diff --git a/src/ImageSharp/Drawing/Shapes/Clipper.cs b/src/ImageSharp/Drawing/Shapes/Clipper.cs
deleted file mode 100644
index 91f0b59ea..000000000
--- a/src/ImageSharp/Drawing/Shapes/Clipper.cs
+++ /dev/null
@@ -1,4924 +0,0 @@
-//
-//pretend to be auto generated to shut stylecop up
-
-/*******************************************************************************
-**
-* Author : Angus Johnson *
-* Version : 6.4.0 *
-* Date : 2 July 2015 *
-* Website : http://www.angusj.com *
-* Copyright : Angus Johnson 2010-2015 *
-* *
-* License: *
-* Use, modification & distribution is subject to Boost Software License Ver 1. *
-* http://www.boost.org/LICENSE_1_0.txt *
-* *
-* Attributions: *
-* The code in this library is an extension of Bala Vatti's clipping algorithm: *
-* "A generic solution to polygon clipping" *
-* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63. *
-* http://portal.acm.org/citation.cfm?id=129906 *
-* *
-* Computer graphics and geometric modeling: implementation and algorithms *
-* By Max K. Agoston *
-* Springer; 1 edition (January 4, 2005) *
-* http://books.google.com/books?q=vatti+clipping+agoston *
-* *
-* See also: *
-* "Polygon Offsetting by Computing Winding Numbers" *
-* Paper no. DETC2005-85513 pp. 565-575 *
-* ASME 2005 International Design Engineering Technical Conferences *
-* and Computers and Information in Engineering Conference (IDETC/CIE2005) *
-* September 24-28, 2005 , Long Beach, California, USA *
-* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf *
-* *
-*******************************************************************************/
-
-/*******************************************************************************
-* *
-* This is a translation of the Delphi Clipper library and the naming style *
-* used has retained a Delphi flavour. *
-* *
-*******************************************************************************/
-
-//use_int32: When enabled 32bit ints are used instead of 64bit ints. This
-//improve performance but coordinate values are limited to the range +/- 46340
-//#define use_int32
-
-//use_xyz: adds a Z member to IntPoint. Adds a minor cost to performance.
-//#define use_xyz
-
-//use_lines: Enables open path clipping. Adds a very minor cost to performance.
-#define use_lines
-
-
-using System;
-using System.Collections.Generic;
-//using System.Text; //for Int128.AsString() & StringBuilder
-//using System.IO; //debugging with streamReader & StreamWriter
-//using System.Windows.Forms; //debugging to clipboard
-
-namespace ClipperLib
-{
-
-#if use_int32
- using cInt = Int32;
-#else
- using cInt = Int64;
-#endif
-
- using Path = List;
- using Paths = List>;
-
- internal struct DoublePoint
- {
- public double X;
- public double Y;
-
- public DoublePoint(double x = 0, double y = 0)
- {
- this.X = x; this.Y = y;
- }
- public DoublePoint(DoublePoint dp)
- {
- this.X = dp.X; this.Y = dp.Y;
- }
- public DoublePoint(IntPoint ip)
- {
- this.X = ip.X; this.Y = ip.Y;
- }
- };
-
-
- //------------------------------------------------------------------------------
- // PolyTree & PolyNode classes
- //------------------------------------------------------------------------------
-
- internal class PolyTree : PolyNode
- {
- internal List m_AllPolys = new List();
-
- //The GC probably handles this cleanup more efficiently ...
- //~PolyTree(){Clear();}
-
- public void Clear()
- {
- for (int i = 0; i < m_AllPolys.Count; i++)
- m_AllPolys[i] = null;
- m_AllPolys.Clear();
- m_Childs.Clear();
- }
-
- public PolyNode GetFirst()
- {
- if (m_Childs.Count > 0)
- return m_Childs[0];
- else
- return null;
- }
-
- public int Total
- {
- get
- {
- int result = m_AllPolys.Count;
- //with negative offsets, ignore the hidden outer polygon ...
- if (result > 0 && m_Childs[0] != m_AllPolys[0]) result--;
- return result;
- }
- }
-
- }
-
- internal class PolyNode
- {
- internal PolyNode m_Parent;
- internal Path m_polygon = new Path();
- internal int m_Index;
- internal JoinType m_jointype;
- internal EndType m_endtype;
- internal List m_Childs = new List();
-
- private bool IsHoleNode()
- {
- bool result = true;
- PolyNode node = m_Parent;
- while (node != null)
- {
- result = !result;
- node = node.m_Parent;
- }
- return result;
- }
-
- public int ChildCount
- {
- get { return m_Childs.Count; }
- }
-
- public Path Contour
- {
- get { return m_polygon; }
- }
-
- internal void AddChild(PolyNode Child)
- {
- int cnt = m_Childs.Count;
- m_Childs.Add(Child);
- Child.m_Parent = this;
- Child.m_Index = cnt;
- }
-
- public PolyNode GetNext()
- {
- if (m_Childs.Count > 0)
- return m_Childs[0];
- else
- return GetNextSiblingUp();
- }
-
- internal PolyNode GetNextSiblingUp()
- {
- if (m_Parent == null)
- return null;
- else if (m_Index == m_Parent.m_Childs.Count - 1)
- return m_Parent.GetNextSiblingUp();
- else
- return m_Parent.m_Childs[m_Index + 1];
- }
-
- public List Childs
- {
- get { return m_Childs; }
- }
-
- public PolyNode Parent
- {
- get { return m_Parent; }
- }
-
- public bool IsHole
- {
- get { return IsHoleNode(); }
- }
-
- public bool IsOpen { get; set; }
- }
-
-
- //------------------------------------------------------------------------------
- // Int128 struct (enables safe math on signed 64bit integers)
- // eg Int128 val1((Int64)9223372036854775807); //ie 2^63 -1
- // Int128 val2((Int64)9223372036854775807);
- // Int128 val3 = val1 * val2;
- // val3.ToString => "85070591730234615847396907784232501249" (8.5e+37)
- //------------------------------------------------------------------------------
-
- internal struct Int128
- {
- private Int64 hi;
- private UInt64 lo;
-
- public Int128(Int64 _lo)
- {
- lo = (UInt64)_lo;
- if (_lo < 0) hi = -1;
- else hi = 0;
- }
-
- public Int128(Int64 _hi, UInt64 _lo)
- {
- lo = _lo;
- hi = _hi;
- }
-
- public Int128(Int128 val)
- {
- hi = val.hi;
- lo = val.lo;
- }
-
- public bool IsNegative()
- {
- return hi < 0;
- }
-
- public static bool operator ==(Int128 val1, Int128 val2)
- {
- if ((object)val1 == (object)val2) return true;
- else if ((object)val1 == null || (object)val2 == null) return false;
- return (val1.hi == val2.hi && val1.lo == val2.lo);
- }
-
- public static bool operator !=(Int128 val1, Int128 val2)
- {
- return !(val1 == val2);
- }
-
- public override bool Equals(System.Object obj)
- {
- if (obj == null || !(obj is Int128))
- return false;
- Int128 i128 = (Int128)obj;
- return (i128.hi == hi && i128.lo == lo);
- }
-
- public override int GetHashCode()
- {
- return hi.GetHashCode() ^ lo.GetHashCode();
- }
-
- public static bool operator >(Int128 val1, Int128 val2)
- {
- if (val1.hi != val2.hi)
- return val1.hi > val2.hi;
- else
- return val1.lo > val2.lo;
- }
-
- public static bool operator <(Int128 val1, Int128 val2)
- {
- if (val1.hi != val2.hi)
- return val1.hi < val2.hi;
- else
- return val1.lo < val2.lo;
- }
-
- public static Int128 operator +(Int128 lhs, Int128 rhs)
- {
- lhs.hi += rhs.hi;
- lhs.lo += rhs.lo;
- if (lhs.lo < rhs.lo) lhs.hi++;
- return lhs;
- }
-
- public static Int128 operator -(Int128 lhs, Int128 rhs)
- {
- return lhs + -rhs;
- }
-
- public static Int128 operator -(Int128 val)
- {
- if (val.lo == 0)
- return new Int128(-val.hi, 0);
- else
- return new Int128(~val.hi, ~val.lo + 1);
- }
-
- public static explicit operator double(Int128 val)
- {
- const double shift64 = 18446744073709551616.0; //2^64
- if (val.hi < 0)
- {
- if (val.lo == 0)
- return (double)val.hi * shift64;
- else
- return -(double)(~val.lo + ~val.hi * shift64);
- }
- else
- return (double)(val.lo + val.hi * shift64);
- }
-
- //nb: Constructing two new Int128 objects every time we want to multiply longs
- //is slow. So, although calling the Int128Mul method doesn't look as clean, the
- //code runs significantly faster than if we'd used the * operator.
-
- public static Int128 Int128Mul(Int64 lhs, Int64 rhs)
- {
- bool negate = (lhs < 0) != (rhs < 0);
- if (lhs < 0) lhs = -lhs;
- if (rhs < 0) rhs = -rhs;
- UInt64 int1Hi = (UInt64)lhs >> 32;
- UInt64 int1Lo = (UInt64)lhs & 0xFFFFFFFF;
- UInt64 int2Hi = (UInt64)rhs >> 32;
- UInt64 int2Lo = (UInt64)rhs & 0xFFFFFFFF;
-
- //nb: see comments in clipper.pas
- UInt64 a = int1Hi * int2Hi;
- UInt64 b = int1Lo * int2Lo;
- UInt64 c = int1Hi * int2Lo + int1Lo * int2Hi;
-
- UInt64 lo;
- Int64 hi;
- hi = (Int64)(a + (c >> 32));
-
- unchecked { lo = (c << 32) + b; }
- if (lo < b) hi++;
- Int128 result = new Int128(hi, lo);
- return negate ? -result : result;
- }
-
- };
-
- //------------------------------------------------------------------------------
- //------------------------------------------------------------------------------
-
- internal struct IntPoint
- {
- public cInt X;
- public cInt Y;
-#if use_xyz
- public cInt Z;
-
- public IntPoint(cInt x, cInt y, cInt z = 0)
- {
- this.X = x; this.Y = y; this.Z = z;
- }
-
- public IntPoint(double x, double y, double z = 0)
- {
- this.X = (cInt)x; this.Y = (cInt)y; this.Z = (cInt)z;
- }
-
- public IntPoint(DoublePoint dp)
- {
- this.X = (cInt)dp.X; this.Y = (cInt)dp.Y; this.Z = 0;
- }
-
- public IntPoint(IntPoint pt)
- {
- this.X = pt.X; this.Y = pt.Y; this.Z = pt.Z;
- }
-#else
- public IntPoint(cInt X, cInt Y)
- {
- this.X = X; this.Y = Y;
- }
- public IntPoint(double x, double y)
- {
- this.X = (cInt)x; this.Y = (cInt)y;
- }
-
- public IntPoint(IntPoint pt)
- {
- this.X = pt.X; this.Y = pt.Y;
- }
-#endif
-
- public static bool operator ==(IntPoint a, IntPoint b)
- {
- return a.X == b.X && a.Y == b.Y;
- }
-
- public static bool operator !=(IntPoint a, IntPoint b)
- {
- return a.X != b.X || a.Y != b.Y;
- }
-
- public override bool Equals(object obj)
- {
- if (obj == null) return false;
- if (obj is IntPoint)
- {
- IntPoint a = (IntPoint)obj;
- return (X == a.X) && (Y == a.Y);
- }
- else return false;
- }
-
- public override int GetHashCode()
- {
- //simply prevents a compiler warning
- return base.GetHashCode();
- }
-
- }// end struct IntPoint
-
- internal struct IntRect
- {
- public cInt left;
- public cInt top;
- public cInt right;
- public cInt bottom;
-
- public IntRect(cInt l, cInt t, cInt r, cInt b)
- {
- this.left = l; this.top = t;
- this.right = r; this.bottom = b;
- }
- public IntRect(IntRect ir)
- {
- this.left = ir.left; this.top = ir.top;
- this.right = ir.right; this.bottom = ir.bottom;
- }
- }
-
- internal enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };
- internal enum PolyType { ptSubject, ptClip };
-
- //By far the most widely used winding rules for polygon filling are
- //EvenOdd & NonZero (GDI, GDI+, XLib, OpenGL, Cairo, AGG, Quartz, SVG, Gr32)
- //Others rules include Positive, Negative and ABS_GTR_EQ_TWO (only in OpenGL)
- //see http://glprogramming.com/red/chapter11.html
- internal enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative };
-
- internal enum JoinType { jtSquare, jtRound, jtMiter };
- internal enum EndType { etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound };
-
- internal enum EdgeSide { esLeft, esRight };
- internal enum Direction { dRightToLeft, dLeftToRight };
-
- internal class TEdge
- {
- internal IntPoint Bot;
- internal IntPoint Curr; //current (updated for every new scanbeam)
- internal IntPoint Top;
- internal IntPoint Delta;
- internal double Dx;
- internal PolyType PolyTyp;
- internal EdgeSide Side; //side only refers to current side of solution poly
- internal int WindDelta; //1 or -1 depending on winding direction
- internal int WindCnt;
- internal int WindCnt2; //winding count of the opposite polytype
- internal int OutIdx;
- internal TEdge Next;
- internal TEdge Prev;
- internal TEdge NextInLML;
- internal TEdge NextInAEL;
- internal TEdge PrevInAEL;
- internal TEdge NextInSEL;
- internal TEdge PrevInSEL;
- };
-
- internal class IntersectNode
- {
- internal TEdge Edge1;
- internal TEdge Edge2;
- internal IntPoint Pt;
- };
-
- internal class MyIntersectNodeSort : IComparer
- {
- public int Compare(IntersectNode node1, IntersectNode node2)
- {
- cInt i = node2.Pt.Y - node1.Pt.Y;
- if (i > 0) return 1;
- else if (i < 0) return -1;
- else return 0;
- }
- }
-
- internal class LocalMinima
- {
- internal cInt Y;
- internal TEdge LeftBound;
- internal TEdge RightBound;
- internal LocalMinima Next;
- };
-
- internal class Scanbeam
- {
- internal cInt Y;
- internal Scanbeam Next;
- };
-
- internal class Maxima
- {
- internal cInt X;
- internal Maxima Next;
- internal Maxima Prev;
- };
-
- //OutRec: contains a path in the clipping solution. Edges in the AEL will
- //carry a pointer to an OutRec when they are part of the clipping solution.
- internal class OutRec
- {
- internal int Idx;
- internal bool IsHole;
- internal bool IsOpen;
- internal OutRec FirstLeft; //see comments in clipper.pas
- internal OutPt Pts;
- internal OutPt BottomPt;
- internal PolyNode PolyNode;
- };
-
- internal class OutPt
- {
- internal int Idx;
- internal IntPoint Pt;
- internal OutPt Next;
- internal OutPt Prev;
- };
-
- internal class Join
- {
- internal OutPt OutPt1;
- internal OutPt OutPt2;
- internal IntPoint OffPt;
- };
-
- internal class ClipperBase
- {
- internal const double horizontal = -3.4E+38;
- internal const int Skip = -2;
- internal const int Unassigned = -1;
- internal const double tolerance = 1.0E-20;
- internal static bool near_zero(double val) { return (val > -tolerance) && (val < tolerance); }
-
-#if use_int32
- public const cInt loRange = 0x7FFF;
- public const cInt hiRange = 0x7FFF;
-#else
- public const cInt loRange = 0x3FFFFFFF;
- public const cInt hiRange = 0x3FFFFFFFFFFFFFFFL;
-#endif
-
- internal LocalMinima m_MinimaList;
- internal LocalMinima m_CurrentLM;
- internal List> m_edges = new List>();
- internal Scanbeam m_Scanbeam;
- internal List m_PolyOuts;
- internal TEdge m_ActiveEdges;
- internal bool m_UseFullRange;
- internal bool m_HasOpenPaths;
-
- //------------------------------------------------------------------------------
-
- public bool PreserveCollinear
- {
- get;
- set;
- }
- //------------------------------------------------------------------------------
-
- public void Swap(ref cInt val1, ref cInt val2)
- {
- cInt tmp = val1;
- val1 = val2;
- val2 = tmp;
- }
- //------------------------------------------------------------------------------
-
- internal static bool IsHorizontal(TEdge e)
- {
- return e.Delta.Y == 0;
- }
- //------------------------------------------------------------------------------
-
- internal bool PointIsVertex(IntPoint pt, OutPt pp)
- {
- OutPt pp2 = pp;
- do
- {
- if (pp2.Pt == pt) return true;
- pp2 = pp2.Next;
- }
- while (pp2 != pp);
- return false;
- }
- //------------------------------------------------------------------------------
-
- internal bool PointOnLineSegment(IntPoint pt,
- IntPoint linePt1, IntPoint linePt2, bool UseFullRange)
- {
- if (UseFullRange)
- return ((pt.X == linePt1.X) && (pt.Y == linePt1.Y)) ||
- ((pt.X == linePt2.X) && (pt.Y == linePt2.Y)) ||
- (((pt.X > linePt1.X) == (pt.X < linePt2.X)) &&
- ((pt.Y > linePt1.Y) == (pt.Y < linePt2.Y)) &&
- ((Int128.Int128Mul((pt.X - linePt1.X), (linePt2.Y - linePt1.Y)) ==
- Int128.Int128Mul((linePt2.X - linePt1.X), (pt.Y - linePt1.Y)))));
- else
- return ((pt.X == linePt1.X) && (pt.Y == linePt1.Y)) ||
- ((pt.X == linePt2.X) && (pt.Y == linePt2.Y)) ||
- (((pt.X > linePt1.X) == (pt.X < linePt2.X)) &&
- ((pt.Y > linePt1.Y) == (pt.Y < linePt2.Y)) &&
- ((pt.X - linePt1.X) * (linePt2.Y - linePt1.Y) ==
- (linePt2.X - linePt1.X) * (pt.Y - linePt1.Y)));
- }
- //------------------------------------------------------------------------------
-
- internal bool PointOnPolygon(IntPoint pt, OutPt pp, bool UseFullRange)
- {
- OutPt pp2 = pp;
- while (true)
- {
- if (PointOnLineSegment(pt, pp2.Pt, pp2.Next.Pt, UseFullRange))
- return true;
- pp2 = pp2.Next;
- if (pp2 == pp) break;
- }
- return false;
- }
- //------------------------------------------------------------------------------
-
- internal static bool SlopesEqual(TEdge e1, TEdge e2, bool UseFullRange)
- {
- if (UseFullRange)
- return Int128.Int128Mul(e1.Delta.Y, e2.Delta.X) ==
- Int128.Int128Mul(e1.Delta.X, e2.Delta.Y);
- else return (cInt)(e1.Delta.Y) * (e2.Delta.X) ==
- (cInt)(e1.Delta.X) * (e2.Delta.Y);
- }
- //------------------------------------------------------------------------------
-
- internal static bool SlopesEqual(IntPoint pt1, IntPoint pt2,
- IntPoint pt3, bool UseFullRange)
- {
- if (UseFullRange)
- return Int128.Int128Mul(pt1.Y - pt2.Y, pt2.X - pt3.X) ==
- Int128.Int128Mul(pt1.X - pt2.X, pt2.Y - pt3.Y);
- else return
- (cInt)(pt1.Y - pt2.Y) * (pt2.X - pt3.X) - (cInt)(pt1.X - pt2.X) * (pt2.Y - pt3.Y) == 0;
- }
- //------------------------------------------------------------------------------
-
- internal static bool SlopesEqual(IntPoint pt1, IntPoint pt2,
- IntPoint pt3, IntPoint pt4, bool UseFullRange)
- {
- if (UseFullRange)
- return Int128.Int128Mul(pt1.Y - pt2.Y, pt3.X - pt4.X) ==
- Int128.Int128Mul(pt1.X - pt2.X, pt3.Y - pt4.Y);
- else return
- (cInt)(pt1.Y - pt2.Y) * (pt3.X - pt4.X) - (cInt)(pt1.X - pt2.X) * (pt3.Y - pt4.Y) == 0;
- }
- //------------------------------------------------------------------------------
-
- internal ClipperBase() //constructor (nb: no external instantiation)
- {
- m_MinimaList = null;
- m_CurrentLM = null;
- m_UseFullRange = false;
- m_HasOpenPaths = false;
- }
- //------------------------------------------------------------------------------
-
- public virtual void Clear()
- {
- DisposeLocalMinimaList();
- for (int i = 0; i < m_edges.Count; ++i)
- {
- for (int j = 0; j < m_edges[i].Count; ++j) m_edges[i][j] = null;
- m_edges[i].Clear();
- }
- m_edges.Clear();
- m_UseFullRange = false;
- m_HasOpenPaths = false;
- }
- //------------------------------------------------------------------------------
-
- private void DisposeLocalMinimaList()
- {
- while (m_MinimaList != null)
- {
- LocalMinima tmpLm = m_MinimaList.Next;
- m_MinimaList = null;
- m_MinimaList = tmpLm;
- }
- m_CurrentLM = null;
- }
- //------------------------------------------------------------------------------
-
- void RangeTest(IntPoint Pt, ref bool useFullRange)
- {
- if (useFullRange)
- {
- if (Pt.X > hiRange || Pt.Y > hiRange || -Pt.X > hiRange || -Pt.Y > hiRange)
- throw new ClipperException("Coordinate outside allowed range");
- }
- else if (Pt.X > loRange || Pt.Y > loRange || -Pt.X > loRange || -Pt.Y > loRange)
- {
- useFullRange = true;
- RangeTest(Pt, ref useFullRange);
- }
- }
- //------------------------------------------------------------------------------
-
- private void InitEdge(TEdge e, TEdge eNext,
- TEdge ePrev, IntPoint pt)
- {
- e.Next = eNext;
- e.Prev = ePrev;
- e.Curr = pt;
- e.OutIdx = Unassigned;
- }
- //------------------------------------------------------------------------------
-
- private void InitEdge2(TEdge e, PolyType polyType)
- {
- if (e.Curr.Y >= e.Next.Curr.Y)
- {
- e.Bot = e.Curr;
- e.Top = e.Next.Curr;
- }
- else
- {
- e.Top = e.Curr;
- e.Bot = e.Next.Curr;
- }
- SetDx(e);
- e.PolyTyp = polyType;
- }
- //------------------------------------------------------------------------------
-
- private TEdge FindNextLocMin(TEdge E)
- {
- TEdge E2;
- for (;;)
- {
- while (E.Bot != E.Prev.Bot || E.Curr == E.Top) E = E.Next;
- if (E.Dx != horizontal && E.Prev.Dx != horizontal) break;
- while (E.Prev.Dx == horizontal) E = E.Prev;
- E2 = E;
- while (E.Dx == horizontal) E = E.Next;
- if (E.Top.Y == E.Prev.Bot.Y) continue; //ie just an intermediate horz.
- if (E2.Prev.Bot.X < E.Bot.X) E = E2;
- break;
- }
- return E;
- }
- //------------------------------------------------------------------------------
-
- private TEdge ProcessBound(TEdge E, bool LeftBoundIsForward)
- {
- TEdge EStart, Result = E;
- TEdge Horz;
-
- if (Result.OutIdx == Skip)
- {
- //check if there are edges beyond the skip edge in the bound and if so
- //create another LocMin and calling ProcessBound once more ...
- E = Result;
- if (LeftBoundIsForward)
- {
- while (E.Top.Y == E.Next.Bot.Y) E = E.Next;
- while (E != Result && E.Dx == horizontal) E = E.Prev;
- }
- else
- {
- while (E.Top.Y == E.Prev.Bot.Y) E = E.Prev;
- while (E != Result && E.Dx == horizontal) E = E.Next;
- }
- if (E == Result)
- {
- if (LeftBoundIsForward) Result = E.Next;
- else Result = E.Prev;
- }
- else
- {
- //there are more edges in the bound beyond result starting with E
- if (LeftBoundIsForward)
- E = Result.Next;
- else
- E = Result.Prev;
- LocalMinima locMin = new LocalMinima();
- locMin.Next = null;
- locMin.Y = E.Bot.Y;
- locMin.LeftBound = null;
- locMin.RightBound = E;
- E.WindDelta = 0;
- Result = ProcessBound(E, LeftBoundIsForward);
- InsertLocalMinima(locMin);
- }
- return Result;
- }
-
- if (E.Dx == horizontal)
- {
- //We need to be careful with open paths because this may not be a
- //true local minima (ie E may be following a skip edge).
- //Also, consecutive horz. edges may start heading left before going right.
- if (LeftBoundIsForward) EStart = E.Prev;
- else EStart = E.Next;
- if (EStart.Dx == horizontal) //ie an adjoining horizontal skip edge
- {
- if (EStart.Bot.X != E.Bot.X && EStart.Top.X != E.Bot.X)
- ReverseHorizontal(E);
- }
- else if (EStart.Bot.X != E.Bot.X)
- ReverseHorizontal(E);
- }
-
- EStart = E;
- if (LeftBoundIsForward)
- {
- while (Result.Top.Y == Result.Next.Bot.Y && Result.Next.OutIdx != Skip)
- Result = Result.Next;
- if (Result.Dx == horizontal && Result.Next.OutIdx != Skip)
- {
- //nb: at the top of a bound, horizontals are added to the bound
- //only when the preceding edge attaches to the horizontal's left vertex
- //unless a Skip edge is encountered when that becomes the top divide
- Horz = Result;
- while (Horz.Prev.Dx == horizontal) Horz = Horz.Prev;
- if (Horz.Prev.Top.X > Result.Next.Top.X) Result = Horz.Prev;
- }
- while (E != Result)
- {
- E.NextInLML = E.Next;
- if (E.Dx == horizontal && E != EStart && E.Bot.X != E.Prev.Top.X)
- ReverseHorizontal(E);
- E = E.Next;
- }
- if (E.Dx == horizontal && E != EStart && E.Bot.X != E.Prev.Top.X)
- ReverseHorizontal(E);
- Result = Result.Next; //move to the edge just beyond current bound
- }
- else
- {
- while (Result.Top.Y == Result.Prev.Bot.Y && Result.Prev.OutIdx != Skip)
- Result = Result.Prev;
- if (Result.Dx == horizontal && Result.Prev.OutIdx != Skip)
- {
- Horz = Result;
- while (Horz.Next.Dx == horizontal) Horz = Horz.Next;
- if (Horz.Next.Top.X == Result.Prev.Top.X ||
- Horz.Next.Top.X > Result.Prev.Top.X) Result = Horz.Next;
- }
-
- while (E != Result)
- {
- E.NextInLML = E.Prev;
- if (E.Dx == horizontal && E != EStart && E.Bot.X != E.Next.Top.X)
- ReverseHorizontal(E);
- E = E.Prev;
- }
- if (E.Dx == horizontal && E != EStart && E.Bot.X != E.Next.Top.X)
- ReverseHorizontal(E);
- Result = Result.Prev; //move to the edge just beyond current bound
- }
- return Result;
- }
- //------------------------------------------------------------------------------
-
-
- public bool AddPath(Path pg, PolyType polyType, bool Closed)
- {
-#if use_lines
- if (!Closed && polyType == PolyType.ptClip)
- throw new ClipperException("AddPath: Open paths must be subject.");
-#else
- if (!Closed)
- throw new ClipperException("AddPath: Open paths have been disabled.");
-#endif
-
- int highI = (int)pg.Count - 1;
- if (Closed) while (highI > 0 && (pg[highI] == pg[0])) --highI;
- while (highI > 0 && (pg[highI] == pg[highI - 1])) --highI;
- if ((Closed && highI < 2) || (!Closed && highI < 1)) return false;
-
- //create a new edge array ...
- List edges = new List(highI + 1);
- for (int i = 0; i <= highI; i++) edges.Add(new TEdge());
-
- bool IsFlat = true;
-
- //1. Basic (first) edge initialization ...
- edges[1].Curr = pg[1];
- RangeTest(pg[0], ref m_UseFullRange);
- RangeTest(pg[highI], ref m_UseFullRange);
- InitEdge(edges[0], edges[1], edges[highI], pg[0]);
- InitEdge(edges[highI], edges[0], edges[highI - 1], pg[highI]);
- for (int i = highI - 1; i >= 1; --i)
- {
- RangeTest(pg[i], ref m_UseFullRange);
- InitEdge(edges[i], edges[i + 1], edges[i - 1], pg[i]);
- }
- TEdge eStart = edges[0];
-
- //2. Remove duplicate vertices, and (when closed) collinear edges ...
- TEdge E = eStart, eLoopStop = eStart;
- for (;;)
- {
- //nb: allows matching start and end points when not Closed ...
- if (E.Curr == E.Next.Curr && (Closed || E.Next != eStart))
- {
- if (E == E.Next) break;
- if (E == eStart) eStart = E.Next;
- E = RemoveEdge(E);
- eLoopStop = E;
- continue;
- }
- if (E.Prev == E.Next)
- break; //only two vertices
- else if (Closed &&
- SlopesEqual(E.Prev.Curr, E.Curr, E.Next.Curr, m_UseFullRange) &&
- (!PreserveCollinear ||
- !Pt2IsBetweenPt1AndPt3(E.Prev.Curr, E.Curr, E.Next.Curr)))
- {
- //Collinear edges are allowed for open paths but in closed paths
- //the default is to merge adjacent collinear edges into a single edge.
- //However, if the PreserveCollinear property is enabled, only overlapping
- //collinear edges (ie spikes) will be removed from closed paths.
- if (E == eStart) eStart = E.Next;
- E = RemoveEdge(E);
- E = E.Prev;
- eLoopStop = E;
- continue;
- }
- E = E.Next;
- if ((E == eLoopStop) || (!Closed && E.Next == eStart)) break;
- }
-
- if ((!Closed && (E == E.Next)) || (Closed && (E.Prev == E.Next)))
- return false;
-
- if (!Closed)
- {
- m_HasOpenPaths = true;
- eStart.Prev.OutIdx = Skip;
- }
-
- //3. Do second stage of edge initialization ...
- E = eStart;
- do
- {
- InitEdge2(E, polyType);
- E = E.Next;
- if (IsFlat && E.Curr.Y != eStart.Curr.Y) IsFlat = false;
- }
- while (E != eStart);
-
- //4. Finally, add edge bounds to LocalMinima list ...
-
- //Totally flat paths must be handled differently when adding them
- //to LocalMinima list to avoid endless loops etc ...
- if (IsFlat)
- {
- if (Closed) return false;
- E.Prev.OutIdx = Skip;
- LocalMinima locMin = new LocalMinima();
- locMin.Next = null;
- locMin.Y = E.Bot.Y;
- locMin.LeftBound = null;
- locMin.RightBound = E;
- locMin.RightBound.Side = EdgeSide.esRight;
- locMin.RightBound.WindDelta = 0;
- for (;;)
- {
- if (E.Bot.X != E.Prev.Top.X) ReverseHorizontal(E);
- if (E.Next.OutIdx == Skip) break;
- E.NextInLML = E.Next;
- E = E.Next;
- }
- InsertLocalMinima(locMin);
- m_edges.Add(edges);
- return true;
- }
-
- m_edges.Add(edges);
- bool leftBoundIsForward;
- TEdge EMin = null;
-
- //workaround to avoid an endless loop in the while loop below when
- //open paths have matching start and end points ...
- if (E.Prev.Bot == E.Prev.Top) E = E.Next;
-
- for (;;)
- {
- E = FindNextLocMin(E);
- if (E == EMin) break;
- else if (EMin == null) EMin = E;
-
- //E and E.Prev now share a local minima (left aligned if horizontal).
- //Compare their slopes to find which starts which bound ...
- LocalMinima locMin = new LocalMinima();
- locMin.Next = null;
- locMin.Y = E.Bot.Y;
- if (E.Dx < E.Prev.Dx)
- {
- locMin.LeftBound = E.Prev;
- locMin.RightBound = E;
- leftBoundIsForward = false; //Q.nextInLML = Q.prev
- }
- else
- {
- locMin.LeftBound = E;
- locMin.RightBound = E.Prev;
- leftBoundIsForward = true; //Q.nextInLML = Q.next
- }
- locMin.LeftBound.Side = EdgeSide.esLeft;
- locMin.RightBound.Side = EdgeSide.esRight;
-
- if (!Closed) locMin.LeftBound.WindDelta = 0;
- else if (locMin.LeftBound.Next == locMin.RightBound)
- locMin.LeftBound.WindDelta = -1;
- else locMin.LeftBound.WindDelta = 1;
- locMin.RightBound.WindDelta = -locMin.LeftBound.WindDelta;
-
- E = ProcessBound(locMin.LeftBound, leftBoundIsForward);
- if (E.OutIdx == Skip) E = ProcessBound(E, leftBoundIsForward);
-
- TEdge E2 = ProcessBound(locMin.RightBound, !leftBoundIsForward);
- if (E2.OutIdx == Skip) E2 = ProcessBound(E2, !leftBoundIsForward);
-
- if (locMin.LeftBound.OutIdx == Skip)
- locMin.LeftBound = null;
- else if (locMin.RightBound.OutIdx == Skip)
- locMin.RightBound = null;
- InsertLocalMinima(locMin);
- if (!leftBoundIsForward) E = E2;
- }
- return true;
-
- }
- //------------------------------------------------------------------------------
-
- public bool AddPaths(Paths ppg, PolyType polyType, bool closed)
- {
- bool result = false;
- for (int i = 0; i < ppg.Count; ++i)
- if (AddPath(ppg[i], polyType, closed)) result = true;
- return result;
- }
- //------------------------------------------------------------------------------
-
- internal bool Pt2IsBetweenPt1AndPt3(IntPoint pt1, IntPoint pt2, IntPoint pt3)
- {
- if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2)) return false;
- else if (pt1.X != pt3.X) return (pt2.X > pt1.X) == (pt2.X < pt3.X);
- else return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y);
- }
- //------------------------------------------------------------------------------
-
- TEdge RemoveEdge(TEdge e)
- {
- //removes e from double_linked_list (but without removing from memory)
- e.Prev.Next = e.Next;
- e.Next.Prev = e.Prev;
- TEdge result = e.Next;
- e.Prev = null; //flag as removed (see ClipperBase.Clear)
- return result;
- }
- //------------------------------------------------------------------------------
-
- private void SetDx(TEdge e)
- {
- e.Delta.X = (e.Top.X - e.Bot.X);
- e.Delta.Y = (e.Top.Y - e.Bot.Y);
- if (e.Delta.Y == 0) e.Dx = horizontal;
- else e.Dx = (double)(e.Delta.X) / (e.Delta.Y);
- }
- //---------------------------------------------------------------------------
-
- private void InsertLocalMinima(LocalMinima newLm)
- {
- if (m_MinimaList == null)
- {
- 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 != null && (newLm.Y < tmpLm.Next.Y))
- tmpLm = tmpLm.Next;
- newLm.Next = tmpLm.Next;
- tmpLm.Next = newLm;
- }
- }
- //------------------------------------------------------------------------------
-
- internal Boolean PopLocalMinima(cInt Y, out LocalMinima current)
- {
- current = m_CurrentLM;
- if (m_CurrentLM != null && m_CurrentLM.Y == Y)
- {
- m_CurrentLM = m_CurrentLM.Next;
- return true;
- }
- return false;
- }
- //------------------------------------------------------------------------------
-
- private void ReverseHorizontal(TEdge e)
- {
- //swap horizontal edges' top and bottom x's so they follow the natural
- //progression of the bounds - ie so their xbots will align with the
- //adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
- Swap(ref e.Top.X, ref e.Bot.X);
-#if use_xyz
- Swap(ref e.Top.Z, ref e.Bot.Z);
-#endif
- }
- //------------------------------------------------------------------------------
-
- internal virtual void Reset()
- {
- m_CurrentLM = m_MinimaList;
- if (m_CurrentLM == null) return; //ie nothing to process
-
- //reset all edges ...
- m_Scanbeam = null;
- LocalMinima lm = m_MinimaList;
- while (lm != null)
- {
- InsertScanbeam(lm.Y);
- TEdge e = lm.LeftBound;
- if (e != null)
- {
- e.Curr = e.Bot;
- e.OutIdx = Unassigned;
- }
- e = lm.RightBound;
- if (e != null)
- {
- e.Curr = e.Bot;
- e.OutIdx = Unassigned;
- }
- lm = lm.Next;
- }
- m_ActiveEdges = null;
- }
- //------------------------------------------------------------------------------
-
- public static IntRect GetBounds(Paths paths)
- {
- int i = 0, cnt = paths.Count;
- while (i < cnt && paths[i].Count == 0) i++;
- if (i == cnt) return new IntRect(0, 0, 0, 0);
- IntRect result = new IntRect();
- result.left = paths[i][0].X;
- result.right = result.left;
- result.top = paths[i][0].Y;
- result.bottom = result.top;
- for (; i < cnt; i++)
- for (int j = 0; j < paths[i].Count; j++)
- {
- if (paths[i][j].X < result.left) result.left = paths[i][j].X;
- else if (paths[i][j].X > result.right) result.right = paths[i][j].X;
- if (paths[i][j].Y < result.top) result.top = paths[i][j].Y;
- else if (paths[i][j].Y > result.bottom) result.bottom = paths[i][j].Y;
- }
- return result;
- }
- //------------------------------------------------------------------------------
-
- internal void InsertScanbeam(cInt Y)
- {
- //single-linked list: sorted descending, ignoring dups.
- if (m_Scanbeam == null)
- {
- m_Scanbeam = new Scanbeam();
- m_Scanbeam.Next = null;
- 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 != null && (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;
- }
- }
- //------------------------------------------------------------------------------
-
- internal Boolean PopScanbeam(out cInt Y)
- {
- if (m_Scanbeam == null)
- {
- Y = 0;
- return false;
- }
- Y = m_Scanbeam.Y;
- m_Scanbeam = m_Scanbeam.Next;
- return true;
- }
- //------------------------------------------------------------------------------
-
- internal Boolean LocalMinimaPending()
- {
- return (m_CurrentLM != null);
- }
- //------------------------------------------------------------------------------
-
- internal OutRec CreateOutRec()
- {
- OutRec result = new OutRec();
- result.Idx = Unassigned;
- result.IsHole = false;
- result.IsOpen = false;
- result.FirstLeft = null;
- result.Pts = null;
- result.BottomPt = null;
- result.PolyNode = null;
- m_PolyOuts.Add(result);
- result.Idx = m_PolyOuts.Count - 1;
- return result;
- }
- //------------------------------------------------------------------------------
-
- internal void DisposeOutRec(int index)
- {
- OutRec outRec = m_PolyOuts[index];
- outRec.Pts = null;
- outRec = null;
- m_PolyOuts[index] = null;
- }
- //------------------------------------------------------------------------------
-
- internal void UpdateEdgeIntoAEL(ref TEdge e)
- {
- if (e.NextInLML == null)
- throw new ClipperException("UpdateEdgeIntoAEL: invalid call");
- TEdge AelPrev = e.PrevInAEL;
- TEdge AelNext = e.NextInAEL;
- e.NextInLML.OutIdx = e.OutIdx;
- if (AelPrev != null)
- AelPrev.NextInAEL = e.NextInLML;
- else m_ActiveEdges = e.NextInLML;
- if (AelNext != null)
- AelNext.PrevInAEL = e.NextInLML;
- e.NextInLML.Side = e.Side;
- e.NextInLML.WindDelta = e.WindDelta;
- e.NextInLML.WindCnt = e.WindCnt;
- e.NextInLML.WindCnt2 = e.WindCnt2;
- e = e.NextInLML;
- e.Curr = e.Bot;
- e.PrevInAEL = AelPrev;
- e.NextInAEL = AelNext;
- if (!IsHorizontal(e)) InsertScanbeam(e.Top.Y);
- }
- //------------------------------------------------------------------------------
-
- internal void SwapPositionsInAEL(TEdge edge1, TEdge edge2)
- {
- //check that one or other edge hasn't already been removed from AEL ...
- if (edge1.NextInAEL == edge1.PrevInAEL ||
- edge2.NextInAEL == edge2.PrevInAEL) return;
-
- if (edge1.NextInAEL == edge2)
- {
- TEdge next = edge2.NextInAEL;
- if (next != null)
- next.PrevInAEL = edge1;
- TEdge prev = edge1.PrevInAEL;
- if (prev != null)
- 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 != null)
- next.PrevInAEL = edge2;
- TEdge prev = edge2.PrevInAEL;
- if (prev != null)
- 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 != null)
- edge1.NextInAEL.PrevInAEL = edge1;
- edge1.PrevInAEL = edge2.PrevInAEL;
- if (edge1.PrevInAEL != null)
- edge1.PrevInAEL.NextInAEL = edge1;
- edge2.NextInAEL = next;
- if (edge2.NextInAEL != null)
- edge2.NextInAEL.PrevInAEL = edge2;
- edge2.PrevInAEL = prev;
- if (edge2.PrevInAEL != null)
- edge2.PrevInAEL.NextInAEL = edge2;
- }
-
- if (edge1.PrevInAEL == null)
- m_ActiveEdges = edge1;
- else if (edge2.PrevInAEL == null)
- m_ActiveEdges = edge2;
- }
- //------------------------------------------------------------------------------
-
- internal void DeleteFromAEL(TEdge e)
- {
- TEdge AelPrev = e.PrevInAEL;
- TEdge AelNext = e.NextInAEL;
- if (AelPrev == null && AelNext == null && (e != m_ActiveEdges))
- return; //already deleted
- if (AelPrev != null)
- AelPrev.NextInAEL = AelNext;
- else m_ActiveEdges = AelNext;
- if (AelNext != null)
- AelNext.PrevInAEL = AelPrev;
- e.NextInAEL = null;
- e.PrevInAEL = null;
- }
- //------------------------------------------------------------------------------
-
- } //end ClipperBase
-
- internal class Clipper : ClipperBase
- {
- //InitOptions that can be passed to the constructor ...
- public const int ioReverseSolution = 1;
- public const int ioStrictlySimple = 2;
- public const int ioPreserveCollinear = 4;
-
- private ClipType m_ClipType;
- private Maxima m_Maxima;
- private TEdge m_SortedEdges;
- private List m_IntersectList;
- IComparer m_IntersectNodeComparer;
- private bool m_ExecuteLocked;
- private PolyFillType m_ClipFillType;
- private PolyFillType m_SubjFillType;
- private List m_Joins;
- private List m_GhostJoins;
- private bool m_UsingPolyTree;
-#if use_xyz
- public delegate void ZFillCallback(IntPoint bot1, IntPoint top1,
- IntPoint bot2, IntPoint top2, ref IntPoint pt);
- public ZFillCallback ZFillFunction { get; set; }
-#endif
- public Clipper(int InitOptions = 0) : base() //constructor
- {
- m_Scanbeam = null;
- m_Maxima = null;
- m_ActiveEdges = null;
- m_SortedEdges = null;
- m_IntersectList = new List();
- m_IntersectNodeComparer = new MyIntersectNodeSort();
- m_ExecuteLocked = false;
- m_UsingPolyTree = false;
- m_PolyOuts = new List();
- m_Joins = new List();
- m_GhostJoins = new List();
- ReverseSolution = (ioReverseSolution & InitOptions) != 0;
- StrictlySimple = (ioStrictlySimple & InitOptions) != 0;
- PreserveCollinear = (ioPreserveCollinear & InitOptions) != 0;
-#if use_xyz
- ZFillFunction = null;
-#endif
- }
- //------------------------------------------------------------------------------
-
- private void InsertMaxima(cInt X)
- {
- //double-linked list: sorted ascending, ignoring dups.
- Maxima newMax = new Maxima();
- newMax.X = X;
- if (m_Maxima == null)
- {
- m_Maxima = newMax;
- m_Maxima.Next = null;
- m_Maxima.Prev = null;
- }
- else if (X < m_Maxima.X)
- {
- newMax.Next = m_Maxima;
- newMax.Prev = null;
- m_Maxima = newMax;
- }
- else
- {
- Maxima m = m_Maxima;
- while (m.Next != null && (X >= m.Next.X)) m = m.Next;
- if (X == m.X) return; //ie ignores duplicates (& CG to clean up newMax)
- //insert newMax between m and m.Next ...
- newMax.Next = m.Next;
- newMax.Prev = m;
- if (m.Next != null) m.Next.Prev = newMax;
- m.Next = newMax;
- }
- }
- //------------------------------------------------------------------------------
-
- public bool ReverseSolution
- {
- get;
- set;
- }
- //------------------------------------------------------------------------------
-
- public bool StrictlySimple
- {
- get;
- set;
- }
- //------------------------------------------------------------------------------
-
- public bool Execute(ClipType clipType, Paths solution,
- PolyFillType FillType = PolyFillType.pftEvenOdd)
- {
- return Execute(clipType, solution, FillType, FillType);
- }
- //------------------------------------------------------------------------------
-
- public bool Execute(ClipType clipType, PolyTree polytree,
- PolyFillType FillType = PolyFillType.pftEvenOdd)
- {
- return Execute(clipType, polytree, FillType, FillType);
- }
- //------------------------------------------------------------------------------
-
- public bool Execute(ClipType clipType, Paths solution,
- PolyFillType subjFillType, PolyFillType clipFillType)
- {
- if (m_ExecuteLocked) return false;
- if (m_HasOpenPaths) throw
- new ClipperException("Error: PolyTree struct is needed for open path clipping.");
-
- m_ExecuteLocked = true;
- solution.Clear();
- m_SubjFillType = subjFillType;
- m_ClipFillType = clipFillType;
- m_ClipType = clipType;
- m_UsingPolyTree = false;
- bool succeeded;
- try
- {
- succeeded = ExecuteInternal();
- //build the return polygons ...
- if (succeeded) BuildResult(solution);
- }
- finally
- {
- DisposeAllPolyPts();
- m_ExecuteLocked = false;
- }
- return succeeded;
- }
- //------------------------------------------------------------------------------
-
- public bool Execute(ClipType clipType, PolyTree polytree,
- PolyFillType subjFillType, PolyFillType clipFillType)
- {
- if (m_ExecuteLocked) return false;
- m_ExecuteLocked = true;
- m_SubjFillType = subjFillType;
- m_ClipFillType = clipFillType;
- m_ClipType = clipType;
- m_UsingPolyTree = true;
- bool succeeded;
- try
- {
- succeeded = ExecuteInternal();
- //build the return polygons ...
- if (succeeded) BuildResult2(polytree);
- }
- finally
- {
- DisposeAllPolyPts();
- m_ExecuteLocked = false;
- }
- return succeeded;
- }
- //------------------------------------------------------------------------------
-
- internal void FixHoleLinkage(OutRec outRec)
- {
- //skip if an outermost polygon or
- //already already points to the correct FirstLeft ...
- if (outRec.FirstLeft == null ||
- (outRec.IsHole != outRec.FirstLeft.IsHole &&
- outRec.FirstLeft.Pts != null)) return;
-
- OutRec orfl = outRec.FirstLeft;
- while (orfl != null && ((orfl.IsHole == outRec.IsHole) || orfl.Pts == null))
- orfl = orfl.FirstLeft;
- outRec.FirstLeft = orfl;
- }
- //------------------------------------------------------------------------------
-
- private bool ExecuteInternal()
- {
- try
- {
- Reset();
- m_SortedEdges = null;
- m_Maxima = null;
-
- cInt botY, topY;
- if (!PopScanbeam(out botY)) return false;
- InsertLocalMinimaIntoAEL(botY);
- while (PopScanbeam(out topY) || LocalMinimaPending())
- {
- ProcessHorizontals();
- m_GhostJoins.Clear();
- if (!ProcessIntersections(topY)) return false;
- ProcessEdgesAtTopOfScanbeam(topY);
- botY = topY;
- InsertLocalMinimaIntoAEL(botY);
- }
-
- //fix orientations ...
- foreach (OutRec outRec in m_PolyOuts)
- {
- if (outRec.Pts == null || outRec.IsOpen) continue;
- if ((outRec.IsHole ^ ReverseSolution) == (Area(outRec) > 0))
- ReversePolyPtLinks(outRec.Pts);
- }
-
- JoinCommonEdges();
-
- foreach (OutRec outRec in m_PolyOuts)
- {
- if (outRec.Pts == null)
- continue;
- else if (outRec.IsOpen)
- FixupOutPolyline(outRec);
- else
- FixupOutPolygon(outRec);
- }
-
- if (StrictlySimple) DoSimplePolygons();
- return true;
- }
- //catch { return false; }
- finally
- {
- m_Joins.Clear();
- m_GhostJoins.Clear();
- }
- }
- //------------------------------------------------------------------------------
-
- private void DisposeAllPolyPts()
- {
- for (int i = 0; i < m_PolyOuts.Count; ++i) DisposeOutRec(i);
- m_PolyOuts.Clear();
- }
- //------------------------------------------------------------------------------
-
- private void AddJoin(OutPt Op1, OutPt Op2, IntPoint OffPt)
- {
- Join j = new Join();
- j.OutPt1 = Op1;
- j.OutPt2 = Op2;
- j.OffPt = OffPt;
- m_Joins.Add(j);
- }
- //------------------------------------------------------------------------------
-
- private void AddGhostJoin(OutPt Op, IntPoint OffPt)
- {
- Join j = new Join();
- j.OutPt1 = Op;
- j.OffPt = OffPt;
- m_GhostJoins.Add(j);
- }
- //------------------------------------------------------------------------------
-
-#if use_xyz
- internal void SetZ(ref IntPoint pt, TEdge e1, TEdge e2)
- {
- if (pt.Z != 0 || ZFillFunction == null) return;
- else if (pt == e1.Bot) pt.Z = e1.Bot.Z;
- else if (pt == e1.Top) pt.Z = e1.Top.Z;
- else if (pt == e2.Bot) pt.Z = e2.Bot.Z;
- else if (pt == e2.Top) pt.Z = e2.Top.Z;
- else ZFillFunction(e1.Bot, e1.Top, e2.Bot, e2.Top, ref pt);
- }
- //------------------------------------------------------------------------------
-#endif
-
- private void InsertLocalMinimaIntoAEL(cInt botY)
- {
- LocalMinima lm;
- while (PopLocalMinima(botY, out lm))
- {
- TEdge lb = lm.LeftBound;
- TEdge rb = lm.RightBound;
-
- OutPt Op1 = null;
- if (lb == null)
- {
- InsertEdgeIntoAEL(rb, null);
- SetWindingCount(rb);
- if (IsContributing(rb))
- Op1 = AddOutPt(rb, rb.Bot);
- }
- else if (rb == null)
- {
- InsertEdgeIntoAEL(lb, null);
- SetWindingCount(lb);
- if (IsContributing(lb))
- Op1 = AddOutPt(lb, lb.Bot);
- InsertScanbeam(lb.Top.Y);
- }
- else
- {
- InsertEdgeIntoAEL(lb, null);
- InsertEdgeIntoAEL(rb, lb);
- SetWindingCount(lb);
- rb.WindCnt = lb.WindCnt;
- rb.WindCnt2 = lb.WindCnt2;
- if (IsContributing(lb))
- Op1 = AddLocalMinPoly(lb, rb, lb.Bot);
- InsertScanbeam(lb.Top.Y);
- }
-
- if (rb != null)
- {
- if (IsHorizontal(rb))
- {
- if (rb.NextInLML != null)
- InsertScanbeam(rb.NextInLML.Top.Y);
- AddEdgeToSEL(rb);
- }
- else
- InsertScanbeam(rb.Top.Y);
- }
-
- if (lb == null || rb == null) continue;
-
- //if output polygons share an Edge with a horizontal rb, they'll need joining later ...
- if (Op1 != null && IsHorizontal(rb) &&
- m_GhostJoins.Count > 0 && rb.WindDelta != 0)
- {
- for (int i = 0; i < m_GhostJoins.Count; i++)
- {
- //if the horizontal Rb and a 'ghost' horizontal overlap, then convert
- //the 'ghost' join to a real join ready for later ...
- Join j = m_GhostJoins[i];
- if (HorzSegmentsOverlap(j.OutPt1.Pt.X, j.OffPt.X, rb.Bot.X, rb.Top.X))
- AddJoin(j.OutPt1, Op1, j.OffPt);
- }
- }
-
- if (lb.OutIdx >= 0 && lb.PrevInAEL != null &&
- lb.PrevInAEL.Curr.X == lb.Bot.X &&
- lb.PrevInAEL.OutIdx >= 0 &&
- SlopesEqual(lb.PrevInAEL.Curr, lb.PrevInAEL.Top, lb.Curr, lb.Top, m_UseFullRange) &&
- lb.WindDelta != 0 && lb.PrevInAEL.WindDelta != 0)
- {
- OutPt Op2 = AddOutPt(lb.PrevInAEL, lb.Bot);
- AddJoin(Op1, Op2, lb.Top);
- }
-
- if (lb.NextInAEL != rb)
- {
-
- if (rb.OutIdx >= 0 && rb.PrevInAEL.OutIdx >= 0 &&
- SlopesEqual(rb.PrevInAEL.Curr, rb.PrevInAEL.Top, rb.Curr, rb.Top, m_UseFullRange) &&
- rb.WindDelta != 0 && rb.PrevInAEL.WindDelta != 0)
- {
- OutPt Op2 = AddOutPt(rb.PrevInAEL, rb.Bot);
- AddJoin(Op1, Op2, rb.Top);
- }
-
- TEdge e = lb.NextInAEL;
- if (e != null)
- while (e != rb)
- {
- //nb: For calculating winding counts etc, IntersectEdges() assumes
- //that param1 will be to the right of param2 ABOVE the intersection ...
- IntersectEdges(rb, e, lb.Curr); //order important here
- e = e.NextInAEL;
- }
- }
- }
- }
- //------------------------------------------------------------------------------
-
- private void InsertEdgeIntoAEL(TEdge edge, TEdge startEdge)
- {
- if (m_ActiveEdges == null)
- {
- edge.PrevInAEL = null;
- edge.NextInAEL = null;
- m_ActiveEdges = edge;
- }
- else if (startEdge == null && E2InsertsBeforeE1(m_ActiveEdges, edge))
- {
- edge.PrevInAEL = null;
- edge.NextInAEL = m_ActiveEdges;
- m_ActiveEdges.PrevInAEL = edge;
- m_ActiveEdges = edge;
- }
- else
- {
- if (startEdge == null) startEdge = m_ActiveEdges;
- while (startEdge.NextInAEL != null &&
- !E2InsertsBeforeE1(startEdge.NextInAEL, edge))
- startEdge = startEdge.NextInAEL;
- edge.NextInAEL = startEdge.NextInAEL;
- if (startEdge.NextInAEL != null) startEdge.NextInAEL.PrevInAEL = edge;
- edge.PrevInAEL = startEdge;
- startEdge.NextInAEL = edge;
- }
- }
- //----------------------------------------------------------------------
-
- private bool E2InsertsBeforeE1(TEdge e1, TEdge e2)
- {
- if (e2.Curr.X == e1.Curr.X)
- {
- if (e2.Top.Y > e1.Top.Y)
- return e2.Top.X < TopX(e1, e2.Top.Y);
- else return e1.Top.X > TopX(e2, e1.Top.Y);
- }
- else return e2.Curr.X < e1.Curr.X;
- }
- //------------------------------------------------------------------------------
-
- private bool IsEvenOddFillType(TEdge edge)
- {
- if (edge.PolyTyp == PolyType.ptSubject)
- return m_SubjFillType == PolyFillType.pftEvenOdd;
- else
- return m_ClipFillType == PolyFillType.pftEvenOdd;
- }
- //------------------------------------------------------------------------------
-
- private bool IsEvenOddAltFillType(TEdge edge)
- {
- if (edge.PolyTyp == PolyType.ptSubject)
- return m_ClipFillType == PolyFillType.pftEvenOdd;
- else
- return m_SubjFillType == PolyFillType.pftEvenOdd;
- }
- //------------------------------------------------------------------------------
-
- private bool IsContributing(TEdge edge)
- {
- PolyFillType pft, pft2;
- if (edge.PolyTyp == PolyType.ptSubject)
- {
- pft = m_SubjFillType;
- pft2 = m_ClipFillType;
- }
- else
- {
- pft = m_ClipFillType;
- pft2 = m_SubjFillType;
- }
-
- switch (pft)
- {
- case PolyFillType.pftEvenOdd:
- //return false if a subj line has been flagged as inside a subj polygon
- if (edge.WindDelta == 0 && edge.WindCnt != 1) return false;
- break;
- case PolyFillType.pftNonZero:
- if (Math.Abs(edge.WindCnt) != 1) return false;
- break;
- case PolyFillType.pftPositive:
- if (edge.WindCnt != 1) return false;
- break;
- default: //PolyFillType.pftNegative
- if (edge.WindCnt != -1) return false;
- break;
- }
-
- switch (m_ClipType)
- {
- case ClipType.ctIntersection:
- switch (pft2)
- {
- case PolyFillType.pftEvenOdd:
- case PolyFillType.pftNonZero:
- return (edge.WindCnt2 != 0);
- case PolyFillType.pftPositive:
- return (edge.WindCnt2 > 0);
- default:
- return (edge.WindCnt2 < 0);
- }
- case ClipType.ctUnion:
- switch (pft2)
- {
- case PolyFillType.pftEvenOdd:
- case PolyFillType.pftNonZero:
- return (edge.WindCnt2 == 0);
- case PolyFillType.pftPositive:
- return (edge.WindCnt2 <= 0);
- default:
- return (edge.WindCnt2 >= 0);
- }
- case ClipType.ctDifference:
- if (edge.PolyTyp == PolyType.ptSubject)
- switch (pft2)
- {
- case PolyFillType.pftEvenOdd:
- case PolyFillType.pftNonZero:
- return (edge.WindCnt2 == 0);
- case PolyFillType.pftPositive:
- return (edge.WindCnt2 <= 0);
- default:
- return (edge.WindCnt2 >= 0);
- }
- else
- switch (pft2)
- {
- case PolyFillType.pftEvenOdd:
- case PolyFillType.pftNonZero:
- return (edge.WindCnt2 != 0);
- case PolyFillType.pftPositive:
- return (edge.WindCnt2 > 0);
- default:
- return (edge.WindCnt2 < 0);
- }
- case ClipType.ctXor:
- if (edge.WindDelta == 0) //XOr always contributing unless open
- switch (pft2)
- {
- case PolyFillType.pftEvenOdd:
- case PolyFillType.pftNonZero:
- return (edge.WindCnt2 == 0);
- case PolyFillType.pftPositive:
- return (edge.WindCnt2 <= 0);
- default:
- return (edge.WindCnt2 >= 0);
- }
- else
- return true;
- }
- return true;
- }
- //------------------------------------------------------------------------------
-
- private void SetWindingCount(TEdge edge)
- {
- TEdge e = edge.PrevInAEL;
- //find the edge of the same polytype that immediately preceeds 'edge' in AEL
- while (e != null && ((e.PolyTyp != edge.PolyTyp) || (e.WindDelta == 0))) e = e.PrevInAEL;
- if (e == null)
- {
- PolyFillType pft;
- pft = (edge.PolyTyp == PolyType.ptSubject ? m_SubjFillType : m_ClipFillType);
- if (edge.WindDelta == 0) edge.WindCnt = (pft == PolyFillType.pftNegative ? -1 : 1);
- else edge.WindCnt = edge.WindDelta;
- edge.WindCnt2 = 0;
- e = m_ActiveEdges; //ie get ready to calc WindCnt2
- }
- else if (edge.WindDelta == 0 && m_ClipType != ClipType.ctUnion)
- {
- edge.WindCnt = 1;
- edge.WindCnt2 = e.WindCnt2;
- e = e.NextInAEL; //ie get ready to calc WindCnt2
- }
- else if (IsEvenOddFillType(edge))
- {
- //EvenOdd filling ...
- if (edge.WindDelta == 0)
- {
- //are we inside a subj polygon ...
- bool Inside = true;
- TEdge e2 = e.PrevInAEL;
- while (e2 != null)
- {
- if (e2.PolyTyp == e.PolyTyp && e2.WindDelta != 0)
- Inside = !Inside;
- e2 = e2.PrevInAEL;
- }
- edge.WindCnt = (Inside ? 0 : 1);
- }
- else
- {
- edge.WindCnt = edge.WindDelta;
- }
- edge.WindCnt2 = e.WindCnt2;
- e = e.NextInAEL; //ie get ready to calc WindCnt2
- }
- else
- {
- //nonZero, Positive or Negative filling ...
- if (e.WindCnt * e.WindDelta < 0)
- {
- //prev edge is 'decreasing' WindCount (WC) toward zero
- //so we're outside the previous polygon ...
- if (Math.Abs(e.WindCnt) > 1)
- {
- //outside prev poly but still inside another.
- //when reversing direction of prev poly use the same WC
- if (e.WindDelta * edge.WindDelta < 0) edge.WindCnt = e.WindCnt;
- //otherwise continue to 'decrease' WC ...
- else edge.WindCnt = e.WindCnt + edge.WindDelta;
- }
- else
- //now outside all polys of same polytype so set own WC ...
- edge.WindCnt = (edge.WindDelta == 0 ? 1 : edge.WindDelta);
- }
- else
- {
- //prev edge is 'increasing' WindCount (WC) away from zero
- //so we're inside the previous polygon ...
- if (edge.WindDelta == 0)
- edge.WindCnt = (e.WindCnt < 0 ? e.WindCnt - 1 : e.WindCnt + 1);
- //if wind direction is reversing prev then use same WC
- else if (e.WindDelta * edge.WindDelta < 0)
- edge.WindCnt = e.WindCnt;
- //otherwise add to WC ...
- else edge.WindCnt = e.WindCnt + edge.WindDelta;
- }
- edge.WindCnt2 = e.WindCnt2;
- e = e.NextInAEL; //ie get ready to calc WindCnt2
- }
-
- //update WindCnt2 ...
- if (IsEvenOddAltFillType(edge))
- {
- //EvenOdd filling ...
- while (e != edge)
- {
- if (e.WindDelta != 0)
- edge.WindCnt2 = (edge.WindCnt2 == 0 ? 1 : 0);
- e = e.NextInAEL;
- }
- }
- else
- {
- //nonZero, Positive or Negative filling ...
- while (e != edge)
- {
- edge.WindCnt2 += e.WindDelta;
- e = e.NextInAEL;
- }
- }
- }
- //------------------------------------------------------------------------------
-
- private void AddEdgeToSEL(TEdge edge)
- {
- //SEL pointers in PEdge are use to build transient lists of horizontal edges.
- //However, since we don't need to worry about processing order, all additions
- //are made to the front of the list ...
- if (m_SortedEdges == null)
- {
- m_SortedEdges = edge;
- edge.PrevInSEL = null;
- edge.NextInSEL = null;
- }
- else
- {
- edge.NextInSEL = m_SortedEdges;
- edge.PrevInSEL = null;
- m_SortedEdges.PrevInSEL = edge;
- m_SortedEdges = edge;
- }
- }
- //------------------------------------------------------------------------------
-
- internal Boolean PopEdgeFromSEL(out TEdge e)
- {
- //Pop edge from front of SEL (ie SEL is a FILO list)
- e = m_SortedEdges;
- if (e == null) return false;
- TEdge oldE = e;
- m_SortedEdges = e.NextInSEL;
- if (m_SortedEdges != null) m_SortedEdges.PrevInSEL = null;
- oldE.NextInSEL = null;
- oldE.PrevInSEL = null;
- return true;
- }
- //------------------------------------------------------------------------------
-
- private void CopyAELToSEL()
- {
- TEdge e = m_ActiveEdges;
- m_SortedEdges = e;
- while (e != null)
- {
- e.PrevInSEL = e.PrevInAEL;
- e.NextInSEL = e.NextInAEL;
- e = e.NextInAEL;
- }
- }
- //------------------------------------------------------------------------------
-
- private void SwapPositionsInSEL(TEdge edge1, TEdge edge2)
- {
- if (edge1.NextInSEL == null && edge1.PrevInSEL == null)
- return;
- if (edge2.NextInSEL == null && edge2.PrevInSEL == null)
- return;
-
- if (edge1.NextInSEL == edge2)
- {
- TEdge next = edge2.NextInSEL;
- if (next != null)
- next.PrevInSEL = edge1;
- TEdge prev = edge1.PrevInSEL;
- if (prev != null)
- 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 != null)
- next.PrevInSEL = edge2;
- TEdge prev = edge2.PrevInSEL;
- if (prev != null)
- 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 != null)
- edge1.NextInSEL.PrevInSEL = edge1;
- edge1.PrevInSEL = edge2.PrevInSEL;
- if (edge1.PrevInSEL != null)
- edge1.PrevInSEL.NextInSEL = edge1;
- edge2.NextInSEL = next;
- if (edge2.NextInSEL != null)
- edge2.NextInSEL.PrevInSEL = edge2;
- edge2.PrevInSEL = prev;
- if (edge2.PrevInSEL != null)
- edge2.PrevInSEL.NextInSEL = edge2;
- }
-
- if (edge1.PrevInSEL == null)
- m_SortedEdges = edge1;
- else if (edge2.PrevInSEL == null)
- m_SortedEdges = edge2;
- }
- //------------------------------------------------------------------------------
-
-
- private void AddLocalMaxPoly(TEdge e1, TEdge e2, IntPoint pt)
- {
- AddOutPt(e1, pt);
- if (e2.WindDelta == 0) AddOutPt(e2, pt);
- if (e1.OutIdx == e2.OutIdx)
- {
- e1.OutIdx = Unassigned;
- e2.OutIdx = Unassigned;
- }
- else if (e1.OutIdx < e2.OutIdx)
- AppendPolygon(e1, e2);
- else
- AppendPolygon(e2, e1);
- }
- //------------------------------------------------------------------------------
-
- private OutPt AddLocalMinPoly(TEdge e1, TEdge e2, IntPoint pt)
- {
- OutPt result;
- TEdge e, prevE;
- if (IsHorizontal(e2) || (e1.Dx > e2.Dx))
- {
- result = AddOutPt(e1, pt);
- e2.OutIdx = e1.OutIdx;
- e1.Side = EdgeSide.esLeft;
- e2.Side = EdgeSide.esRight;
- e = e1;
- if (e.PrevInAEL == e2)
- prevE = e2.PrevInAEL;
- else
- prevE = e.PrevInAEL;
- }
- else
- {
- result = AddOutPt(e2, pt);
- e1.OutIdx = e2.OutIdx;
- e1.Side = EdgeSide.esRight;
- e2.Side = EdgeSide.esLeft;
- e = e2;
- if (e.PrevInAEL == e1)
- prevE = e1.PrevInAEL;
- else
- prevE = e.PrevInAEL;
- }
-
- if (prevE != null && prevE.OutIdx >= 0)
- {
- cInt xPrev = TopX(prevE, pt.Y);
- cInt xE = TopX(e, pt.Y);
- if ((xPrev == xE) && (e.WindDelta != 0) && (prevE.WindDelta != 0) &&
- SlopesEqual(new IntPoint(xPrev, pt.Y), prevE.Top, new IntPoint(xE, pt.Y), e.Top, m_UseFullRange))
- {
- OutPt outPt = AddOutPt(prevE, pt);
- AddJoin(result, outPt, e.Top);
- }
- }
- return result;
- }
- //------------------------------------------------------------------------------
-
- private OutPt AddOutPt(TEdge e, IntPoint pt)
- {
- if (e.OutIdx < 0)
- {
- OutRec outRec = CreateOutRec();
- outRec.IsOpen = (e.WindDelta == 0);
- OutPt newOp = new OutPt();
- outRec.Pts = newOp;
- newOp.Idx = outRec.Idx;
- newOp.Pt = pt;
- newOp.Next = newOp;
- newOp.Prev = newOp;
- if (!outRec.IsOpen)
- SetHoleState(e, outRec);
- e.OutIdx = outRec.Idx; //nb: do this after SetZ !
- return newOp;
- }
- else
- {
- OutRec outRec = m_PolyOuts[e.OutIdx];
- //OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
- OutPt op = outRec.Pts;
- bool ToFront = (e.Side == EdgeSide.esLeft);
- if (ToFront && pt == op.Pt) return op;
- else if (!ToFront && pt == op.Prev.Pt) return op.Prev;
-
- OutPt newOp = new OutPt();
- newOp.Idx = outRec.Idx;
- newOp.Pt = pt;
- newOp.Next = op;
- newOp.Prev = op.Prev;
- newOp.Prev.Next = newOp;
- op.Prev = newOp;
- if (ToFront) outRec.Pts = newOp;
- return newOp;
- }
- }
- //------------------------------------------------------------------------------
-
- private OutPt GetLastOutPt(TEdge e)
- {
- OutRec outRec = m_PolyOuts[e.OutIdx];
- if (e.Side == EdgeSide.esLeft)
- return outRec.Pts;
- else
- return outRec.Pts.Prev;
- }
- //------------------------------------------------------------------------------
-
- internal void SwapPoints(ref IntPoint pt1, ref IntPoint pt2)
- {
- IntPoint tmp = new IntPoint(pt1);
- pt1 = pt2;
- pt2 = tmp;
- }
- //------------------------------------------------------------------------------
-
- private bool HorzSegmentsOverlap(cInt seg1a, cInt seg1b, cInt seg2a, cInt seg2b)
- {
- if (seg1a > seg1b) Swap(ref seg1a, ref seg1b);
- if (seg2a > seg2b) Swap(ref seg2a, ref seg2b);
- return (seg1a < seg2b) && (seg2a < seg1b);
- }
- //------------------------------------------------------------------------------
-
- private void SetHoleState(TEdge e, OutRec outRec)
- {
- TEdge e2 = e.PrevInAEL;
- TEdge eTmp = null;
- while (e2 != null)
- {
- if (e2.OutIdx >= 0 && e2.WindDelta != 0)
- {
- if (eTmp == null)
- eTmp = e2;
- else if (eTmp.OutIdx == e2.OutIdx)
- eTmp = null; //paired
- }
- e2 = e2.PrevInAEL;
- }
-
- if (eTmp == null)
- {
- outRec.FirstLeft = null;
- outRec.IsHole = false;
- }
- else
- {
- outRec.FirstLeft = m_PolyOuts[eTmp.OutIdx];
- outRec.IsHole = !outRec.FirstLeft.IsHole;
- }
- }
- //------------------------------------------------------------------------------
-
- private double GetDx(IntPoint pt1, IntPoint pt2)
- {
- if (pt1.Y == pt2.Y) return horizontal;
- else return (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y);
- }
- //---------------------------------------------------------------------------
-
- private bool FirstIsBottomPt(OutPt btmPt1, OutPt btmPt2)
- {
- OutPt p = btmPt1.Prev;
- while ((p.Pt == btmPt1.Pt) && (p != btmPt1)) p = p.Prev;
- double dx1p = Math.Abs(GetDx(btmPt1.Pt, p.Pt));
- p = btmPt1.Next;
- while ((p.Pt == btmPt1.Pt) && (p != btmPt1)) p = p.Next;
- double dx1n = Math.Abs(GetDx(btmPt1.Pt, p.Pt));
-
- p = btmPt2.Prev;
- while ((p.Pt == btmPt2.Pt) && (p != btmPt2)) p = p.Prev;
- double dx2p = Math.Abs(GetDx(btmPt2.Pt, p.Pt));
- p = btmPt2.Next;
- while ((p.Pt == btmPt2.Pt) && (p != btmPt2)) p = p.Next;
- double dx2n = Math.Abs(GetDx(btmPt2.Pt, p.Pt));
-
- if (Math.Max(dx1p, dx1n) == Math.Max(dx2p, dx2n) &&
- Math.Min(dx1p, dx1n) == Math.Min(dx2p, dx2n))
- return Area(btmPt1) > 0; //if otherwise identical use orientation
- else
- return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
- }
- //------------------------------------------------------------------------------
-
- private OutPt GetBottomPt(OutPt pp)
- {
- OutPt dups = null;
- OutPt p = pp.Next;
- while (p != pp)
- {
- if (p.Pt.Y > pp.Pt.Y)
- {
- pp = p;
- dups = null;
- }
- else if (p.Pt.Y == pp.Pt.Y && p.Pt.X <= pp.Pt.X)
- {
- if (p.Pt.X < pp.Pt.X)
- {
- dups = null;
- pp = p;
- }
- else
- {
- if (p.Next != pp && p.Prev != pp) dups = p;
- }
- }
- p = p.Next;
- }
- if (dups != null)
- {
- //there appears to be at least 2 vertices at bottomPt so ...
- while (dups != p)
- {
- if (!FirstIsBottomPt(p, dups)) pp = dups;
- dups = dups.Next;
- while (dups.Pt != pp.Pt) dups = dups.Next;
- }
- }
- return pp;
- }
- //------------------------------------------------------------------------------
-
- private OutRec GetLowermostRec(OutRec outRec1, OutRec outRec2)
- {
- //work out which polygon fragment has the correct hole state ...
- if (outRec1.BottomPt == null)
- outRec1.BottomPt = GetBottomPt(outRec1.Pts);
- if (outRec2.BottomPt == null)
- outRec2.BottomPt = GetBottomPt(outRec2.Pts);
- OutPt bPt1 = outRec1.BottomPt;
- OutPt bPt2 = outRec2.BottomPt;
- if (bPt1.Pt.Y > bPt2.Pt.Y) return outRec1;
- else if (bPt1.Pt.Y < bPt2.Pt.Y) return outRec2;
- else if (bPt1.Pt.X < bPt2.Pt.X) return outRec1;
- else if (bPt1.Pt.X > bPt2.Pt.X) return outRec2;
- else if (bPt1.Next == bPt1) return outRec2;
- else if (bPt2.Next == bPt2) return outRec1;
- else if (FirstIsBottomPt(bPt1, bPt2)) return outRec1;
- else return outRec2;
- }
- //------------------------------------------------------------------------------
-
- bool OutRec1RightOfOutRec2(OutRec outRec1, OutRec outRec2)
- {
- do
- {
- outRec1 = outRec1.FirstLeft;
- if (outRec1 == outRec2) return true;
- } while (outRec1 != null);
- return false;
- }
- //------------------------------------------------------------------------------
-
- private OutRec GetOutRec(int idx)
- {
- OutRec outrec = m_PolyOuts[idx];
- while (outrec != m_PolyOuts[outrec.Idx])
- outrec = m_PolyOuts[outrec.Idx];
- return outrec;
- }
- //------------------------------------------------------------------------------
-
- private void AppendPolygon(TEdge e1, TEdge e2)
- {
- OutRec outRec1 = m_PolyOuts[e1.OutIdx];
- OutRec outRec2 = m_PolyOuts[e2.OutIdx];
-
- OutRec holeStateRec;
- if (OutRec1RightOfOutRec2(outRec1, outRec2))
- holeStateRec = outRec2;
- else if (OutRec1RightOfOutRec2(outRec2, outRec1))
- holeStateRec = outRec1;
- else
- holeStateRec = GetLowermostRec(outRec1, outRec2);
-
- //get the start and ends of both output polygons and
- //join E2 poly onto E1 poly and delete pointers to E2 ...
- OutPt p1_lft = outRec1.Pts;
- OutPt p1_rt = p1_lft.Prev;
- OutPt p2_lft = outRec2.Pts;
- OutPt p2_rt = p2_lft.Prev;
-
- //join e2 poly onto e1 poly and delete pointers to e2 ...
- if (e1.Side == EdgeSide.esLeft)
- {
- if (e2.Side == EdgeSide.esLeft)
- {
- //z y x a b c
- ReversePolyPtLinks(p2_lft);
- p2_lft.Next = p1_lft;
- p1_lft.Prev = p2_lft;
- p1_rt.Next = p2_rt;
- p2_rt.Prev = p1_rt;
- outRec1.Pts = p2_rt;
- }
- else
- {
- //x y z a b c
- p2_rt.Next = p1_lft;
- p1_lft.Prev = p2_rt;
- p2_lft.Prev = p1_rt;
- p1_rt.Next = p2_lft;
- outRec1.Pts = p2_lft;
- }
- }
- else
- {
- if (e2.Side == EdgeSide.esRight)
- {
- //a b c z y x
- ReversePolyPtLinks(p2_lft);
- p1_rt.Next = p2_rt;
- p2_rt.Prev = p1_rt;
- p2_lft.Next = p1_lft;
- p1_lft.Prev = p2_lft;
- }
- else
- {
- //a b c x y z
- p1_rt.Next = p2_lft;
- p2_lft.Prev = p1_rt;
- p1_lft.Prev = p2_rt;
- p2_rt.Next = p1_lft;
- }
- }
-
- outRec1.BottomPt = null;
- if (holeStateRec == outRec2)
- {
- if (outRec2.FirstLeft != outRec1)
- outRec1.FirstLeft = outRec2.FirstLeft;
- outRec1.IsHole = outRec2.IsHole;
- }
- outRec2.Pts = null;
- outRec2.BottomPt = null;
-
- outRec2.FirstLeft = outRec1;
-
- int OKIdx = e1.OutIdx;
- int ObsoleteIdx = e2.OutIdx;
-
- e1.OutIdx = Unassigned; //nb: safe because we only get here via AddLocalMaxPoly
- e2.OutIdx = Unassigned;
-
- TEdge e = m_ActiveEdges;
- while (e != null)
- {
- if (e.OutIdx == ObsoleteIdx)
- {
- e.OutIdx = OKIdx;
- e.Side = e1.Side;
- break;
- }
- e = e.NextInAEL;
- }
- outRec2.Idx = outRec1.Idx;
- }
- //------------------------------------------------------------------------------
-
- private void ReversePolyPtLinks(OutPt pp)
- {
- if (pp == null) return;
- OutPt pp1;
- OutPt pp2;
- pp1 = pp;
- do
- {
- pp2 = pp1.Next;
- pp1.Next = pp1.Prev;
- pp1.Prev = pp2;
- pp1 = pp2;
- } while (pp1 != pp);
- }
- //------------------------------------------------------------------------------
-
- private static void SwapSides(TEdge edge1, TEdge edge2)
- {
- EdgeSide side = edge1.Side;
- edge1.Side = edge2.Side;
- edge2.Side = side;
- }
- //------------------------------------------------------------------------------
-
- private static void SwapPolyIndexes(TEdge edge1, TEdge edge2)
- {
- int outIdx = edge1.OutIdx;
- edge1.OutIdx = edge2.OutIdx;
- edge2.OutIdx = outIdx;
- }
- //------------------------------------------------------------------------------
-
- private void IntersectEdges(TEdge e1, TEdge e2, IntPoint pt)
- {
- //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 e1Contributing = (e1.OutIdx >= 0);
- bool e2Contributing = (e2.OutIdx >= 0);
-
-#if use_xyz
- SetZ(ref pt, e1, e2);
-#endif
-
-#if use_lines
- //if either edge is on an OPEN path ...
- if (e1.WindDelta == 0 || e2.WindDelta == 0)
- {
- //ignore subject-subject open path intersections UNLESS they
- //are both open paths, AND they are both 'contributing maximas' ...
- if (e1.WindDelta == 0 && e2.WindDelta == 0) return;
- //if intersecting a subj line with a subj poly ...
- else if (e1.PolyTyp == e2.PolyTyp &&
- e1.WindDelta != e2.WindDelta && m_ClipType == ClipType.ctUnion)
- {
- if (e1.WindDelta == 0)
- {
- if (e2Contributing)
- {
- AddOutPt(e1, pt);
- if (e1Contributing) e1.OutIdx = Unassigned;
- }
- }
- else
- {
- if (e1Contributing)
- {
- AddOutPt(e2, pt);
- if (e2Contributing) e2.OutIdx = Unassigned;
- }
- }
- }
- else if (e1.PolyTyp != e2.PolyTyp)
- {
- if ((e1.WindDelta == 0) && Math.Abs(e2.WindCnt) == 1 &&
- (m_ClipType != ClipType.ctUnion || e2.WindCnt2 == 0))
- {
- AddOutPt(e1, pt);
- if (e1Contributing) e1.OutIdx = Unassigned;
- }
- else if ((e2.WindDelta == 0) && (Math.Abs(e1.WindCnt) == 1) &&
- (m_ClipType != ClipType.ctUnion || e1.WindCnt2 == 0))
- {
- AddOutPt(e2, pt);
- if (e2Contributing) e2.OutIdx = Unassigned;
- }
- }
- return;
- }
-#endif
-
- //update winding counts...
- //assumes that e1 will be to the Right of e2 ABOVE the intersection
- if (e1.PolyTyp == e2.PolyTyp)
- {
- if (IsEvenOddFillType(e1))
- {
- int oldE1WindCnt = e1.WindCnt;
- e1.WindCnt = e2.WindCnt;
- e2.WindCnt = oldE1WindCnt;
- }
- else
- {
- if (e1.WindCnt + e2.WindDelta == 0) e1.WindCnt = -e1.WindCnt;
- else e1.WindCnt += e2.WindDelta;
- if (e2.WindCnt - e1.WindDelta == 0) e2.WindCnt = -e2.WindCnt;
- else e2.WindCnt -= e1.WindDelta;
- }
- }
- else
- {
- if (!IsEvenOddFillType(e2)) e1.WindCnt2 += e2.WindDelta;
- else e1.WindCnt2 = (e1.WindCnt2 == 0) ? 1 : 0;
- if (!IsEvenOddFillType(e1)) e2.WindCnt2 -= e1.WindDelta;
- else e2.WindCnt2 = (e2.WindCnt2 == 0) ? 1 : 0;
- }
-
- PolyFillType e1FillType, e2FillType, e1FillType2, e2FillType2;
- if (e1.PolyTyp == PolyType.ptSubject)
- {
- e1FillType = m_SubjFillType;
- e1FillType2 = m_ClipFillType;
- }
- else
- {
- e1FillType = m_ClipFillType;
- e1FillType2 = m_SubjFillType;
- }
- if (e2.PolyTyp == PolyType.ptSubject)
- {
- e2FillType = m_SubjFillType;
- e2FillType2 = m_ClipFillType;
- }
- else
- {
- e2FillType = m_ClipFillType;
- e2FillType2 = m_SubjFillType;
- }
-
- int e1Wc, e2Wc;
- switch (e1FillType)
- {
- case PolyFillType.pftPositive: e1Wc = e1.WindCnt; break;
- case PolyFillType.pftNegative: e1Wc = -e1.WindCnt; break;
- default: e1Wc = Math.Abs(e1.WindCnt); break;
- }
- switch (e2FillType)
- {
- case PolyFillType.pftPositive: e2Wc = e2.WindCnt; break;
- case PolyFillType.pftNegative: e2Wc = -e2.WindCnt; break;
- default: e2Wc = Math.Abs(e2.WindCnt); break;
- }
-
- if (e1Contributing && e2Contributing)
- {
- if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) ||
- (e1.PolyTyp != e2.PolyTyp && m_ClipType != ClipType.ctXor))
- {
- AddLocalMaxPoly(e1, e2, pt);
- }
- else
- {
- AddOutPt(e1, pt);
- AddOutPt(e2, pt);
- SwapSides(e1, e2);
- SwapPolyIndexes(e1, e2);
- }
- }
- else if (e1Contributing)
- {
- if (e2Wc == 0 || e2Wc == 1)
- {
- AddOutPt(e1, pt);
- SwapSides(e1, e2);
- SwapPolyIndexes(e1, e2);
- }
-
- }
- else if (e2Contributing)
- {
- if (e1Wc == 0 || e1Wc == 1)
- {
- AddOutPt(e2, pt);
- SwapSides(e1, e2);
- SwapPolyIndexes(e1, e2);
- }
- }
- else if ((e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1))
- {
- //neither edge is currently contributing ...
- cInt e1Wc2, e2Wc2;
- switch (e1FillType2)
- {
- case PolyFillType.pftPositive: e1Wc2 = e1.WindCnt2; break;
- case PolyFillType.pftNegative: e1Wc2 = -e1.WindCnt2; break;
- default: e1Wc2 = Math.Abs(e1.WindCnt2); break;
- }
- switch (e2FillType2)
- {
- case PolyFillType.pftPositive: e2Wc2 = e2.WindCnt2; break;
- case PolyFillType.pftNegative: e2Wc2 = -e2.WindCnt2; break;
- default: e2Wc2 = Math.Abs(e2.WindCnt2); break;
- }
-
- if (e1.PolyTyp != e2.PolyTyp)
- {
- AddLocalMinPoly(e1, e2, pt);
- }
- else if (e1Wc == 1 && e2Wc == 1)
- switch (m_ClipType)
- {
- case ClipType.ctIntersection:
- if (e1Wc2 > 0 && e2Wc2 > 0)
- AddLocalMinPoly(e1, e2, pt);
- break;
- case ClipType.ctUnion:
- if (e1Wc2 <= 0 && e2Wc2 <= 0)
- AddLocalMinPoly(e1, e2, pt);
- break;
- case ClipType.ctDifference:
- if (((e1.PolyTyp == PolyType.ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
- ((e1.PolyTyp == PolyType.ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
- AddLocalMinPoly(e1, e2, pt);
- break;
- case ClipType.ctXor:
- AddLocalMinPoly(e1, e2, pt);
- break;
- }
- else
- SwapSides(e1, e2);
- }
- }
- //------------------------------------------------------------------------------
-
- private void DeleteFromSEL(TEdge e)
- {
- TEdge SelPrev = e.PrevInSEL;
- TEdge SelNext = e.NextInSEL;
- if (SelPrev == null && SelNext == null && (e != m_SortedEdges))
- return; //already deleted
- if (SelPrev != null)
- SelPrev.NextInSEL = SelNext;
- else m_SortedEdges = SelNext;
- if (SelNext != null)
- SelNext.PrevInSEL = SelPrev;
- e.NextInSEL = null;
- e.PrevInSEL = null;
- }
- //------------------------------------------------------------------------------
-
- private void ProcessHorizontals()
- {
- TEdge horzEdge; //m_SortedEdges;
- while (PopEdgeFromSEL(out horzEdge))
- ProcessHorizontal(horzEdge);
- }
- //------------------------------------------------------------------------------
-
- void GetHorzDirection(TEdge HorzEdge, out Direction Dir, out cInt Left, out cInt Right)
- {
- if (HorzEdge.Bot.X < HorzEdge.Top.X)
- {
- Left = HorzEdge.Bot.X;
- Right = HorzEdge.Top.X;
- Dir = Direction.dLeftToRight;
- }
- else
- {
- Left = HorzEdge.Top.X;
- Right = HorzEdge.Bot.X;
- Dir = Direction.dRightToLeft;
- }
- }
- //------------------------------------------------------------------------
-
- private void ProcessHorizontal(TEdge horzEdge)
- {
- Direction dir;
- cInt horzLeft, horzRight;
- bool IsOpen = horzEdge.WindDelta == 0;
-
- GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
-
- TEdge eLastHorz = horzEdge, eMaxPair = null;
- while (eLastHorz.NextInLML != null && IsHorizontal(eLastHorz.NextInLML))
- eLastHorz = eLastHorz.NextInLML;
- if (eLastHorz.NextInLML == null)
- eMaxPair = GetMaximaPair(eLastHorz);
-
- Maxima currMax = m_Maxima;
- if (currMax != null)
- {
- //get the first maxima in range (X) ...
- if (dir == Direction.dLeftToRight)
- {
- while (currMax != null && currMax.X <= horzEdge.Bot.X)
- currMax = currMax.Next;
- if (currMax != null && currMax.X >= eLastHorz.Top.X)
- currMax = null;
- }
- else
- {
- while (currMax.Next != null && currMax.Next.X < horzEdge.Bot.X)
- currMax = currMax.Next;
- if (currMax.X <= eLastHorz.Top.X) currMax = null;
- }
- }
-
- OutPt op1 = null;
- for (;;) //loop through consec. horizontal edges
- {
- bool IsLastHorz = (horzEdge == eLastHorz);
- TEdge e = GetNextInAEL(horzEdge, dir);
- while (e != null)
- {
-
- //this code block inserts extra coords into horizontal edges (in output
- //polygons) whereever maxima touch these horizontal edges. This helps
- //'simplifying' polygons (ie if the Simplify property is set).
- if (currMax != null)
- {
- if (dir == Direction.dLeftToRight)
- {
- while (currMax != null && currMax.X < e.Curr.X)
- {
- if (horzEdge.OutIdx >= 0 && !IsOpen)
- AddOutPt(horzEdge, new IntPoint(currMax.X, horzEdge.Bot.Y));
- currMax = currMax.Next;
- }
- }
- else
- {
- while (currMax != null && currMax.X > e.Curr.X)
- {
- if (horzEdge.OutIdx >= 0 && !IsOpen)
- AddOutPt(horzEdge, new IntPoint(currMax.X, horzEdge.Bot.Y));
- currMax = currMax.Prev;
- }
- }
- };
-
- if ((dir == Direction.dLeftToRight && e.Curr.X > horzRight) ||
- (dir == Direction.dRightToLeft && e.Curr.X < horzLeft)) break;
-
- //Also break if we've got to the end of an intermediate horizontal edge ...
- //nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
- if (e.Curr.X == horzEdge.Top.X && horzEdge.NextInLML != null &&
- e.Dx < horzEdge.NextInLML.Dx) break;
-
- if (horzEdge.OutIdx >= 0 && !IsOpen) //note: may be done multiple times
- {
- op1 = AddOutPt(horzEdge, e.Curr);
- TEdge eNextHorz = m_SortedEdges;
- while (eNextHorz != null)
- {
- if (eNextHorz.OutIdx >= 0 &&
- HorzSegmentsOverlap(horzEdge.Bot.X,
- horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
- {
- OutPt op2 = GetLastOutPt(eNextHorz);
- AddJoin(op2, op1, eNextHorz.Top);
- }
- eNextHorz = eNextHorz.NextInSEL;
- }
- AddGhostJoin(op1, horzEdge.Bot);
- }
-
- //OK, so far we're still in range of the horizontal Edge but make sure
- //we're at the last of consec. horizontals when matching with eMaxPair
- if (e == eMaxPair && IsLastHorz)
- {
- if (horzEdge.OutIdx >= 0)
- AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge.Top);
- DeleteFromAEL(horzEdge);
- DeleteFromAEL(eMaxPair);
- return;
- }
-
- if (dir == Direction.dLeftToRight)
- {
- IntPoint Pt = new IntPoint(e.Curr.X, horzEdge.Curr.Y);
- IntersectEdges(horzEdge, e, Pt);
- }
- else
- {
- IntPoint Pt = new IntPoint(e.Curr.X, horzEdge.Curr.Y);
- IntersectEdges(e, horzEdge, Pt);
- }
- TEdge eNext = GetNextInAEL(e, dir);
- SwapPositionsInAEL(horzEdge, e);
- e = eNext;
- } //end while(e != null)
-
- //Break out of loop if HorzEdge.NextInLML is not also horizontal ...
- if (horzEdge.NextInLML == null || !IsHorizontal(horzEdge.NextInLML)) break;
-
- UpdateEdgeIntoAEL(ref horzEdge);
- if (horzEdge.OutIdx >= 0) AddOutPt(horzEdge, horzEdge.Bot);
- GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
-
- } //end for (;;)
-
- if (horzEdge.OutIdx >= 0 && op1 == null)
- {
- op1 = GetLastOutPt(horzEdge);
- TEdge eNextHorz = m_SortedEdges;
- while (eNextHorz != null)
- {
- if (eNextHorz.OutIdx >= 0 &&
- HorzSegmentsOverlap(horzEdge.Bot.X,
- horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
- {
- OutPt op2 = GetLastOutPt(eNextHorz);
- AddJoin(op2, op1, eNextHorz.Top);
- }
- eNextHorz = eNextHorz.NextInSEL;
- }
- AddGhostJoin(op1, horzEdge.Top);
- }
-
- if (horzEdge.NextInLML != null)
- {
- if (horzEdge.OutIdx >= 0)
- {
- op1 = AddOutPt(horzEdge, horzEdge.Top);
-
- UpdateEdgeIntoAEL(ref horzEdge);
- if (horzEdge.WindDelta == 0) return;
- //nb: HorzEdge is no longer horizontal here
- TEdge ePrev = horzEdge.PrevInAEL;
- TEdge eNext = horzEdge.NextInAEL;
- if (ePrev != null && ePrev.Curr.X == horzEdge.Bot.X &&
- ePrev.Curr.Y == horzEdge.Bot.Y && ePrev.WindDelta != 0 &&
- (ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y &&
- SlopesEqual(horzEdge, ePrev, m_UseFullRange)))
- {
- OutPt op2 = AddOutPt(ePrev, horzEdge.Bot);
- AddJoin(op1, op2, horzEdge.Top);
- }
- else if (eNext != null && eNext.Curr.X == horzEdge.Bot.X &&
- eNext.Curr.Y == horzEdge.Bot.Y && eNext.WindDelta != 0 &&
- eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y &&
- SlopesEqual(horzEdge, eNext, m_UseFullRange))
- {
- OutPt op2 = AddOutPt(eNext, horzEdge.Bot);
- AddJoin(op1, op2, horzEdge.Top);
- }
- }
- else
- UpdateEdgeIntoAEL(ref horzEdge);
- }
- else
- {
- if (horzEdge.OutIdx >= 0) AddOutPt(horzEdge, horzEdge.Top);
- DeleteFromAEL(horzEdge);
- }
- }
- //------------------------------------------------------------------------------
-
- private TEdge GetNextInAEL(TEdge e, Direction Direction)
- {
- return Direction == Direction.dLeftToRight ? e.NextInAEL : e.PrevInAEL;
- }
- //------------------------------------------------------------------------------
-
- private bool IsMinima(TEdge e)
- {
- return e != null && (e.Prev.NextInLML != e) && (e.Next.NextInLML != e);
- }
- //------------------------------------------------------------------------------
-
- private bool IsMaxima(TEdge e, double Y)
- {
- return (e != null && e.Top.Y == Y && e.NextInLML == null);
- }
- //------------------------------------------------------------------------------
-
- private bool IsIntermediate(TEdge e, double Y)
- {
- return (e.Top.Y == Y && e.NextInLML != null);
- }
- //------------------------------------------------------------------------------
-
- internal TEdge GetMaximaPair(TEdge e)
- {
- if ((e.Next.Top == e.Top) && e.Next.NextInLML == null)
- return e.Next;
- else if ((e.Prev.Top == e.Top) && e.Prev.NextInLML == null)
- return e.Prev;
- else
- return null;
- }
- //------------------------------------------------------------------------------
-
- internal TEdge GetMaximaPairEx(TEdge e)
- {
- //as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
- TEdge result = GetMaximaPair(e);
- if (result == null || result.OutIdx == Skip ||
- ((result.NextInAEL == result.PrevInAEL) && !IsHorizontal(result))) return null;
- return result;
- }
- //------------------------------------------------------------------------------
-
- private bool ProcessIntersections(cInt topY)
- {
- if (m_ActiveEdges == null) return true;
- try
- {
- BuildIntersectList(topY);
- if (m_IntersectList.Count == 0) return true;
- if (m_IntersectList.Count == 1 || FixupIntersectionOrder())
- ProcessIntersectList();
- else
- return false;
- }
- catch
- {
- m_SortedEdges = null;
- m_IntersectList.Clear();
- throw new ClipperException("ProcessIntersections error");
- }
- m_SortedEdges = null;
- return true;
- }
- //------------------------------------------------------------------------------
-
- private void BuildIntersectList(cInt topY)
- {
- if (m_ActiveEdges == null) return;
-
- //prepare for sorting ...
- TEdge e = m_ActiveEdges;
- m_SortedEdges = e;
- while (e != null)
- {
- e.PrevInSEL = e.PrevInAEL;
- e.NextInSEL = e.NextInAEL;
- e.Curr.X = TopX(e, topY);
- e = e.NextInAEL;
- }
-
- //bubblesort ...
- bool isModified = true;
- while (isModified && m_SortedEdges != null)
- {
- isModified = false;
- e = m_SortedEdges;
- while (e.NextInSEL != null)
- {
- TEdge eNext = e.NextInSEL;
- IntPoint pt;
- if (e.Curr.X > eNext.Curr.X)
- {
- IntersectPoint(e, eNext, out pt);
- if (pt.Y < topY)
- pt = new IntPoint(TopX(e, topY), topY);
- IntersectNode newNode = new IntersectNode();
- newNode.Edge1 = e;
- newNode.Edge2 = eNext;
- newNode.Pt = pt;
- m_IntersectList.Add(newNode);
-
- SwapPositionsInSEL(e, eNext);
- isModified = true;
- }
- else
- e = eNext;
- }
- if (e.PrevInSEL != null) e.PrevInSEL.NextInSEL = null;
- else break;
- }
- m_SortedEdges = null;
- }
- //------------------------------------------------------------------------------
-
- private bool EdgesAdjacent(IntersectNode inode)
- {
- return (inode.Edge1.NextInSEL == inode.Edge2) ||
- (inode.Edge1.PrevInSEL == inode.Edge2);
- }
- //------------------------------------------------------------------------------
-
- private static int IntersectNodeSort(IntersectNode node1, IntersectNode node2)
- {
- //the following typecast is safe because the differences in Pt.Y will
- //be limited to the height of the scanbeam.
- return (int)(node2.Pt.Y - node1.Pt.Y);
- }
- //------------------------------------------------------------------------------
-
- private bool FixupIntersectionOrder()
- {
- //pre-condition: intersections are sorted bottom-most first.
- //Now it's crucial that intersections are made only between adjacent edges,
- //so to ensure this the order of intersections may need adjusting ...
- m_IntersectList.Sort(m_IntersectNodeComparer);
-
- CopyAELToSEL();
- int cnt = m_IntersectList.Count;
- for (int i = 0; i < cnt; i++)
- {
- if (!EdgesAdjacent(m_IntersectList[i]))
- {
- int j = i + 1;
- while (j < cnt && !EdgesAdjacent(m_IntersectList[j])) j++;
- if (j == cnt) return false;
-
- IntersectNode tmp = m_IntersectList[i];
- m_IntersectList[i] = m_IntersectList[j];
- m_IntersectList[j] = tmp;
-
- }
- SwapPositionsInSEL(m_IntersectList[i].Edge1, m_IntersectList[i].Edge2);
- }
- return true;
- }
- //------------------------------------------------------------------------------
-
- private void ProcessIntersectList()
- {
- for (int i = 0; i < m_IntersectList.Count; i++)
- {
- IntersectNode iNode = m_IntersectList[i];
- {
- IntersectEdges(iNode.Edge1, iNode.Edge2, iNode.Pt);
- SwapPositionsInAEL(iNode.Edge1, iNode.Edge2);
- }
- }
- m_IntersectList.Clear();
- }
- //------------------------------------------------------------------------------
-
- internal static cInt Round(double value)
- {
- return value < 0 ? (cInt)(value - 0.5) : (cInt)(value + 0.5);
- }
- //------------------------------------------------------------------------------
-
- private static cInt TopX(TEdge edge, cInt currentY)
- {
- if (currentY == edge.Top.Y)
- return edge.Top.X;
- return edge.Bot.X + Round(edge.Dx * (currentY - edge.Bot.Y));
- }
- //------------------------------------------------------------------------------
-
- private void IntersectPoint(TEdge edge1, TEdge edge2, out IntPoint ip)
- {
- ip = new IntPoint();
- double b1, b2;
- //nb: with very large coordinate values, it's possible for SlopesEqual() to
- //return false but for the edge.Dx value be equal due to double precision rounding.
- if (edge1.Dx == edge2.Dx)
- {
- ip.Y = edge1.Curr.Y;
- ip.X = TopX(edge1, ip.Y);
- return;
- }
-
- if (edge1.Delta.X == 0)
- {
- ip.X = edge1.Bot.X;
- if (IsHorizontal(edge2))
- {
- ip.Y = edge2.Bot.Y;
- }
- else
- {
- b2 = edge2.Bot.Y - (edge2.Bot.X / edge2.Dx);
- ip.Y = Round(ip.X / edge2.Dx + b2);
- }
- }
- else if (edge2.Delta.X == 0)
- {
- ip.X = edge2.Bot.X;
- if (IsHorizontal(edge1))
- {
- ip.Y = edge1.Bot.Y;
- }
- else
- {
- b1 = edge1.Bot.Y - (edge1.Bot.X / edge1.Dx);
- ip.Y = Round(ip.X / edge1.Dx + b1);
- }
- }
- else
- {
- b1 = edge1.Bot.X - edge1.Bot.Y * edge1.Dx;
- b2 = edge2.Bot.X - edge2.Bot.Y * edge2.Dx;
- double q = (b2 - b1) / (edge1.Dx - edge2.Dx);
- ip.Y = Round(q);
- if (Math.Abs(edge1.Dx) < Math.Abs(edge2.Dx))
- ip.X = Round(edge1.Dx * q + b1);
- else
- ip.X = Round(edge2.Dx * q + b2);
- }
-
- if (ip.Y < edge1.Top.Y || ip.Y < edge2.Top.Y)
- {
- if (edge1.Top.Y > edge2.Top.Y)
- ip.Y = edge1.Top.Y;
- else
- ip.Y = edge2.Top.Y;
- if (Math.Abs(edge1.Dx) < Math.Abs(edge2.Dx))
- ip.X = TopX(edge1, ip.Y);
- else
- ip.X = TopX(edge2, ip.Y);
- }
- //finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
- if (ip.Y > edge1.Curr.Y)
- {
- ip.Y = edge1.Curr.Y;
- //better to use the more vertical edge to derive X ...
- if (Math.Abs(edge1.Dx) > Math.Abs(edge2.Dx))
- ip.X = TopX(edge2, ip.Y);
- else
- ip.X = TopX(edge1, ip.Y);
- }
- }
- //------------------------------------------------------------------------------
-
- private void ProcessEdgesAtTopOfScanbeam(cInt topY)
- {
- TEdge e = m_ActiveEdges;
- while (e != null)
- {
- //1. process maxima, treating them as if they're 'bent' horizontal edges,
- // but exclude maxima with horizontal edges. nb: e can't be a horizontal.
- bool IsMaximaEdge = IsMaxima(e, topY);
-
- if (IsMaximaEdge)
- {
- TEdge eMaxPair = GetMaximaPairEx(e);
- IsMaximaEdge = (eMaxPair == null || !IsHorizontal(eMaxPair));
- }
-
- if (IsMaximaEdge)
- {
- if (StrictlySimple) InsertMaxima(e.Top.X);
- TEdge ePrev = e.PrevInAEL;
- DoMaxima(e);
- if (ePrev == null) e = m_ActiveEdges;
- else e = ePrev.NextInAEL;
- }
- else
- {
- //2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
- if (IsIntermediate(e, topY) && IsHorizontal(e.NextInLML))
- {
- UpdateEdgeIntoAEL(ref e);
- if (e.OutIdx >= 0)
- AddOutPt(e, e.Bot);
- AddEdgeToSEL(e);
- }
- else
- {
- e.Curr.X = TopX(e, topY);
- e.Curr.Y = topY;
- }
-
- //When StrictlySimple and 'e' is being touched by another edge, then
- //make sure both edges have a vertex here ...
- if (StrictlySimple)
- {
- TEdge ePrev = e.PrevInAEL;
- if ((e.OutIdx >= 0) && (e.WindDelta != 0) && ePrev != null &&
- (ePrev.OutIdx >= 0) && (ePrev.Curr.X == e.Curr.X) &&
- (ePrev.WindDelta != 0))
- {
- IntPoint ip = new IntPoint(e.Curr);
-#if use_xyz
- SetZ(ref ip, ePrev, e);
-#endif
- OutPt op = AddOutPt(ePrev, ip);
- OutPt op2 = AddOutPt(e, ip);
- AddJoin(op, op2, ip); //StrictlySimple (type-3) join
- }
- }
-
- e = e.NextInAEL;
- }
- }
-
- //3. Process horizontals at the Top of the scanbeam ...
- ProcessHorizontals();
- m_Maxima = null;
-
- //4. Promote intermediate vertices ...
- e = m_ActiveEdges;
- while (e != null)
- {
- if (IsIntermediate(e, topY))
- {
- OutPt op = null;
- if (e.OutIdx >= 0)
- op = AddOutPt(e, e.Top);
- UpdateEdgeIntoAEL(ref e);
-
- //if output polygons share an edge, they'll need joining later ...
- TEdge ePrev = e.PrevInAEL;
- TEdge eNext = e.NextInAEL;
- if (ePrev != null && ePrev.Curr.X == e.Bot.X &&
- ePrev.Curr.Y == e.Bot.Y && op != null &&
- ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y &&
- SlopesEqual(e.Curr, e.Top, ePrev.Curr, ePrev.Top, m_UseFullRange) &&
- (e.WindDelta != 0) && (ePrev.WindDelta != 0))
- {
- OutPt op2 = AddOutPt(ePrev, e.Bot);
- AddJoin(op, op2, e.Top);
- }
- else if (eNext != null && eNext.Curr.X == e.Bot.X &&
- eNext.Curr.Y == e.Bot.Y && op != null &&
- eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y &&
- SlopesEqual(e.Curr, e.Top, eNext.Curr, eNext.Top, m_UseFullRange) &&
- (e.WindDelta != 0) && (eNext.WindDelta != 0))
- {
- OutPt op2 = AddOutPt(eNext, e.Bot);
- AddJoin(op, op2, e.Top);
- }
- }
- e = e.NextInAEL;
- }
- }
- //------------------------------------------------------------------------------
-
- private void DoMaxima(TEdge e)
- {
- TEdge eMaxPair = GetMaximaPairEx(e);
- if (eMaxPair == null)
- {
- if (e.OutIdx >= 0)
- AddOutPt(e, e.Top);
- DeleteFromAEL(e);
- return;
- }
-
- TEdge eNext = e.NextInAEL;
- while (eNext != null && eNext != eMaxPair)
- {
- IntersectEdges(e, eNext, e.Top);
- SwapPositionsInAEL(e, eNext);
- eNext = e.NextInAEL;
- }
-
- if (e.OutIdx == Unassigned && eMaxPair.OutIdx == Unassigned)
- {
- DeleteFromAEL(e);
- DeleteFromAEL(eMaxPair);
- }
- else if (e.OutIdx >= 0 && eMaxPair.OutIdx >= 0)
- {
- if (e.OutIdx >= 0) AddLocalMaxPoly(e, eMaxPair, e.Top);
- DeleteFromAEL(e);
- DeleteFromAEL(eMaxPair);
- }
-#if use_lines
- else if (e.WindDelta == 0)
- {
- if (e.OutIdx >= 0)
- {
- AddOutPt(e, e.Top);
- e.OutIdx = Unassigned;
- }
- DeleteFromAEL(e);
-
- if (eMaxPair.OutIdx >= 0)
- {
- AddOutPt(eMaxPair, e.Top);
- eMaxPair.OutIdx = Unassigned;
- }
- DeleteFromAEL(eMaxPair);
- }
-#endif
- else throw new ClipperException("DoMaxima error");
- }
- //------------------------------------------------------------------------------
-
- public static void ReversePaths(Paths polys)
- {
- foreach (var poly in polys) { poly.Reverse(); }
- }
- //------------------------------------------------------------------------------
-
- public static bool Orientation(Path poly)
- {
- return Area(poly) >= 0;
- }
- //------------------------------------------------------------------------------
-
- private int PointCount(OutPt pts)
- {
- if (pts == null) return 0;
- int result = 0;
- OutPt p = pts;
- do
- {
- result++;
- p = p.Next;
- }
- while (p != pts);
- return result;
- }
- //------------------------------------------------------------------------------
-
- private void BuildResult(Paths polyg)
- {
- polyg.Clear();
- polyg.Capacity = m_PolyOuts.Count;
- for (int i = 0; i < m_PolyOuts.Count; i++)
- {
- OutRec outRec = m_PolyOuts[i];
- if (outRec.Pts == null) continue;
- OutPt p = outRec.Pts.Prev;
- int cnt = PointCount(p);
- if (cnt < 2) continue;
- Path pg = new Path(cnt);
- for (int j = 0; j < cnt; j++)
- {
- pg.Add(p.Pt);
- p = p.Prev;
- }
- polyg.Add(pg);
- }
- }
- //------------------------------------------------------------------------------
-
- private void BuildResult2(PolyTree polytree)
- {
- polytree.Clear();
-
- //add each output polygon/contour to polytree ...
- polytree.m_AllPolys.Capacity = m_PolyOuts.Count;
- for (int i = 0; i < m_PolyOuts.Count; i++)
- {
- OutRec outRec = m_PolyOuts[i];
- int cnt = PointCount(outRec.Pts);
- if ((outRec.IsOpen && cnt < 2) ||
- (!outRec.IsOpen && cnt < 3)) continue;
- FixHoleLinkage(outRec);
- PolyNode pn = new PolyNode();
- polytree.m_AllPolys.Add(pn);
- outRec.PolyNode = pn;
- pn.m_polygon.Capacity = cnt;
- OutPt op = outRec.Pts.Prev;
- for (int j = 0; j < cnt; j++)
- {
- pn.m_polygon.Add(op.Pt);
- op = op.Prev;
- }
- }
-
- //fixup PolyNode links etc ...
- polytree.m_Childs.Capacity = m_PolyOuts.Count;
- for (int i = 0; i < m_PolyOuts.Count; i++)
- {
- OutRec outRec = m_PolyOuts[i];
- if (outRec.PolyNode == null) continue;
- else if (outRec.IsOpen)
- {
- outRec.PolyNode.IsOpen = true;
- polytree.AddChild(outRec.PolyNode);
- }
- else if (outRec.FirstLeft != null &&
- outRec.FirstLeft.PolyNode != null)
- outRec.FirstLeft.PolyNode.AddChild(outRec.PolyNode);
- else
- polytree.AddChild(outRec.PolyNode);
- }
- }
- //------------------------------------------------------------------------------
-
- private void FixupOutPolyline(OutRec outrec)
- {
- OutPt pp = outrec.Pts;
- OutPt lastPP = pp.Prev;
- while (pp != lastPP)
- {
- pp = pp.Next;
- if (pp.Pt == pp.Prev.Pt)
- {
- if (pp == lastPP) lastPP = pp.Prev;
- OutPt tmpPP = pp.Prev;
- tmpPP.Next = pp.Next;
- pp.Next.Prev = tmpPP;
- pp = tmpPP;
- }
- }
- if (pp == pp.Prev) outrec.Pts = null;
- }
- //------------------------------------------------------------------------------
-
- private void FixupOutPolygon(OutRec outRec)
- {
- //FixupOutPolygon() - removes duplicate points and simplifies consecutive
- //parallel edges by removing the middle vertex.
- OutPt lastOK = null;
- outRec.BottomPt = null;
- OutPt pp = outRec.Pts;
- bool preserveCol = PreserveCollinear || StrictlySimple;
- for (;;)
- {
- if (pp.Prev == pp || pp.Prev == pp.Next)
- {
- outRec.Pts = null;
- return;
- }
- //test for duplicate points and collinear edges ...
- if ((pp.Pt == pp.Next.Pt) || (pp.Pt == pp.Prev.Pt) ||
- (SlopesEqual(pp.Prev.Pt, pp.Pt, pp.Next.Pt, m_UseFullRange) &&
- (!preserveCol || !Pt2IsBetweenPt1AndPt3(pp.Prev.Pt, pp.Pt, pp.Next.Pt))))
- {
- lastOK = null;
- pp.Prev.Next = pp.Next;
- pp.Next.Prev = pp.Prev;
- pp = pp.Prev;
- }
- else if (pp == lastOK) break;
- else
- {
- if (lastOK == null) lastOK = pp;
- pp = pp.Next;
- }
- }
- outRec.Pts = pp;
- }
- //------------------------------------------------------------------------------
-
- OutPt DupOutPt(OutPt outPt, bool InsertAfter)
- {
- OutPt result = new OutPt();
- result.Pt = outPt.Pt;
- result.Idx = outPt.Idx;
- if (InsertAfter)
- {
- result.Next = outPt.Next;
- result.Prev = outPt;
- outPt.Next.Prev = result;
- outPt.Next = result;
- }
- else
- {
- result.Prev = outPt.Prev;
- result.Next = outPt;
- outPt.Prev.Next = result;
- outPt.Prev = result;
- }
- return result;
- }
- //------------------------------------------------------------------------------
-
- bool GetOverlap(cInt a1, cInt a2, cInt b1, cInt b2, out cInt Left, out cInt Right)
- {
- if (a1 < a2)
- {
- if (b1 < b2) { Left = Math.Max(a1, b1); Right = Math.Min(a2, b2); }
- else { Left = Math.Max(a1, b2); Right = Math.Min(a2, b1); }
- }
- else
- {
- if (b1 < b2) { Left = Math.Max(a2, b1); Right = Math.Min(a1, b2); }
- else { Left = Math.Max(a2, b2); Right = Math.Min(a1, b1); }
- }
- return Left < Right;
- }
- //------------------------------------------------------------------------------
-
- bool JoinHorz(OutPt op1, OutPt op1b, OutPt op2, OutPt op2b,
- IntPoint Pt, bool DiscardLeft)
- {
- Direction Dir1 = (op1.Pt.X > op1b.Pt.X ?
- Direction.dRightToLeft : Direction.dLeftToRight);
- Direction Dir2 = (op2.Pt.X > op2b.Pt.X ?
- Direction.dRightToLeft : Direction.dLeftToRight);
- if (Dir1 == Dir2) return false;
-
- //When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
- //want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
- //So, to facilitate this while inserting Op1b and Op2b ...
- //when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
- //otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
- if (Dir1 == Direction.dLeftToRight)
- {
- while (op1.Next.Pt.X <= Pt.X &&
- op1.Next.Pt.X >= op1.Pt.X && op1.Next.Pt.Y == Pt.Y)
- op1 = op1.Next;
- if (DiscardLeft && (op1.Pt.X != Pt.X)) op1 = op1.Next;
- op1b = DupOutPt(op1, !DiscardLeft);
- if (op1b.Pt != Pt)
- {
- op1 = op1b;
- op1.Pt = Pt;
- op1b = DupOutPt(op1, !DiscardLeft);
- }
- }
- else
- {
- while (op1.Next.Pt.X >= Pt.X &&
- op1.Next.Pt.X <= op1.Pt.X && op1.Next.Pt.Y == Pt.Y)
- op1 = op1.Next;
- if (!DiscardLeft && (op1.Pt.X != Pt.X)) op1 = op1.Next;
- op1b = DupOutPt(op1, DiscardLeft);
- if (op1b.Pt != Pt)
- {
- op1 = op1b;
- op1.Pt = Pt;
- op1b = DupOutPt(op1, DiscardLeft);
- }
- }
-
- if (Dir2 == Direction.dLeftToRight)
- {
- while (op2.Next.Pt.X <= Pt.X &&
- op2.Next.Pt.X >= op2.Pt.X && op2.Next.Pt.Y == Pt.Y)
- op2 = op2.Next;
- if (DiscardLeft && (op2.Pt.X != Pt.X)) op2 = op2.Next;
- op2b = DupOutPt(op2, !DiscardLeft);
- if (op2b.Pt != Pt)
- {
- op2 = op2b;
- op2.Pt = Pt;
- op2b = DupOutPt(op2, !DiscardLeft);
- };
- }
- else
- {
- while (op2.Next.Pt.X >= Pt.X &&
- op2.Next.Pt.X <= op2.Pt.X && op2.Next.Pt.Y == Pt.Y)
- op2 = op2.Next;
- if (!DiscardLeft && (op2.Pt.X != Pt.X)) op2 = op2.Next;
- op2b = DupOutPt(op2, DiscardLeft);
- if (op2b.Pt != Pt)
- {
- op2 = op2b;
- op2.Pt = Pt;
- op2b = DupOutPt(op2, DiscardLeft);
- };
- };
-
- if ((Dir1 == Direction.dLeftToRight) == DiscardLeft)
- {
- op1.Prev = op2;
- op2.Next = op1;
- op1b.Next = op2b;
- op2b.Prev = op1b;
- }
- else
- {
- op1.Next = op2;
- op2.Prev = op1;
- op1b.Prev = op2b;
- op2b.Next = op1b;
- }
- return true;
- }
- //------------------------------------------------------------------------------
-
- private bool JoinPoints(Join j, OutRec outRec1, OutRec outRec2)
- {
- OutPt op1 = j.OutPt1, op1b;
- OutPt op2 = j.OutPt2, op2b;
-
- //There are 3 kinds of joins for output polygons ...
- //1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
- //along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
- //2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
- //location at the Bottom of the overlapping segment (& Join.OffPt is above).
- //3. StrictlySimple joins where edges touch but are not collinear and where
- //Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
- bool isHorizontal = (j.OutPt1.Pt.Y == j.OffPt.Y);
-
- if (isHorizontal && (j.OffPt == j.OutPt1.Pt) && (j.OffPt == j.OutPt2.Pt))
- {
- //Strictly Simple join ...
- if (outRec1 != outRec2) return false;
- op1b = j.OutPt1.Next;
- while (op1b != op1 && (op1b.Pt == j.OffPt))
- op1b = op1b.Next;
- bool reverse1 = (op1b.Pt.Y > j.OffPt.Y);
- op2b = j.OutPt2.Next;
- while (op2b != op2 && (op2b.Pt == j.OffPt))
- op2b = op2b.Next;
- bool reverse2 = (op2b.Pt.Y > j.OffPt.Y);
- if (reverse1 == reverse2) return false;
- if (reverse1)
- {
- op1b = DupOutPt(op1, false);
- op2b = DupOutPt(op2, true);
- op1.Prev = op2;
- op2.Next = op1;
- op1b.Next = op2b;
- op2b.Prev = op1b;
- j.OutPt1 = op1;
- j.OutPt2 = op1b;
- return true;
- }
- else
- {
- op1b = DupOutPt(op1, true);
- op2b = DupOutPt(op2, false);
- op1.Next = op2;
- op2.Prev = op1;
- op1b.Prev = op2b;
- op2b.Next = op1b;
- j.OutPt1 = op1;
- j.OutPt2 = op1b;
- return true;
- }
- }
- else if (isHorizontal)
- {
- //treat horizontal joins differently to non-horizontal joins since with
- //them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
- //may be anywhere along the horizontal edge.
- op1b = op1;
- while (op1.Prev.Pt.Y == op1.Pt.Y && op1.Prev != op1b && op1.Prev != op2)
- op1 = op1.Prev;
- while (op1b.Next.Pt.Y == op1b.Pt.Y && op1b.Next != op1 && op1b.Next != op2)
- op1b = op1b.Next;
- if (op1b.Next == op1 || op1b.Next == op2) return false; //a flat 'polygon'
-
- op2b = op2;
- while (op2.Prev.Pt.Y == op2.Pt.Y && op2.Prev != op2b && op2.Prev != op1b)
- op2 = op2.Prev;
- while (op2b.Next.Pt.Y == op2b.Pt.Y && op2b.Next != op2 && op2b.Next != op1)
- op2b = op2b.Next;
- if (op2b.Next == op2 || op2b.Next == op1) return false; //a flat 'polygon'
-
- cInt Left, Right;
- //Op1 -. Op1b & Op2 -. Op2b are the extremites of the horizontal edges
- if (!GetOverlap(op1.Pt.X, op1b.Pt.X, op2.Pt.X, op2b.Pt.X, out Left, out Right))
- return false;
-
- //DiscardLeftSide: when overlapping edges are joined, a spike will created
- //which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
- //on the discard Side as either may still be needed for other joins ...
- IntPoint Pt;
- bool DiscardLeftSide;
- if (op1.Pt.X >= Left && op1.Pt.X <= Right)
- {
- Pt = op1.Pt; DiscardLeftSide = (op1.Pt.X > op1b.Pt.X);
- }
- else if (op2.Pt.X >= Left && op2.Pt.X <= Right)
- {
- Pt = op2.Pt; DiscardLeftSide = (op2.Pt.X > op2b.Pt.X);
- }
- else if (op1b.Pt.X >= Left && op1b.Pt.X <= Right)
- {
- Pt = op1b.Pt; DiscardLeftSide = op1b.Pt.X > op1.Pt.X;
- }
- else
- {
- Pt = op2b.Pt; DiscardLeftSide = (op2b.Pt.X > op2.Pt.X);
- }
- j.OutPt1 = op1;
- j.OutPt2 = op2;
- return JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide);
- }
- else
- {
- //nb: For non-horizontal joins ...
- // 1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
- // 2. Jr.OutPt1.Pt > Jr.OffPt.Y
-
- //make sure the polygons are correctly oriented ...
- op1b = op1.Next;
- while ((op1b.Pt == op1.Pt) && (op1b != op1)) op1b = op1b.Next;
- bool Reverse1 = ((op1b.Pt.Y > op1.Pt.Y) ||
- !SlopesEqual(op1.Pt, op1b.Pt, j.OffPt, m_UseFullRange));
- if (Reverse1)
- {
- op1b = op1.Prev;
- while ((op1b.Pt == op1.Pt) && (op1b != op1)) op1b = op1b.Prev;
- if ((op1b.Pt.Y > op1.Pt.Y) ||
- !SlopesEqual(op1.Pt, op1b.Pt, j.OffPt, m_UseFullRange)) return false;
- };
- op2b = op2.Next;
- while ((op2b.Pt == op2.Pt) && (op2b != op2)) op2b = op2b.Next;
- bool Reverse2 = ((op2b.Pt.Y > op2.Pt.Y) ||
- !SlopesEqual(op2.Pt, op2b.Pt, j.OffPt, m_UseFullRange));
- if (Reverse2)
- {
- op2b = op2.Prev;
- while ((op2b.Pt == op2.Pt) && (op2b != op2)) op2b = op2b.Prev;
- if ((op2b.Pt.Y > op2.Pt.Y) ||
- !SlopesEqual(op2.Pt, op2b.Pt, j.OffPt, m_UseFullRange)) return false;
- }
-
- if ((op1b == op1) || (op2b == op2) || (op1b == op2b) ||
- ((outRec1 == outRec2) && (Reverse1 == Reverse2))) return false;
-
- if (Reverse1)
- {
- op1b = DupOutPt(op1, false);
- op2b = DupOutPt(op2, true);
- op1.Prev = op2;
- op2.Next = op1;
- op1b.Next = op2b;
- op2b.Prev = op1b;
- j.OutPt1 = op1;
- j.OutPt2 = op1b;
- return true;
- }
- else
- {
- op1b = DupOutPt(op1, true);
- op2b = DupOutPt(op2, false);
- op1.Next = op2;
- op2.Prev = op1;
- op1b.Prev = op2b;
- op2b.Next = op1b;
- j.OutPt1 = op1;
- j.OutPt2 = op1b;
- return true;
- }
- }
- }
- //----------------------------------------------------------------------
-
- public static int PointInPolygon(IntPoint pt, Path path)
- {
- //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
- //See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
- //http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
- int result = 0, cnt = path.Count;
- if (cnt < 3) return 0;
- IntPoint ip = path[0];
- for (int i = 1; i <= cnt; ++i)
- {
- IntPoint ipNext = (i == cnt ? path[0] : path[i]);
- if (ipNext.Y == pt.Y)
- {
- if ((ipNext.X == pt.X) || (ip.Y == pt.Y &&
- ((ipNext.X > pt.X) == (ip.X < pt.X)))) return -1;
- }
- if ((ip.Y < pt.Y) != (ipNext.Y < pt.Y))
- {
- if (ip.X >= pt.X)
- {
- if (ipNext.X > pt.X) result = 1 - result;
- else
- {
- double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
- (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
- if (d == 0) return -1;
- else if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
- }
- }
- else
- {
- if (ipNext.X > pt.X)
- {
- double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
- (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
- if (d == 0) return -1;
- else if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
- }
- }
- }
- ip = ipNext;
- }
- return result;
- }
- //------------------------------------------------------------------------------
-
- //See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
- //http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
- private static int PointInPolygon(IntPoint pt, OutPt op)
- {
- //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
- int result = 0;
- OutPt startOp = op;
- cInt ptx = pt.X, pty = pt.Y;
- cInt poly0x = op.Pt.X, poly0y = op.Pt.Y;
- do
- {
- op = op.Next;
- cInt poly1x = op.Pt.X, poly1y = op.Pt.Y;
-
- if (poly1y == pty)
- {
- if ((poly1x == ptx) || (poly0y == pty &&
- ((poly1x > ptx) == (poly0x < ptx)))) return -1;
- }
- if ((poly0y < pty) != (poly1y < pty))
- {
- if (poly0x >= ptx)
- {
- if (poly1x > ptx) result = 1 - result;
- else
- {
- double d = (double)(poly0x - ptx) * (poly1y - pty) -
- (double)(poly1x - ptx) * (poly0y - pty);
- if (d == 0) return -1;
- if ((d > 0) == (poly1y > poly0y)) result = 1 - result;
- }
- }
- else
- {
- if (poly1x > ptx)
- {
- double d = (double)(poly0x - ptx) * (poly1y - pty) -
- (double)(poly1x - ptx) * (poly0y - pty);
- if (d == 0) return -1;
- if ((d > 0) == (poly1y > poly0y)) result = 1 - result;
- }
- }
- }
- poly0x = poly1x; poly0y = poly1y;
- } while (startOp != op);
- return result;
- }
- //------------------------------------------------------------------------------
-
- private static bool Poly2ContainsPoly1(OutPt outPt1, OutPt outPt2)
- {
- OutPt op = outPt1;
- do
- {
- //nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
- int res = PointInPolygon(op.Pt, outPt2);
- if (res >= 0) return res > 0;
- op = op.Next;
- }
- while (op != outPt1);
- return true;
- }
- //----------------------------------------------------------------------
-
- private void FixupFirstLefts1(OutRec OldOutRec, OutRec NewOutRec)
- {
- foreach (OutRec outRec in m_PolyOuts)
- {
- OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
- if (outRec.Pts != null && firstLeft == OldOutRec)
- {
- if (Poly2ContainsPoly1(outRec.Pts, NewOutRec.Pts))
- outRec.FirstLeft = NewOutRec;
- }
- }
- }
- //----------------------------------------------------------------------
-
- private void FixupFirstLefts2(OutRec innerOutRec, OutRec outerOutRec)
- {
- //A polygon has split into two such that one is now the inner of the other.
- //It's possible that these polygons now wrap around other polygons, so check
- //every polygon that's also contained by OuterOutRec's FirstLeft container
- //(including nil) to see if they've become inner to the new inner polygon ...
- OutRec orfl = outerOutRec.FirstLeft;
- foreach (OutRec outRec in m_PolyOuts)
- {
- if (outRec.Pts == null || outRec == outerOutRec || outRec == innerOutRec)
- continue;
- OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
- if (firstLeft != orfl && firstLeft != innerOutRec && firstLeft != outerOutRec)
- continue;
- if (Poly2ContainsPoly1(outRec.Pts, innerOutRec.Pts))
- outRec.FirstLeft = innerOutRec;
- else if (Poly2ContainsPoly1(outRec.Pts, outerOutRec.Pts))
- outRec.FirstLeft = outerOutRec;
- else if (outRec.FirstLeft == innerOutRec || outRec.FirstLeft == outerOutRec)
- outRec.FirstLeft = orfl;
- }
- }
- //----------------------------------------------------------------------
-
- private void FixupFirstLefts3(OutRec OldOutRec, OutRec NewOutRec)
- {
- //same as FixupFirstLefts1 but doesn't call Poly2ContainsPoly1()
- foreach (OutRec outRec in m_PolyOuts)
- {
- OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
- if (outRec.Pts != null && outRec.FirstLeft == OldOutRec)
- outRec.FirstLeft = NewOutRec;
- }
- }
- //----------------------------------------------------------------------
-
- private static OutRec ParseFirstLeft(OutRec FirstLeft)
- {
- while (FirstLeft != null && FirstLeft.Pts == null)
- FirstLeft = FirstLeft.FirstLeft;
- return FirstLeft;
- }
- //------------------------------------------------------------------------------
-
- private void JoinCommonEdges()
- {
- for (int i = 0; i < m_Joins.Count; i++)
- {
- Join join = m_Joins[i];
-
- OutRec outRec1 = GetOutRec(join.OutPt1.Idx);
- OutRec outRec2 = GetOutRec(join.OutPt2.Idx);
-
- if (outRec1.Pts == null || outRec2.Pts == null) continue;
- if (outRec1.IsOpen || outRec2.IsOpen) continue;
-
- //get the polygon fragment with the correct hole state (FirstLeft)
- //before calling JoinPoints() ...
- OutRec holeStateRec;
- if (outRec1 == outRec2) holeStateRec = outRec1;
- else if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2;
- else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1;
- else holeStateRec = GetLowermostRec(outRec1, outRec2);
-
- if (!JoinPoints(join, outRec1, outRec2)) continue;
-
- if (outRec1 == outRec2)
- {
- //instead of joining two polygons, we've just created a new one by
- //splitting one polygon into two.
- outRec1.Pts = join.OutPt1;
- outRec1.BottomPt = null;
- outRec2 = CreateOutRec();
- outRec2.Pts = join.OutPt2;
-
- //update all OutRec2.Pts Idx's ...
- UpdateOutPtIdxs(outRec2);
-
- if (Poly2ContainsPoly1(outRec2.Pts, outRec1.Pts))
- {
- //outRec1 contains outRec2 ...
- outRec2.IsHole = !outRec1.IsHole;
- outRec2.FirstLeft = outRec1;
-
- if (m_UsingPolyTree) FixupFirstLefts2(outRec2, outRec1);
-
- if ((outRec2.IsHole ^ ReverseSolution) == (Area(outRec2) > 0))
- ReversePolyPtLinks(outRec2.Pts);
-
- }
- else if (Poly2ContainsPoly1(outRec1.Pts, outRec2.Pts))
- {
- //outRec2 contains outRec1 ...
- outRec2.IsHole = outRec1.IsHole;
- outRec1.IsHole = !outRec2.IsHole;
- outRec2.FirstLeft = outRec1.FirstLeft;
- outRec1.FirstLeft = outRec2;
-
- if (m_UsingPolyTree) FixupFirstLefts2(outRec1, outRec2);
-
- if ((outRec1.IsHole ^ ReverseSolution) == (Area(outRec1) > 0))
- ReversePolyPtLinks(outRec1.Pts);
- }
- else
- {
- //the 2 polygons are completely separate ...
- outRec2.IsHole = outRec1.IsHole;
- outRec2.FirstLeft = outRec1.FirstLeft;
-
- //fixup FirstLeft pointers that may need reassigning to OutRec2
- if (m_UsingPolyTree) FixupFirstLefts1(outRec1, outRec2);
- }
-
- }
- else
- {
- //joined 2 polygons together ...
-
- outRec2.Pts = null;
- outRec2.BottomPt = null;
- outRec2.Idx = outRec1.Idx;
-
- outRec1.IsHole = holeStateRec.IsHole;
- if (holeStateRec == outRec2)
- outRec1.FirstLeft = outRec2.FirstLeft;
- outRec2.FirstLeft = outRec1;
-
- //fixup FirstLeft pointers that may need reassigning to OutRec1
- if (m_UsingPolyTree) FixupFirstLefts3(outRec2, outRec1);
- }
- }
- }
- //------------------------------------------------------------------------------
-
- private void UpdateOutPtIdxs(OutRec outrec)
- {
- OutPt op = outrec.Pts;
- do
- {
- op.Idx = outrec.Idx;
- op = op.Prev;
- }
- while (op != outrec.Pts);
- }
- //------------------------------------------------------------------------------
-
- private void DoSimplePolygons()
- {
- int i = 0;
- while (i < m_PolyOuts.Count)
- {
- OutRec outrec = m_PolyOuts[i++];
- OutPt op = outrec.Pts;
- if (op == null || outrec.IsOpen) continue;
- do //for each Pt in Polygon until duplicate found do ...
- {
- OutPt op2 = op.Next;
- while (op2 != outrec.Pts)
- {
- if ((op.Pt == op2.Pt) && op2.Next != op && op2.Prev != op)
- {
- //split the polygon into two ...
- OutPt op3 = op.Prev;
- OutPt op4 = op2.Prev;
- op.Prev = op4;
- op4.Next = op;
- op2.Prev = op3;
- op3.Next = op2;
-
- outrec.Pts = op;
- OutRec outrec2 = CreateOutRec();
- outrec2.Pts = op2;
- UpdateOutPtIdxs(outrec2);
- if (Poly2ContainsPoly1(outrec2.Pts, outrec.Pts))
- {
- //OutRec2 is contained by OutRec1 ...
- outrec2.IsHole = !outrec.IsHole;
- outrec2.FirstLeft = outrec;
- if (m_UsingPolyTree) FixupFirstLefts2(outrec2, outrec);
- }
- else
- if (Poly2ContainsPoly1(outrec.Pts, outrec2.Pts))
- {
- //OutRec1 is contained by OutRec2 ...
- outrec2.IsHole = outrec.IsHole;
- outrec.IsHole = !outrec2.IsHole;
- outrec2.FirstLeft = outrec.FirstLeft;
- outrec.FirstLeft = outrec2;
- if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2);
- }
- else
- {
- //the 2 polygons are separate ...
- outrec2.IsHole = outrec.IsHole;
- outrec2.FirstLeft = outrec.FirstLeft;
- if (m_UsingPolyTree) FixupFirstLefts1(outrec, outrec2);
- }
- op2 = op; //ie get ready for the next iteration
- }
- op2 = op2.Next;
- }
- op = op.Next;
- }
- while (op != outrec.Pts);
- }
- }
- //------------------------------------------------------------------------------
-
- public static double Area(Path poly)
- {
- int cnt = (int)poly.Count;
- if (cnt < 3) return 0;
- double a = 0;
- for (int i = 0, j = cnt - 1; i < cnt; ++i)
- {
- a += ((double)poly[j].X + poly[i].X) * ((double)poly[j].Y - poly[i].Y);
- j = i;
- }
- return -a * 0.5;
- }
- //------------------------------------------------------------------------------
-
- internal double Area(OutRec outRec)
- {
- return Area(outRec.Pts);
- }
- //------------------------------------------------------------------------------
-
- internal double Area(OutPt op)
- {
- OutPt opFirst = op;
- if (op == null) return 0;
- double a = 0;
- do
- {
- a = a + (double)(op.Prev.Pt.X + op.Pt.X) * (double)(op.Prev.Pt.Y - op.Pt.Y);
- op = op.Next;
- } while (op != opFirst);
- return a * 0.5;
- }
-
- //------------------------------------------------------------------------------
- // SimplifyPolygon functions ...
- // Convert self-intersecting polygons into simple polygons
- //------------------------------------------------------------------------------
-
- public static Paths SimplifyPolygon(Path poly,
- PolyFillType fillType = PolyFillType.pftEvenOdd)
- {
- Paths result = new Paths();
- Clipper c = new Clipper();
- c.StrictlySimple = true;
- c.AddPath(poly, PolyType.ptSubject, true);
- c.Execute(ClipType.ctUnion, result, fillType, fillType);
- return result;
- }
- //------------------------------------------------------------------------------
-
- public static Paths SimplifyPolygons(Paths polys,
- PolyFillType fillType = PolyFillType.pftEvenOdd)
- {
- Paths result = new Paths();
- Clipper c = new Clipper();
- c.StrictlySimple = true;
- c.AddPaths(polys, PolyType.ptSubject, true);
- c.Execute(ClipType.ctUnion, result, fillType, fillType);
- return result;
- }
- //------------------------------------------------------------------------------
-
- private static double DistanceSqrd(IntPoint pt1, IntPoint pt2)
- {
- double dx = ((double)pt1.X - pt2.X);
- double dy = ((double)pt1.Y - pt2.Y);
- return (dx * dx + dy * dy);
- }
- //------------------------------------------------------------------------------
-
- private static double DistanceFromLineSqrd(IntPoint pt, IntPoint ln1, IntPoint ln2)
- {
- //The equation of a line in general form (Ax + By + C = 0)
- //given 2 points (x¹,y¹) & (x²,y²) is ...
- //(y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0
- //A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹
- //perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²)
- //see http://en.wikipedia.org/wiki/Perpendicular_distance
- double A = ln1.Y - ln2.Y;
- double B = ln2.X - ln1.X;
- double C = A * ln1.X + B * ln1.Y;
- C = A * pt.X + B * pt.Y - C;
- return (C * C) / (A * A + B * B);
- }
- //---------------------------------------------------------------------------
-
- private static bool SlopesNearCollinear(IntPoint pt1,
- IntPoint pt2, IntPoint pt3, double distSqrd)
- {
- //this function is more accurate when the point that's GEOMETRICALLY
- //between the other 2 points is the one that's tested for distance.
- //nb: with 'spikes', either pt1 or pt3 is geometrically between the other pts
- if (Math.Abs(pt1.X - pt2.X) > Math.Abs(pt1.Y - pt2.Y))
- {
- if ((pt1.X > pt2.X) == (pt1.X < pt3.X))
- return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
- else if ((pt2.X > pt1.X) == (pt2.X < pt3.X))
- return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
- else
- return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
- }
- else
- {
- if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y))
- return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
- else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y))
- return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
- else
- return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
- }
- }
- //------------------------------------------------------------------------------
-
- private static bool PointsAreClose(IntPoint pt1, IntPoint pt2, double distSqrd)
- {
- double dx = (double)pt1.X - pt2.X;
- double dy = (double)pt1.Y - pt2.Y;
- return ((dx * dx) + (dy * dy) <= distSqrd);
- }
- //------------------------------------------------------------------------------
-
- private static OutPt ExcludeOp(OutPt op)
- {
- OutPt result = op.Prev;
- result.Next = op.Next;
- op.Next.Prev = result;
- result.Idx = 0;
- return result;
- }
- //------------------------------------------------------------------------------
-
- public static Path CleanPolygon(Path path, double distance = 1.415)
- {
- //distance = proximity in units/pixels below which vertices will be stripped.
- //Default ~= sqrt(2) so when adjacent vertices or semi-adjacent vertices have
- //both x & y coords within 1 unit, then the second vertex will be stripped.
-
- int cnt = path.Count;
-
- if (cnt == 0) return new Path();
-
- OutPt[] outPts = new OutPt[cnt];
- for (int i = 0; i < cnt; ++i) outPts[i] = new OutPt();
-
- for (int i = 0; i < cnt; ++i)
- {
- outPts[i].Pt = path[i];
- outPts[i].Next = outPts[(i + 1) % cnt];
- outPts[i].Next.Prev = outPts[i];
- outPts[i].Idx = 0;
- }
-
- double distSqrd = distance * distance;
- OutPt op = outPts[0];
- while (op.Idx == 0 && op.Next != op.Prev)
- {
- if (PointsAreClose(op.Pt, op.Prev.Pt, distSqrd))
- {
- op = ExcludeOp(op);
- cnt--;
- }
- else if (PointsAreClose(op.Prev.Pt, op.Next.Pt, distSqrd))
- {
- ExcludeOp(op.Next);
- op = ExcludeOp(op);
- cnt -= 2;
- }
- else if (SlopesNearCollinear(op.Prev.Pt, op.Pt, op.Next.Pt, distSqrd))
- {
- op = ExcludeOp(op);
- cnt--;
- }
- else
- {
- op.Idx = 1;
- op = op.Next;
- }
- }
-
- if (cnt < 3) cnt = 0;
- Path result = new Path(cnt);
- for (int i = 0; i < cnt; ++i)
- {
- result.Add(op.Pt);
- op = op.Next;
- }
- outPts = null;
- return result;
- }
- //------------------------------------------------------------------------------
-
- public static Paths CleanPolygons(Paths polys,
- double distance = 1.415)
- {
- Paths result = new Paths(polys.Count);
- for (int i = 0; i < polys.Count; i++)
- result.Add(CleanPolygon(polys[i], distance));
- return result;
- }
- //------------------------------------------------------------------------------
-
- internal static Paths Minkowski(Path pattern, Path path, bool IsSum, bool IsClosed)
- {
- int delta = (IsClosed ? 1 : 0);
- int polyCnt = pattern.Count;
- int pathCnt = path.Count;
- Paths result = new Paths(pathCnt);
- if (IsSum)
- for (int i = 0; i < pathCnt; i++)
- {
- Path p = new Path(polyCnt);
- foreach (IntPoint ip in pattern)
- p.Add(new IntPoint(path[i].X + ip.X, path[i].Y + ip.Y));
- result.Add(p);
- }
- else
- for (int i = 0; i < pathCnt; i++)
- {
- Path p = new Path(polyCnt);
- foreach (IntPoint ip in pattern)
- p.Add(new IntPoint(path[i].X - ip.X, path[i].Y - ip.Y));
- result.Add(p);
- }
-
- Paths quads = new Paths((pathCnt + delta) * (polyCnt + 1));
- for (int i = 0; i < pathCnt - 1 + delta; i++)
- for (int j = 0; j < polyCnt; j++)
- {
- Path quad = new Path(4);
- quad.Add(result[i % pathCnt][j % polyCnt]);
- quad.Add(result[(i + 1) % pathCnt][j % polyCnt]);
- quad.Add(result[(i + 1) % pathCnt][(j + 1) % polyCnt]);
- quad.Add(result[i % pathCnt][(j + 1) % polyCnt]);
- if (!Orientation(quad)) quad.Reverse();
- quads.Add(quad);
- }
- return quads;
- }
- //------------------------------------------------------------------------------
-
- public static Paths MinkowskiSum(Path pattern, Path path, bool pathIsClosed)
- {
- Paths paths = Minkowski(pattern, path, true, pathIsClosed);
- Clipper c = new Clipper();
- c.AddPaths(paths, PolyType.ptSubject, true);
- c.Execute(ClipType.ctUnion, paths, PolyFillType.pftNonZero, PolyFillType.pftNonZero);
- return paths;
- }
- //------------------------------------------------------------------------------
-
- private static Path TranslatePath(Path path, IntPoint delta)
- {
- Path outPath = new Path(path.Count);
- for (int i = 0; i < path.Count; i++)
- outPath.Add(new IntPoint(path[i].X + delta.X, path[i].Y + delta.Y));
- return outPath;
- }
- //------------------------------------------------------------------------------
-
- public static Paths MinkowskiSum(Path pattern, Paths paths, bool pathIsClosed)
- {
- Paths solution = new Paths();
- Clipper c = new Clipper();
- for (int i = 0; i < paths.Count; ++i)
- {
- Paths tmp = Minkowski(pattern, paths[i], true, pathIsClosed);
- c.AddPaths(tmp, PolyType.ptSubject, true);
- if (pathIsClosed)
- {
- Path path = TranslatePath(paths[i], pattern[0]);
- c.AddPath(path, PolyType.ptClip, true);
- }
- }
- c.Execute(ClipType.ctUnion, solution,
- PolyFillType.pftNonZero, PolyFillType.pftNonZero);
- return solution;
- }
- //------------------------------------------------------------------------------
-
- public static Paths MinkowskiDiff(Path poly1, Path poly2)
- {
- Paths paths = Minkowski(poly1, poly2, false, true);
- Clipper c = new Clipper();
- c.AddPaths(paths, PolyType.ptSubject, true);
- c.Execute(ClipType.ctUnion, paths, PolyFillType.pftNonZero, PolyFillType.pftNonZero);
- return paths;
- }
- //------------------------------------------------------------------------------
-
- internal enum NodeType { ntAny, ntOpen, ntClosed };
-
- public static Paths PolyTreeToPaths(PolyTree polytree)
- {
-
- Paths result = new Paths();
- result.Capacity = polytree.Total;
- AddPolyNodeToPaths(polytree, NodeType.ntAny, result);
- return result;
- }
- //------------------------------------------------------------------------------
-
- internal static void AddPolyNodeToPaths(PolyNode polynode, NodeType nt, Paths paths)
- {
- bool match = true;
- switch (nt)
- {
- case NodeType.ntOpen: return;
- case NodeType.ntClosed: match = !polynode.IsOpen; break;
- default: break;
- }
-
- if (polynode.m_polygon.Count > 0 && match)
- paths.Add(polynode.m_polygon);
- foreach (PolyNode pn in polynode.Childs)
- AddPolyNodeToPaths(pn, nt, paths);
- }
- //------------------------------------------------------------------------------
-
- public static Paths OpenPathsFromPolyTree(PolyTree polytree)
- {
- Paths result = new Paths();
- result.Capacity = polytree.ChildCount;
- for (int i = 0; i < polytree.ChildCount; i++)
- if (polytree.Childs[i].IsOpen)
- result.Add(polytree.Childs[i].m_polygon);
- return result;
- }
- //------------------------------------------------------------------------------
-
- public static Paths ClosedPathsFromPolyTree(PolyTree polytree)
- {
- Paths result = new Paths();
- result.Capacity = polytree.Total;
- AddPolyNodeToPaths(polytree, NodeType.ntClosed, result);
- return result;
- }
- //------------------------------------------------------------------------------
-
- } //end Clipper
-
- internal class ClipperOffset
- {
- private Paths m_destPolys;
- private Path m_srcPoly;
- private Path m_destPoly;
- private List m_normals = new List();
- private double m_delta, m_sinA, m_sin, m_cos;
- private double m_miterLim, m_StepsPerRad;
-
- private IntPoint m_lowest;
- private PolyNode m_polyNodes = new PolyNode();
-
- public double ArcTolerance { get; set; }
- public double MiterLimit { get; set; }
-
- private const double two_pi = Math.PI * 2;
- private const double def_arc_tolerance = 0.25;
-
- public ClipperOffset(
- double miterLimit = 2.0, double arcTolerance = def_arc_tolerance)
- {
- MiterLimit = miterLimit;
- ArcTolerance = arcTolerance;
- m_lowest.X = -1;
- }
- //------------------------------------------------------------------------------
-
- public void Clear()
- {
- m_polyNodes.Childs.Clear();
- m_lowest.X = -1;
- }
- //------------------------------------------------------------------------------
-
- internal static cInt Round(double value)
- {
- return value < 0 ? (cInt)(value - 0.5) : (cInt)(value + 0.5);
- }
- //------------------------------------------------------------------------------
-
- public void AddPath(Path path, JoinType joinType, EndType endType)
- {
- int highI = path.Count - 1;
- if (highI < 0) return;
- PolyNode newNode = new PolyNode();
- newNode.m_jointype = joinType;
- newNode.m_endtype = endType;
-
- //strip duplicate points from path and also get index to the lowest point ...
- if (endType == EndType.etClosedLine || endType == EndType.etClosedPolygon)
- while (highI > 0 && path[0] == path[highI]) highI--;
- newNode.m_polygon.Capacity = highI + 1;
- newNode.m_polygon.Add(path[0]);
- int j = 0, k = 0;
- for (int i = 1; i <= highI; i++)
- if (newNode.m_polygon[j] != path[i])
- {
- j++;
- newNode.m_polygon.Add(path[i]);
- if (path[i].Y > newNode.m_polygon[k].Y ||
- (path[i].Y == newNode.m_polygon[k].Y &&
- path[i].X < newNode.m_polygon[k].X)) k = j;
- }
- if (endType == EndType.etClosedPolygon && j < 2) return;
-
- m_polyNodes.AddChild(newNode);
-
- //if this path's lowest pt is lower than all the others then update m_lowest
- if (endType != EndType.etClosedPolygon) return;
- if (m_lowest.X < 0)
- m_lowest = new IntPoint(m_polyNodes.ChildCount - 1, k);
- else
- {
- IntPoint ip = m_polyNodes.Childs[(int)m_lowest.X].m_polygon[(int)m_lowest.Y];
- if (newNode.m_polygon[k].Y > ip.Y ||
- (newNode.m_polygon[k].Y == ip.Y &&
- newNode.m_polygon[k].X < ip.X))
- m_lowest = new IntPoint(m_polyNodes.ChildCount - 1, k);
- }
- }
- //------------------------------------------------------------------------------
-
- public void AddPaths(Paths paths, JoinType joinType, EndType endType)
- {
- foreach (Path p in paths)
- AddPath(p, joinType, endType);
- }
- //------------------------------------------------------------------------------
-
- private void FixOrientations()
- {
- //fixup orientations of all closed paths if the orientation of the
- //closed path with the lowermost vertex is wrong ...
- if (m_lowest.X >= 0 &&
- !Clipper.Orientation(m_polyNodes.Childs[(int)m_lowest.X].m_polygon))
- {
- for (int i = 0; i < m_polyNodes.ChildCount; i++)
- {
- PolyNode node = m_polyNodes.Childs[i];
- if (node.m_endtype == EndType.etClosedPolygon ||
- (node.m_endtype == EndType.etClosedLine &&
- Clipper.Orientation(node.m_polygon)))
- node.m_polygon.Reverse();
- }
- }
- else
- {
- for (int i = 0; i < m_polyNodes.ChildCount; i++)
- {
- PolyNode node = m_polyNodes.Childs[i];
- if (node.m_endtype == EndType.etClosedLine &&
- !Clipper.Orientation(node.m_polygon))
- node.m_polygon.Reverse();
- }
- }
- }
- //------------------------------------------------------------------------------
-
- internal static DoublePoint GetUnitNormal(IntPoint pt1, IntPoint pt2)
- {
- double dx = (pt2.X - pt1.X);
- double dy = (pt2.Y - pt1.Y);
- if ((dx == 0) && (dy == 0)) return new DoublePoint();
-
- double f = 1 * 1.0 / Math.Sqrt(dx * dx + dy * dy);
- dx *= f;
- dy *= f;
-
- return new DoublePoint(dy, -dx);
- }
- //------------------------------------------------------------------------------
-
- private void DoOffset(double delta)
- {
- m_destPolys = new Paths();
- m_delta = delta;
-
- //if Zero offset, just copy any CLOSED polygons to m_p and return ...
- if (ClipperBase.near_zero(delta))
- {
- m_destPolys.Capacity = m_polyNodes.ChildCount;
- for (int i = 0; i < m_polyNodes.ChildCount; i++)
- {
- PolyNode node = m_polyNodes.Childs[i];
- if (node.m_endtype == EndType.etClosedPolygon)
- m_destPolys.Add(node.m_polygon);
- }
- return;
- }
-
- //see offset_triginometry3.svg in the documentation folder ...
- if (MiterLimit > 2) m_miterLim = 2 / (MiterLimit * MiterLimit);
- else m_miterLim = 0.5;
-
- double y;
- if (ArcTolerance <= 0.0)
- y = def_arc_tolerance;
- else if (ArcTolerance > Math.Abs(delta) * def_arc_tolerance)
- y = Math.Abs(delta) * def_arc_tolerance;
- else
- y = ArcTolerance;
- //see offset_triginometry2.svg in the documentation folder ...
- double steps = Math.PI / Math.Acos(1 - y / Math.Abs(delta));
- m_sin = Math.Sin(two_pi / steps);
- m_cos = Math.Cos(two_pi / steps);
- m_StepsPerRad = steps / two_pi;
- if (delta < 0.0) m_sin = -m_sin;
-
- m_destPolys.Capacity = m_polyNodes.ChildCount * 2;
- for (int i = 0; i < m_polyNodes.ChildCount; i++)
- {
- PolyNode node = m_polyNodes.Childs[i];
- m_srcPoly = node.m_polygon;
-
- int len = m_srcPoly.Count;
-
- if (len == 0 || (delta <= 0 && (len < 3 ||
- node.m_endtype != EndType.etClosedPolygon)))
- continue;
-
- m_destPoly = new Path();
-
- if (len == 1)
- {
- if (node.m_jointype == JoinType.jtRound)
- {
- double X = 1.0, Y = 0.0;
- for (int j = 1; j <= steps; j++)
- {
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[0].X + X * delta),
- Round(m_srcPoly[0].Y + Y * delta)));
- double X2 = X;
- X = X * m_cos - m_sin * Y;
- Y = X2 * m_sin + Y * m_cos;
- }
- }
- else
- {
- double X = -1.0, Y = -1.0;
- for (int j = 0; j < 4; ++j)
- {
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[0].X + X * delta),
- Round(m_srcPoly[0].Y + Y * delta)));
- if (X < 0) X = 1;
- else if (Y < 0) Y = 1;
- else X = -1;
- }
- }
- m_destPolys.Add(m_destPoly);
- continue;
- }
-
- //build m_normals ...
- m_normals.Clear();
- m_normals.Capacity = len;
- for (int j = 0; j < len - 1; j++)
- m_normals.Add(GetUnitNormal(m_srcPoly[j], m_srcPoly[j + 1]));
- if (node.m_endtype == EndType.etClosedLine ||
- node.m_endtype == EndType.etClosedPolygon)
- m_normals.Add(GetUnitNormal(m_srcPoly[len - 1], m_srcPoly[0]));
- else
- m_normals.Add(new DoublePoint(m_normals[len - 2]));
-
- if (node.m_endtype == EndType.etClosedPolygon)
- {
- int k = len - 1;
- for (int j = 0; j < len; j++)
- OffsetPoint(j, ref k, node.m_jointype);
- m_destPolys.Add(m_destPoly);
- }
- else if (node.m_endtype == EndType.etClosedLine)
- {
- int k = len - 1;
- for (int j = 0; j < len; j++)
- OffsetPoint(j, ref k, node.m_jointype);
- m_destPolys.Add(m_destPoly);
- m_destPoly = new Path();
- //re-build m_normals ...
- DoublePoint n = m_normals[len - 1];
- for (int j = len - 1; j > 0; j--)
- m_normals[j] = new DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
- m_normals[0] = new DoublePoint(-n.X, -n.Y);
- k = 0;
- for (int j = len - 1; j >= 0; j--)
- OffsetPoint(j, ref k, node.m_jointype);
- m_destPolys.Add(m_destPoly);
- }
- else
- {
- int k = 0;
- for (int j = 1; j < len - 1; ++j)
- OffsetPoint(j, ref k, node.m_jointype);
-
- IntPoint pt1;
- if (node.m_endtype == EndType.etOpenButt)
- {
- int j = len - 1;
- pt1 = new IntPoint((cInt)Round(m_srcPoly[j].X + m_normals[j].X *
- delta), (cInt)Round(m_srcPoly[j].Y + m_normals[j].Y * delta));
- m_destPoly.Add(pt1);
- pt1 = new IntPoint((cInt)Round(m_srcPoly[j].X - m_normals[j].X *
- delta), (cInt)Round(m_srcPoly[j].Y - m_normals[j].Y * delta));
- m_destPoly.Add(pt1);
- }
- else
- {
- int j = len - 1;
- k = len - 2;
- m_sinA = 0;
- m_normals[j] = new DoublePoint(-m_normals[j].X, -m_normals[j].Y);
- if (node.m_endtype == EndType.etOpenSquare)
- DoSquare(j, k);
- else
- DoRound(j, k);
- }
-
- //re-build m_normals ...
- for (int j = len - 1; j > 0; j--)
- m_normals[j] = new DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
-
- m_normals[0] = new DoublePoint(-m_normals[1].X, -m_normals[1].Y);
-
- k = len - 1;
- for (int j = k - 1; j > 0; --j)
- OffsetPoint(j, ref k, node.m_jointype);
-
- if (node.m_endtype == EndType.etOpenButt)
- {
- pt1 = new IntPoint((cInt)Round(m_srcPoly[0].X - m_normals[0].X * delta),
- (cInt)Round(m_srcPoly[0].Y - m_normals[0].Y * delta));
- m_destPoly.Add(pt1);
- pt1 = new IntPoint((cInt)Round(m_srcPoly[0].X + m_normals[0].X * delta),
- (cInt)Round(m_srcPoly[0].Y + m_normals[0].Y * delta));
- m_destPoly.Add(pt1);
- }
- else
- {
- k = 1;
- m_sinA = 0;
- if (node.m_endtype == EndType.etOpenSquare)
- DoSquare(0, 1);
- else
- DoRound(0, 1);
- }
- m_destPolys.Add(m_destPoly);
- }
- }
- }
- //------------------------------------------------------------------------------
-
- public void Execute(ref Paths solution, double delta)
- {
- solution.Clear();
- FixOrientations();
- DoOffset(delta);
- //now clean up 'corners' ...
- Clipper clpr = new Clipper();
- clpr.AddPaths(m_destPolys, PolyType.ptSubject, true);
- if (delta > 0)
- {
- clpr.Execute(ClipType.ctUnion, solution,
- PolyFillType.pftPositive, PolyFillType.pftPositive);
- }
- else
- {
- IntRect r = Clipper.GetBounds(m_destPolys);
- Path outer = new Path(4);
-
- outer.Add(new IntPoint(r.left - 10, r.bottom + 10));
- outer.Add(new IntPoint(r.right + 10, r.bottom + 10));
- outer.Add(new IntPoint(r.right + 10, r.top - 10));
- outer.Add(new IntPoint(r.left - 10, r.top - 10));
-
- clpr.AddPath(outer, PolyType.ptSubject, true);
- clpr.ReverseSolution = true;
- clpr.Execute(ClipType.ctUnion, solution, PolyFillType.pftNegative, PolyFillType.pftNegative);
- if (solution.Count > 0) solution.RemoveAt(0);
- }
- }
- //------------------------------------------------------------------------------
-
- public void Execute(ref PolyTree solution, double delta)
- {
- solution.Clear();
- FixOrientations();
- DoOffset(delta);
-
- //now clean up 'corners' ...
- Clipper clpr = new Clipper();
- clpr.AddPaths(m_destPolys, PolyType.ptSubject, true);
- if (delta > 0)
- {
- clpr.Execute(ClipType.ctUnion, solution,
- PolyFillType.pftPositive, PolyFillType.pftPositive);
- }
- else
- {
- IntRect r = Clipper.GetBounds(m_destPolys);
- Path outer = new Path(4);
-
- outer.Add(new IntPoint(r.left - 10, r.bottom + 10));
- outer.Add(new IntPoint(r.right + 10, r.bottom + 10));
- outer.Add(new IntPoint(r.right + 10, r.top - 10));
- outer.Add(new IntPoint(r.left - 10, r.top - 10));
-
- clpr.AddPath(outer, PolyType.ptSubject, true);
- clpr.ReverseSolution = true;
- clpr.Execute(ClipType.ctUnion, solution, PolyFillType.pftNegative, PolyFillType.pftNegative);
- //remove the outer PolyNode rectangle ...
- if (solution.ChildCount == 1 && solution.Childs[0].ChildCount > 0)
- {
- PolyNode outerNode = solution.Childs[0];
- solution.Childs.Capacity = outerNode.ChildCount;
- solution.Childs[0] = outerNode.Childs[0];
- solution.Childs[0].m_Parent = solution;
- for (int i = 1; i < outerNode.ChildCount; i++)
- solution.AddChild(outerNode.Childs[i]);
- }
- else
- solution.Clear();
- }
- }
- //------------------------------------------------------------------------------
-
- void OffsetPoint(int j, ref int k, JoinType jointype)
- {
- //cross product ...
- m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y);
-
- if (Math.Abs(m_sinA * m_delta) < 1.0)
- {
- //dot product ...
- double cosA = (m_normals[k].X * m_normals[j].X + m_normals[j].Y * m_normals[k].Y);
- if (cosA > 0) // angle ==> 0 degrees
- {
- m_destPoly.Add(new IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
- Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
- return;
- }
- //else angle ==> 180 degrees
- }
- else if (m_sinA > 1.0) m_sinA = 1.0;
- else if (m_sinA < -1.0) m_sinA = -1.0;
-
- if (m_sinA * m_delta < 0)
- {
- m_destPoly.Add(new IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
- Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
- m_destPoly.Add(m_srcPoly[j]);
- m_destPoly.Add(new IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
- Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
- }
- else
- switch (jointype)
- {
- case JoinType.jtMiter:
- {
- double r = 1 + (m_normals[j].X * m_normals[k].X +
- m_normals[j].Y * m_normals[k].Y);
- if (r >= m_miterLim) DoMiter(j, k, r); else DoSquare(j, k);
- break;
- }
- case JoinType.jtSquare: DoSquare(j, k); break;
- case JoinType.jtRound: DoRound(j, k); break;
- }
- k = j;
- }
- //------------------------------------------------------------------------------
-
- internal void DoSquare(int j, int k)
- {
- double dx = Math.Tan(Math.Atan2(m_sinA,
- m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y) / 4);
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[j].X + m_delta * (m_normals[k].X - m_normals[k].Y * dx)),
- Round(m_srcPoly[j].Y + m_delta * (m_normals[k].Y + m_normals[k].X * dx))));
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[j].X + m_delta * (m_normals[j].X + m_normals[j].Y * dx)),
- Round(m_srcPoly[j].Y + m_delta * (m_normals[j].Y - m_normals[j].X * dx))));
- }
- //------------------------------------------------------------------------------
-
- internal void DoMiter(int j, int k, double r)
- {
- double q = m_delta / r;
- m_destPoly.Add(new IntPoint(Round(m_srcPoly[j].X + (m_normals[k].X + m_normals[j].X) * q),
- Round(m_srcPoly[j].Y + (m_normals[k].Y + m_normals[j].Y) * q)));
- }
- //------------------------------------------------------------------------------
-
- internal void DoRound(int j, int k)
- {
- double a = Math.Atan2(m_sinA,
- m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y);
- int steps = Math.Max((int)Round(m_StepsPerRad * Math.Abs(a)), 1);
-
- double X = m_normals[k].X, Y = m_normals[k].Y, X2;
- for (int i = 0; i < steps; ++i)
- {
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[j].X + X * m_delta),
- Round(m_srcPoly[j].Y + Y * m_delta)));
- X2 = X;
- X = X * m_cos - m_sin * Y;
- Y = X2 * m_sin + Y * m_cos;
- }
- m_destPoly.Add(new IntPoint(
- Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
- Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
- }
- //------------------------------------------------------------------------------
- }
-
- class ClipperException : Exception
- {
- public ClipperException(string description) : base(description) { }
- }
- //------------------------------------------------------------------------------
-
-} //end ClipperLib namespace
diff --git a/src/ImageSharp/Drawing/Shapes/ComplexPolygon.cs b/src/ImageSharp/Drawing/Shapes/ComplexPolygon.cs
index d42cae872..d9b83d341 100644
--- a/src/ImageSharp/Drawing/Shapes/ComplexPolygon.cs
+++ b/src/ImageSharp/Drawing/Shapes/ComplexPolygon.cs
@@ -11,6 +11,7 @@ namespace ImageSharp.Drawing.Shapes
using System.Numerics;
using Paths;
+ using PolygonClipper;
///
/// Represents a complex polygon made up of one or more outline
@@ -124,156 +125,78 @@ namespace ImageSharp.Drawing.Shapes
return this.GetEnumerator();
}
- private void AddPoints(ClipperLib.Clipper clipper, IShape shape, ClipperLib.PolyType polyType)
+ private void AddPoints(Clipper clipper, IShape shape, PolyType polyType)
{
- foreach (var path in shape)
+ // if the path is already the shape use it directly and skip the path loop.
+ if (shape is IPath)
{
- var points = path.AsSimpleLinearPath();
- var clipperPoints = new List();
- foreach (var point in points)
- {
- var p = point * ClipperScaleFactor;
-
- clipperPoints.Add(new ClipperLib.IntPoint((long)p.X, (long)p.Y));
- }
-
clipper.AddPath(
- clipperPoints,
- polyType,
- path.IsClosed);
+ (IPath)shape,
+ polyType);
}
- }
-
- private void AddPoints(ClipperLib.Clipper clipper, IShape[] shapes, bool[] shouldInclude, ClipperLib.PolyType polyType)
- {
- for (var i = 0; i < shapes.Length; i++)
+ else
{
- if (shouldInclude[i])
+ foreach (var path in shape)
{
- this.AddPoints(clipper, shapes[i], polyType);
+ clipper.AddPath(
+ path,
+ polyType);
}
}
}
- private void ExtractOutlines(ClipperLib.PolyNode tree, List shapes)
+ private void AddPoints(Clipper clipper, IEnumerable shapes, PolyType polyType)
{
- if (tree.Contour.Any())
+ foreach (var shape in shapes)
{
- // convert the Clipper Contour from scaled ints back down to the origional size (this is going to be lossy but not significantly)
- var pointCount = tree.Contour.Count;
- var vectors = new Vector2[pointCount];
- for (var i = 0; i < pointCount; i++)
- {
- var p = tree.Contour[i];
- vectors[i] = new Vector2(p.X, p.Y) / ClipperScaleFactor;
- }
-
- var polygon = new Polygon(new LinearLineSegment(vectors));
-
- shapes.Add(polygon);
- }
-
- foreach (var c in tree.Childs)
- {
- this.ExtractOutlines(c, shapes);
+ this.AddPoints(clipper, shape, polyType);
}
}
- ///
- /// Determines if the s bounding boxes overlap.
- ///
- /// The source.
- /// The target.
- /// true if the 2 shapes bounding boxes overlap.
- private bool OverlappingBoundingBoxes(IShape source, IShape target)
- {
- return source.Bounds.Intersects(target.Bounds);
- }
-
- private void FixAndSetShapes(IShape[] outlines, IShape[] holes)
+ private void ExtractOutlines(PolyNode tree, List shapes, List paths)
{
- // if any outline doesn't overlap another shape then we don't have to bother with sending them through clipper
- // as sending then though clipper will turn them into generic polygons and loose thier shape specific optimisations
- int outlineLength = outlines.Length;
- int holesLength = holes?.Length ?? 0;
- bool[] overlappingOutlines = new bool[outlineLength];
- bool[] overlappingHoles = new bool[holesLength];
- bool anyOutlinesOverlapping = false;
- bool anyHolesOverlapping = false;
-
- for (int i = 0; i < outlineLength; i++)
+ if (tree.Contour.Any())
{
- for (int j = i + 1; j < outlineLength; j++)
+ // if the source path is set then we clipper retained the full path intact thus we can freely
+ // use it and get any shape optimisations that are availible.
+ if (tree.SourcePath != null)
{
- // skip the bounds check if they are already tested
- if (overlappingOutlines[i] == false || overlappingOutlines[j] == false)
- {
- if (this.OverlappingBoundingBoxes(outlines[i], outlines[j]))
- {
- overlappingOutlines[i] = true;
- overlappingOutlines[j] = true;
- anyOutlinesOverlapping = true;
- }
- }
+ shapes.Add((IShape)tree.SourcePath);
+ paths.Add(tree.SourcePath);
}
-
- for (int k = 0; k < holesLength; k++)
+ else
{
- if (overlappingOutlines[i] == false || overlappingHoles[k] == false)
- {
- if (this.OverlappingBoundingBoxes(outlines[i], holes[k]))
- {
- overlappingOutlines[i] = true;
- overlappingHoles[k] = true;
- anyOutlinesOverlapping = true;
- anyHolesOverlapping = true;
- }
- }
+ // convert the Clipper Contour from scaled ints back down to the origional size (this is going to be lossy but not significantly)
+ var polygon = new Polygon(new Paths.LinearLineSegment(tree.Contour.ToArray()));
+
+ shapes.Add(polygon);
+ paths.Add(polygon);
}
}
- if (anyOutlinesOverlapping)
+ foreach (var c in tree.Children)
{
- var clipper = new ClipperLib.Clipper();
-
- // add the outlines and the holes to clipper, scaling up from the float source to the int based system clipper uses
- this.AddPoints(clipper, outlines, overlappingOutlines, ClipperLib.PolyType.ptSubject);
- if (anyHolesOverlapping)
- {
- this.AddPoints(clipper, holes, overlappingHoles, ClipperLib.PolyType.ptClip);
- }
-
- var tree = new ClipperLib.PolyTree();
- clipper.Execute(ClipperLib.ClipType.ctDifference, tree);
-
- List newShapes = new List();
+ this.ExtractOutlines(c, shapes, paths);
+ }
+ }
- // convert the 'tree' back to shapes
- this.ExtractOutlines(tree, newShapes);
+ private void FixAndSetShapes(IEnumerable outlines, IEnumerable holes)
+ {
+ var clipper = new Clipper();
- // add the origional outlines that where not overlapping
- for (int i = 0; i < outlineLength - 1; i++)
- {
- if (!overlappingOutlines[i])
- {
- newShapes.Add(outlines[i]);
- }
- }
+ // add the outlines and the holes to clipper, scaling up from the float source to the int based system clipper uses
+ this.AddPoints(clipper, outlines, PolyType.Subject);
+ this.AddPoints(clipper, holes, PolyType.Clip);
- this.shapes = newShapes.ToArray();
- }
- else
- {
- this.shapes = outlines;
- }
+ var tree = clipper.Execute();
- var paths = new List();
- foreach (var o in this.shapes)
- {
- paths.AddRange(o);
- }
+ List shapes = new List();
+ List paths = new List();
- this.paths = paths;
+ // convert the 'tree' back to paths
+ this.ExtractOutlines(tree, shapes, paths);
+ this.shapes = shapes.ToArray();
+ this.paths = paths.ToArray();
}
}
}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/Clipper.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Clipper.cs
new file mode 100644
index 000000000..c13acec8f
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Clipper.cs
@@ -0,0 +1,3860 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Library to clip polygons.
+ ///
+ internal class Clipper
+ {
+ private const double HorizontalDeltaLimit = -3.4E+38;
+ private const int Skip = -2;
+ private const int Unassigned = -1; // InitOptions that can be passed to the constructor ...
+
+ private Maxima maxima;
+ private TEdge sortedEdges;
+ private List intersectList;
+ private IComparer intersectNodeComparer = new IntersectNodeSort();
+ private bool executeLocked;
+
+ private List joins;
+ private List ghostJoins;
+ private bool usingPolyTree;
+ private LocalMinima minimaList = null;
+ private LocalMinima currentLM = null;
+ private List> edges = new List>();
+ private Scanbeam scanbeam;
+ private List polyOuts;
+ private TEdge activeEdges;
+
+ ///
+ /// Initializes a new instance of the class.
+ ///
+ public Clipper()
+ {
+ this.scanbeam = null;
+ this.maxima = null;
+ this.activeEdges = null;
+ this.sortedEdges = null;
+ this.intersectList = new List();
+ this.executeLocked = false;
+ this.usingPolyTree = false;
+ this.polyOuts = new List();
+ this.joins = new List();
+ this.ghostJoins = new List();
+ }
+
+ ///
+ /// Node types
+ ///
+ private enum NodeType
+ {
+ ///
+ /// Any
+ ///
+ Any,
+
+ ///
+ /// The open
+ ///
+ Open,
+
+ ///
+ /// The closed
+ ///
+ Closed
+ }
+
+ ///
+ /// Adds the path.
+ ///
+ /// The path.
+ /// Type of the poly.
+ /// True if the path was added.
+ /// AddPath: Open paths have been disabled.
+ public bool AddPath(IPath path, PolyType polyType)
+ {
+ var pg = path.AsSimpleLinearPath();
+
+ int highI = pg.Length - 1;
+ while (highI > 0 && (pg[highI] == pg[0]))
+ {
+ --highI;
+ }
+
+ while (highI > 0 && (pg[highI] == pg[highI - 1]))
+ {
+ --highI;
+ }
+
+ if (highI < 2)
+ {
+ return false;
+ }
+
+ // create a new edge array ...
+ List edges = new List(highI + 1);
+ for (int i = 0; i <= highI; i++)
+ {
+ edges.Add(new TEdge() { SourcePath = path });
+ }
+
+ bool isFlat = true;
+
+ // 1. Basic (first) edge initialization ...
+ edges[1].Curr = pg[1];
+
+ InitEdge(edges[0], edges[1], edges[highI], pg[0]);
+ InitEdge(edges[highI], edges[0], edges[highI - 1], pg[highI]);
+ for (int i = highI - 1; i >= 1; --i)
+ {
+ InitEdge(edges[i], edges[i + 1], edges[i - 1], pg[i]);
+ }
+
+ TEdge eStart = edges[0];
+
+ // 2. Remove duplicate vertices, and (when closed) collinear edges ...
+ TEdge edge = eStart, eLoopStop = eStart;
+ while (true)
+ {
+ // nb: allows matching start and end points when not Closed ...
+ if (edge.Curr == edge.Next.Curr)
+ {
+ if (edge == edge.Next)
+ {
+ break;
+ }
+
+ if (edge == eStart)
+ {
+ eStart = edge.Next;
+ }
+
+ edge = RemoveEdge(edge);
+ eLoopStop = edge;
+ continue;
+ }
+
+ if (edge.Prev == edge.Next)
+ {
+ break; // only two vertices
+ }
+ else if (SlopesEqual(edge.Prev.Curr, edge.Curr, edge.Next.Curr))
+ {
+ // Collinear edges are allowed for open paths but in closed paths
+ // the default is to merge adjacent collinear edges into a single edge.
+ // However, if the PreserveCollinear property is enabled, only overlapping
+ // collinear edges (ie spikes) will be removed from closed paths.
+ if (edge == eStart)
+ {
+ eStart = edge.Next;
+ }
+
+ edge = RemoveEdge(edge);
+ edge = edge.Prev;
+ eLoopStop = edge;
+ continue;
+ }
+
+ edge = edge.Next;
+ if (edge == eLoopStop)
+ {
+ break;
+ }
+ }
+
+ if (edge.Prev == edge.Next)
+ {
+ return false;
+ }
+
+ // 3. Do second stage of edge initialization ...
+ edge = eStart;
+ do
+ {
+ this.InitEdge2(edge, polyType);
+ edge = edge.Next;
+ if (isFlat && edge.Curr.Y != eStart.Curr.Y)
+ {
+ isFlat = false;
+ }
+ }
+ while (edge != eStart);
+
+ // 4. Finally, add edge bounds to LocalMinima list ...
+ // Totally flat paths must be handled differently when adding them
+ // to LocalMinima list to avoid endless loops etc ...
+ if (isFlat)
+ {
+ return false;
+ }
+
+ this.edges.Add(edges);
+ bool leftBoundIsForward;
+ TEdge emIn = null;
+
+ // workaround to avoid an endless loop in the while loop below when
+ // open paths have matching start and end points ...
+ if (edge.Prev.Bot == edge.Prev.Top)
+ {
+ edge = edge.Next;
+ }
+
+ while (true)
+ {
+ edge = FindNextLocMin(edge);
+ if (edge == emIn)
+ {
+ break;
+ }
+ else if (emIn == null)
+ {
+ emIn = edge;
+ }
+
+ // E and E.Prev now share a local minima (left aligned if horizontal).
+ // Compare their slopes to find which starts which bound ...
+ LocalMinima locMin = new LocalMinima();
+ locMin.Next = null;
+ locMin.Y = edge.Bot.Y;
+ if (edge.Dx < edge.Prev.Dx)
+ {
+ locMin.LeftBound = edge.Prev;
+ locMin.RightBound = edge;
+ leftBoundIsForward = false; // Q.nextInLML = Q.prev
+ }
+ else
+ {
+ locMin.LeftBound = edge;
+ locMin.RightBound = edge.Prev;
+ leftBoundIsForward = true; // Q.nextInLML = Q.next
+ }
+
+ locMin.LeftBound.Side = EdgeSide.Left;
+ locMin.RightBound.Side = EdgeSide.Right;
+
+ if (locMin.LeftBound.Next == locMin.RightBound)
+ {
+ locMin.LeftBound.WindDelta = -1;
+ }
+ else
+ {
+ locMin.LeftBound.WindDelta = 1;
+ }
+
+ locMin.RightBound.WindDelta = -locMin.LeftBound.WindDelta;
+
+ edge = this.ProcessBound(locMin.LeftBound, leftBoundIsForward);
+ if (edge.OutIdx == Skip)
+ {
+ edge = this.ProcessBound(edge, leftBoundIsForward);
+ }
+
+ TEdge edge2 = this.ProcessBound(locMin.RightBound, !leftBoundIsForward);
+ if (edge2.OutIdx == Skip)
+ {
+ edge2 = this.ProcessBound(edge2, !leftBoundIsForward);
+ }
+
+ if (locMin.LeftBound.OutIdx == Skip)
+ {
+ locMin.LeftBound = null;
+ }
+ else if (locMin.RightBound.OutIdx == Skip)
+ {
+ locMin.RightBound = null;
+ }
+
+ this.InsertLocalMinima(locMin);
+ if (!leftBoundIsForward)
+ {
+ edge = edge2;
+ }
+ }
+
+ return true;
+ }
+
+ ///
+ /// Executes the specified clip type.
+ ///
+ ///
+ /// Returns the polytree containing the converted polygons.
+ ///
+ public PolyTree Execute()
+ {
+ PolyTree polytree = new PolyTree();
+
+ if (this.executeLocked)
+ {
+ return null;
+ }
+
+ this.executeLocked = true;
+ this.usingPolyTree = true;
+ bool succeeded;
+ try
+ {
+ succeeded = this.ExecuteInternal();
+
+ // build the return polygons ...
+ if (succeeded)
+ {
+ this.BuildResult2(polytree);
+ }
+ }
+ finally
+ {
+ this.DisposeAllPolyPts();
+ this.executeLocked = false;
+ }
+
+ if (succeeded)
+ {
+ return polytree;
+ }
+
+ return null;
+ }
+
+ private static float Round(double value)
+ {
+ return value < 0 ? (float)(value - 0.5) : (float)(value + 0.5);
+ }
+
+ private static float TopX(TEdge edge, float currentY)
+ {
+ if (currentY == edge.Top.Y)
+ {
+ return edge.Top.X;
+ }
+
+ return edge.Bot.X + Round(edge.Dx * (currentY - edge.Bot.Y));
+ }
+
+ private static void AddPolyNodeToPaths(PolyNode polynode, NodeType nt, List> paths)
+ {
+ bool match = true;
+ switch (nt)
+ {
+ case NodeType.Open: return;
+ case NodeType.Closed: match = !polynode.IsOpen; break;
+ default: break;
+ }
+
+ if (polynode.Polygon.Count > 0 && match)
+ {
+ paths.Add(polynode.Polygon);
+ }
+
+ foreach (PolyNode pn in polynode.Children)
+ {
+ AddPolyNodeToPaths(pn, nt, paths);
+ }
+ }
+
+ private static double DistanceFromLineSqrd(Vector2 pt, Vector2 ln1, Vector2 ln2)
+ {
+ // The equation of a line in general form (Ax + By + C = 0)
+ // given 2 points (x¹,y¹) & (x²,y²) is ...
+ // (y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0
+ // A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹
+ // perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²)
+ // see http://en.wikipedia.org/wiki/Perpendicular_distance
+ double a = ln1.Y - ln2.Y;
+ double b = ln2.X - ln1.X;
+ double c = (a * ln1.X) + (b * ln1.Y);
+ c = (a * pt.X) + (b * pt.Y) - c;
+ return (c * c) / ((a * a) + (b * b));
+ }
+
+ private static bool SlopesNearCollinear(Vector2 pt1, Vector2 pt2, Vector2 pt3, double distSqrd)
+ {
+ // this function is more accurate when the point that's GEOMETRICALLY
+ // between the other 2 points is the one that's tested for distance.
+ // nb: with 'spikes', either pt1 or pt3 is geometrically between the other pts
+ if (Math.Abs(pt1.X - pt2.X) > Math.Abs(pt1.Y - pt2.Y))
+ {
+ if ((pt1.X > pt2.X) == (pt1.X < pt3.X))
+ {
+ return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+ }
+ else if ((pt2.X > pt1.X) == (pt2.X < pt3.X))
+ {
+ return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+ }
+ else
+ {
+ return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+ }
+ }
+ else
+ {
+ if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y))
+ {
+ return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+ }
+ else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y))
+ {
+ return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+ }
+ else
+ {
+ return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+ }
+ }
+ }
+
+ private static bool PointsAreClose(Vector2 pt1, Vector2 pt2, double distSqrd)
+ {
+ return Vector2.DistanceSquared(pt1, pt2) <= distSqrd;
+ }
+
+ private static OutPt ExcludeOp(OutPt op)
+ {
+ OutPt result = op.Prev;
+ result.Next = op.Next;
+ op.Next.Prev = result;
+ result.Idx = 0;
+ return result;
+ }
+
+ private static void FixHoleLinkage(OutRec outRec)
+ {
+ // skip if an outermost polygon or
+ // already already points to the correct FirstLeft ...
+ if (outRec.FirstLeft == null ||
+ (outRec.IsHole != outRec.FirstLeft.IsHole &&
+ outRec.FirstLeft.Pts != null))
+ {
+ return;
+ }
+
+ OutRec orfl = outRec.FirstLeft;
+ while (orfl != null && ((orfl.IsHole == outRec.IsHole) || orfl.Pts == null))
+ {
+ orfl = orfl.FirstLeft;
+ }
+
+ outRec.FirstLeft = orfl;
+ }
+
+ // See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
+ // http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
+ private static int PointInPolygon(Vector2 pt, OutPt op)
+ {
+ // returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+ int result = 0;
+ OutPt startOp = op;
+ float ptx = pt.X, pty = pt.Y;
+ float poly0x = op.Pt.X, poly0y = op.Pt.Y;
+ do
+ {
+ op = op.Next;
+ float poly1x = op.Pt.X, poly1y = op.Pt.Y;
+
+ if (poly1y == pty)
+ {
+ if ((poly1x == ptx) || (poly0y == pty &&
+ ((poly1x > ptx) == (poly0x < ptx))))
+ {
+ return -1;
+ }
+ }
+
+ if ((poly0y < pty) != (poly1y < pty))
+ {
+ if (poly0x >= ptx)
+ {
+ if (poly1x > ptx)
+ {
+ result = 1 - result;
+ }
+ else
+ {
+ double d = (double)((poly0x - ptx) * (poly1y - pty)) -
+ (double)((poly1x - ptx) * (poly0y - pty));
+ if (d == 0)
+ {
+ return -1;
+ }
+
+ if ((d > 0) == (poly1y > poly0y))
+ {
+ result = 1 - result;
+ }
+ }
+ }
+ else
+ {
+ if (poly1x > ptx)
+ {
+ double d = (double)((poly0x - ptx) * (poly1y - pty)) - (double)((poly1x - ptx) * (poly0y - pty));
+ if (d == 0)
+ {
+ return -1;
+ }
+
+ if ((d > 0) == (poly1y > poly0y))
+ {
+ result = 1 - result;
+ }
+ }
+ }
+ }
+
+ poly0x = poly1x;
+ poly0y = poly1y;
+ }
+ while (startOp != op);
+
+ return result;
+ }
+
+ private static bool Poly2ContainsPoly1(OutPt outPt1, OutPt outPt2)
+ {
+ OutPt op = outPt1;
+ do
+ {
+ // nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
+ int res = PointInPolygon(op.Pt, outPt2);
+ if (res >= 0)
+ {
+ return res > 0;
+ }
+
+ op = op.Next;
+ }
+ while (op != outPt1);
+ return true;
+ }
+
+ private static void SwapSides(TEdge edge1, TEdge edge2)
+ {
+ EdgeSide side = edge1.Side;
+ edge1.Side = edge2.Side;
+ edge2.Side = side;
+ }
+
+ private static void SwapPolyIndexes(TEdge edge1, TEdge edge2)
+ {
+ int outIdx = edge1.OutIdx;
+ edge1.OutIdx = edge2.OutIdx;
+ edge2.OutIdx = outIdx;
+ }
+
+ private static double GetDx(Vector2 pt1, Vector2 pt2)
+ {
+ if (pt1.Y == pt2.Y)
+ {
+ return HorizontalDeltaLimit;
+ }
+ else
+ {
+ return (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y);
+ }
+ }
+
+ private static bool HorzSegmentsOverlap(float seg1a, float seg1b, float seg2a, float seg2b)
+ {
+ if (seg1a > seg1b)
+ {
+ Swap(ref seg1a, ref seg1b);
+ }
+
+ if (seg2a > seg2b)
+ {
+ Swap(ref seg2a, ref seg2b);
+ }
+
+ return (seg1a < seg2b) && (seg2a < seg1b);
+ }
+
+ private static TEdge FindNextLocMin(TEdge edge)
+ {
+ TEdge edge2;
+ while (true)
+ {
+ while (edge.Bot != edge.Prev.Bot || edge.Curr == edge.Top)
+ {
+ edge = edge.Next;
+ }
+
+ if (edge.Dx != HorizontalDeltaLimit && edge.Prev.Dx != HorizontalDeltaLimit)
+ {
+ break;
+ }
+
+ while (edge.Prev.Dx == HorizontalDeltaLimit)
+ {
+ edge = edge.Prev;
+ }
+
+ edge2 = edge;
+ while (edge.Dx == HorizontalDeltaLimit)
+ {
+ edge = edge.Next;
+ }
+
+ if (edge.Top.Y == edge.Prev.Bot.Y)
+ {
+ continue; // ie just an intermediate horz.
+ }
+
+ if (edge2.Prev.Bot.X < edge.Bot.X)
+ {
+ edge = edge2;
+ }
+
+ break;
+ }
+
+ return edge;
+ }
+
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
+ private static void Swap(ref float val1, ref float val2)
+ {
+ float tmp = val1;
+ val1 = val2;
+ val2 = tmp;
+ }
+
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
+ private static bool IsHorizontal(TEdge e)
+ {
+ return e.Delta.Y == 0;
+ }
+
+ private static bool SlopesEqual(TEdge e1, TEdge e2)
+ {
+ return e1.Delta.Y * e2.Delta.X == e1.Delta.X * e2.Delta.Y;
+ }
+
+ private static bool SlopesEqual(Vector2 pt1, Vector2 pt2, Vector2 pt3)
+ {
+ var dif12 = pt1 - pt2;
+ var dif23 = pt2 - pt3;
+ return (dif12.Y * dif23.X) - (dif12.X * dif23.Y) == 0;
+ }
+
+ private static bool SlopesEqual(Vector2 pt1, Vector2 pt2, Vector2 pt3, Vector2 pt4)
+ {
+ var dif12 = pt1 - pt2;
+ var dif34 = pt3 - pt4;
+
+ return (dif12.Y * dif34.X) - (dif12.X * dif34.Y) == 0;
+ }
+
+ private static void InitEdge(TEdge e, TEdge eNext, TEdge ePrev, Vector2 pt)
+ {
+ e.Next = eNext;
+ e.Prev = ePrev;
+ e.Curr = pt;
+ e.OutIdx = Unassigned;
+ }
+
+ private static OutRec ParseFirstLeft(OutRec firstLeft)
+ {
+ while (firstLeft != null && firstLeft.Pts == null)
+ {
+ firstLeft = firstLeft.FirstLeft;
+ }
+
+ return firstLeft;
+ }
+
+ private static bool Pt2IsBetweenPt1AndPt3(Vector2 pt1, Vector2 pt2, Vector2 pt3)
+ {
+ if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2))
+ {
+ return false;
+ }
+ else if (pt1.X != pt3.X)
+ {
+ return (pt2.X > pt1.X) == (pt2.X < pt3.X);
+ }
+ else
+ {
+ return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y);
+ }
+ }
+
+ private static TEdge RemoveEdge(TEdge e)
+ {
+ // removes e from double_linked_list (but without removing from memory)
+ e.Prev.Next = e.Next;
+ e.Next.Prev = e.Prev;
+ TEdge result = e.Next;
+ e.Prev = null; // flag as removed (see ClipperBase.Clear)
+ return result;
+ }
+
+ private static void ReverseHorizontal(TEdge e)
+ {
+ // swap horizontal edges' top and bottom x's so they follow the natural
+ // progression of the bounds - ie so their xbots will align with the
+ // adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
+ Swap(ref e.Top.X, ref e.Bot.X);
+ }
+
+ private void InsertMaxima(float x)
+ {
+ // double-linked list: sorted ascending, ignoring dups.
+ Maxima newMax = new Maxima();
+ newMax.X = x;
+ if (this.maxima == null)
+ {
+ this.maxima = newMax;
+ this.maxima.Next = null;
+ this.maxima.Prev = null;
+ }
+ else if (x < this.maxima.X)
+ {
+ newMax.Next = this.maxima;
+ newMax.Prev = null;
+ this.maxima = newMax;
+ }
+ else
+ {
+ Maxima m = this.maxima;
+ while (m.Next != null && (x >= m.Next.X))
+ {
+ m = m.Next;
+ }
+
+ if (x == m.X)
+ {
+ return; // ie ignores duplicates (& CG to clean up newMax)
+ }
+
+ // insert newMax between m and m.Next ...
+ newMax.Next = m.Next;
+ newMax.Prev = m;
+ if (m.Next != null)
+ {
+ m.Next.Prev = newMax;
+ }
+
+ m.Next = newMax;
+ }
+ }
+
+ private bool ExecuteInternal()
+ {
+ try
+ {
+ this.Reset();
+ this.sortedEdges = null;
+ this.maxima = null;
+
+ float botY, topY;
+ if (!this.PopScanbeam(out botY))
+ {
+ return false;
+ }
+
+ this.InsertLocalMinimaIntoAEL(botY);
+ while (this.PopScanbeam(out topY) || this.LocalMinimaPending())
+ {
+ this.ProcessHorizontals();
+ this.ghostJoins.Clear();
+ if (!this.ProcessIntersections(topY))
+ {
+ return false;
+ }
+
+ this.ProcessEdgesAtTopOfScanbeam(topY);
+ botY = topY;
+ this.InsertLocalMinimaIntoAEL(botY);
+ }
+
+ // fix orientations ...
+ foreach (OutRec outRec in this.polyOuts)
+ {
+ if (outRec.Pts == null || outRec.IsOpen)
+ {
+ continue;
+ }
+ }
+
+ this.JoinCommonEdges();
+
+ foreach (OutRec outRec in this.polyOuts)
+ {
+ if (outRec.Pts == null)
+ {
+ continue;
+ }
+ else if (outRec.IsOpen)
+ {
+ this.FixupOutPolyline(outRec);
+ }
+ else
+ {
+ this.FixupOutPolygon(outRec);
+ }
+ }
+
+ return true;
+ }
+ finally
+ {
+ this.joins.Clear();
+ this.ghostJoins.Clear();
+ }
+ }
+
+ private void DisposeAllPolyPts()
+ {
+ for (int i = 0; i < this.polyOuts.Count; ++i)
+ {
+ this.DisposeOutRec(i);
+ }
+
+ this.polyOuts.Clear();
+ }
+
+ private void AddJoin(OutPt op1, OutPt op2, Vector2 offPt)
+ {
+ Join j = new Join();
+ j.OutPt1 = op1;
+ j.OutPt2 = op2;
+ j.OffPt = offPt;
+ this.joins.Add(j);
+ }
+
+ private void AddGhostJoin(OutPt op, Vector2 offPt)
+ {
+ Join j = new Join();
+ j.OutPt1 = op;
+ j.OffPt = offPt;
+ this.ghostJoins.Add(j);
+ }
+
+ private void InsertLocalMinimaIntoAEL(float botY)
+ {
+ LocalMinima lm;
+ while (this.PopLocalMinima(botY, out lm))
+ {
+ TEdge lb = lm.LeftBound;
+ TEdge rb = lm.RightBound;
+
+ OutPt op1 = null;
+ if (lb == null)
+ {
+ this.InsertEdgeIntoAEL(rb, null);
+ this.SetWindingCount(rb);
+ if (this.IsContributing(rb))
+ {
+ op1 = this.AddOutPt(rb, rb.Bot);
+ }
+ }
+ else if (rb == null)
+ {
+ this.InsertEdgeIntoAEL(lb, null);
+ this.SetWindingCount(lb);
+ if (this.IsContributing(lb))
+ {
+ op1 = this.AddOutPt(lb, lb.Bot);
+ }
+
+ this.InsertScanbeam(lb.Top.Y);
+ }
+ else
+ {
+ this.InsertEdgeIntoAEL(lb, null);
+ this.InsertEdgeIntoAEL(rb, lb);
+ this.SetWindingCount(lb);
+ rb.WindCnt = lb.WindCnt;
+ rb.WindCnt2 = lb.WindCnt2;
+ if (this.IsContributing(lb))
+ {
+ op1 = this.AddLocalMinPoly(lb, rb, lb.Bot);
+ }
+
+ this.InsertScanbeam(lb.Top.Y);
+ }
+
+ if (rb != null)
+ {
+ if (IsHorizontal(rb))
+ {
+ if (rb.NextInLML != null)
+ {
+ this.InsertScanbeam(rb.NextInLML.Top.Y);
+ }
+
+ this.AddEdgeToSEL(rb);
+ }
+ else
+ {
+ this.InsertScanbeam(rb.Top.Y);
+ }
+ }
+
+ if (lb == null || rb == null)
+ {
+ continue;
+ }
+
+ // if output polygons share an Edge with a horizontal rb, they'll need joining later ...
+ if (op1 != null && IsHorizontal(rb) &&
+ this.ghostJoins.Count > 0 && rb.WindDelta != 0)
+ {
+ for (int i = 0; i < this.ghostJoins.Count; i++)
+ {
+ // if the horizontal Rb and a 'ghost' horizontal overlap, then convert
+ // the 'ghost' join to a real join ready for later ...
+ Join j = this.ghostJoins[i];
+ if (HorzSegmentsOverlap(j.OutPt1.Pt.X, j.OffPt.X, rb.Bot.X, rb.Top.X))
+ {
+ this.AddJoin(j.OutPt1, op1, j.OffPt);
+ }
+ }
+ }
+
+ if (lb.OutIdx >= 0 && lb.PrevInAEL != null &&
+ lb.PrevInAEL.Curr.X == lb.Bot.X &&
+ lb.PrevInAEL.OutIdx >= 0 &&
+ SlopesEqual(lb.PrevInAEL.Curr, lb.PrevInAEL.Top, lb.Curr, lb.Top) &&
+ lb.WindDelta != 0 && lb.PrevInAEL.WindDelta != 0)
+ {
+ OutPt op2 = this.AddOutPt(lb.PrevInAEL, lb.Bot);
+ this.AddJoin(op1, op2, lb.Top);
+ }
+
+ if (lb.NextInAEL != rb)
+ {
+ if (rb.OutIdx >= 0 && rb.PrevInAEL.OutIdx >= 0 &&
+ SlopesEqual(rb.PrevInAEL.Curr, rb.PrevInAEL.Top, rb.Curr, rb.Top) &&
+ rb.WindDelta != 0 && rb.PrevInAEL.WindDelta != 0)
+ {
+ OutPt op2 = this.AddOutPt(rb.PrevInAEL, rb.Bot);
+ this.AddJoin(op1, op2, rb.Top);
+ }
+
+ TEdge e = lb.NextInAEL;
+ if (e != null)
+ {
+ while (e != rb)
+ {
+ // nb: For calculating winding counts etc, IntersectEdges() assumes
+ // that param1 will be to the right of param2 ABOVE the intersection ...
+ this.IntersectEdges(rb, e, lb.Curr); // order important here
+ e = e.NextInAEL;
+ }
+ }
+ }
+ }
+ }
+
+ private void InsertEdgeIntoAEL(TEdge edge, TEdge startEdge)
+ {
+ if (this.activeEdges == null)
+ {
+ edge.PrevInAEL = null;
+ edge.NextInAEL = null;
+ this.activeEdges = edge;
+ }
+ else if (startEdge == null && this.E2InsertsBeforeE1(this.activeEdges, edge))
+ {
+ edge.PrevInAEL = null;
+ edge.NextInAEL = this.activeEdges;
+ this.activeEdges.PrevInAEL = edge;
+ this.activeEdges = edge;
+ }
+ else
+ {
+ if (startEdge == null)
+ {
+ startEdge = this.activeEdges;
+ }
+
+ while (startEdge.NextInAEL != null &&
+ !this.E2InsertsBeforeE1(startEdge.NextInAEL, edge))
+ {
+ startEdge = startEdge.NextInAEL;
+ }
+
+ edge.NextInAEL = startEdge.NextInAEL;
+ if (startEdge.NextInAEL != null)
+ {
+ startEdge.NextInAEL.PrevInAEL = edge;
+ }
+
+ edge.PrevInAEL = startEdge;
+ startEdge.NextInAEL = edge;
+ }
+ }
+
+ private bool E2InsertsBeforeE1(TEdge e1, TEdge e2)
+ {
+ if (e2.Curr.X == e1.Curr.X)
+ {
+ if (e2.Top.Y > e1.Top.Y)
+ {
+ return e2.Top.X < TopX(e1, e2.Top.Y);
+ }
+ else
+ {
+ return e1.Top.X > TopX(e2, e1.Top.Y);
+ }
+ }
+ else
+ {
+ return e2.Curr.X < e1.Curr.X;
+ }
+ }
+
+ private bool IsContributing(TEdge edge)
+ {
+ // return false if a subj line has been flagged as inside a subj polygon
+ if (edge.WindDelta == 0 && edge.WindCnt != 1)
+ {
+ return false;
+ }
+
+ if (edge.PolyTyp == PolyType.Subject)
+ {
+ return edge.WindCnt2 == 0;
+ }
+ else
+ {
+ return edge.WindCnt2 != 0;
+ }
+ }
+
+ private void SetWindingCount(TEdge edge)
+ {
+ TEdge e = edge.PrevInAEL;
+
+ // find the edge of the same polytype that immediately preceeds 'edge' in AEL
+ while (e != null && ((e.PolyTyp != edge.PolyTyp) || (e.WindDelta == 0)))
+ {
+ e = e.PrevInAEL;
+ }
+
+ if (e == null)
+ {
+ if (edge.WindDelta == 0)
+ {
+ edge.WindCnt = 1;
+ }
+ else
+ {
+ edge.WindCnt = edge.WindDelta;
+ }
+
+ edge.WindCnt2 = 0;
+ e = this.activeEdges; // ie get ready to calc WindCnt2
+ }
+ else if (edge.WindDelta == 0)
+ {
+ edge.WindCnt = 1;
+ edge.WindCnt2 = e.WindCnt2;
+ e = e.NextInAEL; // ie get ready to calc WindCnt2
+ }
+ else
+ {
+ // EvenOdd filling ...
+ if (edge.WindDelta == 0)
+ {
+ // are we inside a subj polygon ...
+ bool inside = true;
+ TEdge e2 = e.PrevInAEL;
+ while (e2 != null)
+ {
+ if (e2.PolyTyp == e.PolyTyp && e2.WindDelta != 0)
+ {
+ inside = !inside;
+ }
+
+ e2 = e2.PrevInAEL;
+ }
+
+ edge.WindCnt = inside ? 0 : 1;
+ }
+ else
+ {
+ edge.WindCnt = edge.WindDelta;
+ }
+
+ edge.WindCnt2 = e.WindCnt2;
+ e = e.NextInAEL; // ie get ready to calc WindCnt2
+ }
+
+ // update WindCnt2 ...
+ // EvenOdd filling ...
+ while (e != edge)
+ {
+ if (e.WindDelta != 0)
+ {
+ edge.WindCnt2 = edge.WindCnt2 == 0 ? 1 : 0;
+ }
+
+ e = e.NextInAEL;
+ }
+ }
+
+ private void AddEdgeToSEL(TEdge edge)
+ {
+ // SEL pointers in PEdge are use to build transient lists of horizontal edges.
+ // However, since we don't need to worry about processing order, all additions
+ // are made to the front of the list ...
+ if (this.sortedEdges == null)
+ {
+ this.sortedEdges = edge;
+ edge.PrevInSEL = null;
+ edge.NextInSEL = null;
+ }
+ else
+ {
+ edge.NextInSEL = this.sortedEdges;
+ edge.PrevInSEL = null;
+ this.sortedEdges.PrevInSEL = edge;
+ this.sortedEdges = edge;
+ }
+ }
+
+ private bool PopEdgeFromSEL(out TEdge e)
+ {
+ // Pop edge from front of SEL (ie SEL is a FILO list)
+ e = this.sortedEdges;
+ if (e == null)
+ {
+ return false;
+ }
+
+ TEdge oldE = e;
+ this.sortedEdges = e.NextInSEL;
+ if (this.sortedEdges != null)
+ {
+ this.sortedEdges.PrevInSEL = null;
+ }
+
+ oldE.NextInSEL = null;
+ oldE.PrevInSEL = null;
+ return true;
+ }
+
+ private void CopyAELToSEL()
+ {
+ TEdge e = this.activeEdges;
+ this.sortedEdges = e;
+ while (e != null)
+ {
+ e.PrevInSEL = e.PrevInAEL;
+ e.NextInSEL = e.NextInAEL;
+ e = e.NextInAEL;
+ }
+ }
+
+ private void SwapPositionsInSEL(TEdge edge1, TEdge edge2)
+ {
+ if (edge1.NextInSEL == null && edge1.PrevInSEL == null)
+ {
+ return;
+ }
+
+ if (edge2.NextInSEL == null && edge2.PrevInSEL == null)
+ {
+ return;
+ }
+
+ if (edge1.NextInSEL == edge2)
+ {
+ TEdge next = edge2.NextInSEL;
+ if (next != null)
+ {
+ next.PrevInSEL = edge1;
+ }
+
+ TEdge prev = edge1.PrevInSEL;
+ if (prev != null)
+ {
+ 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 != null)
+ {
+ next.PrevInSEL = edge2;
+ }
+
+ TEdge prev = edge2.PrevInSEL;
+ if (prev != null)
+ {
+ 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 != null)
+ {
+ edge1.NextInSEL.PrevInSEL = edge1;
+ }
+
+ edge1.PrevInSEL = edge2.PrevInSEL;
+ if (edge1.PrevInSEL != null)
+ {
+ edge1.PrevInSEL.NextInSEL = edge1;
+ }
+
+ edge2.NextInSEL = next;
+ if (edge2.NextInSEL != null)
+ {
+ edge2.NextInSEL.PrevInSEL = edge2;
+ }
+
+ edge2.PrevInSEL = prev;
+ if (edge2.PrevInSEL != null)
+ {
+ edge2.PrevInSEL.NextInSEL = edge2;
+ }
+ }
+
+ if (edge1.PrevInSEL == null)
+ {
+ this.sortedEdges = edge1;
+ }
+ else if (edge2.PrevInSEL == null)
+ {
+ this.sortedEdges = edge2;
+ }
+ }
+
+ private void AddLocalMaxPoly(TEdge e1, TEdge e2, Vector2 pt)
+ {
+ this.AddOutPt(e1, pt);
+ if (e2.WindDelta == 0)
+ {
+ this.AddOutPt(e2, pt);
+ }
+
+ if (e1.OutIdx == e2.OutIdx)
+ {
+ e1.OutIdx = Unassigned;
+ e2.OutIdx = Unassigned;
+ }
+ else if (e1.OutIdx < e2.OutIdx)
+ {
+ this.AppendPolygon(e1, e2);
+ }
+ else
+ {
+ this.AppendPolygon(e2, e1);
+ }
+ }
+
+ private OutPt AddLocalMinPoly(TEdge e1, TEdge e2, Vector2 pt)
+ {
+ OutPt result;
+ TEdge e, prevE;
+ if (IsHorizontal(e2) || (e1.Dx > e2.Dx))
+ {
+ result = this.AddOutPt(e1, pt);
+ e2.OutIdx = e1.OutIdx;
+ e1.Side = EdgeSide.Left;
+ e2.Side = EdgeSide.Right;
+ e = e1;
+ if (e.PrevInAEL == e2)
+ {
+ prevE = e2.PrevInAEL;
+ }
+ else
+ {
+ prevE = e.PrevInAEL;
+ }
+ }
+ else
+ {
+ result = this.AddOutPt(e2, pt);
+ e1.OutIdx = e2.OutIdx;
+ e1.Side = EdgeSide.Right;
+ e2.Side = EdgeSide.Left;
+ e = e2;
+ if (e.PrevInAEL == e1)
+ {
+ prevE = e1.PrevInAEL;
+ }
+ else
+ {
+ prevE = e.PrevInAEL;
+ }
+ }
+
+ if (prevE != null && prevE.OutIdx >= 0)
+ {
+ float xPrev = TopX(prevE, pt.Y);
+ float xE = TopX(e, pt.Y);
+ if ((xPrev == xE) &&
+ (e.WindDelta != 0) &&
+ (prevE.WindDelta != 0) &&
+ SlopesEqual(new Vector2(xPrev, pt.Y), prevE.Top, new Vector2(xE, pt.Y), e.Top))
+ {
+ OutPt outPt = this.AddOutPt(prevE, pt);
+ this.AddJoin(result, outPt, e.Top);
+ }
+ }
+
+ return result;
+ }
+
+ private OutPt AddOutPt(TEdge e, Vector2 pt)
+ {
+ if (e.OutIdx < 0)
+ {
+ OutRec outRec = this.CreateOutRec();
+ outRec.SourcePath = e.SourcePath; // copy source from edge to outrec
+ outRec.IsOpen = e.WindDelta == 0;
+ OutPt newOp = new OutPt();
+ outRec.Pts = newOp;
+ newOp.Idx = outRec.Idx;
+ newOp.Pt = pt;
+ newOp.Next = newOp;
+ newOp.Prev = newOp;
+ if (!outRec.IsOpen)
+ {
+ this.SetHoleState(e, outRec);
+ }
+
+ e.OutIdx = outRec.Idx; // nb: do this after SetZ !
+ return newOp;
+ }
+ else
+ {
+ OutRec outRec = this.polyOuts[e.OutIdx];
+
+ if (outRec.SourcePath != e.SourcePath)
+ {
+ // this edge was from a different/unknown source
+ outRec.SourcePath = null; // drop source form output
+ }
+
+ // OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
+ OutPt op = outRec.Pts;
+ bool toFront = e.Side == EdgeSide.Left;
+ if (toFront && pt == op.Pt)
+ {
+ return op;
+ }
+ else if (!toFront && pt == op.Prev.Pt)
+ {
+ return op.Prev;
+ }
+
+ // do we need to move the source to the point???
+ OutPt newOp = new OutPt();
+ newOp.Idx = outRec.Idx;
+ newOp.Pt = pt;
+ newOp.Next = op;
+ newOp.Prev = op.Prev;
+ newOp.Prev.Next = newOp;
+ op.Prev = newOp;
+ if (toFront)
+ {
+ outRec.Pts = newOp;
+ }
+
+ return newOp;
+ }
+ }
+
+ private OutPt GetLastOutPt(TEdge e)
+ {
+ OutRec outRec = this.polyOuts[e.OutIdx];
+ if (e.Side == EdgeSide.Left)
+ {
+ return outRec.Pts;
+ }
+ else
+ {
+ return outRec.Pts.Prev;
+ }
+ }
+
+ private void SetHoleState(TEdge e, OutRec outRec)
+ {
+ TEdge e2 = e.PrevInAEL;
+ TEdge eTmp = null;
+ while (e2 != null)
+ {
+ if (e2.OutIdx >= 0 && e2.WindDelta != 0)
+ {
+ if (eTmp == null)
+ {
+ eTmp = e2;
+ }
+ else if (eTmp.OutIdx == e2.OutIdx)
+ {
+ eTmp = null; // paired
+ }
+ }
+
+ e2 = e2.PrevInAEL;
+ }
+
+ if (eTmp == null)
+ {
+ outRec.FirstLeft = null;
+ outRec.IsHole = false;
+ }
+ else
+ {
+ outRec.FirstLeft = this.polyOuts[eTmp.OutIdx];
+ outRec.IsHole = !outRec.FirstLeft.IsHole;
+ }
+ }
+
+ private bool FirstIsBottomPt(OutPt btmPt1, OutPt btmPt2)
+ {
+ OutPt p = btmPt1.Prev;
+ while ((p.Pt == btmPt1.Pt) && (p != btmPt1))
+ {
+ p = p.Prev;
+ }
+
+ double dx1p = Math.Abs(GetDx(btmPt1.Pt, p.Pt));
+ p = btmPt1.Next;
+ while ((p.Pt == btmPt1.Pt) && (p != btmPt1))
+ {
+ p = p.Next;
+ }
+
+ double dx1n = Math.Abs(GetDx(btmPt1.Pt, p.Pt));
+
+ p = btmPt2.Prev;
+ while ((p.Pt == btmPt2.Pt) && (p != btmPt2))
+ {
+ p = p.Prev;
+ }
+
+ double dx2p = Math.Abs(GetDx(btmPt2.Pt, p.Pt));
+ p = btmPt2.Next;
+ while ((p.Pt == btmPt2.Pt) && (p != btmPt2))
+ {
+ p = p.Next;
+ }
+
+ double dx2n = Math.Abs(GetDx(btmPt2.Pt, p.Pt));
+
+ if (Math.Max(dx1p, dx1n) == Math.Max(dx2p, dx2n) &&
+ Math.Min(dx1p, dx1n) == Math.Min(dx2p, dx2n))
+ {
+ return this.Area(btmPt1) > 0; // if otherwise identical use orientation
+ }
+ else
+ {
+ return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
+ }
+ }
+
+ private OutPt GetBottomPt(OutPt pp)
+ {
+ OutPt dups = null;
+ OutPt p = pp.Next;
+ while (p != pp)
+ {
+ if (p.Pt.Y > pp.Pt.Y)
+ {
+ pp = p;
+ dups = null;
+ }
+ else if (p.Pt.Y == pp.Pt.Y && p.Pt.X <= pp.Pt.X)
+ {
+ if (p.Pt.X < pp.Pt.X)
+ {
+ dups = null;
+ pp = p;
+ }
+ else
+ {
+ if (p.Next != pp && p.Prev != pp)
+ {
+ dups = p;
+ }
+ }
+ }
+
+ p = p.Next;
+ }
+
+ if (dups != null)
+ {
+ // there appears to be at least 2 vertices at bottomPt so ...
+ while (dups != p)
+ {
+ if (!this.FirstIsBottomPt(p, dups))
+ {
+ pp = dups;
+ }
+
+ dups = dups.Next;
+ while (dups.Pt != pp.Pt)
+ {
+ dups = dups.Next;
+ }
+ }
+ }
+
+ return pp;
+ }
+
+ private OutRec GetLowermostRec(OutRec outRec1, OutRec outRec2)
+ {
+ // work out which polygon fragment has the correct hole state ...
+ if (outRec1.BottomPt == null)
+ {
+ outRec1.BottomPt = this.GetBottomPt(outRec1.Pts);
+ }
+
+ if (outRec2.BottomPt == null)
+ {
+ outRec2.BottomPt = this.GetBottomPt(outRec2.Pts);
+ }
+
+ OutPt bPt1 = outRec1.BottomPt;
+ OutPt bPt2 = outRec2.BottomPt;
+ if (bPt1.Pt.Y > bPt2.Pt.Y)
+ {
+ return outRec1;
+ }
+ else if (bPt1.Pt.Y < bPt2.Pt.Y)
+ {
+ return outRec2;
+ }
+ else if (bPt1.Pt.X < bPt2.Pt.X)
+ {
+ return outRec1;
+ }
+ else if (bPt1.Pt.X > bPt2.Pt.X)
+ {
+ return outRec2;
+ }
+ else if (bPt1.Next == bPt1)
+ {
+ return outRec2;
+ }
+ else if (bPt2.Next == bPt2)
+ {
+ return outRec1;
+ }
+ else if (this.FirstIsBottomPt(bPt1, bPt2))
+ {
+ return outRec1;
+ }
+ else
+ {
+ return outRec2;
+ }
+ }
+
+ private bool OutRec1RightOfOutRec2(OutRec outRec1, OutRec outRec2)
+ {
+ do
+ {
+ outRec1 = outRec1.FirstLeft;
+ if (outRec1 == outRec2)
+ {
+ return true;
+ }
+ }
+ while (outRec1 != null);
+
+ return false;
+ }
+
+ private OutRec GetOutRec(int idx)
+ {
+ OutRec outrec = this.polyOuts[idx];
+ while (outrec != this.polyOuts[outrec.Idx])
+ {
+ outrec = this.polyOuts[outrec.Idx];
+ }
+
+ return outrec;
+ }
+
+ private void AppendPolygon(TEdge e1, TEdge e2)
+ {
+ OutRec outRec1 = this.polyOuts[e1.OutIdx];
+ OutRec outRec2 = this.polyOuts[e2.OutIdx];
+
+ OutRec holeStateRec;
+ if (this.OutRec1RightOfOutRec2(outRec1, outRec2))
+ {
+ holeStateRec = outRec2;
+ }
+ else if (this.OutRec1RightOfOutRec2(outRec2, outRec1))
+ {
+ holeStateRec = outRec1;
+ }
+ else
+ {
+ holeStateRec = this.GetLowermostRec(outRec1, outRec2);
+ }
+
+ // get the start and ends of both output polygons and
+ // join E2 poly onto E1 poly and delete pointers to E2 ...
+ OutPt p1_lft = outRec1.Pts;
+ OutPt p1_rt = p1_lft.Prev;
+ OutPt p2_lft = outRec2.Pts;
+ OutPt p2_rt = p2_lft.Prev;
+
+ // join e2 poly onto e1 poly and delete pointers to e2 ...
+ if (e1.Side == EdgeSide.Left)
+ {
+ if (e2.Side == EdgeSide.Left)
+ {
+ // z y x a b c
+ this.ReversePolyPtLinks(p2_lft);
+ p2_lft.Next = p1_lft;
+ p1_lft.Prev = p2_lft;
+ p1_rt.Next = p2_rt;
+ p2_rt.Prev = p1_rt;
+ outRec1.Pts = p2_rt;
+ }
+ else
+ {
+ // x y z a b c
+ p2_rt.Next = p1_lft;
+ p1_lft.Prev = p2_rt;
+ p2_lft.Prev = p1_rt;
+ p1_rt.Next = p2_lft;
+ outRec1.Pts = p2_lft;
+ }
+ }
+ else
+ {
+ if (e2.Side == EdgeSide.Right)
+ {
+ // a b c z y x
+ this.ReversePolyPtLinks(p2_lft);
+ p1_rt.Next = p2_rt;
+ p2_rt.Prev = p1_rt;
+ p2_lft.Next = p1_lft;
+ p1_lft.Prev = p2_lft;
+ }
+ else
+ {
+ // a b c x y z
+ p1_rt.Next = p2_lft;
+ p2_lft.Prev = p1_rt;
+ p1_lft.Prev = p2_rt;
+ p2_rt.Next = p1_lft;
+ }
+ }
+
+ outRec1.BottomPt = null;
+ if (holeStateRec == outRec2)
+ {
+ if (outRec2.FirstLeft != outRec1)
+ {
+ outRec1.FirstLeft = outRec2.FirstLeft;
+ }
+
+ outRec1.IsHole = outRec2.IsHole;
+ }
+
+ outRec2.Pts = null;
+ outRec2.BottomPt = null;
+
+ outRec2.FirstLeft = outRec1;
+
+ int okIdx = e1.OutIdx;
+ int obsoleteIdx = e2.OutIdx;
+
+ e1.OutIdx = Unassigned; // nb: safe because we only get here via AddLocalMaxPoly
+ e2.OutIdx = Unassigned;
+
+ TEdge e = this.activeEdges;
+ while (e != null)
+ {
+ if (e.OutIdx == obsoleteIdx)
+ {
+ e.OutIdx = okIdx;
+ e.Side = e1.Side;
+ break;
+ }
+
+ e = e.NextInAEL;
+ }
+
+ outRec2.Idx = outRec1.Idx;
+ }
+
+ private void ReversePolyPtLinks(OutPt pp)
+ {
+ if (pp == null)
+ {
+ return;
+ }
+
+ OutPt pp1;
+ OutPt pp2;
+ pp1 = pp;
+ do
+ {
+ pp2 = pp1.Next;
+ pp1.Next = pp1.Prev;
+ pp1.Prev = pp2;
+ pp1 = pp2;
+ }
+ while (pp1 != pp);
+ }
+
+ private void IntersectEdges(TEdge e1, TEdge e2, Vector2 pt)
+ {
+ // 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 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.PolyTyp == e2.PolyTyp)
+ {
+ int oldE1WindCnt = e1.WindCnt;
+ e1.WindCnt = e2.WindCnt;
+ e2.WindCnt = oldE1WindCnt;
+ }
+ else
+ {
+ e1.WindCnt2 = (e1.WindCnt2 == 0) ? 1 : 0;
+ e2.WindCnt2 = (e2.WindCnt2 == 0) ? 1 : 0;
+ }
+
+ int e1Wc, e2Wc;
+ e1Wc = Math.Abs(e1.WindCnt);
+ e2Wc = Math.Abs(e2.WindCnt);
+
+ if (e1Contributing && e2Contributing)
+ {
+ if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) ||
+ (e1.PolyTyp != e2.PolyTyp))
+ {
+ this.AddLocalMaxPoly(e1, e2, pt);
+ }
+ else
+ {
+ this.AddOutPt(e1, pt);
+ this.AddOutPt(e2, pt);
+ SwapSides(e1, e2);
+ SwapPolyIndexes(e1, e2);
+ }
+ }
+ else if (e1Contributing)
+ {
+ if (e2Wc == 0 || e2Wc == 1)
+ {
+ this.AddOutPt(e1, pt);
+ SwapSides(e1, e2);
+ SwapPolyIndexes(e1, e2);
+ }
+ }
+ else if (e2Contributing)
+ {
+ if (e1Wc == 0 || e1Wc == 1)
+ {
+ this.AddOutPt(e2, pt);
+ SwapSides(e1, e2);
+ SwapPolyIndexes(e1, e2);
+ }
+ }
+ else if ((e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1))
+ {
+ // neither edge is currently contributing ...
+ float e1Wc2, e2Wc2;
+
+ e1Wc2 = Math.Abs(e1.WindCnt2);
+ e2Wc2 = Math.Abs(e2.WindCnt2);
+
+ if (e1.PolyTyp != e2.PolyTyp)
+ {
+ this.AddLocalMinPoly(e1, e2, pt);
+ }
+ else if (e1Wc == 1 && e2Wc == 1)
+ {
+ if (((e1.PolyTyp == PolyType.Clip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
+ ((e1.PolyTyp == PolyType.Subject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
+ {
+ this.AddLocalMinPoly(e1, e2, pt);
+ }
+ }
+ else
+ {
+ SwapSides(e1, e2);
+ }
+ }
+ }
+
+ private void ProcessHorizontals()
+ {
+ TEdge horzEdge; // m_SortedEdges;
+ while (this.PopEdgeFromSEL(out horzEdge))
+ {
+ this.ProcessHorizontal(horzEdge);
+ }
+ }
+
+ private void GetHorzDirection(TEdge horzEdge, out Direction dir, out float left, out float right)
+ {
+ if (horzEdge.Bot.X < horzEdge.Top.X)
+ {
+ left = horzEdge.Bot.X;
+ right = horzEdge.Top.X;
+ dir = Direction.LeftToRight;
+ }
+ else
+ {
+ left = horzEdge.Top.X;
+ right = horzEdge.Bot.X;
+ dir = Direction.RightToLeft;
+ }
+ }
+
+ private void ProcessHorizontal(TEdge horzEdge)
+ {
+ Direction dir;
+ float horzLeft, horzRight;
+ bool isOpen = horzEdge.WindDelta == 0;
+
+ this.GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
+
+ TEdge eLastHorz = horzEdge, eMaxPair = null;
+ while (eLastHorz.NextInLML != null && IsHorizontal(eLastHorz.NextInLML))
+ {
+ eLastHorz = eLastHorz.NextInLML;
+ }
+
+ if (eLastHorz.NextInLML == null)
+ {
+ eMaxPair = this.GetMaximaPair(eLastHorz);
+ }
+
+ Maxima currMax = this.maxima;
+ if (currMax != null)
+ {
+ // get the first maxima in range (X) ...
+ if (dir == Direction.LeftToRight)
+ {
+ while (currMax != null && currMax.X <= horzEdge.Bot.X)
+ {
+ currMax = currMax.Next;
+ }
+
+ if (currMax != null && currMax.X >= eLastHorz.Top.X)
+ {
+ currMax = null;
+ }
+ }
+ else
+ {
+ while (currMax.Next != null && currMax.Next.X < horzEdge.Bot.X)
+ {
+ currMax = currMax.Next;
+ }
+
+ if (currMax.X <= eLastHorz.Top.X)
+ {
+ currMax = null;
+ }
+ }
+ }
+
+ OutPt op1 = null;
+
+ // loop through consec. horizontal edges
+ while (true)
+ {
+ bool isLastHorz = horzEdge == eLastHorz;
+ TEdge e = this.GetNextInAEL(horzEdge, dir);
+ while (e != null)
+ {
+ // this code block inserts extra coords into horizontal edges (in output
+ // polygons) whereever maxima touch these horizontal edges. This helps
+ // 'simplifying' polygons (ie if the Simplify property is set).
+ if (currMax != null)
+ {
+ if (dir == Direction.LeftToRight)
+ {
+ while (currMax != null && currMax.X < e.Curr.X)
+ {
+ if (horzEdge.OutIdx >= 0 && !isOpen)
+ {
+ this.AddOutPt(horzEdge, new Vector2(currMax.X, horzEdge.Bot.Y));
+ }
+
+ currMax = currMax.Next;
+ }
+ }
+ else
+ {
+ while (currMax != null && currMax.X > e.Curr.X)
+ {
+ if (horzEdge.OutIdx >= 0 && !isOpen)
+ {
+ this.AddOutPt(horzEdge, new Vector2(currMax.X, horzEdge.Bot.Y));
+ }
+
+ currMax = currMax.Prev;
+ }
+ }
+ }
+
+ if ((dir == Direction.LeftToRight && e.Curr.X > horzRight) ||
+ (dir == Direction.RightToLeft && e.Curr.X < horzLeft))
+ {
+ break;
+ }
+
+ // Also break if we've got to the end of an intermediate horizontal edge ...
+ // nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
+ if (e.Curr.X == horzEdge.Top.X && horzEdge.NextInLML != null &&
+ e.Dx < horzEdge.NextInLML.Dx)
+ {
+ break;
+ }
+
+ // note: may be done multiple times
+ if (horzEdge.OutIdx >= 0 && !isOpen)
+ {
+ op1 = this.AddOutPt(horzEdge, e.Curr);
+ TEdge eNextHorz = this.sortedEdges;
+ while (eNextHorz != null)
+ {
+ if (eNextHorz.OutIdx >= 0 &&
+ HorzSegmentsOverlap(horzEdge.Bot.X, horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
+ {
+ OutPt op2 = this.GetLastOutPt(eNextHorz);
+ this.AddJoin(op2, op1, eNextHorz.Top);
+ }
+
+ eNextHorz = eNextHorz.NextInSEL;
+ }
+
+ this.AddGhostJoin(op1, horzEdge.Bot);
+ }
+
+ // OK, so far we're still in range of the horizontal Edge but make sure
+ // we're at the last of consec. horizontals when matching with eMaxPair
+ if (e == eMaxPair && isLastHorz)
+ {
+ if (horzEdge.OutIdx >= 0)
+ {
+ this.AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge.Top);
+ }
+
+ this.DeleteFromAEL(horzEdge);
+ this.DeleteFromAEL(eMaxPair);
+ return;
+ }
+
+ if (dir == Direction.LeftToRight)
+ {
+ Vector2 pt = new Vector2(e.Curr.X, horzEdge.Curr.Y);
+ this.IntersectEdges(horzEdge, e, pt);
+ }
+ else
+ {
+ Vector2 pt = new Vector2(e.Curr.X, horzEdge.Curr.Y);
+ this.IntersectEdges(e, horzEdge, pt);
+ }
+
+ TEdge eNext = this.GetNextInAEL(e, dir);
+ this.SwapPositionsInAEL(horzEdge, e);
+ e = eNext;
+ } // end while(e != null)
+
+ // Break out of loop if HorzEdge.NextInLML is not also horizontal ...
+ if (horzEdge.NextInLML == null || !IsHorizontal(horzEdge.NextInLML))
+ {
+ break;
+ }
+
+ this.UpdateEdgeIntoAEL(ref horzEdge);
+ if (horzEdge.OutIdx >= 0)
+ {
+ this.AddOutPt(horzEdge, horzEdge.Bot);
+ }
+
+ this.GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
+ }
+
+ if (horzEdge.OutIdx >= 0 && op1 == null)
+ {
+ op1 = this.GetLastOutPt(horzEdge);
+ TEdge eNextHorz = this.sortedEdges;
+ while (eNextHorz != null)
+ {
+ if (eNextHorz.OutIdx >= 0 &&
+ HorzSegmentsOverlap(horzEdge.Bot.X, horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
+ {
+ OutPt op2 = this.GetLastOutPt(eNextHorz);
+ this.AddJoin(op2, op1, eNextHorz.Top);
+ }
+
+ eNextHorz = eNextHorz.NextInSEL;
+ }
+
+ this.AddGhostJoin(op1, horzEdge.Top);
+ }
+
+ if (horzEdge.NextInLML != null)
+ {
+ if (horzEdge.OutIdx >= 0)
+ {
+ op1 = this.AddOutPt(horzEdge, horzEdge.Top);
+
+ this.UpdateEdgeIntoAEL(ref horzEdge);
+ if (horzEdge.WindDelta == 0)
+ {
+ return;
+ }
+
+ // nb: HorzEdge is no longer horizontal here
+ TEdge ePrev = horzEdge.PrevInAEL;
+ TEdge eNext = horzEdge.NextInAEL;
+ if (ePrev != null && ePrev.Curr.X == horzEdge.Bot.X &&
+ ePrev.Curr.Y == horzEdge.Bot.Y && ePrev.WindDelta != 0 &&
+ (ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y &&
+ SlopesEqual(horzEdge, ePrev)))
+ {
+ OutPt op2 = this.AddOutPt(ePrev, horzEdge.Bot);
+ this.AddJoin(op1, op2, horzEdge.Top);
+ }
+ else if (eNext != null && eNext.Curr.X == horzEdge.Bot.X &&
+ eNext.Curr.Y == horzEdge.Bot.Y && eNext.WindDelta != 0 &&
+ eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y &&
+ SlopesEqual(horzEdge, eNext))
+ {
+ OutPt op2 = this.AddOutPt(eNext, horzEdge.Bot);
+ this.AddJoin(op1, op2, horzEdge.Top);
+ }
+ }
+ else
+ {
+ this.UpdateEdgeIntoAEL(ref horzEdge);
+ }
+ }
+ else
+ {
+ if (horzEdge.OutIdx >= 0)
+ {
+ this.AddOutPt(horzEdge, horzEdge.Top);
+ }
+
+ this.DeleteFromAEL(horzEdge);
+ }
+ }
+
+ private TEdge GetNextInAEL(TEdge e, Direction direction)
+ {
+ return direction == Direction.LeftToRight ? e.NextInAEL : e.PrevInAEL;
+ }
+
+ private bool IsMaxima(TEdge e, double y)
+ {
+ return e != null && e.Top.Y == y && e.NextInLML == null;
+ }
+
+ private bool IsIntermediate(TEdge e, double y)
+ {
+ return e.Top.Y == y && e.NextInLML != null;
+ }
+
+ private TEdge GetMaximaPair(TEdge e)
+ {
+ if ((e.Next.Top == e.Top) && e.Next.NextInLML == null)
+ {
+ return e.Next;
+ }
+ else if ((e.Prev.Top == e.Top) && e.Prev.NextInLML == null)
+ {
+ return e.Prev;
+ }
+ else
+ {
+ return null;
+ }
+ }
+
+ private TEdge GetMaximaPairEx(TEdge e)
+ {
+ // as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
+ TEdge result = this.GetMaximaPair(e);
+ if (result == null || result.OutIdx == Skip ||
+ ((result.NextInAEL == result.PrevInAEL) && !IsHorizontal(result)))
+ {
+ return null;
+ }
+
+ return result;
+ }
+
+ private bool ProcessIntersections(float topY)
+ {
+ if (this.activeEdges == null)
+ {
+ return true;
+ }
+
+ try
+ {
+ this.BuildIntersectList(topY);
+ if (this.intersectList.Count == 0)
+ {
+ return true;
+ }
+
+ if (this.intersectList.Count == 1 || this.FixupIntersectionOrder())
+ {
+ this.ProcessIntersectList();
+ }
+ else
+ {
+ return false;
+ }
+ }
+ catch
+ {
+ this.sortedEdges = null;
+ this.intersectList.Clear();
+ throw new ClipperException("ProcessIntersections error");
+ }
+
+ this.sortedEdges = null;
+ return true;
+ }
+
+ private void BuildIntersectList(float topY)
+ {
+ if (this.activeEdges == null)
+ {
+ return;
+ }
+
+ // prepare for sorting ...
+ TEdge e = this.activeEdges;
+ this.sortedEdges = e;
+ while (e != null)
+ {
+ e.PrevInSEL = e.PrevInAEL;
+ e.NextInSEL = e.NextInAEL;
+ e.Curr.X = TopX(e, topY);
+ e = e.NextInAEL;
+ }
+
+ // bubblesort ...
+ bool isModified = true;
+ while (isModified && this.sortedEdges != null)
+ {
+ isModified = false;
+ e = this.sortedEdges;
+ while (e.NextInSEL != null)
+ {
+ TEdge eNext = e.NextInSEL;
+ Vector2 pt;
+ if (e.Curr.X > eNext.Curr.X)
+ {
+ this.IntersectPoint(e, eNext, out pt);
+ if (pt.Y < topY)
+ {
+ pt = new Vector2(TopX(e, topY), topY);
+ }
+
+ IntersectNode newNode = new IntersectNode();
+ newNode.Edge1 = e;
+ newNode.Edge2 = eNext;
+ newNode.Pt = pt;
+ this.intersectList.Add(newNode);
+
+ this.SwapPositionsInSEL(e, eNext);
+ isModified = true;
+ }
+ else
+ {
+ e = eNext;
+ }
+ }
+
+ if (e.PrevInSEL != null)
+ {
+ e.PrevInSEL.NextInSEL = null;
+ }
+ else
+ {
+ break;
+ }
+ }
+
+ this.sortedEdges = null;
+ }
+
+ private bool EdgesAdjacent(IntersectNode inode)
+ {
+ return (inode.Edge1.NextInSEL == inode.Edge2) ||
+ (inode.Edge1.PrevInSEL == inode.Edge2);
+ }
+
+ private bool FixupIntersectionOrder()
+ {
+ // pre-condition: intersections are sorted bottom-most first.
+ // Now it's crucial that intersections are made only between adjacent edges,
+ // so to ensure this the order of intersections may need adjusting ...
+ this.intersectList.Sort(this.intersectNodeComparer);
+
+ this.CopyAELToSEL();
+ int cnt = this.intersectList.Count;
+ for (int i = 0; i < cnt; i++)
+ {
+ if (!this.EdgesAdjacent(this.intersectList[i]))
+ {
+ int j = i + 1;
+ while (j < cnt && !this.EdgesAdjacent(this.intersectList[j]))
+ {
+ j++;
+ }
+
+ if (j == cnt)
+ {
+ return false;
+ }
+
+ IntersectNode tmp = this.intersectList[i];
+ this.intersectList[i] = this.intersectList[j];
+ this.intersectList[j] = tmp;
+ }
+
+ this.SwapPositionsInSEL(this.intersectList[i].Edge1, this.intersectList[i].Edge2);
+ }
+
+ return true;
+ }
+
+ private void ProcessIntersectList()
+ {
+ for (int i = 0; i < this.intersectList.Count; i++)
+ {
+ IntersectNode iNode = this.intersectList[i];
+ {
+ this.IntersectEdges(iNode.Edge1, iNode.Edge2, iNode.Pt);
+ this.SwapPositionsInAEL(iNode.Edge1, iNode.Edge2);
+ }
+ }
+
+ this.intersectList.Clear();
+ }
+
+ private void IntersectPoint(TEdge edge1, TEdge edge2, out Vector2 ip)
+ {
+ ip = default(Vector2);
+ double b1, b2;
+
+ // nb: with very large coordinate values, it's possible for SlopesEqual() to
+ // return false but for the edge.Dx value be equal due to double precision rounding.
+ if (edge1.Dx == edge2.Dx)
+ {
+ ip.Y = edge1.Curr.Y;
+ ip.X = TopX(edge1, ip.Y);
+ return;
+ }
+
+ if (edge1.Delta.X == 0)
+ {
+ ip.X = edge1.Bot.X;
+ if (IsHorizontal(edge2))
+ {
+ ip.Y = edge2.Bot.Y;
+ }
+ else
+ {
+ b2 = edge2.Bot.Y - (edge2.Bot.X / edge2.Dx);
+ ip.Y = Round((ip.X / edge2.Dx) + b2);
+ }
+ }
+ else if (edge2.Delta.X == 0)
+ {
+ ip.X = edge2.Bot.X;
+ if (IsHorizontal(edge1))
+ {
+ ip.Y = edge1.Bot.Y;
+ }
+ else
+ {
+ b1 = edge1.Bot.Y - (edge1.Bot.X / edge1.Dx);
+ ip.Y = Round((ip.X / edge1.Dx) + b1);
+ }
+ }
+ else
+ {
+ b1 = edge1.Bot.X - (edge1.Bot.Y * edge1.Dx);
+ b2 = edge2.Bot.X - (edge2.Bot.Y * edge2.Dx);
+ double q = (b2 - b1) / (edge1.Dx - edge2.Dx);
+ ip.Y = Round(q);
+ if (Math.Abs(edge1.Dx) < Math.Abs(edge2.Dx))
+ {
+ ip.X = Round((edge1.Dx * q) + b1);
+ }
+ else
+ {
+ ip.X = Round((edge2.Dx * q) + b2);
+ }
+ }
+
+ if (ip.Y < edge1.Top.Y || ip.Y < edge2.Top.Y)
+ {
+ if (edge1.Top.Y > edge2.Top.Y)
+ {
+ ip.Y = edge1.Top.Y;
+ }
+ else
+ {
+ ip.Y = edge2.Top.Y;
+ }
+
+ if (Math.Abs(edge1.Dx) < Math.Abs(edge2.Dx))
+ {
+ ip.X = TopX(edge1, ip.Y);
+ }
+ else
+ {
+ ip.X = TopX(edge2, ip.Y);
+ }
+ }
+
+ // finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
+ if (ip.Y > edge1.Curr.Y)
+ {
+ ip.Y = edge1.Curr.Y;
+
+ // better to use the more vertical edge to derive X ...
+ if (Math.Abs(edge1.Dx) > Math.Abs(edge2.Dx))
+ {
+ ip.X = TopX(edge2, ip.Y);
+ }
+ else
+ {
+ ip.X = TopX(edge1, ip.Y);
+ }
+ }
+ }
+
+ private void ProcessEdgesAtTopOfScanbeam(float topY)
+ {
+ TEdge e = this.activeEdges;
+ while (e != null)
+ {
+ // 1. process maxima, treating them as if they're 'bent' horizontal edges,
+ // but exclude maxima with horizontal edges. nb: e can't be a horizontal.
+ bool isMaximaEdge = this.IsMaxima(e, topY);
+
+ if (isMaximaEdge)
+ {
+ TEdge eMaxPair = this.GetMaximaPairEx(e);
+ isMaximaEdge = eMaxPair == null || !IsHorizontal(eMaxPair);
+ }
+
+ if (isMaximaEdge)
+ {
+ TEdge ePrev = e.PrevInAEL;
+ this.DoMaxima(e);
+ if (ePrev == null)
+ {
+ e = this.activeEdges;
+ }
+ else
+ {
+ e = ePrev.NextInAEL;
+ }
+ }
+ else
+ {
+ // 2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
+ if (this.IsIntermediate(e, topY) && IsHorizontal(e.NextInLML))
+ {
+ this.UpdateEdgeIntoAEL(ref e);
+ if (e.OutIdx >= 0)
+ {
+ this.AddOutPt(e, e.Bot);
+ }
+
+ this.AddEdgeToSEL(e);
+ }
+ else
+ {
+ e.Curr.X = TopX(e, topY);
+ e.Curr.Y = topY;
+ }
+
+ e = e.NextInAEL;
+ }
+ }
+
+ // 3. Process horizontals at the Top of the scanbeam ...
+ this.ProcessHorizontals();
+ this.maxima = null;
+
+ // 4. Promote intermediate vertices ...
+ e = this.activeEdges;
+ while (e != null)
+ {
+ if (this.IsIntermediate(e, topY))
+ {
+ OutPt op = null;
+ if (e.OutIdx >= 0)
+ {
+ op = this.AddOutPt(e, e.Top);
+ }
+
+ this.UpdateEdgeIntoAEL(ref e);
+
+ // if output polygons share an edge, they'll need joining later ...
+ TEdge ePrev = e.PrevInAEL;
+ TEdge eNext = e.NextInAEL;
+ if (ePrev != null && ePrev.Curr.X == e.Bot.X &&
+ ePrev.Curr.Y == e.Bot.Y && op != null &&
+ ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y &&
+ SlopesEqual(e.Curr, e.Top, ePrev.Curr, ePrev.Top) &&
+ (e.WindDelta != 0) && (ePrev.WindDelta != 0))
+ {
+ OutPt op2 = this.AddOutPt(ePrev, e.Bot);
+ this.AddJoin(op, op2, e.Top);
+ }
+ else if (eNext != null && eNext.Curr.X == e.Bot.X &&
+ eNext.Curr.Y == e.Bot.Y && op != null &&
+ eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y &&
+ SlopesEqual(e.Curr, e.Top, eNext.Curr, eNext.Top) &&
+ (e.WindDelta != 0) && (eNext.WindDelta != 0))
+ {
+ OutPt op2 = this.AddOutPt(eNext, e.Bot);
+ this.AddJoin(op, op2, e.Top);
+ }
+ }
+
+ e = e.NextInAEL;
+ }
+ }
+
+ private void DoMaxima(TEdge e)
+ {
+ TEdge eMaxPair = this.GetMaximaPairEx(e);
+ if (eMaxPair == null)
+ {
+ if (e.OutIdx >= 0)
+ {
+ this.AddOutPt(e, e.Top);
+ }
+
+ this.DeleteFromAEL(e);
+ return;
+ }
+
+ TEdge eNext = e.NextInAEL;
+ while (eNext != null && eNext != eMaxPair)
+ {
+ this.IntersectEdges(e, eNext, e.Top);
+ this.SwapPositionsInAEL(e, eNext);
+ eNext = e.NextInAEL;
+ }
+
+ if (e.OutIdx == Unassigned && eMaxPair.OutIdx == Unassigned)
+ {
+ this.DeleteFromAEL(e);
+ this.DeleteFromAEL(eMaxPair);
+ }
+ else if (e.OutIdx >= 0 && eMaxPair.OutIdx >= 0)
+ {
+ if (e.OutIdx >= 0)
+ {
+ this.AddLocalMaxPoly(e, eMaxPair, e.Top);
+ }
+
+ this.DeleteFromAEL(e);
+ this.DeleteFromAEL(eMaxPair);
+ }
+ else
+ {
+ throw new ClipperException("DoMaxima error");
+ }
+ }
+
+ private int PointCount(OutPt pts)
+ {
+ if (pts == null)
+ {
+ return 0;
+ }
+
+ int result = 0;
+ OutPt p = pts;
+ do
+ {
+ result++;
+ p = p.Next;
+ }
+ while (p != pts);
+ return result;
+ }
+
+ private void BuildResult2(PolyTree polytree)
+ {
+ polytree.Clear();
+
+ // add each output polygon/contour to polytree ...
+ polytree.AllPolys.Capacity = this.polyOuts.Count;
+ for (int i = 0; i < this.polyOuts.Count; i++)
+ {
+ OutRec outRec = this.polyOuts[i];
+ int cnt = this.PointCount(outRec.Pts);
+ if ((outRec.IsOpen && cnt < 2) ||
+ (!outRec.IsOpen && cnt < 3))
+ {
+ continue;
+ }
+
+ FixHoleLinkage(outRec);
+ PolyNode pn = new PolyNode();
+ pn.SourcePath = outRec.SourcePath;
+ polytree.AllPolys.Add(pn);
+ outRec.PolyNode = pn;
+ pn.Polygon.Capacity = cnt;
+ OutPt op = outRec.Pts.Prev;
+ for (int j = 0; j < cnt; j++)
+ {
+ pn.Polygon.Add(op.Pt);
+ op = op.Prev;
+ }
+ }
+
+ // fixup PolyNode links etc ...
+ polytree.Children.Capacity = this.polyOuts.Count;
+ for (int i = 0; i < this.polyOuts.Count; i++)
+ {
+ OutRec outRec = this.polyOuts[i];
+ if (outRec.PolyNode == null)
+ {
+ continue;
+ }
+ else if (outRec.IsOpen)
+ {
+ outRec.PolyNode.IsOpen = true;
+ polytree.AddChild(outRec.PolyNode);
+ }
+ else if (outRec.FirstLeft != null &&
+ outRec.FirstLeft.PolyNode != null)
+ {
+ outRec.FirstLeft.PolyNode.AddChild(outRec.PolyNode);
+ }
+ else
+ {
+ polytree.AddChild(outRec.PolyNode);
+ }
+ }
+ }
+
+ private void FixupOutPolyline(OutRec outrec)
+ {
+ OutPt pp = outrec.Pts;
+ OutPt lastPP = pp.Prev;
+ while (pp != lastPP)
+ {
+ pp = pp.Next;
+ if (pp.Pt == pp.Prev.Pt)
+ {
+ if (pp == lastPP)
+ {
+ lastPP = pp.Prev;
+ }
+
+ OutPt tmpPP = pp.Prev;
+ tmpPP.Next = pp.Next;
+ pp.Next.Prev = tmpPP;
+ pp = tmpPP;
+ }
+ }
+
+ if (pp == pp.Prev)
+ {
+ outrec.Pts = null;
+ }
+ }
+
+ private void FixupOutPolygon(OutRec outRec)
+ {
+ // FixupOutPolygon() - removes duplicate points and simplifies consecutive
+ // parallel edges by removing the middle vertex.
+ OutPt lastOK = null;
+ outRec.BottomPt = null;
+ OutPt pp = outRec.Pts;
+ while (true)
+ {
+ if (pp.Prev == pp || pp.Prev == pp.Next)
+ {
+ outRec.Pts = null;
+ return;
+ }
+
+ // test for duplicate points and collinear edges ...
+ if ((pp.Pt == pp.Next.Pt) || (pp.Pt == pp.Prev.Pt) ||
+ SlopesEqual(pp.Prev.Pt, pp.Pt, pp.Next.Pt))
+ {
+ lastOK = null;
+ pp.Prev.Next = pp.Next;
+ pp.Next.Prev = pp.Prev;
+ pp = pp.Prev;
+ }
+ else if (pp == lastOK)
+ {
+ break;
+ }
+ else
+ {
+ if (lastOK == null)
+ {
+ lastOK = pp;
+ }
+
+ pp = pp.Next;
+ }
+ }
+
+ outRec.Pts = pp;
+ }
+
+ private OutPt DupOutPt(OutPt outPt, bool insertAfter)
+ {
+ OutPt result = new OutPt();
+ result.Pt = outPt.Pt;
+ result.Idx = outPt.Idx;
+ if (insertAfter)
+ {
+ result.Next = outPt.Next;
+ result.Prev = outPt;
+ outPt.Next.Prev = result;
+ outPt.Next = result;
+ }
+ else
+ {
+ result.Prev = outPt.Prev;
+ result.Next = outPt;
+ outPt.Prev.Next = result;
+ outPt.Prev = result;
+ }
+
+ return result;
+ }
+
+ private bool GetOverlap(float a1, float a2, float b1, float b2, out float left, out float right)
+ {
+ if (a1 < a2)
+ {
+ if (b1 < b2)
+ {
+ left = Math.Max(a1, b1);
+ right = Math.Min(a2, b2);
+ }
+ else
+ {
+ left = Math.Max(a1, b2);
+ right = Math.Min(a2, b1);
+ }
+ }
+ else
+ {
+ if (b1 < b2)
+ {
+ left = Math.Max(a2, b1);
+ right = Math.Min(a1, b2);
+ }
+ else
+ {
+ left = Math.Max(a2, b2);
+ right = Math.Min(a1, b1);
+ }
+ }
+
+ return left < right;
+ }
+
+ private bool JoinHorz(OutPt op1, OutPt op1b, OutPt op2, OutPt op2b, Vector2 pt, bool discardLeft)
+ {
+ Direction dir1 = op1.Pt.X > op1b.Pt.X ? Direction.RightToLeft : Direction.LeftToRight;
+ Direction dir2 = op2.Pt.X > op2b.Pt.X ? Direction.RightToLeft : Direction.LeftToRight;
+ if (dir1 == dir2)
+ {
+ return false;
+ }
+
+ // When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
+ // want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
+ // So, to facilitate this while inserting Op1b and Op2b ...
+ // when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
+ // otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
+ if (dir1 == Direction.LeftToRight)
+ {
+ while (op1.Next.Pt.X <= pt.X &&
+ op1.Next.Pt.X >= op1.Pt.X && op1.Next.Pt.Y == pt.Y)
+ {
+ op1 = op1.Next;
+ }
+
+ if (discardLeft && (op1.Pt.X != pt.X))
+ {
+ op1 = op1.Next;
+ }
+
+ op1b = this.DupOutPt(op1, !discardLeft);
+ if (op1b.Pt != pt)
+ {
+ op1 = op1b;
+ op1.Pt = pt;
+ op1b = this.DupOutPt(op1, !discardLeft);
+ }
+ }
+ else
+ {
+ while (op1.Next.Pt.X >= pt.X &&
+ op1.Next.Pt.X <= op1.Pt.X &&
+ op1.Next.Pt.Y == pt.Y)
+ {
+ op1 = op1.Next;
+ }
+
+ if (!discardLeft && (op1.Pt.X != pt.X))
+ {
+ op1 = op1.Next;
+ }
+
+ op1b = this.DupOutPt(op1, discardLeft);
+ if (op1b.Pt != pt)
+ {
+ op1 = op1b;
+ op1.Pt = pt;
+ op1b = this.DupOutPt(op1, discardLeft);
+ }
+ }
+
+ if (dir2 == Direction.LeftToRight)
+ {
+ while (op2.Next.Pt.X <= pt.X &&
+ op2.Next.Pt.X >= op2.Pt.X &&
+ op2.Next.Pt.Y == pt.Y)
+ {
+ op2 = op2.Next;
+ }
+
+ if (discardLeft && (op2.Pt.X != pt.X))
+ {
+ op2 = op2.Next;
+ }
+
+ op2b = this.DupOutPt(op2, !discardLeft);
+ if (op2b.Pt != pt)
+ {
+ op2 = op2b;
+ op2.Pt = pt;
+ op2b = this.DupOutPt(op2, !discardLeft);
+ }
+ }
+ else
+ {
+ while (op2.Next.Pt.X >= pt.X &&
+ op2.Next.Pt.X <= op2.Pt.X &&
+ op2.Next.Pt.Y == pt.Y)
+ {
+ op2 = op2.Next;
+ }
+
+ if (!discardLeft && (op2.Pt.X != pt.X))
+ {
+ op2 = op2.Next;
+ }
+
+ op2b = this.DupOutPt(op2, discardLeft);
+ if (op2b.Pt != pt)
+ {
+ op2 = op2b;
+ op2.Pt = pt;
+ op2b = this.DupOutPt(op2, discardLeft);
+ }
+ }
+
+ if ((dir1 == Direction.LeftToRight) == discardLeft)
+ {
+ op1.Prev = op2;
+ op2.Next = op1;
+ op1b.Next = op2b;
+ op2b.Prev = op1b;
+ }
+ else
+ {
+ op1.Next = op2;
+ op2.Prev = op1;
+ op1b.Prev = op2b;
+ op2b.Next = op1b;
+ }
+
+ return true;
+ }
+
+ private bool JoinPoints(Join j, OutRec outRec1, OutRec outRec2)
+ {
+ OutPt op1 = j.OutPt1, op1b;
+ OutPt op2 = j.OutPt2, op2b;
+
+ // There are 3 kinds of joins for output polygons ...
+ // 1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
+ // along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
+ // 2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
+ // location at the Bottom of the overlapping segment (& Join.OffPt is above).
+ // 3. StrictlySimple joins where edges touch but are not collinear and where
+ // Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
+ bool isHorizontal = j.OutPt1.Pt.Y == j.OffPt.Y;
+
+ if (isHorizontal && (j.OffPt == j.OutPt1.Pt) && (j.OffPt == j.OutPt2.Pt))
+ {
+ // Strictly Simple join ...
+ if (outRec1 != outRec2)
+ {
+ return false;
+ }
+
+ op1b = j.OutPt1.Next;
+ while (op1b != op1 && (op1b.Pt == j.OffPt))
+ {
+ op1b = op1b.Next;
+ }
+
+ bool reverse1 = op1b.Pt.Y > j.OffPt.Y;
+ op2b = j.OutPt2.Next;
+ while (op2b != op2 && (op2b.Pt == j.OffPt))
+ {
+ op2b = op2b.Next;
+ }
+
+ bool reverse2 = op2b.Pt.Y > j.OffPt.Y;
+ if (reverse1 == reverse2)
+ {
+ return false;
+ }
+
+ if (reverse1)
+ {
+ op1b = this.DupOutPt(op1, false);
+ op2b = this.DupOutPt(op2, true);
+ op1.Prev = op2;
+ op2.Next = op1;
+ op1b.Next = op2b;
+ op2b.Prev = op1b;
+ j.OutPt1 = op1;
+ j.OutPt2 = op1b;
+ return true;
+ }
+ else
+ {
+ op1b = this.DupOutPt(op1, true);
+ op2b = this.DupOutPt(op2, false);
+ op1.Next = op2;
+ op2.Prev = op1;
+ op1b.Prev = op2b;
+ op2b.Next = op1b;
+ j.OutPt1 = op1;
+ j.OutPt2 = op1b;
+ return true;
+ }
+ }
+ else if (isHorizontal)
+ {
+ // treat horizontal joins differently to non-horizontal joins since with
+ // them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
+ // may be anywhere along the horizontal edge.
+ op1b = op1;
+ while (op1.Prev.Pt.Y == op1.Pt.Y && op1.Prev != op1b && op1.Prev != op2)
+ {
+ op1 = op1.Prev;
+ }
+
+ while (op1b.Next.Pt.Y == op1b.Pt.Y && op1b.Next != op1 && op1b.Next != op2)
+ {
+ op1b = op1b.Next;
+ }
+
+ if (op1b.Next == op1 || op1b.Next == op2)
+ {
+ return false; // a flat 'polygon'
+ }
+
+ op2b = op2;
+ while (op2.Prev.Pt.Y == op2.Pt.Y && op2.Prev != op2b && op2.Prev != op1b)
+ {
+ op2 = op2.Prev;
+ }
+
+ while (op2b.Next.Pt.Y == op2b.Pt.Y && op2b.Next != op2 && op2b.Next != op1)
+ {
+ op2b = op2b.Next;
+ }
+
+ if (op2b.Next == op2 || op2b.Next == op1)
+ {
+ return false; // a flat 'polygon'
+ }
+
+ float left, right;
+
+ // Op1 -. Op1b & Op2 -. Op2b are the extremites of the horizontal edges
+ if (!this.GetOverlap(op1.Pt.X, op1b.Pt.X, op2.Pt.X, op2b.Pt.X, out left, out right))
+ {
+ return false;
+ }
+
+ // DiscardLeftSide: when overlapping edges are joined, a spike will created
+ // which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
+ // on the discard Side as either may still be needed for other joins ...
+ Vector2 pt;
+ bool discardLeftSide;
+ if (op1.Pt.X >= left && op1.Pt.X <= right)
+ {
+ pt = op1.Pt;
+ discardLeftSide = op1.Pt.X > op1b.Pt.X;
+ }
+ else if (op2.Pt.X >= left && op2.Pt.X <= right)
+ {
+ pt = op2.Pt;
+ discardLeftSide = op2.Pt.X > op2b.Pt.X;
+ }
+ else if (op1b.Pt.X >= left && op1b.Pt.X <= right)
+ {
+ pt = op1b.Pt;
+ discardLeftSide = op1b.Pt.X > op1.Pt.X;
+ }
+ else
+ {
+ pt = op2b.Pt;
+ discardLeftSide = op2b.Pt.X > op2.Pt.X;
+ }
+
+ j.OutPt1 = op1;
+ j.OutPt2 = op2;
+ return this.JoinHorz(op1, op1b, op2, op2b, pt, discardLeftSide);
+ }
+ else
+ {
+ // nb: For non-horizontal joins ...
+ // 1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
+ // 2. Jr.OutPt1.Pt > Jr.OffPt.Y
+
+ // make sure the polygons are correctly oriented ...
+ op1b = op1.Next;
+ while ((op1b.Pt == op1.Pt) && (op1b != op1))
+ {
+ op1b = op1b.Next;
+ }
+
+ bool reverse1 = (op1b.Pt.Y > op1.Pt.Y) || !SlopesEqual(op1.Pt, op1b.Pt, j.OffPt);
+ if (reverse1)
+ {
+ op1b = op1.Prev;
+ while ((op1b.Pt == op1.Pt) && (op1b != op1))
+ {
+ op1b = op1b.Prev;
+ }
+
+ if ((op1b.Pt.Y > op1.Pt.Y) ||
+ !SlopesEqual(op1.Pt, op1b.Pt, j.OffPt))
+ {
+ return false;
+ }
+ }
+
+ op2b = op2.Next;
+ while ((op2b.Pt == op2.Pt) && (op2b != op2))
+ {
+ op2b = op2b.Next;
+ }
+
+ bool reverse2 = (op2b.Pt.Y > op2.Pt.Y) || !SlopesEqual(op2.Pt, op2b.Pt, j.OffPt);
+ if (reverse2)
+ {
+ op2b = op2.Prev;
+ while ((op2b.Pt == op2.Pt) && (op2b != op2))
+ {
+ op2b = op2b.Prev;
+ }
+
+ if ((op2b.Pt.Y > op2.Pt.Y) ||
+ !SlopesEqual(op2.Pt, op2b.Pt, j.OffPt))
+ {
+ return false;
+ }
+ }
+
+ if ((op1b == op1) || (op2b == op2) || (op1b == op2b) ||
+ ((outRec1 == outRec2) && (reverse1 == reverse2)))
+ {
+ return false;
+ }
+
+ if (reverse1)
+ {
+ op1b = this.DupOutPt(op1, false);
+ op2b = this.DupOutPt(op2, true);
+ op1.Prev = op2;
+ op2.Next = op1;
+ op1b.Next = op2b;
+ op2b.Prev = op1b;
+ j.OutPt1 = op1;
+ j.OutPt2 = op1b;
+ return true;
+ }
+ else
+ {
+ op1b = this.DupOutPt(op1, true);
+ op2b = this.DupOutPt(op2, false);
+ op1.Next = op2;
+ op2.Prev = op1;
+ op1b.Prev = op2b;
+ op2b.Next = op1b;
+ j.OutPt1 = op1;
+ j.OutPt2 = op1b;
+ return true;
+ }
+ }
+ }
+
+ private void FixupFirstLefts1(OutRec oldOutRec, OutRec newOutRec)
+ {
+ foreach (OutRec outRec in this.polyOuts)
+ {
+ OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
+ if (outRec.Pts != null && firstLeft == oldOutRec)
+ {
+ if (Poly2ContainsPoly1(outRec.Pts, newOutRec.Pts))
+ {
+ outRec.FirstLeft = newOutRec;
+ }
+ }
+ }
+ }
+
+ private void FixupFirstLefts2(OutRec innerOutRec, OutRec outerOutRec)
+ {
+ // A polygon has split into two such that one is now the inner of the other.
+ // It's possible that these polygons now wrap around other polygons, so check
+ // every polygon that's also contained by OuterOutRec's FirstLeft container
+ // (including nil) to see if they've become inner to the new inner polygon ...
+ OutRec orfl = outerOutRec.FirstLeft;
+ foreach (OutRec outRec in this.polyOuts)
+ {
+ if (outRec.Pts == null || outRec == outerOutRec || outRec == innerOutRec)
+ {
+ continue;
+ }
+
+ OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
+ if (firstLeft != orfl && firstLeft != innerOutRec && firstLeft != outerOutRec)
+ {
+ continue;
+ }
+
+ if (Poly2ContainsPoly1(outRec.Pts, innerOutRec.Pts))
+ {
+ outRec.FirstLeft = innerOutRec;
+ }
+ else if (Poly2ContainsPoly1(outRec.Pts, outerOutRec.Pts))
+ {
+ outRec.FirstLeft = outerOutRec;
+ }
+ else if (outRec.FirstLeft == innerOutRec || outRec.FirstLeft == outerOutRec)
+ {
+ outRec.FirstLeft = orfl;
+ }
+ }
+ }
+
+ private void FixupFirstLefts3(OutRec oldOutRec, OutRec newOutRec)
+ {
+ // same as FixupFirstLefts1 but doesn't call Poly2ContainsPoly1()
+ foreach (OutRec outRec in this.polyOuts)
+ {
+ OutRec firstLeft = ParseFirstLeft(outRec.FirstLeft);
+ if (outRec.Pts != null && outRec.FirstLeft == oldOutRec)
+ {
+ outRec.FirstLeft = newOutRec;
+ }
+ }
+ }
+
+ private void JoinCommonEdges()
+ {
+ for (int i = 0; i < this.joins.Count; i++)
+ {
+ Join join = this.joins[i];
+
+ OutRec outRec1 = this.GetOutRec(join.OutPt1.Idx);
+ OutRec outRec2 = this.GetOutRec(join.OutPt2.Idx);
+
+ if (outRec1.Pts == null || outRec2.Pts == null)
+ {
+ continue;
+ }
+
+ if (outRec1.IsOpen || outRec2.IsOpen)
+ {
+ continue;
+ }
+
+ // get the polygon fragment with the correct hole state (FirstLeft)
+ // before calling JoinPoints() ...
+ OutRec holeStateRec;
+ if (outRec1 == outRec2)
+ {
+ holeStateRec = outRec1;
+ }
+ else if (this.OutRec1RightOfOutRec2(outRec1, outRec2))
+ {
+ holeStateRec = outRec2;
+ }
+ else if (this.OutRec1RightOfOutRec2(outRec2, outRec1))
+ {
+ holeStateRec = outRec1;
+ }
+ else
+ {
+ holeStateRec = this.GetLowermostRec(outRec1, outRec2);
+ }
+
+ if (!this.JoinPoints(join, outRec1, outRec2))
+ {
+ continue;
+ }
+
+ if (outRec1 == outRec2)
+ {
+ // instead of joining two polygons, we've just created a new one by
+ // splitting one polygon into two.
+ outRec1.Pts = join.OutPt1;
+ outRec1.BottomPt = null;
+ outRec2 = this.CreateOutRec();
+ outRec2.Pts = join.OutPt2;
+
+ // update all OutRec2.Pts Idx's ...
+ this.UpdateOutPtIdxs(outRec2);
+
+ if (Poly2ContainsPoly1(outRec2.Pts, outRec1.Pts))
+ {
+ // outRec1 contains outRec2 ...
+ outRec2.IsHole = !outRec1.IsHole;
+ outRec2.FirstLeft = outRec1;
+
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts2(outRec2, outRec1);
+ }
+ }
+ else if (Poly2ContainsPoly1(outRec1.Pts, outRec2.Pts))
+ {
+ // outRec2 contains outRec1 ...
+ outRec2.IsHole = outRec1.IsHole;
+ outRec1.IsHole = !outRec2.IsHole;
+ outRec2.FirstLeft = outRec1.FirstLeft;
+ outRec1.FirstLeft = outRec2;
+
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts2(outRec1, outRec2);
+ }
+ }
+ else
+ {
+ // the 2 polygons are completely separate ...
+ outRec2.IsHole = outRec1.IsHole;
+ outRec2.FirstLeft = outRec1.FirstLeft;
+
+ // fixup FirstLeft pointers that may need reassigning to OutRec2
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts1(outRec1, outRec2);
+ }
+ }
+ }
+ else
+ {
+ // joined 2 polygons together ...
+ outRec2.Pts = null;
+ outRec2.BottomPt = null;
+ outRec2.Idx = outRec1.Idx;
+
+ outRec1.IsHole = holeStateRec.IsHole;
+ if (holeStateRec == outRec2)
+ {
+ outRec1.FirstLeft = outRec2.FirstLeft;
+ }
+
+ outRec2.FirstLeft = outRec1;
+
+ // fixup FirstLeft pointers that may need reassigning to OutRec1
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts3(outRec2, outRec1);
+ }
+ }
+ }
+ }
+
+ private void UpdateOutPtIdxs(OutRec outrec)
+ {
+ OutPt op = outrec.Pts;
+ do
+ {
+ op.Idx = outrec.Idx;
+ op = op.Prev;
+ }
+ while (op != outrec.Pts);
+ }
+
+ private void DoSimplePolygons()
+ {
+ int i = 0;
+ while (i < this.polyOuts.Count)
+ {
+ OutRec outrec = this.polyOuts[i++];
+ OutPt op = outrec.Pts;
+ if (op == null || outrec.IsOpen)
+ {
+ continue;
+ }
+
+ do
+ {
+ // for each Pt in Polygon until duplicate found do ...
+ OutPt op2 = op.Next;
+ while (op2 != outrec.Pts)
+ {
+ if ((op.Pt == op2.Pt) && op2.Next != op && op2.Prev != op)
+ {
+ // split the polygon into two ...
+ OutPt op3 = op.Prev;
+ OutPt op4 = op2.Prev;
+ op.Prev = op4;
+ op4.Next = op;
+ op2.Prev = op3;
+ op3.Next = op2;
+
+ outrec.Pts = op;
+ OutRec outrec2 = this.CreateOutRec();
+ outrec2.Pts = op2;
+ this.UpdateOutPtIdxs(outrec2);
+ if (Poly2ContainsPoly1(outrec2.Pts, outrec.Pts))
+ {
+ // OutRec2 is contained by OutRec1 ...
+ outrec2.IsHole = !outrec.IsHole;
+ outrec2.FirstLeft = outrec;
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts2(outrec2, outrec);
+ }
+ }
+ else
+ if (Poly2ContainsPoly1(outrec.Pts, outrec2.Pts))
+ {
+ // OutRec1 is contained by OutRec2 ...
+ outrec2.IsHole = outrec.IsHole;
+ outrec.IsHole = !outrec2.IsHole;
+ outrec2.FirstLeft = outrec.FirstLeft;
+ outrec.FirstLeft = outrec2;
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts2(outrec, outrec2);
+ }
+ }
+ else
+ {
+ // the 2 polygons are separate ...
+ outrec2.IsHole = outrec.IsHole;
+ outrec2.FirstLeft = outrec.FirstLeft;
+ if (this.usingPolyTree)
+ {
+ this.FixupFirstLefts1(outrec, outrec2);
+ }
+ }
+
+ op2 = op; // ie get ready for the next iteration
+ }
+
+ op2 = op2.Next;
+ }
+
+ op = op.Next;
+ }
+ while (op != outrec.Pts);
+ }
+ }
+
+ private double Area(OutRec outRec)
+ {
+ return this.Area(outRec.Pts);
+ }
+
+ private double Area(OutPt op)
+ {
+ OutPt opFirst = op;
+ if (op == null)
+ {
+ return 0;
+ }
+
+ double a = 0;
+ do
+ {
+ a = a + ((op.Prev.Pt.X + op.Pt.X) * (op.Prev.Pt.Y - op.Pt.Y));
+ op = op.Next;
+ }
+ while (op != opFirst);
+
+ return a * 0.5;
+ }
+
+ private void SetDx(TEdge e)
+ {
+ e.Delta.X = e.Top.X - e.Bot.X;
+ e.Delta.Y = e.Top.Y - e.Bot.Y;
+ if (e.Delta.Y == 0)
+ {
+ e.Dx = HorizontalDeltaLimit;
+ }
+ else
+ {
+ e.Dx = e.Delta.X / e.Delta.Y;
+ }
+ }
+
+ private void InsertLocalMinima(LocalMinima newLm)
+ {
+ if (this.minimaList == null)
+ {
+ this.minimaList = newLm;
+ }
+ else if (newLm.Y >= this.minimaList.Y)
+ {
+ newLm.Next = this.minimaList;
+ this.minimaList = newLm;
+ }
+ else
+ {
+ LocalMinima tmpLm = this.minimaList;
+ while (tmpLm.Next != null && (newLm.Y < tmpLm.Next.Y))
+ {
+ tmpLm = tmpLm.Next;
+ }
+
+ newLm.Next = tmpLm.Next;
+ tmpLm.Next = newLm;
+ }
+ }
+
+ private bool PopLocalMinima(float y, out LocalMinima current)
+ {
+ current = this.currentLM;
+ if (this.currentLM != null && this.currentLM.Y == y)
+ {
+ this.currentLM = this.currentLM.Next;
+ return true;
+ }
+
+ return false;
+ }
+
+ private void Reset()
+ {
+ this.currentLM = this.minimaList;
+ if (this.currentLM == null)
+ {
+ return; // ie nothing to process
+ }
+
+ // reset all edges ...
+ this.scanbeam = null;
+ LocalMinima lm = this.minimaList;
+ while (lm != null)
+ {
+ this.InsertScanbeam(lm.Y);
+ TEdge e = lm.LeftBound;
+ if (e != null)
+ {
+ e.Curr = e.Bot;
+ e.OutIdx = Unassigned;
+ }
+
+ e = lm.RightBound;
+ if (e != null)
+ {
+ e.Curr = e.Bot;
+ e.OutIdx = Unassigned;
+ }
+
+ lm = lm.Next;
+ }
+
+ this.activeEdges = null;
+ }
+
+ private void InsertScanbeam(float y)
+ {
+ // single-linked list: sorted descending, ignoring dups.
+ if (this.scanbeam == null)
+ {
+ this.scanbeam = new Scanbeam();
+ this.scanbeam.Next = null;
+ this.scanbeam.Y = y;
+ }
+ else if (y > this.scanbeam.Y)
+ {
+ Scanbeam newSb = new Scanbeam();
+ newSb.Y = y;
+ newSb.Next = this.scanbeam;
+ this.scanbeam = newSb;
+ }
+ else
+ {
+ Scanbeam sb2 = this.scanbeam;
+ while (sb2.Next != null && (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;
+ }
+ }
+
+ private bool PopScanbeam(out float y)
+ {
+ if (this.scanbeam == null)
+ {
+ y = 0;
+ return false;
+ }
+
+ y = this.scanbeam.Y;
+ this.scanbeam = this.scanbeam.Next;
+ return true;
+ }
+
+ private bool LocalMinimaPending()
+ {
+ return this.currentLM != null;
+ }
+
+ private OutRec CreateOutRec()
+ {
+ OutRec result = new OutRec();
+ result.Idx = Unassigned;
+ result.IsHole = false;
+ result.IsOpen = false;
+ result.FirstLeft = null;
+ result.Pts = null;
+ result.BottomPt = null;
+ result.PolyNode = null;
+ this.polyOuts.Add(result);
+ result.Idx = this.polyOuts.Count - 1;
+ return result;
+ }
+
+ private void DisposeOutRec(int index)
+ {
+ OutRec outRec = this.polyOuts[index];
+ outRec.Pts = null;
+ outRec = null;
+ this.polyOuts[index] = null;
+ }
+
+ private void UpdateEdgeIntoAEL(ref TEdge e)
+ {
+ if (e.NextInLML == null)
+ {
+ throw new ClipperException("UpdateEdgeIntoAEL: invalid call");
+ }
+
+ TEdge aelPrev = e.PrevInAEL;
+ TEdge aelNext = e.NextInAEL;
+ e.NextInLML.OutIdx = e.OutIdx;
+ if (aelPrev != null)
+ {
+ aelPrev.NextInAEL = e.NextInLML;
+ }
+ else
+ {
+ this.activeEdges = e.NextInLML;
+ }
+
+ if (aelNext != null)
+ {
+ aelNext.PrevInAEL = e.NextInLML;
+ }
+
+ e.NextInLML.Side = e.Side;
+ e.NextInLML.WindDelta = e.WindDelta;
+ e.NextInLML.WindCnt = e.WindCnt;
+ e.NextInLML.WindCnt2 = e.WindCnt2;
+ e = e.NextInLML;
+ e.Curr = e.Bot;
+ e.PrevInAEL = aelPrev;
+ e.NextInAEL = aelNext;
+ if (!IsHorizontal(e))
+ {
+ this.InsertScanbeam(e.Top.Y);
+ }
+ }
+
+ private void SwapPositionsInAEL(TEdge edge1, TEdge edge2)
+ {
+ // check that one or other edge hasn't already been removed from AEL ...
+ if (edge1.NextInAEL == edge1.PrevInAEL ||
+ edge2.NextInAEL == edge2.PrevInAEL)
+ {
+ return;
+ }
+
+ if (edge1.NextInAEL == edge2)
+ {
+ TEdge next = edge2.NextInAEL;
+ if (next != null)
+ {
+ next.PrevInAEL = edge1;
+ }
+
+ TEdge prev = edge1.PrevInAEL;
+ if (prev != null)
+ {
+ 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 != null)
+ {
+ next.PrevInAEL = edge2;
+ }
+
+ TEdge prev = edge2.PrevInAEL;
+ if (prev != null)
+ {
+ 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 != null)
+ {
+ edge1.NextInAEL.PrevInAEL = edge1;
+ }
+
+ edge1.PrevInAEL = edge2.PrevInAEL;
+ if (edge1.PrevInAEL != null)
+ {
+ edge1.PrevInAEL.NextInAEL = edge1;
+ }
+
+ edge2.NextInAEL = next;
+ if (edge2.NextInAEL != null)
+ {
+ edge2.NextInAEL.PrevInAEL = edge2;
+ }
+
+ edge2.PrevInAEL = prev;
+ if (edge2.PrevInAEL != null)
+ {
+ edge2.PrevInAEL.NextInAEL = edge2;
+ }
+ }
+
+ if (edge1.PrevInAEL == null)
+ {
+ this.activeEdges = edge1;
+ }
+ else if (edge2.PrevInAEL == null)
+ {
+ this.activeEdges = edge2;
+ }
+ }
+
+ private void DeleteFromAEL(TEdge e)
+ {
+ TEdge aelPrev = e.PrevInAEL;
+ TEdge aelNext = e.NextInAEL;
+ if (aelPrev == null && aelNext == null && (e != this.activeEdges))
+ {
+ return; // already deleted
+ }
+
+ if (aelPrev != null)
+ {
+ aelPrev.NextInAEL = aelNext;
+ }
+ else
+ {
+ this.activeEdges = aelNext;
+ }
+
+ if (aelNext != null)
+ {
+ aelNext.PrevInAEL = aelPrev;
+ }
+
+ e.NextInAEL = null;
+ e.PrevInAEL = null;
+ }
+
+ private void InitEdge2(TEdge e, PolyType polyType)
+ {
+ if (e.Curr.Y >= e.Next.Curr.Y)
+ {
+ e.Bot = e.Curr;
+ e.Top = e.Next.Curr;
+ }
+ else
+ {
+ e.Top = e.Curr;
+ e.Bot = e.Next.Curr;
+ }
+
+ this.SetDx(e);
+ e.PolyTyp = polyType;
+ }
+
+ private TEdge ProcessBound(TEdge edge, bool leftBoundIsForward)
+ {
+ TEdge eStart, result = edge;
+ TEdge horz;
+
+ if (result.OutIdx == Skip)
+ {
+ // check if there are edges beyond the skip edge in the bound and if so
+ // create another LocMin and calling ProcessBound once more ...
+ edge = result;
+ if (leftBoundIsForward)
+ {
+ while (edge.Top.Y == edge.Next.Bot.Y)
+ {
+ edge = edge.Next;
+ }
+
+ while (edge != result && edge.Dx == HorizontalDeltaLimit)
+ {
+ edge = edge.Prev;
+ }
+ }
+ else
+ {
+ while (edge.Top.Y == edge.Prev.Bot.Y)
+ {
+ edge = edge.Prev;
+ }
+
+ while (edge != result && edge.Dx == HorizontalDeltaLimit)
+ {
+ edge = edge.Next;
+ }
+ }
+
+ if (edge == result)
+ {
+ if (leftBoundIsForward)
+ {
+ result = edge.Next;
+ }
+ else
+ {
+ result = edge.Prev;
+ }
+ }
+ else
+ {
+ // there are more edges in the bound beyond result starting with E
+ if (leftBoundIsForward)
+ {
+ edge = result.Next;
+ }
+ else
+ {
+ edge = result.Prev;
+ }
+
+ LocalMinima locMin = new LocalMinima();
+ locMin.Next = null;
+ locMin.Y = edge.Bot.Y;
+ locMin.LeftBound = null;
+ locMin.RightBound = edge;
+ edge.WindDelta = 0;
+ result = this.ProcessBound(edge, leftBoundIsForward);
+ this.InsertLocalMinima(locMin);
+ }
+
+ return result;
+ }
+
+ if (edge.Dx == HorizontalDeltaLimit)
+ {
+ // We need to be careful with open paths because this may not be a
+ // true local minima (ie E may be following a skip edge).
+ // Also, consecutive horz. edges may start heading left before going right.
+ if (leftBoundIsForward)
+ {
+ eStart = edge.Prev;
+ }
+ else
+ {
+ eStart = edge.Next;
+ }
+
+ // ie an adjoining horizontal skip edge
+ if (eStart.Dx == HorizontalDeltaLimit)
+ {
+ if (eStart.Bot.X != edge.Bot.X && eStart.Top.X != edge.Bot.X)
+ {
+ ReverseHorizontal(edge);
+ }
+ }
+ else if (eStart.Bot.X != edge.Bot.X)
+ {
+ ReverseHorizontal(edge);
+ }
+ }
+
+ eStart = edge;
+ if (leftBoundIsForward)
+ {
+ while (result.Top.Y == result.Next.Bot.Y && result.Next.OutIdx != Skip)
+ {
+ result = result.Next;
+ }
+
+ if (result.Dx == HorizontalDeltaLimit && result.Next.OutIdx != Skip)
+ {
+ // nb: at the top of a bound, horizontals are added to the bound
+ // only when the preceding edge attaches to the horizontal's left vertex
+ // unless a Skip edge is encountered when that becomes the top divide
+ horz = result;
+ while (horz.Prev.Dx == HorizontalDeltaLimit)
+ {
+ horz = horz.Prev;
+ }
+
+ if (horz.Prev.Top.X > result.Next.Top.X)
+ {
+ result = horz.Prev;
+ }
+ }
+
+ while (edge != result)
+ {
+ edge.NextInLML = edge.Next;
+ if (edge.Dx == HorizontalDeltaLimit && edge != eStart && edge.Bot.X != edge.Prev.Top.X)
+ {
+ ReverseHorizontal(edge);
+ }
+
+ edge = edge.Next;
+ }
+
+ if (edge.Dx == HorizontalDeltaLimit && edge != eStart && edge.Bot.X != edge.Prev.Top.X)
+ {
+ ReverseHorizontal(edge);
+ }
+
+ result = result.Next; // move to the edge just beyond current bound
+ }
+ else
+ {
+ while (result.Top.Y == result.Prev.Bot.Y && result.Prev.OutIdx != Skip)
+ {
+ result = result.Prev;
+ }
+
+ if (result.Dx == HorizontalDeltaLimit && result.Prev.OutIdx != Skip)
+ {
+ horz = result;
+ while (horz.Next.Dx == HorizontalDeltaLimit)
+ {
+ horz = horz.Next;
+ }
+
+ if (horz.Next.Top.X == result.Prev.Top.X || horz.Next.Top.X > result.Prev.Top.X)
+ {
+ result = horz.Next;
+ }
+ }
+
+ while (edge != result)
+ {
+ edge.NextInLML = edge.Prev;
+ if (edge.Dx == HorizontalDeltaLimit && edge != eStart && edge.Bot.X != edge.Next.Top.X)
+ {
+ ReverseHorizontal(edge);
+ }
+
+ edge = edge.Prev;
+ }
+
+ if (edge.Dx == HorizontalDeltaLimit && edge != eStart && edge.Bot.X != edge.Next.Top.X)
+ {
+ ReverseHorizontal(edge);
+ }
+
+ result = result.Prev; // move to the edge just beyond current bound
+ }
+
+ return result;
+ }
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/ClipperException.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/ClipperException.cs
new file mode 100644
index 000000000..cefd268af
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/ClipperException.cs
@@ -0,0 +1,31 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Clipper Exception
+ ///
+ ///
+ internal class ClipperException : Exception
+ {
+ ///
+ /// Initializes a new instance of the class.
+ ///
+ /// The description.
+ public ClipperException(string description)
+ : base(description)
+ {
+ }
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/Direction.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Direction.cs
new file mode 100644
index 000000000..5fa877fd4
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Direction.cs
@@ -0,0 +1,31 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ???
+ ///
+ internal enum Direction
+ {
+ ///
+ /// The right to left
+ ///
+ RightToLeft,
+
+ ///
+ /// The left to right
+ ///
+ LeftToRight
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/EdgeSide.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/EdgeSide.cs
new file mode 100644
index 000000000..5093958d1
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/EdgeSide.cs
@@ -0,0 +1,31 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal enum EdgeSide
+ {
+ ///
+ /// The left
+ ///
+ Left,
+
+ ///
+ /// The right
+ ///
+ Right
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNode.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNode.cs
new file mode 100644
index 000000000..7cd0562b0
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNode.cs
@@ -0,0 +1,38 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal class IntersectNode
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The edge1
+ ///
+ internal TEdge Edge1;
+
+ ///
+ /// The edge2
+ ///
+ internal TEdge Edge2;
+
+ ///
+ /// The pt
+ ///
+ internal System.Numerics.Vector2 Pt;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNodeSort.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNodeSort.cs
new file mode 100644
index 000000000..f4524fa9b
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/IntersectNodeSort.cs
@@ -0,0 +1,48 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Compares s
+ ///
+ internal class IntersectNodeSort : IComparer
+ {
+ ///
+ /// Compares the specified node1.
+ ///
+ /// The node1.
+ /// The node2.
+ ///
+ /// 1 if node2 %gt; node1
+ /// -1 if node2 $lt; node1
+ /// 0 if same
+ ///
+ public int Compare(IntersectNode node1, IntersectNode node2)
+ {
+ float i = node2.Pt.Y - node1.Pt.Y;
+ if (i > 0)
+ {
+ return 1;
+ }
+ else if (i < 0)
+ {
+ return -1;
+ }
+ else
+ {
+ return 0;
+ }
+ }
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/Join.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Join.cs
new file mode 100644
index 000000000..be948fbf7
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Join.cs
@@ -0,0 +1,38 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal class Join
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The out PT1
+ ///
+ internal OutPt OutPt1;
+
+ ///
+ /// The out PT2
+ ///
+ internal OutPt OutPt2;
+
+ ///
+ /// The off pt
+ ///
+ internal System.Numerics.Vector2 OffPt;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/LocalMinima.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/LocalMinima.cs
new file mode 100644
index 000000000..b48a53cab
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/LocalMinima.cs
@@ -0,0 +1,44 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal class LocalMinima
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The y
+ ///
+ internal float Y;
+
+ ///
+ /// The left bound
+ ///
+ internal TEdge LeftBound;
+
+ ///
+ /// The right bound
+ ///
+ internal TEdge RightBound;
+
+ ///
+ /// The next
+ ///
+ internal LocalMinima Next;
+
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/Maxima.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Maxima.cs
new file mode 100644
index 000000000..85168e8e8
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Maxima.cs
@@ -0,0 +1,38 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal class Maxima
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The x
+ ///
+ internal float X;
+
+ ///
+ /// The next
+ ///
+ internal Maxima Next;
+
+ ///
+ /// The previous
+ ///
+ internal Maxima Prev;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutPt.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutPt.cs
new file mode 100644
index 000000000..8dae5780a
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutPt.cs
@@ -0,0 +1,43 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// ??
+ ///
+ internal class OutPt
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The index
+ ///
+ internal int Idx;
+
+ ///
+ /// The pt
+ ///
+ internal System.Numerics.Vector2 Pt;
+
+ ///
+ /// The next
+ ///
+ internal OutPt Next;
+
+ ///
+ /// The previous
+ ///
+ internal OutPt Prev;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutRec.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutRec.cs
new file mode 100644
index 000000000..7c2d41a72
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/OutRec.cs
@@ -0,0 +1,64 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// OutRec: contains a path in the clipping solution. Edges in the AEL will
+ /// carry a pointer to an OutRec when they are part of the clipping solution.
+ ///
+ internal class OutRec
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The source path
+ ///
+ internal IPath SourcePath;
+
+ ///
+ /// The index
+ ///
+ internal int Idx;
+
+ ///
+ /// The is hole
+ ///
+ internal bool IsHole;
+
+ ///
+ /// The is open
+ ///
+ internal bool IsOpen;
+
+ ///
+ /// The first left
+ ///
+ internal OutRec FirstLeft;
+
+ ///
+ /// The PTS
+ ///
+ internal OutPt Pts;
+
+ ///
+ /// The bottom pt
+ ///
+ internal OutPt BottomPt;
+
+ ///
+ /// The poly node
+ ///
+ internal PolyNode PolyNode;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyNode.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyNode.cs
new file mode 100644
index 000000000..9d9c35504
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyNode.cs
@@ -0,0 +1,179 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Poly Node
+ ///
+ internal class PolyNode
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The polygon
+ ///
+ internal List Polygon = new List();
+
+ ///
+ /// The index
+ ///
+ internal int Index;
+
+ ///
+ /// The childs
+ ///
+ protected List children = new List();
+
+ private PolyNode parent;
+#pragma warning restore SA1401 // Field must be private
+
+ ///
+ /// Gets the child count.
+ ///
+ ///
+ /// The child count.
+ ///
+ public int ChildCount
+ {
+ get { return this.children.Count; }
+ }
+
+ ///
+ /// Gets the contour.
+ ///
+ ///
+ /// The contour.
+ ///
+ public List Contour
+ {
+ get { return this.Polygon; }
+ }
+
+ ///
+ /// Gets the childs.
+ ///
+ ///
+ /// The childs.
+ ///
+ public List Children
+ {
+ get { return this.children; }
+ }
+
+ ///
+ /// Gets or sets the parent.
+ ///
+ ///
+ /// The parent.
+ ///
+ public PolyNode Parent
+ {
+ get { return this.parent; }
+ internal set { this.parent = value; }
+ }
+
+ ///
+ /// Gets a value indicating whether this instance is hole.
+ ///
+ ///
+ /// true if this instance is hole; otherwise, false.
+ ///
+ public bool IsHole
+ {
+ get { return this.IsHoleNode(); }
+ }
+
+ ///
+ /// Gets or sets a value indicating whether this instance is open.
+ ///
+ ///
+ /// true if this instance is open; otherwise, false.
+ ///
+ public bool IsOpen { get; set; }
+
+ ///
+ /// Gets or sets the source path.
+ ///
+ ///
+ /// The source path.
+ ///
+ public IPath SourcePath { get; internal set; }
+
+ ///
+ /// Gets the next.
+ ///
+ /// The next node
+ public PolyNode GetNext()
+ {
+ if (this.children.Count > 0)
+ {
+ return this.children[0];
+ }
+ else
+ {
+ return this.GetNextSiblingUp();
+ }
+ }
+
+ ///
+ /// Adds the child.
+ ///
+ /// The child.
+ internal void AddChild(PolyNode child)
+ {
+ int cnt = this.children.Count;
+ this.children.Add(child);
+ child.parent = this;
+ child.Index = cnt;
+ }
+
+ ///
+ /// Gets the next sibling up.
+ ///
+ /// The next sibling up
+ internal PolyNode GetNextSiblingUp()
+ {
+ if (this.parent == null)
+ {
+ return null;
+ }
+ else if (this.Index == this.parent.children.Count - 1)
+ {
+ return this.parent.GetNextSiblingUp();
+ }
+ else
+ {
+ return this.parent.Children[this.Index + 1];
+ }
+ }
+
+ ///
+ /// Determines whether [is hole node].
+ ///
+ ///
+ /// true if [is hole node]; otherwise, false.
+ ///
+ private bool IsHoleNode()
+ {
+ bool result = true;
+ PolyNode node = this.parent;
+ while (node != null)
+ {
+ result = !result;
+ node = node.parent;
+ }
+
+ return result;
+ }
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyTree.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyTree.cs
new file mode 100644
index 000000000..3c35f389c
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyTree.cs
@@ -0,0 +1,81 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Poly Tree
+ ///
+ ///
+ internal class PolyTree : PolyNode
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// All polys
+ ///
+ internal List AllPolys = new List();
+#pragma warning restore SA1401 // Field must be private
+
+ ///
+ /// Gets the total.
+ ///
+ ///
+ /// The total.
+ ///
+ public int Total
+ {
+ get
+ {
+ int result = this.AllPolys.Count;
+
+ // with negative offsets, ignore the hidden outer polygon ...
+ if (result > 0 && this.Children[0] != this.AllPolys[0])
+ {
+ result--;
+ }
+
+ return result;
+ }
+ }
+
+ ///
+ /// Clears this instance.
+ ///
+ public void Clear()
+ {
+ for (int i = 0; i < this.AllPolys.Count; i++)
+ {
+ this.AllPolys[i] = null;
+ }
+
+ this.AllPolys.Clear();
+ this.Children.Clear();
+ }
+
+ ///
+ /// Gets the first.
+ ///
+ /// the first node
+ public PolyNode GetFirst()
+ {
+ if (this.Children.Count > 0)
+ {
+ return this.Children[0];
+ }
+ else
+ {
+ return null;
+ }
+ }
+ }
+}
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyType.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyType.cs
new file mode 100644
index 000000000..2a130f509
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/PolyType.cs
@@ -0,0 +1,31 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Poly Type
+ ///
+ internal enum PolyType
+ {
+ ///
+ /// The subject
+ ///
+ Subject,
+
+ ///
+ /// The clip
+ ///
+ Clip
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/README.md b/src/ImageSharp/Drawing/Shapes/PolygonClipper/README.md
new file mode 100644
index 000000000..c0f2ff65f
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/README.md
@@ -0,0 +1,40 @@
+# Clipper
+
+License details for code in this folder, this is code original written by **Angus Johnson**
+
+The license header onthe original file which has now be split across multiple files in this folder.
+
+```
+/*******************************************************************************
+* *
+* Author : Angus Johnson *
+* Version : 6.4.0 *
+* Date : 2 July 2015 *
+* Website : http://www.angusj.com *
+* Copyright : Angus Johnson 2010-2015 *
+* *
+* License: *
+* Use, modification & distribution is subject to Boost Software License Ver 1. *
+* http://www.boost.org/LICENSE_1_0.txt *
+* *
+* Attributions: *
+* The code in this library is an extension of Bala Vatti's clipping algorithm: *
+* "A generic solution to polygon clipping" *
+* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63. *
+* http://portal.acm.org/citation.cfm?id=129906 *
+* *
+* Computer graphics and geometric modeling: implementation and algorithms *
+* By Max K. Agoston *
+* Springer; 1 edition (January 4, 2005) *
+* http://books.google.com/books?q=vatti+clipping+agoston *
+* *
+* See also: *
+* "Polygon Offsetting by Computing Winding Numbers" *
+* Paper no. DETC2005-85513 pp. 565-575 *
+* ASME 2005 International Design Engineering Technical Conferences *
+* and Computers and Information in Engineering Conference (IDETC/CIE2005) *
+* September 24-28, 2005 , Long Beach, California, USA *
+* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf *
+* *
+*******************************************************************************/
+```
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/Scanbeam.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Scanbeam.cs
new file mode 100644
index 000000000..28b341004
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/Scanbeam.cs
@@ -0,0 +1,33 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// Scanbeam
+ ///
+ internal class Scanbeam // would this work as a struct?
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The y
+ ///
+ internal float Y;
+
+ ///
+ /// The next
+ ///
+ internal Scanbeam Next;
+#pragma warning restore SA1401 // Field must be private
+ }
+}
\ No newline at end of file
diff --git a/src/ImageSharp/Drawing/Shapes/PolygonClipper/TEdge.cs b/src/ImageSharp/Drawing/Shapes/PolygonClipper/TEdge.cs
new file mode 100644
index 000000000..97f5b2ec7
--- /dev/null
+++ b/src/ImageSharp/Drawing/Shapes/PolygonClipper/TEdge.cs
@@ -0,0 +1,118 @@
+//
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+//
+
+namespace ImageSharp.Drawing.Shapes.PolygonClipper
+{
+ using System;
+ using System.Collections.Generic;
+ using System.Linq;
+ using System.Numerics;
+ using System.Runtime.CompilerServices;
+
+ using Paths;
+
+ ///
+ /// TEdge
+ ///
+ internal class TEdge
+ {
+#pragma warning disable SA1401 // Field must be private
+ ///
+ /// The source path, see if we can link this back later
+ ///
+ internal IPath SourcePath;
+
+ ///
+ /// The bot
+ ///
+ internal System.Numerics.Vector2 Bot;
+
+ ///
+ /// The current (updated for every new scanbeam)
+ ///
+ internal System.Numerics.Vector2 Curr;
+
+ ///
+ /// The top
+ ///
+ internal System.Numerics.Vector2 Top;
+
+ ///
+ /// The delta
+ ///
+ internal System.Numerics.Vector2 Delta;
+
+ ///
+ /// The dx
+ ///
+ internal double Dx;
+
+ ///
+ /// The poly type
+ ///
+ internal PolyType PolyTyp;
+
+ ///
+ /// Side only refers to current side of solution poly
+ ///
+ internal EdgeSide Side;
+
+ ///
+ /// 1 or -1 depending on winding direction
+ ///
+ internal int WindDelta;
+
+ ///
+ /// The winding count
+ ///
+ internal int WindCnt;
+
+ ///
+ /// The winding count of the opposite polytype
+ ///
+ internal int WindCnt2;
+
+ ///
+ /// The out index
+ ///
+ internal int OutIdx;
+
+ ///
+ /// The next
+ ///
+ internal TEdge Next;
+
+ ///
+ /// The previous
+ ///
+ internal TEdge Prev;
+
+ ///
+ /// The next in LML
+ ///
+ internal TEdge NextInLML;
+
+ ///
+ /// The next in ael
+ ///
+ internal TEdge NextInAEL;
+
+ ///
+ /// The previous in ael
+ ///
+ internal TEdge PrevInAEL;
+
+ ///
+ /// The next in sel
+ ///
+ internal TEdge NextInSEL;
+
+ ///
+ /// The previous in sel
+ ///
+ internal TEdge PrevInSEL;
+#pragma warning restore SA1401 // Field must be
+ }
+}
\ No newline at end of file