/******************************************************************************* * * * Author : Angus Johnson * * Version : 6.4.2 * * Date : 27 February 2017 * * Website : http://www.angusj.com * * Copyright : Angus Johnson 2010-2017 * * * * 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 Cinemachine { #if use_int32 using cInt = Int32; #else using cInt = Int64; #endif using Path = List; using Paths = List>; internal static class ClipperLib { public 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 //------------------------------------------------------------------------------ public 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; } } } public 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; } }; //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ public 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 public 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; } } public enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor }; public 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 public enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative }; public enum JoinType { jtSquare, jtRound, jtMiter }; public 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; }; public class IntersectNode { internal TEdge Edge1; internal TEdge Edge2; internal IntPoint Pt; }; public 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; }; public 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 public 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 && prevE.Top.Y < pt.Y && e.Top.Y < pt.Y) { 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 { #if use_xyz if (dir == Direction.dLeftToRight) SetZ(ref e.Curr, horzEdge, e); else SetZ(ref e.Curr, e, horzEdge); #endif 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; #if use_xyz if (e.Top.Y == topY) e.Curr.Z = e.Top.Z; else if (e.Bot.Y == topY) e.Curr.Z = e.Bot.Z; else e.Curr.Z = 0; #endif } //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 && 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 public 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 } //end Cinemachine namespace