound->side = esLeft;
+ newLm->rightBound->side = esRight;
+ InsertLocalMinima( newLm );
+
+ for (;;)
+ {
+ if ( e->next->ytop == e->ytop && e->next->dx != horizontal ) break;
+ e->nextInLML = e->next;
+ e = e->next;
+ if ( e->dx == horizontal && e->xbot != e->prev->xtop) SwapX(*e);
+ }
+ return e->next;
+}
+//------------------------------------------------------------------------------
+
+bool ClipperBase::AddPolygons(const Polygons &ppg, PolyType polyType)
+{
+ bool result = true;
+ for (Polygons::size_type i = 0; i < ppg.size(); ++i)
+ if (AddPolygon(ppg[i], polyType)) result = false;
+ return result;
+}
+//------------------------------------------------------------------------------
+
+void ClipperBase::Clear()
+{
+ DisposeLocalMinimaList();
+ for (EdgeList::size_type i = 0; i < m_edges.size(); ++i) delete [] m_edges[i];
+ m_edges.clear();
+ m_UseFullRange = 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;
+ while( e )
+ {
+ e->xcurr = e->xbot;
+ e->ycurr = e->ybot;
+ e->side = esLeft;
+ e->outIdx = -1;
+ e = e->nextInLML;
+ }
+ e = lm->rightBound;
+ while( e )
+ {
+ e->xcurr = e->xbot;
+ e->ycurr = e->ybot;
+ e->side = esRight;
+ e->outIdx = -1;
+ e = e->nextInLML;
+ }
+ 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->xbot;
+ result.top = lm->leftBound->ybot;
+ result.right = lm->leftBound->xbot;
+ result.bottom = lm->leftBound->ybot;
+ while (lm)
+ {
+ if (lm->leftBound->ybot > result.bottom)
+ result.bottom = lm->leftBound->ybot;
+ TEdge* e = lm->leftBound;
+ for (;;) {
+ TEdge* bottomE = e;
+ while (e->nextInLML)
+ {
+ if (e->xbot < result.left) result.left = e->xbot;
+ if (e->xbot > result.right) result.right = e->xbot;
+ e = e->nextInLML;
+ }
+ if (e->xbot < result.left) result.left = e->xbot;
+ if (e->xbot > result.right) result.right = e->xbot;
+ if (e->xtop < result.left) result.left = e->xtop;
+ if (e->xtop > result.right) result.right = e->xtop;
+ if (e->ytop < result.top) result.top = e->ytop;
+
+ if (bottomE == lm->leftBound) e = lm->rightBound;
+ else break;
+ }
+ lm = lm->next;
+ }
+ return result;
+}
+
+
+//------------------------------------------------------------------------------
+// TClipper methods ...
+//------------------------------------------------------------------------------
+
+Clipper::Clipper() : ClipperBase() //constructor
+{
+ m_Scanbeam = 0;
+ m_ActiveEdges = 0;
+ m_SortedEdges = 0;
+ m_IntersectNodes = 0;
+ m_ExecuteLocked = false;
+ m_UseFullRange = false;
+ m_ReverseOutput = false;
+};
+//------------------------------------------------------------------------------
+
+Clipper::~Clipper() //destructor
+{
+ Clear();
+ DisposeScanbeamList();
+};
+//------------------------------------------------------------------------------
+
+void Clipper::Clear()
+{
+ if (m_edges.size() == 0) return; //avoids problems with ClipperBase destructor
+ DisposeAllPolyPts();
+ ClipperBase::Clear();
+};
+//------------------------------------------------------------------------------
+
+void Clipper::DisposeScanbeamList()
+{
+ while ( m_Scanbeam ) {
+ Scanbeam* sb2 = m_Scanbeam->next;
+ delete m_Scanbeam;
+ m_Scanbeam = sb2;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::Reset()
+{
+ ClipperBase::Reset();
+ m_Scanbeam = 0;
+ m_ActiveEdges = 0;
+ m_SortedEdges = 0;
+ LocalMinima* lm = m_MinimaList;
+ while (lm)
+ {
+ InsertScanbeam(lm->Y);
+ InsertScanbeam(lm->leftBound->ytop);
+ lm = lm->next;
+ }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::Execute(ClipType clipType, Polygons &solution,
+ PolyFillType subjFillType, PolyFillType clipFillType)
+{
+ if( m_ExecuteLocked ) return false;
+ m_ExecuteLocked = true;
+ solution.resize(0);
+ m_SubjFillType = subjFillType;
+ m_ClipFillType = clipFillType;
+ m_ClipType = clipType;
+ bool succeeded = ExecuteInternal(false);
+ if (succeeded) BuildResult(solution);
+ m_ExecuteLocked = false;
+ return succeeded;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::Execute(ClipType clipType, ExPolygons &solution,
+ PolyFillType subjFillType, PolyFillType clipFillType)
+{
+ if( m_ExecuteLocked ) return false;
+ m_ExecuteLocked = true;
+ solution.resize(0);
+ m_SubjFillType = subjFillType;
+ m_ClipFillType = clipFillType;
+ m_ClipType = clipType;
+ bool succeeded = ExecuteInternal(true);
+ if (succeeded) BuildResultEx(solution);
+ m_ExecuteLocked = false;
+ return succeeded;
+}
+//------------------------------------------------------------------------------
+
+bool PolySort(OutRec *or1, OutRec *or2)
+{
+ if (or1 == or2) return false;
+ if (!or1->pts || !or2->pts)
+ {
+ if (or1->pts != or2->pts)
+ {
+ if (or1->pts) return true; else return false;
+ }
+ else return false;
+ }
+ int i1, i2;
+ if (or1->isHole)
+ i1 = or1->FirstLeft->idx; else
+ i1 = or1->idx;
+ if (or2->isHole)
+ i2 = or2->FirstLeft->idx; else
+ i2 = or2->idx;
+ int result = i1 - i2;
+ if (result == 0 && (or1->isHole != or2->isHole))
+ {
+ if (or1->isHole) return false;
+ else return true;
+ }
+ else return result < 0;
+}
+//------------------------------------------------------------------------------
+
+OutRec* FindAppendLinkEnd(OutRec *outRec)
+{
+ while (outRec->AppendLink) outRec = outRec->AppendLink;
+ return outRec;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::FixHoleLinkage(OutRec *outRec)
+{
+ OutRec *tmp;
+ if (outRec->bottomPt)
+ tmp = m_PolyOuts[outRec->bottomPt->idx]->FirstLeft;
+ else
+ tmp = outRec->FirstLeft;
+ if (outRec == tmp) throw clipperException("HoleLinkage error");
+
+ if (tmp)
+ {
+ if (tmp->AppendLink) tmp = FindAppendLinkEnd(tmp);
+ if (tmp == outRec) tmp = 0;
+ else if (tmp->isHole)
+ {
+ FixHoleLinkage(tmp);
+ tmp = tmp->FirstLeft;
+ }
+ }
+ outRec->FirstLeft = tmp;
+ if (!tmp) outRec->isHole = false;
+ outRec->AppendLink = 0;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::ExecuteInternal(bool fixHoleLinkages)
+{
+ bool succeeded;
+ try {
+ Reset();
+ if (!m_CurrentLM ) return true;
+ long64 botY = PopScanbeam();
+ do {
+ InsertLocalMinimaIntoAEL(botY);
+ ClearHorzJoins();
+ ProcessHorizontals();
+ long64 topY = PopScanbeam();
+ succeeded = ProcessIntersections(botY, topY);
+ if (!succeeded) break;
+ ProcessEdgesAtTopOfScanbeam(topY);
+ botY = topY;
+ } while( m_Scanbeam );
+ }
+ catch(...) {
+ succeeded = false;
+ }
+
+ if (succeeded)
+ {
+ //tidy up output polygons and fix orientations where necessary ...
+ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+ {
+ OutRec *outRec = m_PolyOuts[i];
+ if (!outRec->pts) continue;
+ FixupOutPolygon(*outRec);
+ if (!outRec->pts) continue;
+ if (outRec->isHole && fixHoleLinkages) FixHoleLinkage(outRec);
+ if (outRec->isHole ==
+ (m_ReverseOutput ^ Orientation(outRec, m_UseFullRange)))
+ ReversePolyPtLinks(*outRec->pts);
+ }
+
+ JoinCommonEdges(fixHoleLinkages);
+ if (fixHoleLinkages)
+ std::sort(m_PolyOuts.begin(), m_PolyOuts.end(), PolySort);
+ }
+
+ ClearJoins();
+ ClearHorzJoins();
+ return succeeded;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::InsertScanbeam(const long64 Y)
+{
+ if( !m_Scanbeam )
+ {
+ m_Scanbeam = new Scanbeam;
+ m_Scanbeam->next = 0;
+ m_Scanbeam->Y = Y;
+ }
+ else if( Y > m_Scanbeam->Y )
+ {
+ Scanbeam* newSb = new Scanbeam;
+ newSb->Y = Y;
+ newSb->next = m_Scanbeam;
+ m_Scanbeam = newSb;
+ } else
+ {
+ Scanbeam* sb2 = m_Scanbeam;
+ while( sb2->next && ( Y <= sb2->next->Y ) ) sb2 = sb2->next;
+ if( Y == sb2->Y ) return; //ie ignores duplicates
+ Scanbeam* newSb = new Scanbeam;
+ newSb->Y = Y;
+ newSb->next = sb2->next;
+ sb2->next = newSb;
+ }
+}
+//------------------------------------------------------------------------------
+
+long64 Clipper::PopScanbeam()
+{
+ long64 Y = m_Scanbeam->Y;
+ Scanbeam* sb2 = m_Scanbeam;
+ m_Scanbeam = m_Scanbeam->next;
+ delete sb2;
+ return Y;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DisposeAllPolyPts(){
+ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+ DisposeOutRec(i);
+ m_PolyOuts.clear();
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DisposeOutRec(PolyOutList::size_type index, bool ignorePts)
+{
+ OutRec *outRec = m_PolyOuts[index];
+ if (!ignorePts && 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->polyType != edge.polyType ) e = e->prevInAEL;
+ if ( !e )
+ {
+ edge.windCnt = edge.windDelta;
+ edge.windCnt2 = 0;
+ e = m_ActiveEdges; //ie get ready to calc windCnt2
+ } else if ( IsNonZeroFillType(edge) )
+ {
+ //nonZero filling ...
+ if ( e->windCnt * e->windDelta < 0 )
+ {
+ if (Abs(e->windCnt) > 1)
+ {
+ if (e->windDelta * edge.windDelta < 0) edge.windCnt = e->windCnt;
+ else edge.windCnt = e->windCnt + edge.windDelta;
+ } else
+ edge.windCnt = e->windCnt + e->windDelta + edge.windDelta;
+ } else
+ {
+ if ( Abs(e->windCnt) > 1 && e->windDelta * edge.windDelta < 0)
+ edge.windCnt = e->windCnt;
+ else if ( e->windCnt + edge.windDelta == 0 )
+ edge.windCnt = e->windCnt;
+ else edge.windCnt = e->windCnt + edge.windDelta;
+ }
+ edge.windCnt2 = e->windCnt2;
+ e = e->nextInAEL; //ie get ready to calc windCnt2
+ } else
+ {
+ //even-odd filling ...
+ edge.windCnt = 1;
+ edge.windCnt2 = e->windCnt2;
+ e = e->nextInAEL; //ie get ready to calc windCnt2
+ }
+
+ //update windCnt2 ...
+ if ( IsNonZeroAltFillType(edge) )
+ {
+ //nonZero filling ...
+ while ( e != &edge )
+ {
+ edge.windCnt2 += e->windDelta;
+ e = e->nextInAEL;
+ }
+ } else
+ {
+ //even-odd filling ...
+ while ( e != &edge )
+ {
+ edge.windCnt2 = (edge.windCnt2 == 0) ? 1 : 0;
+ e = e->nextInAEL;
+ }
+ }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsNonZeroFillType(const TEdge& edge) const
+{
+ if (edge.polyType == ptSubject)
+ return m_SubjFillType == pftNonZero; else
+ return m_ClipFillType == pftNonZero;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsNonZeroAltFillType(const TEdge& edge) const
+{
+ if (edge.polyType == ptSubject)
+ return m_ClipFillType == pftNonZero; else
+ return m_SubjFillType == pftNonZero;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsContributing(const TEdge& edge) const
+{
+ switch( m_ClipType ){
+ case ctIntersection:
+ if ( edge.polyType == ptSubject )
+ return Abs(edge.windCnt) == 1 && edge.windCnt2 != 0; else
+ return Abs(edge.windCnt2) > 0 && Abs(edge.windCnt) == 1;
+ case ctUnion:
+ return Abs(edge.windCnt) == 1 && edge.windCnt2 == 0;
+ case ctDifference:
+ if ( edge.polyType == ptSubject )
+ return std::abs(edge.windCnt) == 1 && edge.windCnt2 == 0; else
+ return std::abs(edge.windCnt) == 1 && edge.windCnt2 != 0;
+ default: //case ctXor:
+ return std::abs(edge.windCnt) == 1;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt)
+{
+ if( e2->dx == horizontal || ( e1->dx > e2->dx ) )
+ {
+ AddOutPt( e1, e2, pt );
+ e2->outIdx = e1->outIdx;
+ e1->side = esLeft;
+ e2->side = esRight;
+ } else
+ {
+ AddOutPt( e2, e1, pt );
+ e1->outIdx = e2->outIdx;
+ e1->side = esRight;
+ e2->side = esLeft;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt)
+{
+ AddOutPt( e1, 0, pt );
+ if( e1->outIdx == e2->outIdx )
+ {
+ e1->outIdx = -1;
+ e2->outIdx = -1;
+ }
+ else
+ AppendPolygon( e1, e2 );
+}
+//------------------------------------------------------------------------------
+
+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;
+ if (!m_ActiveEdges) return;
+ m_SortedEdges->prevInSEL = 0;
+ e = e->nextInAEL;
+ while ( e )
+ {
+ e->prevInSEL = e->prevInAEL;
+ e->prevInSEL->nextInSEL = e;
+ e->nextInSEL = 0;
+ e = e->nextInAEL;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddJoin(TEdge *e1, TEdge *e2, int e1OutIdx, int e2OutIdx)
+{
+ JoinRec* jr = new JoinRec;
+ if (e1OutIdx >= 0)
+ jr->poly1Idx = e1OutIdx; else
+ jr->poly1Idx = e1->outIdx;
+ jr->pt1a = IntPoint(e1->xcurr, e1->ycurr);
+ jr->pt1b = IntPoint(e1->xtop, e1->ytop);
+ if (e2OutIdx >= 0)
+ jr->poly2Idx = e2OutIdx; else
+ jr->poly2Idx = e2->outIdx;
+ jr->pt2a = IntPoint(e2->xcurr, e2->ycurr);
+ jr->pt2b = IntPoint(e2->xtop, e2->ytop);
+ m_Joins.push_back(jr);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ClearJoins()
+{
+ for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+ delete m_Joins[i];
+ m_Joins.resize(0);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddHorzJoin(TEdge *e, int idx)
+{
+ HorzJoinRec* hj = new HorzJoinRec;
+ hj->edge = e;
+ hj->savedIdx = idx;
+ m_HorizJoins.push_back(hj);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ClearHorzJoins()
+{
+ for (HorzJoinList::size_type i = 0; i < m_HorizJoins.size(); i++)
+ delete m_HorizJoins[i];
+ m_HorizJoins.resize(0);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::InsertLocalMinimaIntoAEL( const long64 botY)
+{
+ while( m_CurrentLM && ( m_CurrentLM->Y == botY ) )
+ {
+ TEdge* lb = m_CurrentLM->leftBound;
+ TEdge* rb = m_CurrentLM->rightBound;
+
+ InsertEdgeIntoAEL( lb );
+ InsertScanbeam( lb->ytop );
+ InsertEdgeIntoAEL( rb );
+
+ if ( IsNonZeroFillType( *lb) )
+ rb->windDelta = -lb->windDelta;
+ else
+ {
+ lb->windDelta = 1;
+ rb->windDelta = 1;
+ }
+ SetWindingCount( *lb );
+ rb->windCnt = lb->windCnt;
+ rb->windCnt2 = lb->windCnt2;
+
+ if( rb->dx == horizontal )
+ {
+ //nb: only rightbounds can have a horizontal bottom edge
+ AddEdgeToSEL( rb );
+ InsertScanbeam( rb->nextInLML->ytop );
+ }
+ else
+ InsertScanbeam( rb->ytop );
+
+ if( IsContributing(*lb) )
+ AddLocalMinPoly( lb, rb, IntPoint(lb->xcurr, m_CurrentLM->Y) );
+
+ //if output polygons share an edge, they'll need joining later ...
+ if (lb->outIdx >= 0 && lb->prevInAEL &&
+ lb->prevInAEL->outIdx >= 0 && lb->prevInAEL->xcurr == lb->xbot &&
+ SlopesEqual(*lb, *lb->prevInAEL, m_UseFullRange))
+ AddJoin(lb, lb->prevInAEL);
+
+ //if any output polygons share an edge, they'll need joining later ...
+ if (rb->outIdx >= 0)
+ {
+ if (rb->dx == horizontal)
+ {
+ for (HorzJoinList::size_type i = 0; i < m_HorizJoins.size(); ++i)
+ {
+ IntPoint pt, pt2; //returned by GetOverlapSegment() but unused here.
+ HorzJoinRec* hj = m_HorizJoins[i];
+ //if horizontals rb and hj.edge overlap, flag for joining later ...
+ if (GetOverlapSegment(IntPoint(hj->edge->xbot, hj->edge->ybot),
+ IntPoint(hj->edge->xtop, hj->edge->ytop),
+ IntPoint(rb->xbot, rb->ybot),
+ IntPoint(rb->xtop, rb->ytop), pt, pt2))
+ AddJoin(hj->edge, rb, hj->savedIdx);
+ }
+ }
+ }
+
+ if( lb->nextInAEL != rb )
+ {
+ if (rb->outIdx >= 0 && rb->prevInAEL->outIdx >= 0 &&
+ SlopesEqual(*rb->prevInAEL, *rb, m_UseFullRange))
+ AddJoin(rb, rb->prevInAEL);
+
+ TEdge* e = lb->nextInAEL;
+ IntPoint pt = IntPoint(lb->xcurr, lb->ycurr);
+ while( e != rb )
+ {
+ if(!e) throw clipperException("InsertLocalMinimaIntoAEL: missing rightbound!");
+ //nb: For calculating winding counts etc, IntersectEdges() assumes
+ //that param1 will be to the right of param2 ABOVE the intersection ...
+ IntersectEdges( rb , e , pt , ipNone); //order important here
+ e = e->nextInAEL;
+ }
+ }
+ PopLocalMinima();
+ }
+}
+//------------------------------------------------------------------------------
+
+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;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::IntersectEdges(TEdge *e1, TEdge *e2,
+ const IntPoint &pt, IntersectProtects protects)
+{
+ //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 = !(ipLeft & protects) && !e1->nextInLML &&
+ e1->xtop == pt.X && e1->ytop == pt.Y;
+ bool e2stops = !(ipRight & protects) && !e2->nextInLML &&
+ e2->xtop == pt.X && e2->ytop == pt.Y;
+ bool e1Contributing = ( e1->outIdx >= 0 );
+ bool e2contributing = ( e2->outIdx >= 0 );
+
+ //update winding counts...
+ //assumes that e1 will be to the right of e2 ABOVE the intersection
+ if ( e1->polyType == e2->polyType )
+ {
+ if ( IsNonZeroFillType( *e1) )
+ {
+ 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
+ {
+ int oldE1WindCnt = e1->windCnt;
+ e1->windCnt = e2->windCnt;
+ e2->windCnt = oldE1WindCnt;
+ }
+ } else
+ {
+ if ( IsNonZeroFillType(*e2) ) e1->windCnt2 += e2->windDelta;
+ else e1->windCnt2 = ( e1->windCnt2 == 0 ) ? 1 : 0;
+ if ( IsNonZeroFillType(*e1) ) e2->windCnt2 -= e1->windDelta;
+ else e2->windCnt2 = ( e2->windCnt2 == 0 ) ? 1 : 0;
+ }
+
+ if ( e1Contributing && e2contributing )
+ {
+ if ( e1stops || e2stops || std::abs(e1->windCnt) > 1 ||
+ std::abs(e2->windCnt) > 1 ||
+ (e1->polyType != e2->polyType && m_ClipType != ctXor) )
+ AddLocalMaxPoly(e1, e2, pt); else
+ DoBothEdges( e1, e2, pt );
+ }
+ else if ( e1Contributing )
+ {
+ switch( m_ClipType ) {
+ case ctIntersection:
+ if ( (e2->polyType == ptSubject || e2->windCnt2 != 0) &&
+ std::abs(e2->windCnt) < 2 ) DoEdge1( e1, e2, pt);
+ break;
+ default:
+ if ( std::abs(e2->windCnt) < 2 ) DoEdge1(e1, e2, pt);
+ }
+ }
+ else if ( e2contributing )
+ {
+ if ( m_ClipType == ctIntersection )
+ {
+ if ( (e1->polyType == ptSubject || e1->windCnt2 != 0) &&
+ std::abs(e1->windCnt) < 2 ) DoEdge2( e1, e2, pt );
+ }
+ else
+ if (std::abs(e1->windCnt) < 2) DoEdge2( e1, e2, pt );
+
+ } else if ( std::abs(e1->windCnt) < 2 && std::abs(e2->windCnt) < 2 &&
+ !e1stops && !e2stops )
+ {
+ //nb: neither edge is currently contributing ...
+ if ( e1->polyType != e2->polyType )
+ AddLocalMinPoly(e1, e2, pt);
+ else if ( std::abs(e1->windCnt) == 1 && std::abs(e2->windCnt) == 1 )
+ switch( m_ClipType ) {
+ case ctIntersection:
+ if ( std::abs(e1->windCnt2) > 0 && std::abs(e2->windCnt2) > 0 )
+ AddLocalMinPoly(e1, e2, pt);
+ break;
+ case ctUnion:
+ if ( e1->windCnt2 == 0 && e2->windCnt2 == 0 )
+ AddLocalMinPoly(e1, e2, pt);
+ break;
+ case ctDifference:
+ if ( (e1->polyType == ptClip && e2->polyType == ptClip &&
+ e1->windCnt2 != 0 && e2->windCnt2 != 0) ||
+ (e1->polyType == ptSubject && e2->polyType == ptSubject &&
+ e1->windCnt2 == 0 && e2->windCnt2 == 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)
+ {
+ isHole = !isHole;
+ if (! outRec->FirstLeft)
+ outRec->FirstLeft = m_PolyOuts[e2->outIdx];
+ }
+ e2 = e2->prevInAEL;
+ }
+ if (isHole) outRec->isHole = true;
+}
+//------------------------------------------------------------------------------
+
+bool GetNextNonDupOutPt(OutPt* pp, OutPt*& next)
+{
+ next = pp->next;
+ while (next != pp && PointsEqual(pp->pt, next->pt))
+ next = next->next;
+ return next != pp;
+}
+//------------------------------------------------------------------------------
+
+bool GetPrevNonDupOutPt(OutPt* pp, OutPt*& prev)
+{
+ prev = pp->prev;
+ while (prev != pp && PointsEqual(pp->pt, prev->pt))
+ prev = prev->prev;
+ return prev != pp;
+}
+//------------------------------------------------------------------------------
+
+OutRec* GetLowermostRec(OutRec *outRec1, OutRec *outRec2)
+{
+ //work out which polygon fragment has the correct hole state ...
+ 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 (outRec1->bottomE2 == 0) return outRec2;
+ else if (outRec2->bottomE2 == 0) return outRec1;
+ else
+ {
+ double dx1 = std::max(outRec1->bottomE1->dx, outRec1->bottomE2->dx);
+ double dx2 = std::max(outRec2->bottomE1->dx, outRec2->bottomE2->dx);
+ if (dx2 > dx1) return outRec2; else return outRec1;
+ }
+}
+//------------------------------------------------------------------------------
+
+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 = GetLowermostRec(outRec1, outRec2);
+
+ //fixup hole status ...
+ if (outRec1->isHole != outRec2->isHole)
+ {
+ if (holeStateRec == outRec2)
+ outRec1->isHole = outRec2->isHole;
+ else
+ outRec2->isHole = outRec1->isHole;
+ }
+
+ 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;
+ }
+
+ if (holeStateRec == outRec2)
+ {
+ outRec1->bottomPt = outRec2->bottomPt;
+ outRec1->bottomPt->idx = outRec1->idx;
+ outRec1->bottomE1 = outRec2->bottomE1;
+ outRec1->bottomE2 = outRec2->bottomE2;
+
+ if (outRec2->FirstLeft != outRec1)
+ outRec1->FirstLeft = outRec2->FirstLeft;
+ }
+ outRec2->pts = 0;
+ outRec2->bottomPt = 0;
+ outRec2->AppendLink = outRec1;
+ int OKIdx = e1->outIdx;
+ int ObsoleteIdx = e2->outIdx;
+
+ e1->outIdx = -1; //nb: safe because we only get here via AddLocalMaxPoly
+ e2->outIdx = -1;
+
+ TEdge* e = m_ActiveEdges;
+ while( e )
+ {
+ if( e->outIdx == ObsoleteIdx )
+ {
+ e->outIdx = OKIdx;
+ e->side = side;
+ break;
+ }
+ e = e->nextInAEL;
+ }
+
+ for (JoinList::size_type i = 0; i < m_Joins.size(); ++i)
+ {
+ if (m_Joins[i]->poly1Idx == ObsoleteIdx) m_Joins[i]->poly1Idx = OKIdx;
+ if (m_Joins[i]->poly2Idx == ObsoleteIdx) m_Joins[i]->poly2Idx = OKIdx;
+ }
+
+ for (HorzJoinList::size_type i = 0; i < m_HorizJoins.size(); ++i)
+ {
+ if (m_HorizJoins[i]->savedIdx == ObsoleteIdx)
+ m_HorizJoins[i]->savedIdx = OKIdx;
+ }
+
+}
+//------------------------------------------------------------------------------
+
+
+OutRec* Clipper::CreateOutRec()
+{
+ OutRec* result = new OutRec;
+ result->isHole = false;
+ result->FirstLeft = 0;
+ result->AppendLink = 0;
+ result->pts = 0;
+ result->bottomPt = 0;
+ return result;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddOutPt(TEdge *e, TEdge *altE, const IntPoint &pt)
+{
+ bool ToFront = (e->side == esLeft);
+ if( e->outIdx < 0 )
+ {
+ OutRec *outRec = CreateOutRec();
+ m_PolyOuts.push_back(outRec);
+ outRec->idx = (int)m_PolyOuts.size()-1;
+ e->outIdx = outRec->idx;
+ OutPt* op = new OutPt;
+ outRec->pts = op;
+ outRec->bottomE1 = e;
+ outRec->bottomE2 = altE;
+ outRec->bottomPt = op;
+ op->pt = pt;
+ op->idx = outRec->idx;
+ op->next = op;
+ op->prev = op;
+ SetHoleState(e, outRec);
+ } else
+ {
+ OutRec *outRec = m_PolyOuts[e->outIdx];
+ OutPt* op = outRec->pts;
+ if ((ToFront && PointsEqual(pt, op->pt)) ||
+ (!ToFront && PointsEqual(pt, op->prev->pt))) return;
+ OutPt* op2 = new OutPt;
+ op2->pt = pt;
+ op2->idx = outRec->idx;
+ if (op2->pt.Y == outRec->bottomPt->pt.Y &&
+ op2->pt.X < outRec->bottomPt->pt.X)
+ {
+ outRec->bottomPt = op2;
+ outRec->bottomE1 = e;
+ outRec->bottomE2 = altE;
+ }
+ op2->next = op;
+ op2->prev = op->prev;
+ op2->prev->next = op2;
+ op->prev = op2;
+ if (ToFront) outRec->pts = op2;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessHorizontals()
+{
+ TEdge* horzEdge = m_SortedEdges;
+ while( horzEdge )
+ {
+ DeleteFromSEL( horzEdge );
+ ProcessHorizontal( horzEdge );
+ horzEdge = m_SortedEdges;
+ }
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::IsTopHorz(const long64 XPos)
+{
+ TEdge* e = m_SortedEdges;
+ while( e )
+ {
+ if( ( XPos >= std::min(e->xcurr, e->xtop) ) &&
+ ( XPos <= std::max(e->xcurr, e->xtop) ) ) return false;
+ e = e->nextInSEL;
+ }
+ return true;
+}
+//------------------------------------------------------------------------------
+
+bool IsMinima(TEdge *e)
+{
+ return e && (e->prev->nextInLML != e) && (e->next->nextInLML != e);
+}
+//------------------------------------------------------------------------------
+
+bool IsMaxima(TEdge *e, const long64 Y)
+{
+ return e && e->ytop == Y && !e->nextInLML;
+}
+//------------------------------------------------------------------------------
+
+bool IsIntermediate(TEdge *e, const long64 Y)
+{
+ return e->ytop == Y && e->nextInLML;
+}
+//------------------------------------------------------------------------------
+
+TEdge *GetMaximaPair(TEdge *e)
+{
+ if( !IsMaxima(e->next, e->ytop) || e->next->xtop != e->xtop )
+ return e->prev; else
+ return e->next;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::SwapPositionsInAEL(TEdge *edge1, TEdge *edge2)
+{
+ if( !edge1->nextInAEL && !edge1->prevInAEL ) return;
+ if( !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)
+{
+ if( dir == dLeftToRight ) return e->nextInAEL;
+ else return e->prevInAEL;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessHorizontal(TEdge *horzEdge)
+{
+ Direction dir;
+ long64 horzLeft, horzRight;
+
+ if( horzEdge->xcurr < horzEdge->xtop )
+ {
+ horzLeft = horzEdge->xcurr;
+ horzRight = horzEdge->xtop;
+ dir = dLeftToRight;
+ } else
+ {
+ horzLeft = horzEdge->xtop;
+ horzRight = horzEdge->xcurr;
+ dir = dRightToLeft;
+ }
+
+ TEdge* eMaxPair;
+ if( horzEdge->nextInLML ) eMaxPair = 0;
+ else eMaxPair = GetMaximaPair(horzEdge);
+
+ TEdge* e = GetNextInAEL( horzEdge , dir );
+ while( e )
+ {
+ TEdge* eNext = GetNextInAEL( e, dir );
+
+ if (eMaxPair ||
+ ((dir == dLeftToRight) && (e->xcurr <= horzRight)) ||
+ ((dir == dRightToLeft) && (e->xcurr >= horzLeft)))
+ {
+ //ok, so far it looks like we're still in range of the horizontal edge
+ if ( e->xcurr == horzEdge->xtop && !eMaxPair )
+ {
+ if (SlopesEqual(*e, *horzEdge->nextInLML, m_UseFullRange))
+ {
+ //if output polygons share an edge, they'll need joining later ...
+ if (horzEdge->outIdx >= 0 && e->outIdx >= 0)
+ AddJoin(horzEdge->nextInLML, e, horzEdge->outIdx);
+ break; //we've reached the end of the horizontal line
+ }
+ else if (e->dx < horzEdge->nextInLML->dx)
+ //we really have got to the end of the intermediate horz edge so quit.
+ //nb: More -ve slopes follow more +ve slopes ABOVE the horizontal.
+ break;
+ }
+
+ if( e == eMaxPair )
+ {
+ //horzEdge is evidently a maxima horizontal and we've arrived at its end.
+ if (dir == dLeftToRight)
+ IntersectEdges(horzEdge, e, IntPoint(e->xcurr, horzEdge->ycurr), ipNone);
+ else
+ IntersectEdges(e, horzEdge, IntPoint(e->xcurr, horzEdge->ycurr), ipNone);
+ if (eMaxPair->outIdx >= 0) throw clipperException("ProcessHorizontal error");
+ return;
+ }
+ else if( e->dx == horizontal && !IsMinima(e) && !(e->xcurr > e->xtop) )
+ {
+ //An overlapping horizontal edge. Overlapping horizontal edges are
+ //processed as if layered with the current horizontal edge (horizEdge)
+ //being infinitesimally lower that the next (e). Therfore, we
+ //intersect with e only if e.xcurr is within the bounds of horzEdge ...
+ if( dir == dLeftToRight )
+ IntersectEdges( horzEdge , e, IntPoint(e->xcurr, horzEdge->ycurr),
+ (IsTopHorz( e->xcurr ))? ipLeft : ipBoth );
+ else
+ IntersectEdges( e, horzEdge, IntPoint(e->xcurr, horzEdge->ycurr),
+ (IsTopHorz( e->xcurr ))? ipRight : ipBoth );
+ }
+ else if( dir == dLeftToRight )
+ {
+ IntersectEdges( horzEdge, e, IntPoint(e->xcurr, horzEdge->ycurr),
+ (IsTopHorz( e->xcurr ))? ipLeft : ipBoth );
+ }
+ else
+ {
+ IntersectEdges( e, horzEdge, IntPoint(e->xcurr, horzEdge->ycurr),
+ (IsTopHorz( e->xcurr ))? ipRight : ipBoth );
+ }
+ SwapPositionsInAEL( horzEdge, e );
+ }
+ else if( (dir == dLeftToRight && e->xcurr > horzRight && m_SortedEdges) ||
+ (dir == dRightToLeft && e->xcurr < horzLeft && m_SortedEdges) ) break;
+ e = eNext;
+ } //end while
+
+ if( horzEdge->nextInLML )
+ {
+ if( horzEdge->outIdx >= 0 )
+ AddOutPt( horzEdge, 0, IntPoint(horzEdge->xtop, horzEdge->ytop));
+ UpdateEdgeIntoAEL( horzEdge );
+ }
+ else
+ {
+ if ( horzEdge->outIdx >= 0 )
+ IntersectEdges( horzEdge, eMaxPair,
+ IntPoint(horzEdge->xtop, horzEdge->ycurr), ipBoth);
+ if (eMaxPair->outIdx >= 0) throw clipperException("ProcessHorizontal error");
+ DeleteFromAEL(eMaxPair);
+ DeleteFromAEL(horzEdge);
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::UpdateEdgeIntoAEL(TEdge *&e)
+{
+ if( !e->nextInLML ) throw
+ clipperException("UpdateEdgeIntoAEL: invalid call");
+ TEdge* AelPrev = e->prevInAEL;
+ TEdge* AelNext = e->nextInAEL;
+ e->nextInLML->outIdx = e->outIdx;
+ 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->prevInAEL = AelPrev;
+ e->nextInAEL = AelNext;
+ if( e->dx != horizontal ) InsertScanbeam( e->ytop );
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::ProcessIntersections(const long64 botY, const long64 topY)
+{
+ if( !m_ActiveEdges ) return true;
+ try {
+ BuildIntersectList(botY, topY);
+ if ( !m_IntersectNodes) return true;
+ if ( FixupIntersections() ) ProcessIntersectList();
+ else return false;
+ }
+ catch(...) {
+ m_SortedEdges = 0;
+ DisposeIntersectNodes();
+ throw clipperException("ProcessIntersections error");
+ }
+ return true;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DisposeIntersectNodes()
+{
+ while ( m_IntersectNodes )
+ {
+ IntersectNode* iNode = m_IntersectNodes->next;
+ delete m_IntersectNodes;
+ m_IntersectNodes = iNode;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildIntersectList(const long64 botY, const long64 topY)
+{
+ if ( !m_ActiveEdges ) return;
+
+ //prepare for sorting ...
+ TEdge* e = m_ActiveEdges;
+ e->tmpX = TopX( *e, topY );
+ m_SortedEdges = e;
+ m_SortedEdges->prevInSEL = 0;
+ e = e->nextInAEL;
+ while( e )
+ {
+ e->prevInSEL = e->prevInAEL;
+ e->prevInSEL->nextInSEL = e;
+ e->nextInSEL = 0;
+ e->tmpX = TopX( *e, topY );
+ e = e->nextInAEL;
+ }
+
+ //bubblesort ...
+ bool isModified = true;
+ while( isModified && m_SortedEdges )
+ {
+ isModified = false;
+ e = m_SortedEdges;
+ while( e->nextInSEL )
+ {
+ TEdge *eNext = e->nextInSEL;
+ IntPoint pt;
+ if(e->tmpX > eNext->tmpX &&
+ IntersectPoint(*e, *eNext, pt, m_UseFullRange))
+ {
+ if (pt.Y > botY)
+ {
+ pt.Y = botY;
+ pt.X = TopX(*e, pt.Y);
+ }
+ AddIntersectNode( e, eNext, pt );
+ SwapPositionsInSEL(e, eNext);
+ isModified = true;
+ }
+ else
+ e = eNext;
+ }
+ if( e->prevInSEL ) e->prevInSEL->nextInSEL = 0;
+ else break;
+ }
+ m_SortedEdges = 0;
+}
+//------------------------------------------------------------------------------
+
+bool Process1Before2(IntersectNode &node1, IntersectNode &node2)
+{
+ bool result;
+ if (node1.pt.Y == node2.pt.Y)
+ {
+ if (node1.edge1 == node2.edge1 || node1.edge2 == node2.edge1)
+ {
+ result = node2.pt.X > node1.pt.X;
+ if (node2.edge1->dx > 0) return !result; else return result;
+ }
+ else if (node1.edge1 == node2.edge2 || node1.edge2 == node2.edge2)
+ {
+ result = node2.pt.X > node1.pt.X;
+ if (node2.edge2->dx > 0) return !result; else return result;
+ }
+ else return node2.pt.X > node1.pt.X;
+ }
+ else return node1.pt.Y > node2.pt.Y;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::AddIntersectNode(TEdge *e1, TEdge *e2, const IntPoint &pt)
+{
+ IntersectNode* newNode = new IntersectNode;
+ newNode->edge1 = e1;
+ newNode->edge2 = e2;
+ newNode->pt = pt;
+ newNode->next = 0;
+ if( !m_IntersectNodes ) m_IntersectNodes = newNode;
+ else if( Process1Before2(*newNode, *m_IntersectNodes) )
+ {
+ newNode->next = m_IntersectNodes;
+ m_IntersectNodes = newNode;
+ }
+ else
+ {
+ IntersectNode* iNode = m_IntersectNodes;
+ while( iNode->next && Process1Before2(*iNode->next, *newNode) )
+ iNode = iNode->next;
+ newNode->next = iNode->next;
+ iNode->next = newNode;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessIntersectList()
+{
+ while( m_IntersectNodes )
+ {
+ IntersectNode* iNode = m_IntersectNodes->next;
+ {
+ IntersectEdges( m_IntersectNodes->edge1 ,
+ m_IntersectNodes->edge2 , m_IntersectNodes->pt, ipBoth );
+ SwapPositionsInAEL( m_IntersectNodes->edge1 , m_IntersectNodes->edge2 );
+ }
+ delete m_IntersectNodes;
+ m_IntersectNodes = iNode;
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::DoMaxima(TEdge *e, long64 topY)
+{
+ TEdge* eMaxPair = GetMaximaPair(e);
+ long64 X = e->xtop;
+ TEdge* eNext = e->nextInAEL;
+ while( eNext != eMaxPair )
+ {
+ if (!eNext) throw clipperException("DoMaxima error");
+ IntersectEdges( e, eNext, IntPoint(X, topY), ipBoth );
+ eNext = eNext->nextInAEL;
+ }
+ if( e->outIdx < 0 && eMaxPair->outIdx < 0 )
+ {
+ DeleteFromAEL( e );
+ DeleteFromAEL( eMaxPair );
+ }
+ else if( e->outIdx >= 0 && eMaxPair->outIdx >= 0 )
+ {
+ IntersectEdges( e, eMaxPair, IntPoint(X, topY), ipNone );
+ }
+ else throw clipperException("DoMaxima error");
+}
+//------------------------------------------------------------------------------
+
+void Clipper::ProcessEdgesAtTopOfScanbeam(const long64 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.
+ if( IsMaxima(e, topY) && GetMaximaPair(e)->dx != horizontal )
+ {
+ //'e' might be removed from AEL, as may any following edges so ...
+ TEdge* ePrior = e->prevInAEL;
+ DoMaxima(e, topY);
+ if( !ePrior ) e = m_ActiveEdges;
+ else e = ePrior->nextInAEL;
+ }
+ else
+ {
+ //2. promote horizontal edges, otherwise update xcurr and ycurr ...
+ if( IsIntermediate(e, topY) && e->nextInLML->dx == horizontal )
+ {
+ if (e->outIdx >= 0)
+ {
+ AddOutPt(e, 0, IntPoint(e->xtop, e->ytop));
+
+ for (HorzJoinList::size_type i = 0; i < m_HorizJoins.size(); ++i)
+ {
+ IntPoint pt, pt2;
+ HorzJoinRec* hj = m_HorizJoins[i];
+ if (GetOverlapSegment(IntPoint(hj->edge->xbot, hj->edge->ybot),
+ IntPoint(hj->edge->xtop, hj->edge->ytop),
+ IntPoint(e->nextInLML->xbot, e->nextInLML->ybot),
+ IntPoint(e->nextInLML->xtop, e->nextInLML->ytop), pt, pt2))
+ AddJoin(hj->edge, e->nextInLML, hj->savedIdx, e->outIdx);
+ }
+
+ AddHorzJoin(e->nextInLML, e->outIdx);
+ }
+ UpdateEdgeIntoAEL(e);
+ AddEdgeToSEL(e);
+ } else
+ {
+ //this just simplifies horizontal processing ...
+ e->xcurr = TopX( *e, topY );
+ e->ycurr = topY;
+ }
+ e = e->nextInAEL;
+ }
+ }
+
+ //3. Process horizontals at the top of the scanbeam ...
+ ProcessHorizontals();
+
+ //4. Promote intermediate vertices ...
+ e = m_ActiveEdges;
+ while( e )
+ {
+ if( IsIntermediate( e, topY ) )
+ {
+ if( e->outIdx >= 0 ) AddOutPt(e, 0, IntPoint(e->xtop,e->ytop));
+ UpdateEdgeIntoAEL(e);
+
+ //if output polygons share an edge, they'll need joining later ...
+ if (e->outIdx >= 0 && e->prevInAEL && e->prevInAEL->outIdx >= 0 &&
+ e->prevInAEL->xcurr == e->xbot && e->prevInAEL->ycurr == e->ybot &&
+ SlopesEqual(IntPoint(e->xbot,e->ybot), IntPoint(e->xtop, e->ytop),
+ IntPoint(e->xbot,e->ybot),
+ IntPoint(e->prevInAEL->xtop, e->prevInAEL->ytop), m_UseFullRange))
+ {
+ AddOutPt(e->prevInAEL, 0, IntPoint(e->xbot, e->ybot));
+ AddJoin(e, e->prevInAEL);
+ }
+ else if (e->outIdx >= 0 && e->nextInAEL && e->nextInAEL->outIdx >= 0 &&
+ e->nextInAEL->ycurr > e->nextInAEL->ytop &&
+ e->nextInAEL->ycurr < e->nextInAEL->ybot &&
+ e->nextInAEL->xcurr == e->xbot && e->nextInAEL->ycurr == e->ybot &&
+ SlopesEqual(IntPoint(e->xbot,e->ybot), IntPoint(e->xtop, e->ytop),
+ IntPoint(e->xbot,e->ybot),
+ IntPoint(e->nextInAEL->xtop, e->nextInAEL->ytop), m_UseFullRange))
+ {
+ AddOutPt(e->nextInAEL, 0, IntPoint(e->xbot, e->ybot));
+ AddJoin(e, e->nextInAEL);
+ }
+ }
+ 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.pts = outRec.bottomPt;
+ OutPt *pp = outRec.bottomPt;
+
+ for (;;)
+ {
+ if (pp->prev == pp || pp->prev == pp->next )
+ {
+ DisposeOutPts(pp);
+ outRec.pts = 0;
+ outRec.bottomPt = 0;
+ return;
+ }
+ //test for duplicate points and for same slope (cross-product) ...
+ if ( PointsEqual(pp->pt, pp->next->pt) ||
+ SlopesEqual(pp->prev->pt, pp->pt, pp->next->pt, m_UseFullRange) )
+ {
+ lastOK = 0;
+ OutPt *tmp = pp;
+ if (pp == outRec.bottomPt)
+ {
+ if (tmp->prev->pt.Y > tmp->next->pt.Y)
+ outRec.bottomPt = tmp->prev; else
+ outRec.bottomPt = tmp->next;
+ outRec.pts = outRec.bottomPt;
+ outRec.bottomPt->idx = outRec.idx;
+ }
+ 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;
+ }
+ }
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildResult(Polygons &polys)
+{
+ int k = 0;
+ polys.resize(m_PolyOuts.size());
+ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+ {
+ if (m_PolyOuts[i]->pts)
+ {
+ Polygon* pg = &polys[k];
+ pg->clear();
+ OutPt* p = m_PolyOuts[i]->pts;
+ do
+ {
+ pg->push_back(p->pt);
+ p = p->next;
+ } while (p != m_PolyOuts[i]->pts);
+ //make sure each polygon has at least 3 vertices ...
+ if (pg->size() < 3) pg->clear(); else k++;
+ }
+ }
+ polys.resize(k);
+}
+//------------------------------------------------------------------------------
+
+void Clipper::BuildResultEx(ExPolygons &polys)
+{
+ PolyOutList::size_type i = 0;
+ int k = 0;
+ polys.resize(0);
+ polys.reserve(m_PolyOuts.size());
+ while (i < m_PolyOuts.size() && m_PolyOuts[i]->pts)
+ {
+ ExPolygon epg;
+ OutPt* p = m_PolyOuts[i]->pts;
+ do {
+ epg.outer.push_back(p->pt);
+ p = p->next;
+ } while (p != m_PolyOuts[i]->pts);
+ i++;
+ //make sure polygons have at least 3 vertices ...
+ if (epg.outer.size() < 3) continue;
+ while (i < m_PolyOuts.size()
+ && m_PolyOuts[i]->pts && m_PolyOuts[i]->isHole)
+ {
+ Polygon pg;
+ p = m_PolyOuts[i]->pts;
+ do {
+ pg.push_back(p->pt);
+ p = p->next;
+ } while (p != m_PolyOuts[i]->pts);
+ epg.holes.push_back(pg);
+ i++;
+ }
+ polys.push_back(epg);
+ k++;
+ }
+ polys.resize(k);
+}
+//------------------------------------------------------------------------------
+
+void SwapIntersectNodes(IntersectNode &int1, IntersectNode &int2)
+{
+ TEdge *e1 = int1.edge1;
+ TEdge *e2 = int1.edge2;
+ IntPoint p = int1.pt;
+
+ int1.edge1 = int2.edge1;
+ int1.edge2 = int2.edge2;
+ int1.pt = int2.pt;
+
+ int2.edge1 = e1;
+ int2.edge2 = e2;
+ int2.pt = p;
+}
+//------------------------------------------------------------------------------
+
+bool Clipper::FixupIntersections()
+{
+ if ( !m_IntersectNodes->next ) return true;
+
+ CopyAELToSEL();
+ IntersectNode *int1 = m_IntersectNodes;
+ IntersectNode *int2 = m_IntersectNodes->next;
+ while (int2)
+ {
+ TEdge *e1 = int1->edge1;
+ TEdge *e2;
+ if (e1->prevInSEL == int1->edge2) e2 = e1->prevInSEL;
+ else if (e1->nextInSEL == int1->edge2) e2 = e1->nextInSEL;
+ else
+ {
+ //The current intersection is out of order, so try and swap it with
+ //a subsequent intersection ...
+ while (int2)
+ {
+ if (int2->edge1->nextInSEL == int2->edge2 ||
+ int2->edge1->prevInSEL == int2->edge2) break;
+ else int2 = int2->next;
+ }
+ if ( !int2 ) return false; //oops!!!
+
+ //found an intersect node that can be swapped ...
+ SwapIntersectNodes(*int1, *int2);
+ e1 = int1->edge1;
+ e2 = int1->edge2;
+ }
+ SwapPositionsInSEL(e1, e2);
+ int1 = int1->next;
+ int2 = int1->next;
+ }
+
+ m_SortedEdges = 0;
+
+ //finally, check the last intersection too ...
+ return (int1->edge1->prevInSEL == int1->edge2 ||
+ int1->edge1->nextInSEL == int1->edge2);
+}
+//------------------------------------------------------------------------------
+
+bool E2InsertsBeforeE1(TEdge &e1, TEdge &e2)
+{
+ if (e2.xcurr == e1.xcurr) return e2.dx > e1.dx;
+ else return e2.xcurr < e1.xcurr;
+}
+//------------------------------------------------------------------------------
+
+void Clipper::InsertEdgeIntoAEL(TEdge *edge)
+{
+ edge->prevInAEL = 0;
+ edge->nextInAEL = 0;
+ if( !m_ActiveEdges )
+ {
+ m_ActiveEdges = edge;
+ }
+ else if( E2InsertsBeforeE1(*m_ActiveEdges, *edge) )
+ {
+ edge->nextInAEL = m_ActiveEdges;
+ m_ActiveEdges->prevInAEL = edge;
+ m_ActiveEdges = edge;
+ } else
+ {
+ TEdge* e = m_ActiveEdges;
+ while( e->nextInAEL && !E2InsertsBeforeE1(*e->nextInAEL , *edge) )
+ e = e->nextInAEL;
+ edge->nextInAEL = e->nextInAEL;
+ if( e->nextInAEL ) e->nextInAEL->prevInAEL = edge;
+ edge->prevInAEL = e;
+ e->nextInAEL = edge;
+ }
+}
+//----------------------------------------------------------------------
+
+void Clipper::DoEdge1(TEdge *edge1, TEdge *edge2, const IntPoint &pt)
+{
+ AddOutPt(edge1, edge2, pt);
+ SwapSides(*edge1, *edge2);
+ SwapPolyIndexes(*edge1, *edge2);
+}
+//----------------------------------------------------------------------
+
+void Clipper::DoEdge2(TEdge *edge1, TEdge *edge2, const IntPoint &pt)
+{
+ AddOutPt(edge2, edge1, pt);
+ SwapSides(*edge1, *edge2);
+ SwapPolyIndexes(*edge1, *edge2);
+}
+//----------------------------------------------------------------------
+
+void Clipper::DoBothEdges(TEdge *edge1, TEdge *edge2, const IntPoint &pt)
+{
+ AddOutPt(edge1, edge2, pt);
+ AddOutPt(edge2, edge1, pt);
+ SwapSides( *edge1 , *edge2 );
+ SwapPolyIndexes( *edge1 , *edge2 );
+}
+//----------------------------------------------------------------------
+
+void Clipper::CheckHoleLinkages1(OutRec *outRec1, OutRec *outRec2)
+{
+ //when a polygon is split into 2 polygons, make sure any holes the original
+ //polygon contained link to the correct polygon ...
+ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+ {
+ OutRec *or1 = m_PolyOuts[i];
+ if (or1->isHole && or1->bottomPt && or1->FirstLeft == outRec1 &&
+ !PointInPolygon(or1->bottomPt->pt, outRec1->pts, m_UseFullRange))
+ or1->FirstLeft = outRec2;
+ }
+}
+//----------------------------------------------------------------------
+
+void Clipper::CheckHoleLinkages2(OutRec *outRec1, OutRec *outRec2)
+{
+ //if a hole is owned by outRec2 then make it owned by outRec1 ...
+ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+ if (m_PolyOuts[i]->isHole && m_PolyOuts[i]->bottomPt &&
+ m_PolyOuts[i]->FirstLeft == outRec2)
+ m_PolyOuts[i]->FirstLeft = outRec1;
+}
+//----------------------------------------------------------------------
+
+void Clipper::JoinCommonEdges(bool fixHoleLinkages)
+{
+ for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+ {
+ JoinRec* j = m_Joins[i];
+ OutRec *outRec1 = m_PolyOuts[j->poly1Idx];
+ OutPt *pp1a = outRec1->pts;
+ OutRec *outRec2 = m_PolyOuts[j->poly2Idx];
+ OutPt *pp2a = outRec2->pts;
+ IntPoint pt1 = j->pt2a, pt2 = j->pt2b;
+ IntPoint pt3 = j->pt1a, pt4 = j->pt1b;
+ if (!FindSegment(pp1a, pt1, pt2)) continue;
+ if (j->poly1Idx == j->poly2Idx)
+ {
+ //we're searching the same polygon for overlapping segments so
+ //segment 2 mustn't be the same as segment 1 ...
+ pp2a = pp1a->next;
+ if (!FindSegment(pp2a, pt3, pt4) || (pp2a == pp1a)) continue;
+ }
+ else if (!FindSegment(pp2a, pt3, pt4)) continue;
+
+ if (!GetOverlapSegment(pt1, pt2, pt3, pt4, pt1, pt2)) continue;
+
+ OutPt *p1, *p2, *p3, *p4;
+ OutPt *prev = pp1a->prev;
+ //get p1 & p2 polypts - the overlap start & endpoints on poly1
+ if (PointsEqual(pp1a->pt, pt1)) p1 = pp1a;
+ else if (PointsEqual(prev->pt, pt1)) p1 = prev;
+ else p1 = InsertPolyPtBetween(pp1a, prev, pt1);
+
+ if (PointsEqual(pp1a->pt, pt2)) p2 = pp1a;
+ else if (PointsEqual(prev->pt, pt2)) p2 = prev;
+ else if ((p1 == pp1a) || (p1 == prev))
+ p2 = InsertPolyPtBetween(pp1a, prev, pt2);
+ else if (Pt3IsBetweenPt1AndPt2(pp1a->pt, p1->pt, pt2))
+ p2 = InsertPolyPtBetween(pp1a, p1, pt2); else
+ p2 = InsertPolyPtBetween(p1, prev, pt2);
+
+ //get p3 & p4 polypts - the overlap start & endpoints on poly2
+ prev = pp2a->prev;
+ if (PointsEqual(pp2a->pt, pt1)) p3 = pp2a;
+ else if (PointsEqual(prev->pt, pt1)) p3 = prev;
+ else p3 = InsertPolyPtBetween(pp2a, prev, pt1);
+
+ if (PointsEqual(pp2a->pt, pt2)) p4 = pp2a;
+ else if (PointsEqual(prev->pt, pt2)) p4 = prev;
+ else if ((p3 == pp2a) || (p3 == prev))
+ p4 = InsertPolyPtBetween(pp2a, prev, pt2);
+ else if (Pt3IsBetweenPt1AndPt2(pp2a->pt, p3->pt, pt2))
+ p4 = InsertPolyPtBetween(pp2a, p3, pt2); else
+ p4 = InsertPolyPtBetween(p3, prev, pt2);
+
+ //p1.pt == p3.pt and p2.pt == p4.pt so join p1 to p3 and p2 to p4 ...
+ if (p1->next == p2 && p3->prev == p4)
+ {
+ p1->next = p3;
+ p3->prev = p1;
+ p2->prev = p4;
+ p4->next = p2;
+ }
+ else if (p1->prev == p2 && p3->next == p4)
+ {
+ p1->prev = p3;
+ p3->next = p1;
+ p2->next = p4;
+ p4->prev = p2;
+ }
+ else
+ continue; //an orientation is probably wrong
+
+ if (j->poly2Idx == j->poly1Idx)
+ {
+ //instead of joining two polygons, we've just created a new one by
+ //splitting one polygon into two.
+ outRec1->pts = PolygonBottom(p1);
+ outRec1->bottomPt = outRec1->pts;
+ outRec1->bottomPt->idx = outRec1->idx;
+ outRec2 = CreateOutRec();
+ m_PolyOuts.push_back(outRec2);
+ outRec2->idx = (int)m_PolyOuts.size()-1;
+ j->poly2Idx = outRec2->idx;
+ outRec2->pts = PolygonBottom(p2);
+ outRec2->bottomPt = outRec2->pts;
+ outRec2->bottomPt->idx = outRec2->idx;
+
+ if (PointInPolygon(outRec2->pts->pt, outRec1->pts, m_UseFullRange))
+ {
+ outRec2->isHole = !outRec1->isHole;
+ outRec2->FirstLeft = outRec1;
+ if (outRec2->isHole == Orientation(outRec2, m_UseFullRange))
+ ReversePolyPtLinks(*outRec2->pts);
+ } else if (PointInPolygon(outRec1->pts->pt, outRec2->pts, m_UseFullRange))
+ {
+ outRec2->isHole = outRec1->isHole;
+ outRec1->isHole = !outRec2->isHole;
+ outRec2->FirstLeft = outRec1->FirstLeft;
+ outRec1->FirstLeft = outRec2;
+ if (outRec1->isHole == Orientation(outRec1, m_UseFullRange))
+ ReversePolyPtLinks(*outRec1->pts);
+ } else
+ {
+ outRec2->isHole = outRec1->isHole;
+ outRec2->FirstLeft = outRec1->FirstLeft;
+ //make sure any contained holes now link to the correct polygon ...
+ if (fixHoleLinkages) CheckHoleLinkages1(outRec1, outRec2);
+ }
+
+ //now fixup any subsequent joins that match this polygon
+ for (JoinList::size_type k = i+1; k < m_Joins.size(); k++)
+ {
+ JoinRec* j2 = m_Joins[k];
+ if (j2->poly1Idx == j->poly1Idx && PointIsVertex(j2->pt1a, p2))
+ j2->poly1Idx = j->poly2Idx;
+ if (j2->poly2Idx == j->poly1Idx && PointIsVertex(j2->pt2a, p2))
+ j2->poly2Idx = j->poly2Idx;
+ }
+
+ //now cleanup redundant edges too ...
+ FixupOutPolygon(*outRec1);
+ FixupOutPolygon(*outRec2);
+ } else
+ {
+ //joined 2 polygons together ...
+
+ //make sure any holes contained by outRec2 now link to outRec1 ...
+ if (fixHoleLinkages) CheckHoleLinkages2(outRec1, outRec2);
+
+ //delete the obsolete pointer ...
+ int OKIdx = outRec1->idx;
+ int ObsoleteIdx = outRec2->idx;
+ outRec2->pts = 0;
+ outRec2->bottomPt = 0;
+ outRec2->AppendLink = outRec1;
+ //holes are practically always joined to outers, not vice versa ...
+ if (outRec1->isHole && !outRec2->isHole) outRec1->isHole = false;
+
+ //now fixup any subsequent Joins that match this polygon
+ for (JoinList::size_type k = i+1; k < m_Joins.size(); k++)
+ {
+ JoinRec* j2 = m_Joins[k];
+ if (j2->poly1Idx == ObsoleteIdx) j2->poly1Idx = OKIdx;
+ if (j2->poly2Idx == ObsoleteIdx) j2->poly2Idx = OKIdx;
+ }
+
+ //now cleanup redundant edges too ...
+ if (outRec1->pts)
+ FixupOutPolygon(*outRec1);
+ else
+ FixupOutPolygon(*outRec2);
+ }
+ }
+}
+//------------------------------------------------------------------------------
+
+void ReversePoints(Polygon& p)
+{
+ std::reverse(p.begin(), p.end());
+};
+//------------------------------------------------------------------------------
+
+void ReversePoints(Polygons& p)
+{
+ for (Polygons::size_type i = 0; i < p.size(); ++i)
+ ReversePoints(p[i]);
+};
+
+//------------------------------------------------------------------------------
+// OffsetPolygon functions ...
+//------------------------------------------------------------------------------
+
+struct DoublePoint
+{
+ double X;
+ double Y;
+ DoublePoint(double x = 0, double y = 0) : X(x), Y(y) {}
+};
+//------------------------------------------------------------------------------
+
+Polygon BuildArc(const IntPoint &pt,
+ const double a1, const double a2, const double r)
+{
+ int steps = std::max(6, int(std::sqrt(std::fabs(r)) * std::fabs(a2 - a1)));
+ Polygon result(steps);
+ int n = steps - 1;
+ double da = (a2 - a1) / n;
+ double a = a1;
+ for (int i = 0; i <= n; ++i)
+ {
+ result[i].X = pt.X + Round(std::cos(a)*r);
+ result[i].Y = pt.Y + Round(std::sin(a)*r);
+ a += da;
+ }
+ return result;
+}
+//------------------------------------------------------------------------------
+
+DoublePoint GetUnitNormal( const IntPoint &pt1, const IntPoint &pt2)
+{
+ double dx = (double)(pt2.X - pt1.X);
+ double dy = (double)(pt2.Y - pt1.Y);
+ if( ( dx == 0 ) && ( dy == 0 ) ) return DoublePoint( 0, 0 );
+
+ double f = 1 *1.0/ std::sqrt( dx*dx + dy*dy );
+ dx *= f;
+ dy *= f;
+ return DoublePoint(dy, -dx);
+}
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+class PolyOffsetBuilder
+{
+private:
+ Polygons m_p;
+ Polygon* m_curr_poly;
+ std::vector<DoublePoint> normals;
+ double m_delta, m_RMin;
+ int m_highJ;
+ static const int buffLength = 128;
+ JoinType m_jointype;
+
+public:
+
+PolyOffsetBuilder(const Polygons& in_polys, Polygons& out_polys,
+ double delta, JoinType jointype, double MiterLimit)
+{
+ //nb precondition - out_polys != ptsin_polys
+ if (delta == 0)
+ {
+ out_polys = in_polys;
+ return;
+ }
+
+ this->m_p = in_polys;
+ this->m_delta = delta;
+ this->m_jointype = jointype;
+ if (MiterLimit <= 1) MiterLimit = 1;
+ m_RMin = 2/(MiterLimit*MiterLimit);
+
+ double deltaSq = delta*delta;
+ out_polys.clear();
+ out_polys.resize(in_polys.size());
+ for (Polygons::size_type i = 0; i < in_polys.size(); i++)
+ {
+ m_curr_poly = &out_polys[i];
+ int len = (int)in_polys[i].size();
+ if (len > 1 && m_p[i][0].X == m_p[i][len - 1].X &&
+ m_p[i][0].Y == m_p[i][len - 1].Y) len--;
+ m_highJ = len - 1;
+
+ //to minimize artefacts, strip out those polygons where
+ //it's being shrunk and where its area < Sqr(delta) ...
+ double a1 = Area(in_polys[i]);
+ if (delta < 0) { if (a1 > 0 && a1 < deltaSq) len = 0; }
+ else if (a1 < 0 && -a1 < deltaSq) len = 0; //nb: a hole if area < 0
+
+ if (len == 0 || (len < 3 && delta <= 0)) continue;
+ if (len == 1)
+ {
+ Polygon arc;
+ arc = BuildArc(in_polys[i][m_highJ], 0, 2 * pi, delta);
+ out_polys[i] = arc;
+ continue;
+ }
+
+ //build normals ...
+ normals.clear();
+ normals.resize(len);
+ normals[0] = GetUnitNormal(in_polys[i][m_highJ], in_polys[i][0]);
+ for (int j = 1; j < len; ++j)
+ normals[j] = GetUnitNormal(in_polys[i][j - 1], in_polys[i][j]);
+
+ switch (jointype)
+ {
+ case jtMiter:
+ for (int j = 0; j < len; ++j) DoMiter(i, j, MiterLimit);
+ break;
+ case jtRound:
+ for (int j = 0; j < len; ++j) DoRound(i, j);
+ break;
+ case jtSquare:
+ for (int j = 0; j < len; ++j) DoSquare(i, j, 1.0);
+ break;
+ }
+ }
+
+ //finally, clean up untidy corners using Clipper ...
+ Clipper clpr;
+ clpr.AddPolygons(out_polys, ptSubject);
+ if (delta > 0)
+ {
+ if (!clpr.Execute(ctUnion, out_polys, pftNonZero, pftNonZero))
+ out_polys.clear();
+ }
+ else
+ {
+ IntRect r = clpr.GetBounds();
+ Polygon 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.AddPolygon(outer, ptSubject);
+ if (clpr.Execute(ctUnion, out_polys, pftNonZero, pftNonZero))
+ {
+ out_polys.erase(out_polys.begin());
+ ReversePoints(out_polys);
+
+ } else
+ out_polys.clear();
+ }
+}
+//------------------------------------------------------------------------------
+
+private:
+
+void AddPoint(IntPoint& pt)
+{
+ Polygon::size_type len = m_curr_poly->size();
+ if (len == m_curr_poly->capacity())
+ m_curr_poly->reserve(len + buffLength);
+ m_curr_poly->push_back(pt);
+}
+//------------------------------------------------------------------------------
+
+void DoSquare(int i, int j, double mul)
+{
+ int k;
+ if (j == m_highJ) k = 0; else k = j + 1;
+ IntPoint pt1 = IntPoint((long64)Round(m_p[i][j].X + normals[j].X * m_delta),
+ (long64)Round(m_p[i][j].Y + normals[j].Y * m_delta));
+ IntPoint pt2 = IntPoint((long64)Round(m_p[i][j].X + normals[k].X * m_delta),
+ (long64)Round(m_p[i][j].Y + normals[k].Y * m_delta));
+ if ((normals[j].X * normals[k].Y - normals[k].X * normals[j].Y) * m_delta >= 0)
+ {
+ double a1 = std::atan2(normals[j].Y, normals[j].X);
+ double a2 = std::atan2(-normals[k].Y, -normals[k].X);
+ a1 = std::fabs(a2 - a1);
+ if (a1 > pi) a1 = pi * 2 - a1;
+ double dx = std::tan((pi - a1)/4) * std::fabs(m_delta * mul);
+ pt1 = IntPoint((long64)(pt1.X -normals[j].Y * dx),
+ (long64)(pt1.Y + normals[j].X * dx));
+ AddPoint(pt1);
+ pt2 = IntPoint((long64)(pt2.X + normals[k].Y * dx),
+ (long64)(pt2.Y -normals[k].X * dx));
+ AddPoint(pt2);
+ }
+ else
+ {
+ AddPoint(pt1);
+ AddPoint(pt2);
+ }
+}
+//------------------------------------------------------------------------------
+
+void DoMiter(int i, int j, double mul)
+{
+ int k;
+ if (j == m_highJ) k = 0; else k = j + 1;
+ double R = 1 + (normals[j].X*normals[k].X + normals[j].Y*normals[k].Y);
+ if (R >= m_RMin)
+ {
+ if ((normals[j].X*normals[k].Y - normals[k].X*normals[j].Y) * m_delta >= 0) //ie angle > 180
+ {
+ R = m_delta / R;
+ IntPoint pt1 =
+ IntPoint((long64)Round(m_p[i][j].X + (normals[j].X + normals[k].X) *R),
+ (long64)Round(m_p[i][j].Y + (normals[j].Y + normals[k].Y) *R));
+ AddPoint(pt1);
+ }
+ else
+ {
+ IntPoint pt1 = IntPoint((long64)Round(m_p[i][j].X + normals[j].X *
+ m_delta), (long64)Round(m_p[i][j].Y + normals[j].Y * m_delta));
+ IntPoint pt2 = IntPoint((long64)Round(m_p[i][j].X + normals[k].X *
+ m_delta), (long64)Round(m_p[i][j].Y + normals[k].Y * m_delta));
+ AddPoint(pt1);
+ AddPoint(pt2);
+ }
+ }
+ else
+ DoSquare(i, j, mul);
+}
+//------------------------------------------------------------------------------
+
+void DoRound(int i, int j)
+{
+ int k;
+ if (j == m_highJ) k = 0; else k = j + 1;
+ IntPoint pt1 = IntPoint((long64)Round(m_p[i][j].X + normals[j].X * m_delta),
+ (long64)Round(m_p[i][j].Y + normals[j].Y * m_delta));
+ IntPoint pt2 = IntPoint((long64)Round(m_p[i][j].X + normals[k].X * m_delta),
+ (long64)Round(m_p[i][j].Y + normals[k].Y * m_delta));
+ AddPoint(pt1);
+ //round off reflex angles (ie > 180 deg) unless it's
+ //almost flat (ie < 10deg angle).
+ //cross product normals < 0 -> angle > 180 deg.
+ //dot product normals == 1 -> no angle
+ if ((normals[j].X*normals[k].Y - normals[k].X*normals[j].Y) * m_delta >= 0 &&
+ (normals[k].X * normals[j].X + normals[k].Y * normals[j].Y) < 0.985)
+ {
+ double a1 = std::atan2(normals[j].Y, normals[j].X);
+ double a2 = std::atan2(normals[k].Y, normals[k].X);
+ if (m_delta > 0 && a2 < a1) a2 += pi *2;
+ else if (m_delta < 0 && a2 > a1) a2 -= pi *2;
+ Polygon arc = BuildArc(m_p[i][j], a1, a2, m_delta);
+ for (Polygon::size_type m = 0; m < arc.size(); m++)
+ AddPoint(arc[m]);
+ }
+ AddPoint(pt2);
+}
+//--------------------------------------------------------------------------
+
+}; //class PolyOffsetBuilder
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+void OffsetPolygons(const Polygons &in_polys, Polygons &out_polys,
+ double delta, JoinType jointype, double MiterLimit)
+{
+ if (&out_polys == &in_polys)
+ {
+ Polygons poly2(in_polys);
+ PolyOffsetBuilder(poly2, out_polys, delta, jointype, MiterLimit);
+ }
+ else PolyOffsetBuilder(in_polys, out_polys, delta, jointype, MiterLimit);
+}
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, IntPoint& p)
+{
+ s << p.X << ' ' << p.Y << "\n";
+ return s;
+};
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, Polygon &p)
+{
+ for (Polygon::size_type i = 0; i < p.size(); i++)
+ s << p[i];
+ s << "\n";
+ return s;
+}
+//------------------------------------------------------------------------------
+
+std::ostream& operator <<(std::ostream &s, Polygons &p)
+{
+ for (Polygons::size_type i = 0; i < p.size(); i++)
+ s << p[i];
+ s << "\n";
+ return s;
+}
+//------------------------------------------------------------------------------
+
+}; //ClipperLib namespace
diff --git a/src/Lib/Polygon/clipper.hpp b/src/Lib/Polygon/clipper.hpp
new file mode 100644
index 00000000..5ae6185e
--- /dev/null
+++ b/src/Lib/Polygon/clipper.hpp
@@ -0,0 +1,294 @@
+/*******************************************************************************
+* *
+* Author : Angus Johnson *
+* Version : 4.5.5 *
+* Date : 6 October 2011 *
+* Website : http://www.angusj.com *
+* Copyright : Angus Johnson 2010-2011 *
+* *
+* 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 *
+* *
+*******************************************************************************/
+
+#ifndef clipper_hpp
+#define clipper_hpp
+
+#include <vector>
+#include <stdexcept>
+#include <cstring>
+#include <cstdlib>
+#include <ostream>
+
+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://www.songho.ca/opengl/gl_tessellation.html#winding_rules
+enum PolyFillType { pftEvenOdd, pftNonZero };
+
+typedef signed long long long64;
+typedef unsigned long long ulong64;
+
+struct IntPoint {
+public:
+ long64 X;
+ long64 Y;
+ IntPoint(long64 x = 0, long64 y = 0): X(x), Y(y) {};
+ friend std::ostream& operator <<(std::ostream &s, IntPoint &p);
+};
+
+typedef std::vector< IntPoint > Polygon;
+typedef std::vector< Polygon > Polygons;
+
+std::ostream& operator <<(std::ostream &s, Polygon &p);
+std::ostream& operator <<(std::ostream &s, Polygons &p);
+
+struct ExPolygon {
+ Polygon outer;
+ Polygons holes;
+};
+typedef std::vector< ExPolygon > ExPolygons;
+
+enum JoinType { jtSquare, jtMiter, jtRound };
+
+bool Orientation(const Polygon &poly);
+double Area(const Polygon &poly);
+void OffsetPolygons(const Polygons &in_polys, Polygons &out_polys,
+ double delta, JoinType jointype = jtSquare, double MiterLimit = 2);
+
+void ReversePoints(Polygon& p);
+void ReversePoints(Polygons& p);
+
+//used internally ...
+enum EdgeSide { esLeft, esRight };
+enum IntersectProtects { ipNone = 0, ipLeft = 1, ipRight = 2, ipBoth = 3 };
+
+struct TEdge {
+ long64 xbot;
+ long64 ybot;
+ long64 xcurr;
+ long64 ycurr;
+ long64 xtop;
+ long64 ytop;
+ double dx;
+ long64 tmpX;
+ PolyType polyType;
+ 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;
+ IntersectNode *next;
+};
+
+struct LocalMinima {
+ long64 Y;
+ TEdge *leftBound;
+ TEdge *rightBound;
+ LocalMinima *next;
+};
+
+struct Scanbeam {
+ long64 Y;
+ Scanbeam *next;
+};
+
+struct OutPt; //forward declaration
+
+struct OutRec {
+ int idx;
+ bool isHole;
+ OutRec *FirstLeft;
+ OutRec *AppendLink;
+ OutPt *pts;
+ OutPt *bottomPt;
+ TEdge *bottomE1;
+ TEdge *bottomE2;
+};
+
+struct OutPt {
+ int idx;
+ IntPoint pt;
+ OutPt *next;
+ OutPt *prev;
+};
+
+struct JoinRec {
+ IntPoint pt1a;
+ IntPoint pt1b;
+ int poly1Idx;
+ IntPoint pt2a;
+ IntPoint pt2b;
+ int poly2Idx;
+};
+
+struct HorzJoinRec {
+ TEdge *edge;
+ int savedIdx;
+};
+
+struct IntRect { long64 left; long64 top; long64 right; long64 bottom; };
+
+typedef std::vector < OutRec* > PolyOutList;
+typedef std::vector < TEdge* > EdgeList;
+typedef std::vector < JoinRec* > JoinList;
+typedef std::vector < HorzJoinRec* > HorzJoinList;
+
+//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 AddPolygon(const Polygon &pg, PolyType polyType);
+ bool AddPolygons( const Polygons &ppg, PolyType polyType);
+ virtual void Clear();
+ IntRect GetBounds();
+protected:
+ void DisposeLocalMinimaList();
+ TEdge* AddBoundsToLML(TEdge *e);
+ void PopLocalMinima();
+ virtual void Reset();
+ void InsertLocalMinima(LocalMinima *newLm);
+ LocalMinima *m_CurrentLM;
+ LocalMinima *m_MinimaList;
+ bool m_UseFullRange;
+ EdgeList m_edges;
+};
+
+class Clipper : public virtual ClipperBase
+{
+public:
+ Clipper();
+ ~Clipper();
+ bool Execute(ClipType clipType,
+ Polygons &solution,
+ PolyFillType subjFillType = pftEvenOdd,
+ PolyFillType clipFillType = pftEvenOdd);
+ bool Execute(ClipType clipType,
+ ExPolygons &solution,
+ PolyFillType subjFillType = pftEvenOdd,
+ PolyFillType clipFillType = pftEvenOdd);
+ void Clear();
+ bool ReverseSolution() {return m_ReverseOutput;};
+ void ReverseSolution(bool value) {m_ReverseOutput = value;};
+protected:
+ void Reset();
+ virtual bool ExecuteInternal(bool fixHoleLinkages);
+private:
+ PolyOutList m_PolyOuts;
+ JoinList m_Joins;
+ HorzJoinList m_HorizJoins;
+ ClipType m_ClipType;
+ Scanbeam *m_Scanbeam;
+ TEdge *m_ActiveEdges;
+ TEdge *m_SortedEdges;
+ IntersectNode *m_IntersectNodes;
+ bool m_ExecuteLocked;
+ PolyFillType m_ClipFillType;
+ PolyFillType m_SubjFillType;
+ bool m_ReverseOutput;
+ void DisposeScanbeamList();
+ void SetWindingCount(TEdge& edge);
+ bool IsNonZeroFillType(const TEdge& edge) const;
+ bool IsNonZeroAltFillType(const TEdge& edge) const;
+ void InsertScanbeam(const long64 Y);
+ long64 PopScanbeam();
+ void InsertLocalMinimaIntoAEL(const long64 botY);
+ void InsertEdgeIntoAEL(TEdge *edge);
+ 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 long64 XPos);
+ void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
+ void DoMaxima(TEdge *e, long64 topY);
+ void ProcessHorizontals();
+ void ProcessHorizontal(TEdge *horzEdge);
+ void AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
+ void AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
+ void AppendPolygon(TEdge *e1, TEdge *e2);
+ void DoEdge1(TEdge *edge1, TEdge *edge2, const IntPoint &pt);
+ void DoEdge2(TEdge *edge1, TEdge *edge2, const IntPoint &pt);
+ void DoBothEdges(TEdge *edge1, TEdge *edge2, const IntPoint &pt);
+ void IntersectEdges(TEdge *e1, TEdge *e2,
+ const IntPoint &pt, IntersectProtects protects);
+ OutRec* CreateOutRec();
+ void AddOutPt(TEdge *e, TEdge *altE, const IntPoint &pt);
+ void DisposeAllPolyPts();
+ void DisposeOutRec(PolyOutList::size_type index, bool ignorePts = false);
+ bool ProcessIntersections(const long64 botY, const long64 topY);
+ void AddIntersectNode(TEdge *e1, TEdge *e2, const IntPoint &pt);
+ void BuildIntersectList(const long64 botY, const long64 topY);
+ void ProcessIntersectList();
+ void ProcessEdgesAtTopOfScanbeam(const long64 topY);
+ void BuildResult(Polygons& polys);
+ void BuildResultEx(ExPolygons& polys);
+ void SetHoleState(TEdge *e, OutRec *OutRec);
+ void DisposeIntersectNodes();
+ bool FixupIntersections();
+ void FixupOutPolygon(OutRec &outRec);
+ bool IsHole(TEdge *e);
+ void FixHoleLinkage(OutRec *outRec);
+ void CheckHoleLinkages1(OutRec *outRec1, OutRec *outRec2);
+ void CheckHoleLinkages2(OutRec *outRec1, OutRec *outRec2);
+ void AddJoin(TEdge *e1, TEdge *e2, int e1OutIdx = -1, int e2OutIdx = -1);
+ void ClearJoins();
+ void AddHorzJoin(TEdge *e, int idx);
+ void ClearHorzJoins();
+ void JoinCommonEdges(bool fixHoleLinkages);
+};
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+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
+
+