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Firstborn/Library/PackageCache/com.unity.render-pipelines..../Runtime/2D/Clipper.cs

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/*******************************************************************************
* *
* 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. *
* *
*******************************************************************************/
// Changes introduced. (Venkify).
// * Ability to query Normals along the generated path wrt pivot.
// * Additional information that is helpful if the path needs Tessellation.
// * Above functionality has been tested against single path Offset.
// * Removed unused/unsupported code.
// 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 UnityEngine.Rendering.Universal
{
using ClipInt = Int64;
using Path = List<IntPoint>;
using Paths = List<List<IntPoint>>;
internal struct DoublePoint
{
public double X;
public double Y;
public DoublePoint(double x = 0, double y = 0)
{
this.X = x; this.Y = y;
}
public DoublePoint(DoublePoint dp)
{
this.X = dp.X; this.Y = dp.Y;
}
public DoublePoint(IntPoint ip)
{
this.X = ip.X; this.Y = ip.Y;
}
};
//------------------------------------------------------------------------------
// PolyTree & PolyNode classes
//------------------------------------------------------------------------------
internal class PolyTree : PolyNode
{
internal List<PolyNode> m_AllPolys = new List<PolyNode>();
//The GC probably handles this cleanup more efficiently ...
//~PolyTree(){Clear();}
public void Clear()
{
for (int i = 0; i < m_AllPolys.Count; i++)
m_AllPolys[i] = null;
m_AllPolys.Clear();
m_Childs.Clear();
}
public PolyNode GetFirst()
{
if (m_Childs.Count > 0)
return m_Childs[0];
else
return null;
}
public int Total
{
get
{
int result = m_AllPolys.Count;
//with negative offsets, ignore the hidden outer polygon ...
if (result > 0 && m_Childs[0] != m_AllPolys[0]) result--;
return result;
}
}
}
internal class PolyNode
{
internal PolyNode m_Parent;
internal Path m_polygon = new Path();
internal int m_Index;
internal JoinType m_jointype;
internal EndType m_endtype;
internal List<PolyNode> m_Childs = new List<PolyNode>();
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<PolyNode> Childs
{
get { return m_Childs; }
}
public PolyNode Parent
{
get { return m_Parent; }
}
public bool IsHole
{
get { return IsHoleNode(); }
}
public bool IsOpen { get; set; }
}
//------------------------------------------------------------------------------
// Int128 struct (enables safe math on signed 64bit integers)
// eg Int128 val1((Int64)9223372036854775807); //ie 2^63 -1
// Int128 val2((Int64)9223372036854775807);
// Int128 val3 = val1 * val2;
// val3.ToString => "85070591730234615847396907784232501249" (8.5e+37)
//------------------------------------------------------------------------------
internal struct Int128
{
private Int64 hi;
private UInt64 lo;
public Int128(Int64 _lo)
{
lo = (UInt64)_lo;
if (_lo < 0) hi = -1;
else hi = 0;
}
public Int128(Int64 _hi, UInt64 _lo)
{
lo = _lo;
hi = _hi;
}
public Int128(Int128 val)
{
hi = val.hi;
lo = val.lo;
}
public bool IsNegative()
{
return hi < 0;
}
public static bool operator ==(Int128 val1, Int128 val2)
{
if ((object)val1 == (object)val2) return true;
else if ((object)val1 == null || (object)val2 == null) return false;
return (val1.hi == val2.hi && val1.lo == val2.lo);
}
public static bool operator !=(Int128 val1, Int128 val2)
{
return !(val1 == val2);
}
public override bool Equals(System.Object obj)
{
if (obj == null || !(obj is Int128))
return false;
Int128 i128 = (Int128)obj;
return (i128.hi == hi && i128.lo == lo);
}
public override int GetHashCode()
{
return hi.GetHashCode() ^ lo.GetHashCode();
}
public static bool operator >(Int128 val1, Int128 val2)
{
if (val1.hi != val2.hi)
return val1.hi > val2.hi;
else
return val1.lo > val2.lo;
}
public static bool operator <(Int128 val1, Int128 val2)
{
if (val1.hi != val2.hi)
return val1.hi < val2.hi;
else
return val1.lo < val2.lo;
}
public static Int128 operator +(Int128 lhs, Int128 rhs)
{
lhs.hi += rhs.hi;
lhs.lo += rhs.lo;
if (lhs.lo < rhs.lo) lhs.hi++;
return lhs;
}
public static Int128 operator -(Int128 lhs, Int128 rhs)
{
return lhs + -rhs;
}
public static Int128 operator -(Int128 val)
{
if (val.lo == 0)
return new Int128(-val.hi, 0);
else
return new Int128(~val.hi, ~val.lo + 1);
}
public static explicit operator double(Int128 val)
{
const double shift64 = 18446744073709551616.0; //2^64
if (val.hi < 0)
{
if (val.lo == 0)
return (double)val.hi * shift64;
else
return -(double)(~val.lo + ~val.hi * shift64);
}
else
return (double)(val.lo + val.hi * shift64);
}
//nb: Constructing two new Int128 objects every time we want to multiply longs
//is slow. So, although calling the Int128Mul method doesn't look as clean, the
//code runs significantly faster than if we'd used the * operator.
public static Int128 Int128Mul(Int64 lhs, Int64 rhs)
{
bool negate = (lhs < 0) != (rhs < 0);
if (lhs < 0) lhs = -lhs;
if (rhs < 0) rhs = -rhs;
UInt64 int1Hi = (UInt64)lhs >> 32;
UInt64 int1Lo = (UInt64)lhs & 0xFFFFFFFF;
UInt64 int2Hi = (UInt64)rhs >> 32;
UInt64 int2Lo = (UInt64)rhs & 0xFFFFFFFF;
//nb: see comments in clipper.pas
UInt64 a = int1Hi * int2Hi;
UInt64 b = int1Lo * int2Lo;
UInt64 c = int1Hi * int2Lo + int1Lo * int2Hi;
UInt64 lo;
Int64 hi;
hi = (Int64)(a + (c >> 32));
unchecked { lo = (c << 32) + b; }
if (lo < b) hi++;
Int128 result = new Int128(hi, lo);
return negate ? -result : result;
}
};
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
internal struct IntPoint
{
public ClipInt N;
public ClipInt X;
public ClipInt Y;
public ClipInt D;
public double NX;
public double NY;
public IntPoint(ClipInt X, ClipInt Y)
{
this.X = X; this.Y = Y;
this.NX = 0; this.NY = 0;
this.N = -1; this.D = 0;
}
public IntPoint(double x, double y)
{
this.X = (ClipInt)x; this.Y = (ClipInt)y;
this.NX = 0; this.NY = 0;
this.N = -1; this.D = 0;
}
public IntPoint(IntPoint pt)
{
this.X = pt.X; this.Y = pt.Y;
this.NX = pt.NX; this.NY = pt.NY;
this.N = pt.N; this.D = pt.D;
}
public static bool operator ==(IntPoint a, IntPoint b)
{
return a.X == b.X && a.Y == b.Y;
}
public static bool operator !=(IntPoint a, IntPoint b)
{
return a.X != b.X || a.Y != b.Y;
}
public override bool Equals(object obj)
{
if (obj == null) return false;
if (obj is IntPoint)
{
IntPoint a = (IntPoint)obj;
return (X == a.X) && (Y == a.Y);
}
else return false;
}
public override int GetHashCode()
{
//simply prevents a compiler warning
return base.GetHashCode();
}
}// end struct IntPoint
internal struct IntRect
{
public ClipInt left;
public ClipInt top;
public ClipInt right;
public ClipInt bottom;
public IntRect(ClipInt l, ClipInt t, ClipInt r, ClipInt 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 { jtRound };
public enum EndType { etClosedPolygon, etClosedLine };
internal enum EdgeSide { esLeft, esRight };
internal enum Direction { dRightToLeft, dLeftToRight };
internal class TEdge
{
internal IntPoint Bot;
internal IntPoint Curr; //current (updated for every new scanbeam)
internal IntPoint Top;
internal IntPoint Delta;
internal double Dx;
internal PolyType PolyTyp;
internal EdgeSide Side; //side only refers to current side of solution poly
internal int WindDelta; //1 or -1 depending on winding direction
internal int WindCnt;
internal int WindCnt2; //winding count of the opposite polytype
internal int OutIdx;
internal TEdge Next;
internal TEdge Prev;
internal TEdge NextInLML;
internal TEdge NextInAEL;
internal TEdge PrevInAEL;
internal TEdge NextInSEL;
internal TEdge PrevInSEL;
};
internal class IntersectNode
{
internal TEdge Edge1;
internal TEdge Edge2;
internal IntPoint Pt;
};
internal class MyIntersectNodeSort : IComparer<IntersectNode>
{
public int Compare(IntersectNode node1, IntersectNode node2)
{
ClipInt 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 ClipInt Y;
internal TEdge LeftBound;
internal TEdge RightBound;
internal LocalMinima Next;
};
internal class Scanbeam
{
internal ClipInt Y;
internal Scanbeam Next;
};
internal class Maxima
{
internal ClipInt X;
internal Maxima Next;
internal Maxima Prev;
};
//OutRec: contains a path in the clipping solution. Edges in the AEL will
//carry a pointer to an OutRec when they are part of the clipping solution.
internal class OutRec
{
internal int Idx;
internal bool IsHole;
internal bool IsOpen;
internal OutRec FirstLeft; //see comments in clipper.pas
internal OutPt Pts;
internal OutPt BottomPt;
internal PolyNode PolyNode;
};
internal class OutPt
{
internal int Idx;
internal IntPoint Pt;
internal OutPt Next;
internal OutPt Prev;
};
internal class Join
{
internal OutPt OutPt1;
internal OutPt OutPt2;
internal IntPoint OffPt;
};
internal class ClipperBase
{
internal const double horizontal = -3.4E+38;
internal const int Skip = -2;
internal const int Unassigned = -1;
internal const double tolerance = 1.0E-20;
internal static bool near_zero(double val) { return (val > -tolerance) && (val < tolerance); }
public const ClipInt loRange = 0x3FFFFFFF;
public const ClipInt hiRange = 0x3FFFFFFFFFFFFFFFL;
internal LocalMinima m_MinimaList;
internal LocalMinima m_CurrentLM;
internal List<List<TEdge>> m_edges = new List<List<TEdge>>();
internal Scanbeam m_Scanbeam;
internal List<OutRec> m_PolyOuts;
internal TEdge m_ActiveEdges;
internal bool m_UseFullRange;
internal bool m_HasOpenPaths;
//------------------------------------------------------------------------------
public bool PreserveCollinear
{
get;
set;
}
//------------------------------------------------------------------------------
public void Swap(ref ClipInt val1, ref ClipInt val2)
{
ClipInt 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 (ClipInt)(e1.Delta.Y) * (e2.Delta.X) ==
(ClipInt)(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
(ClipInt)(pt1.Y - pt2.Y) * (pt2.X - pt3.X) - (ClipInt)(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
(ClipInt)(pt1.Y - pt2.Y) * (pt3.X - pt4.X) - (ClipInt)(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<TEdge> edges = new List<TEdge>(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(ClipInt 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);
}
//------------------------------------------------------------------------------
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(ClipInt 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 ClipInt Y)
{
if (m_Scanbeam == null)
{
Y = 0;
return false;
}
Y = m_Scanbeam.Y;
m_Scanbeam = m_Scanbeam.Next;
return true;
}
//------------------------------------------------------------------------------
internal Boolean LocalMinimaPending()
{
return (m_CurrentLM != null);
}
//------------------------------------------------------------------------------
internal OutRec CreateOutRec()
{
OutRec result = new OutRec();
result.Idx = Unassigned;
result.IsHole = false;
result.IsOpen = false;
result.FirstLeft = null;
result.Pts = null;
result.BottomPt = null;
result.PolyNode = null;
m_PolyOuts.Add(result);
result.Idx = m_PolyOuts.Count - 1;
return result;
}
//------------------------------------------------------------------------------
internal void DisposeOutRec(int index)
{
OutRec outRec = m_PolyOuts[index];
outRec.Pts = null;
outRec = null;
m_PolyOuts[index] = null;
}
//------------------------------------------------------------------------------
internal void UpdateEdgeIntoAEL(ref TEdge e)
{
if (e.NextInLML == null)
throw new ClipperException("UpdateEdgeIntoAEL: invalid call");
TEdge AelPrev = e.PrevInAEL;
TEdge AelNext = e.NextInAEL;
e.NextInLML.OutIdx = e.OutIdx;
if (AelPrev != null)
AelPrev.NextInAEL = e.NextInLML;
else m_ActiveEdges = e.NextInLML;
if (AelNext != null)
AelNext.PrevInAEL = e.NextInLML;
e.NextInLML.Side = e.Side;
e.NextInLML.WindDelta = e.WindDelta;
e.NextInLML.WindCnt = e.WindCnt;
e.NextInLML.WindCnt2 = e.WindCnt2;
e = e.NextInLML;
e.Curr = e.Bot;
e.PrevInAEL = AelPrev;
e.NextInAEL = AelNext;
if (!IsHorizontal(e)) InsertScanbeam(e.Top.Y);
}
//------------------------------------------------------------------------------
internal void SwapPositionsInAEL(TEdge edge1, TEdge edge2)
{
//check that one or other edge hasn't already been removed from AEL ...
if (edge1.NextInAEL == edge1.PrevInAEL ||
edge2.NextInAEL == edge2.PrevInAEL) return;
if (edge1.NextInAEL == edge2)
{
TEdge next = edge2.NextInAEL;
if (next != null)
next.PrevInAEL = edge1;
TEdge prev = edge1.PrevInAEL;
if (prev != null)
prev.NextInAEL = edge2;
edge2.PrevInAEL = prev;
edge2.NextInAEL = edge1;
edge1.PrevInAEL = edge2;
edge1.NextInAEL = next;
}
else if (edge2.NextInAEL == edge1)
{
TEdge next = edge1.NextInAEL;
if (next != null)
next.PrevInAEL = edge2;
TEdge prev = edge2.PrevInAEL;
if (prev != null)
prev.NextInAEL = edge1;
edge1.PrevInAEL = prev;
edge1.NextInAEL = edge2;
edge2.PrevInAEL = edge1;
edge2.NextInAEL = next;
}
else
{
TEdge next = edge1.NextInAEL;
TEdge prev = edge1.PrevInAEL;
edge1.NextInAEL = edge2.NextInAEL;
if (edge1.NextInAEL != null)
edge1.NextInAEL.PrevInAEL = edge1;
edge1.PrevInAEL = edge2.PrevInAEL;
if (edge1.PrevInAEL != null)
edge1.PrevInAEL.NextInAEL = edge1;
edge2.NextInAEL = next;
if (edge2.NextInAEL != null)
edge2.NextInAEL.PrevInAEL = edge2;
edge2.PrevInAEL = prev;
if (edge2.PrevInAEL != null)
edge2.PrevInAEL.NextInAEL = edge2;
}
if (edge1.PrevInAEL == null)
m_ActiveEdges = edge1;
else if (edge2.PrevInAEL == null)
m_ActiveEdges = edge2;
}
//------------------------------------------------------------------------------
internal void DeleteFromAEL(TEdge e)
{
TEdge AelPrev = e.PrevInAEL;
TEdge AelNext = e.NextInAEL;
if (AelPrev == null && AelNext == null && (e != m_ActiveEdges))
return; //already deleted
if (AelPrev != null)
AelPrev.NextInAEL = AelNext;
else m_ActiveEdges = AelNext;
if (AelNext != null)
AelNext.PrevInAEL = AelPrev;
e.NextInAEL = null;
e.PrevInAEL = null;
}
//------------------------------------------------------------------------------
} //end ClipperBase
internal class Clipper : ClipperBase
{
//InitOptions that can be passed to the constructor ...
public const int ioReverseSolution = 1;
public const int ioStrictlySimple = 2;
public const int ioPreserveCollinear = 4;
private ClipType m_ClipType;
private Maxima m_Maxima;
private TEdge m_SortedEdges;
private List<IntersectNode> m_IntersectList;
IComparer<IntersectNode> m_IntersectNodeComparer;
private bool m_ExecuteLocked;
private PolyFillType m_ClipFillType;
private PolyFillType m_SubjFillType;
private List<Join> m_Joins;
private List<Join> m_GhostJoins;
private bool m_UsingPolyTree;
public Clipper(int InitOptions = 0) : base() //constructor
{
m_Scanbeam = null;
m_Maxima = null;
m_ActiveEdges = null;
m_SortedEdges = null;
m_IntersectList = new List<IntersectNode>();
m_IntersectNodeComparer = new MyIntersectNodeSort();
m_ExecuteLocked = false;
m_UsingPolyTree = false;
m_PolyOuts = new List<OutRec>();
m_Joins = new List<Join>();
m_GhostJoins = new List<Join>();
ReverseSolution = (ioReverseSolution & InitOptions) != 0;
StrictlySimple = (ioStrictlySimple & InitOptions) != 0;
PreserveCollinear = (ioPreserveCollinear & InitOptions) != 0;
}
//------------------------------------------------------------------------------
private void InsertMaxima(ClipInt 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 int LastIndex
{
get;
set;
}
//------------------------------------------------------------------------------
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;
ClipInt 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);
}
private void InsertLocalMinimaIntoAEL(ClipInt 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)
{
ClipInt xPrev = TopX(prevE, pt.Y);
ClipInt 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(ClipInt seg1a, ClipInt seg1b, ClipInt seg2a, ClipInt 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_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 ...
ClipInt 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 ClipInt Left, out ClipInt 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;
ClipInt horzLeft, horzRight;
bool IsOpen = horzEdge.WindDelta == 0;
GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
TEdge eLastHorz = horzEdge, eMaxPair = null;
while (eLastHorz.NextInLML != null && IsHorizontal(eLastHorz.NextInLML))
eLastHorz = eLastHorz.NextInLML;
if (eLastHorz.NextInLML == null)
eMaxPair = GetMaximaPair(eLastHorz);
Maxima currMax = m_Maxima;
if (currMax != null)
{
//get the first maxima in range (X) ...
if (dir == Direction.dLeftToRight)
{
while (currMax != null && currMax.X <= horzEdge.Bot.X)
currMax = currMax.Next;
if (currMax != null && currMax.X >= eLastHorz.Top.X)
currMax = null;
}
else
{
while (currMax.Next != null && currMax.Next.X < horzEdge.Bot.X)
currMax = currMax.Next;
if (currMax.X <= eLastHorz.Top.X) currMax = null;
}
}
OutPt op1 = null;
for (; ; ) //loop through consec. horizontal edges
{
bool IsLastHorz = (horzEdge == eLastHorz);
TEdge e = GetNextInAEL(horzEdge, dir);
while (e != null)
{
//this code block inserts extra coords into horizontal edges (in output
//polygons) whereever maxima touch these horizontal edges. This helps
//'simplifying' polygons (ie if the Simplify property is set).
if (currMax != null)
{
if (dir == Direction.dLeftToRight)
{
while (currMax != null && currMax.X < e.Curr.X)
{
if (horzEdge.OutIdx >= 0 && !IsOpen)
AddOutPt(horzEdge, new IntPoint(currMax.X, horzEdge.Bot.Y));
currMax = currMax.Next;
}
}
else
{
while (currMax != null && currMax.X > e.Curr.X)
{
if (horzEdge.OutIdx >= 0 && !IsOpen)
AddOutPt(horzEdge, new IntPoint(currMax.X, horzEdge.Bot.Y));
currMax = currMax.Prev;
}
}
}
if ((dir == Direction.dLeftToRight && e.Curr.X > horzRight) ||
(dir == Direction.dRightToLeft && e.Curr.X < horzLeft)) break;
//Also break if we've got to the end of an intermediate horizontal edge ...
//nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
if (e.Curr.X == horzEdge.Top.X && horzEdge.NextInLML != null &&
e.Dx < horzEdge.NextInLML.Dx) break;
if (horzEdge.OutIdx >= 0 && !IsOpen) //note: may be done multiple times
{
op1 = AddOutPt(horzEdge, e.Curr);
TEdge eNextHorz = m_SortedEdges;
while (eNextHorz != null)
{
if (eNextHorz.OutIdx >= 0 &&
HorzSegmentsOverlap(horzEdge.Bot.X,
horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
{
OutPt op2 = GetLastOutPt(eNextHorz);
AddJoin(op2, op1, eNextHorz.Top);
}
eNextHorz = eNextHorz.NextInSEL;
}
AddGhostJoin(op1, horzEdge.Bot);
}
//OK, so far we're still in range of the horizontal Edge but make sure
//we're at the last of consec. horizontals when matching with eMaxPair
if (e == eMaxPair && IsLastHorz)
{
if (horzEdge.OutIdx >= 0)
AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge.Top);
DeleteFromAEL(horzEdge);
DeleteFromAEL(eMaxPair);
return;
}
if (dir == Direction.dLeftToRight)
{
IntPoint Pt = new IntPoint(e.Curr.X, horzEdge.Curr.Y);
IntersectEdges(horzEdge, e, Pt);
}
else
{
IntPoint Pt = new IntPoint(e.Curr.X, horzEdge.Curr.Y);
IntersectEdges(e, horzEdge, Pt);
}
TEdge eNext = GetNextInAEL(e, dir);
SwapPositionsInAEL(horzEdge, e);
e = eNext;
} //end while(e != null)
//Break out of loop if HorzEdge.NextInLML is not also horizontal ...
if (horzEdge.NextInLML == null || !IsHorizontal(horzEdge.NextInLML)) break;
UpdateEdgeIntoAEL(ref horzEdge);
if (horzEdge.OutIdx >= 0) AddOutPt(horzEdge, horzEdge.Bot);
GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
} //end for (;;)
if (horzEdge.OutIdx >= 0 && op1 == null)
{
op1 = GetLastOutPt(horzEdge);
TEdge eNextHorz = m_SortedEdges;
while (eNextHorz != null)
{
if (eNextHorz.OutIdx >= 0 &&
HorzSegmentsOverlap(horzEdge.Bot.X,
horzEdge.Top.X, eNextHorz.Bot.X, eNextHorz.Top.X))
{
OutPt op2 = GetLastOutPt(eNextHorz);
AddJoin(op2, op1, eNextHorz.Top);
}
eNextHorz = eNextHorz.NextInSEL;
}
AddGhostJoin(op1, horzEdge.Top);
}
if (horzEdge.NextInLML != null)
{
if (horzEdge.OutIdx >= 0)
{
op1 = AddOutPt(horzEdge, horzEdge.Top);
UpdateEdgeIntoAEL(ref horzEdge);
if (horzEdge.WindDelta == 0) return;
//nb: HorzEdge is no longer horizontal here
TEdge ePrev = horzEdge.PrevInAEL;
TEdge eNext = horzEdge.NextInAEL;
if (ePrev != null && ePrev.Curr.X == horzEdge.Bot.X &&
ePrev.Curr.Y == horzEdge.Bot.Y && ePrev.WindDelta != 0 &&
(ePrev.OutIdx >= 0 && ePrev.Curr.Y > ePrev.Top.Y &&
SlopesEqual(horzEdge, ePrev, m_UseFullRange)))
{
OutPt op2 = AddOutPt(ePrev, horzEdge.Bot);
AddJoin(op1, op2, horzEdge.Top);
}
else if (eNext != null && eNext.Curr.X == horzEdge.Bot.X &&
eNext.Curr.Y == horzEdge.Bot.Y && eNext.WindDelta != 0 &&
eNext.OutIdx >= 0 && eNext.Curr.Y > eNext.Top.Y &&
SlopesEqual(horzEdge, eNext, m_UseFullRange))
{
OutPt op2 = AddOutPt(eNext, horzEdge.Bot);
AddJoin(op1, op2, horzEdge.Top);
}
}
else
UpdateEdgeIntoAEL(ref horzEdge);
}
else
{
if (horzEdge.OutIdx >= 0) AddOutPt(horzEdge, horzEdge.Top);
DeleteFromAEL(horzEdge);
}
}
//------------------------------------------------------------------------------
private TEdge GetNextInAEL(TEdge e, Direction Direction)
{
return Direction == Direction.dLeftToRight ? e.NextInAEL : e.PrevInAEL;
}
//------------------------------------------------------------------------------
private bool IsMinima(TEdge e)
{
return e != null && (e.Prev.NextInLML != e) && (e.Next.NextInLML != e);
}
//------------------------------------------------------------------------------
private bool IsMaxima(TEdge e, double Y)
{
return (e != null && e.Top.Y == Y && e.NextInLML == null);
}
//------------------------------------------------------------------------------
private bool IsIntermediate(TEdge e, double Y)
{
return (e.Top.Y == Y && e.NextInLML != null);
}
//------------------------------------------------------------------------------
internal TEdge GetMaximaPair(TEdge e)
{
if ((e.Next.Top == e.Top) && e.Next.NextInLML == null)
return e.Next;
else if ((e.Prev.Top == e.Top) && e.Prev.NextInLML == null)
return e.Prev;
else
return null;
}
//------------------------------------------------------------------------------
internal TEdge GetMaximaPairEx(TEdge e)
{
//as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
TEdge result = GetMaximaPair(e);
if (result == null || result.OutIdx == Skip ||
((result.NextInAEL == result.PrevInAEL) && !IsHorizontal(result))) return null;
return result;
}
//------------------------------------------------------------------------------
private bool ProcessIntersections(ClipInt 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(ClipInt 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 ClipInt Round(double value)
{
return value < 0 ? (ClipInt)(value - 0.5) : (ClipInt)(value + 0.5);
}
//------------------------------------------------------------------------------
private static ClipInt TopX(TEdge edge, ClipInt 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();
long pivotPoint = -1;
bool isClamp = (edge2.Curr.N > 0 && edge2.Curr.N < LastIndex) && (edge1.Curr.N > 0 && edge1.Curr.N < LastIndex);
if (edge1.Curr.N > edge2.Curr.N)
{
if (edge2.Curr.N != -1)
{
if (isClamp)
{
pivotPoint = (edge1.Curr.N > 0) ? edge1.Curr.N - 1 : 0;
}
}
else
{
pivotPoint = edge1.Curr.N;
}
}
else
{
if (edge1.Curr.N != -1)
{
if (isClamp)
{
pivotPoint = edge2.Curr.N;
}
}
else
{
pivotPoint = (edge2.Curr.N > 0) ? edge2.Curr.N - 1 : 0;
}
}
ip.D = 2; ip.N = isClamp ? pivotPoint : -1;
//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;
}
double b1, b2;
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(ClipInt topY)
{
TEdge e = m_ActiveEdges;
while (e != null)
{
//1. process maxima, treating them as if they're 'bent' horizontal edges,
// but exclude maxima with horizontal edges. nb: e can't be a horizontal.
bool IsMaximaEdge = IsMaxima(e, topY);
if (IsMaximaEdge)
{
TEdge eMaxPair = GetMaximaPairEx(e);
IsMaximaEdge = (eMaxPair == null || !IsHorizontal(eMaxPair));
}
if (IsMaximaEdge)
{
if (StrictlySimple) InsertMaxima(e.Top.X);
TEdge ePrev = e.PrevInAEL;
DoMaxima(e);
if (ePrev == null) e = m_ActiveEdges;
else e = ePrev.NextInAEL;
}
else
{
//2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
if (IsIntermediate(e, topY) && IsHorizontal(e.NextInLML))
{
UpdateEdgeIntoAEL(ref e);
if (e.OutIdx >= 0)
AddOutPt(e, e.Bot);
AddEdgeToSEL(e);
}
else
{
e.Curr.X = TopX(e, topY);
e.Curr.Y = topY;
}
//When StrictlySimple and 'e' is being touched by another edge, then
//make sure both edges have a vertex here ...
if (StrictlySimple)
{
TEdge ePrev = e.PrevInAEL;
if ((e.OutIdx >= 0) && (e.WindDelta != 0) && ePrev != null &&
(ePrev.OutIdx >= 0) && (ePrev.Curr.X == e.Curr.X) &&
(ePrev.WindDelta != 0))
{
IntPoint ip = new IntPoint(e.Curr);
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(ClipInt a1, ClipInt a2, ClipInt b1, ClipInt b2, out ClipInt Left, out ClipInt 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'
ClipInt 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;
ClipInt ptx = pt.X, pty = pt.Y;
ClipInt poly0x = op.Pt.X, poly0y = op.Pt.Y;
do
{
op = op.Next;
ClipInt 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
internal class ClipperOffset
{
private Paths m_destPolys;
private Path m_srcPoly;
private Path m_destPoly;
private List<DoublePoint> m_normals = new List<DoublePoint>();
private double m_delta, m_sinA, m_sin, m_cos;
private double m_StepsPerRad;
private IntPoint m_lowest;
private PolyNode m_polyNodes = new PolyNode();
public double ArcTolerance { get; set; }
private const double two_pi = Math.PI * 2;
private const double def_arc_tolerance = 0.25;
public ClipperOffset(double arcTolerance = def_arc_tolerance)
{
ArcTolerance = arcTolerance;
m_lowest.X = -1;
}
//------------------------------------------------------------------------------
public void Clear()
{
m_polyNodes.Childs.Clear();
m_lowest.X = -1;
}
//------------------------------------------------------------------------------
internal static ClipInt Round(double value)
{
return value < 0 ? (ClipInt)(value - 0.5) : (ClipInt)(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;
}
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);
{
int j = len - 1;
k = len - 2;
m_sinA = 0;
m_normals[j] = new DoublePoint(-m_normals[j].X, -m_normals[j].Y);
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);
{
k = 1;
m_sinA = 0;
DoRound(0, 1);
}
m_destPolys.Add(m_destPoly);
}
}
}
//------------------------------------------------------------------------------
public void Execute(ref Paths solution, double delta, int inputSize)
{
solution.Clear();
FixOrientations();
DoOffset(delta);
//now clean up 'corners' ...
Clipper clpr = new Clipper();
clpr.AddPaths(m_destPolys, PolyType.ptSubject, true);
clpr.LastIndex = inputSize - 1;
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
{
var item = new IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta));
item.NX = m_normals[k].X; item.NY = m_normals[k].Y; item.N = j; item.D = 1;
m_destPoly.Add(item);
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)
{
var pt = new IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta));
pt.NX = m_normals[k].X; pt.NY = m_normals[k].Y;
m_destPoly.Add(pt);
pt = m_srcPoly[j];
pt.NX = m_normals[k].X; pt.NY = m_normals[k].Y; pt.N = j; pt.D = 1;
m_destPoly.Add(pt);
pt = new IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta));
pt.NX = m_normals[j].X; pt.NY = m_normals[j].Y; pt.N = j; pt.D = 1;
m_destPoly.Add(pt);
}
else
switch (jointype)
{
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);
var pt = 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)));
pt.NX = m_normals[k].X - m_normals[k].Y * dx; pt.NY = m_normals[k].Y + m_normals[k].X * dx;
m_destPoly.Add(pt);
pt = 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)));
pt.NX = m_normals[k].X + m_normals[k].Y * dx; pt.NY = m_normals[k].Y - m_normals[k].X * dx;
m_destPoly.Add(pt);
}
//------------------------------------------------------------------------------
internal void DoMiter(int j, int k, double r)
{
double q = m_delta / r;
var pt = 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));
pt.NX = (m_normals[k].X + m_normals[j].X) * q; pt.NY = (m_normals[k].Y + m_normals[j].Y) * q;
m_destPoly.Add(pt);
}
//------------------------------------------------------------------------------
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)
{
var pt = new IntPoint(
Round(m_srcPoly[j].X + X * m_delta),
Round(m_srcPoly[j].Y + Y * m_delta));
pt.NX = X; pt.NY = Y; pt.N = j; pt.D = 1;
m_destPoly.Add(pt);
X2 = X;
X = X * m_cos - m_sin * Y;
Y = X2 * m_sin + Y * m_cos;
}
var pt1 = new IntPoint(
Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta));
pt1.NX = m_normals[j].X; pt1.NY = m_normals[j].Y; pt1.N = j; pt1.D = 1;
m_destPoly.Add(pt1);
}
//------------------------------------------------------------------------------
}
class ClipperException : Exception
{
public ClipperException(string description) : base(description) { }
}
//------------------------------------------------------------------------------
} //end ClipperLib namespace