//------------------------------------------------------------------------------
private void AddIntersectNode(TEdge4 e1, TEdge4 e2, IntPoint pt)
{
IntersectNode newNode = new IntersectNode();
newNode.edge1 = e1;
newNode.edge2 = e2;
newNode.pt = pt;
newNode.next = null;
if (m_IntersectNodes == null) m_IntersectNodes = newNode;
else if( Process1Before2(newNode, m_IntersectNodes) )
{
newNode.next = m_IntersectNodes;
m_IntersectNodes = newNode;
}
else
{
IntersectNode iNode = m_IntersectNodes;
while( iNode.next != null && Process1Before2(iNode.next, newNode) )
iNode = iNode.next;
newNode.next = iNode.next;
iNode.next = newNode;
}
}
//------------------------------------------------------------------------------
private void AddLocalMaxPoly(TEdge4 e1, TEdge4 e2, IntPoint pt)
{
AddPolyPt(e1, pt);
if (e1.outIdx == e2.outIdx)
{
e1.outIdx = -1;
e2.outIdx = -1;
}
else AppendPolygon(e1, e2);
}
//------------------------------------------------------------------------------
private void IntersectEdges(TEdge4 e1, TEdge4 e2, IntPoint pt, Protects protects)
{
//e1 will be to the left of e2 BELOW the intersection. Therefore e1 is before
//e2 in AEL except when e1 is being inserted at the intersection point ...
bool e1stops = (Protects.ipLeft & protects) == 0 && e1.nextInLML == null &&
e1.xtop == pt.X && e1.ytop == pt.Y;
bool e2stops = (Protects.ipRight & protects) == 0 && e2.nextInLML == null &&
e2.xtop == pt.X && e2.ytop == pt.Y;
bool e1Contributing = (e1.outIdx >= 0);
bool e2contributing = (e2.outIdx >= 0);
//update winding counts...
//assumes that e1 will be to the right of e2 ABOVE the intersection
if (e1.polyType == e2.polyType)
{
if (IsNonZeroFillType(e1))
{
if (e1.windCnt + e2.windDelta == 0) e1.windCnt = -e1.windCnt;
else e1.windCnt += e2.windDelta;
if (e2.windCnt - e1.windDelta == 0) e2.windCnt = -e2.windCnt;
else e2.windCnt -= e1.windDelta;
}
else
{
int oldE1WindCnt = e1.windCnt;
e1.windCnt = e2.windCnt;
e2.windCnt = oldE1WindCnt;
}
}
else
{
if (IsNonZeroFillType(e2)) e1.windCnt2 += e2.windDelta;
else e1.windCnt2 = (e1.windCnt2 == 0) ? 1 : 0;
if (IsNonZeroFillType(e1)) e2.windCnt2 -= e1.windDelta;
else e2.windCnt2 = (e2.windCnt2 == 0) ? 1 : 0;
}
if (e1Contributing && e2contributing)
{
if (e1stops || e2stops || Math.Abs(e1.windCnt) > 1 ||
Math.Abs(e2.windCnt) > 1 ||
(e1.polyType != e2.polyType && m_ClipType != ClipType.ctXor))
AddLocalMaxPoly(e1, e2, pt);
else
DoBothEdges(e1, e2, pt);
}
else if (e1Contributing)
{
if (m_ClipType == ClipType.ctIntersection)
{
if ((e2.polyType == PolyType.ptSubject || e2.windCnt2 != 0) &&
Math.Abs(e2.windCnt) < 2)
DoEdge1(e1, e2, pt);
}
else
{
if (Math.Abs(e2.windCnt) < 2)
DoEdge1(e1, e2, pt);
}
}
else if (e2contributing)
{
if (m_ClipType == ClipType.ctIntersection)
{
if ((e1.polyType == PolyType.ptSubject || e1.windCnt2 != 0) &&
Math.Abs(e1.windCnt) < 2) DoEdge2(e1, e2, pt);
}
else
{
if (Math.Abs(e1.windCnt) < 2)
DoEdge2(e1, e2, pt);
}
}
else if (Math.Abs(e1.windCnt) < 2 && Math.Abs(e2.windCnt) < 2)
{
//neither edge is currently contributing ...
if (e1.polyType != e2.polyType && !e1stops && !e2stops &&
Math.Abs(e1.windCnt) < 2 && Math.Abs(e2.windCnt) < 2)
AddLocalMinPoly(e1, e2, pt);
else if (Math.Abs(e1.windCnt) == 1 && Math.Abs(e2.windCnt) == 1)
switch (m_ClipType)
{
case ClipType.ctIntersection:
{
if (Math.Abs(e1.windCnt2) > 0 && Math.Abs(e2.windCnt2) > 0)
AddLocalMinPoly(e1, e2, pt);
break;
}
case ClipType.ctUnion:
{
if (e1.windCnt2 == 0 && e2.windCnt2 == 0)
AddLocalMinPoly(e1, e2, pt);
break;
}
case ClipType.ctDifference:
{
if ((e1.polyType == PolyType.ptClip && e2.polyType == PolyType.ptClip &&
e1.windCnt2 != 0 && e2.windCnt2 != 0) ||
(e1.polyType == PolyType.ptSubject && e2.polyType == PolyType.ptSubject &&
e1.windCnt2 == 0 && e2.windCnt2 == 0))
AddLocalMinPoly(e1, e2, pt);
break;
}
case ClipType.ctXor:
{
AddLocalMinPoly(e1, e2, pt);
break;
}
}
else if (Math.Abs(e1.windCnt) < 2 && Math.Abs(e2.windCnt) < 2)
SwapSides(e1, e2);
}
if ((e1stops != e2stops) &&
((e1stops && (e1.outIdx >= 0)) || (e2stops && (e2.outIdx >= 0))))
{
SwapSides(e1, e2);
SwapPolyIndexes(e1, e2);
}
//finally, delete any non-contributing maxima edges ...
if (e1stops) DeleteFromAEL(e1);
if (e2stops) DeleteFromAEL(e2);
}
//------------------------------------------------------------------------------
internal void SwapPoints(ref IntPoint pt1, ref IntPoint pt2)
{
IntPoint tmp = pt1;
pt1 = pt2;
pt2 = tmp;
}
//------------------------------------------------------------------------------
private bool FindSegment(ref PolyPt pp, IntPoint pt1, IntPoint pt2)
{
if (pp == null) return false;
PolyPt pp2 = pp;
do
{
if (PointsEqual(pp.pt, pt1) &&
(PointsEqual(pp.next.pt, pt2) || PointsEqual(pp.prev.pt, pt2)))
return true;
pp = pp.next;
}
while (pp != pp2);
return false;
}
//------------------------------------------------------------------------------
private void InsertLocalMinimaIntoAEL(int botY)
{
while( m_CurrentLM != null && ( m_CurrentLM.Y == botY ) )
{
TEdge4 lb = m_CurrentLM.leftBound;
TEdge4 rb = m_CurrentLM.rightBound;
InsertEdgeIntoAEL( lb );
InsertScanbeam( lb.ytop );
InsertEdgeIntoAEL( rb );
if ( IsNonZeroFillType( lb) )
rb.windDelta = -lb.windDelta;
else
{
lb.windDelta = 1;
rb.windDelta = 1;
}
SetWindingCount( lb );
rb.windCnt = lb.windCnt;
rb.windCnt2 = lb.windCnt2;
if( rb.dx == horizontal )
{
//nb: only rightbounds can have a horizontal bottom edge
AddEdgeToSEL( rb );
InsertScanbeam( rb.nextInLML.ytop );
}
else
InsertScanbeam( rb.ytop );
if( IsContributing(lb) )
AddLocalMinPoly(lb, rb, new IntPoint(lb.xcurr, m_CurrentLM.Y));
//if output polygons share an edge, they'll need joining later ...
if (lb.outIdx >= 0 && lb.prevInAEL != null &&
lb.prevInAEL.outIdx >= 0 && lb.prevInAEL.xcurr == lb.xbot &&
SlopesEqual(lb, lb.prevInAEL))
AddJoin(lb, lb.prevInAEL);
//if any output polygons share an edge, they'll need joining later ...
if (rb.outIdx >= 0)
{
if (rb.dx == horizontal)
{
for (int i = 0; i < m_HorizJoins.Count; i++)
{
IntPoint pt = new IntPoint(), pt2 = new IntPoint(); //used as dummy params.
HorzJoinRec hj = m_HorizJoins[i];
//if horizontals rb and hj.edge overlap, flag for joining later ...
if (GetOverlapSegment(new IntPoint(hj.edge.xbot, hj.edge.ybot),
new IntPoint(hj.edge.xtop, hj.edge.ytop),
new IntPoint(rb.xbot, rb.ybot),
new IntPoint(rb.xtop, rb.ytop),
ref pt, ref pt2))
AddJoin(hj.edge, rb, hj.savedIdx);
}
}
}
if( lb.nextInAEL != rb )
{
TEdge4 e = lb.nextInAEL;
IntPoint pt = new IntPoint(lb.xcurr, lb.ycurr);
while( e != rb )
{
if(e == null)
throw new ClipperException("InsertLocalMinimaIntoAEL: missing rightbound!");
//nb: For calculating winding counts etc, IntersectEdges() assumes
//that param1 will be to the right of param2 ABOVE the intersection ...
IntersectEdges( rb , e , pt , Protects.ipNone); //order important here
e = e.nextInAEL;
}
}
PopLocalMinima();
}
}
//------------------------------------------------------------------------------
private void InitEdge(TEdge4 e, TEdge4 eNext,
TEdge4 ePrev, IntPoint pt, PolyType polyType)
{
e.next = eNext;
e.prev = ePrev;
e.xcurr = pt.X;
e.ycurr = pt.Y;
if (e.ycurr >= e.next.ycurr)
{
e.xbot = e.xcurr;
e.ybot = e.ycurr;
e.xtop = e.next.xcurr;
e.ytop = e.next.ycurr;
e.windDelta = 1;
} else
{
e.xtop = e.xcurr;
e.ytop = e.ycurr;
e.xbot = e.next.xcurr;
e.ybot = e.next.ycurr;
e.windDelta = -1;
}
SetDx(e);
e.polyType = polyType;
e.outIdx = -1;
}
//------------------------------------------------------------------------------
private void BuildIntersectList(int topY)
{
if ( m_ActiveEdges == null ) return;
//prepare for sorting ...
TEdge4 e = m_ActiveEdges;
e.tmpX = TopX( e, topY );
m_SortedEdges = e;
m_SortedEdges.prevInSEL = null;
e = e.nextInAEL;
while( e != null )
{
e.prevInSEL = e.prevInAEL;
e.prevInSEL.nextInSEL = e;
e.nextInSEL = null;
e.tmpX = TopX( e, topY );
e = e.nextInAEL;
}
//bubblesort ...
bool isModified = true;
while( isModified && m_SortedEdges != null )
{
isModified = false;
e = m_SortedEdges;
while( e.nextInSEL != null )
{
TEdge4 eNext = e.nextInSEL;
IntPoint pt = new IntPoint();
if(e.tmpX > eNext.tmpX && IntersectPoint(e, eNext, ref pt))
{
AddIntersectNode( e, eNext, pt );
SwapPositionsInSEL(e, eNext);
isModified = true;
}
else
e = eNext;
}
if( e.prevInSEL != null ) e.prevInSEL.nextInSEL = null;
else break;
}
m_SortedEdges = null;
}
//------------------------------------------------------------------------------
protected bool PointsEqual(IntPoint pt1, IntPoint pt2)
{
return ( pt1.X == pt2.X && pt1.Y == pt2.Y );
}
//------------------------------------------------------------------------------
protected bool SlopesEqual(IntPoint pt1, IntPoint pt2, IntPoint pt3)
{
if (pt1.Y == pt2.Y) return (pt2.Y == pt3.Y);
else if (pt2.Y == pt3.Y) return false;
else return
(Int64)(pt1.Y-pt2.Y)*(pt2.X-pt3.X) - (Int64)(pt1.X-pt2.X)*(pt2.Y-pt3.Y) == 0;
}
//------------------------------------------------------------------------------
private int TopX(IntPoint pt1, IntPoint pt2, int currentY)
{
//preconditions: pt1.Y <> pt2.Y and pt1.Y > pt2.Y
if (currentY >= pt1.Y) return pt1.X;
else if (currentY == pt2.Y) return pt2.X;
else if (pt1.X == pt2.X) return pt1.X;
else
{
double q = (pt1.X-pt2.X)/(pt1.Y-pt2.Y);
return (int)(pt1.X + (currentY - pt1.Y) *q);
}
}
//----------------------------------------------------------------------
private void JoinCommonEdges()
{
for (int i = 0; i < m_Joins.Count; i++)
{
PolyPt pp1a, pp1b, pp2a, pp2b;
IntPoint pt1 = new IntPoint(), pt2 = new IntPoint();
JoinRec j = m_Joins[i];
if (j.poly1Idx < 0 || j.poly2Idx < 0)
throw new ClipperException("JoinCommonEdges error");
pp1a = m_PolyPts[j.poly1Idx];
pp2a = m_PolyPts[j.poly2Idx];
if (FindSegment(ref pp1a, j.pt1a, j.pt1b) &&
FindSegment(ref pp2a, j.pt2a, j.pt2b))
{
if (PointsEqual(pp1a.next.pt, j.pt1b))
pp1b = pp1a.next; else pp1b = pp1a.prev;
if (PointsEqual(pp2a.next.pt, j.pt2b))
pp2b = pp2a.next; else pp2b = pp2a.prev;
if (j.poly1Idx != j.poly2Idx &&
GetOverlapSegment(pp1a.pt, pp1b.pt, pp2a.pt, pp2b.pt, ref pt1, ref pt2))
{
PolyPt p1, p2, p3, p4;
//get p1 & p2 polypts - the overlap start & endpoints on poly1
Position pos1 = GetPosition(pp1a.pt, pp1b.pt, pt1);
if (pos1 == Position.pFirst) p1 = pp1a;
else if (pos1 == Position.pSecond) p1 = pp1b;
else p1 = InsertPolyPtBetween(pp1a, pp1b, pt1);
Position pos2 = GetPosition(pp1a.pt, pp1b.pt, pt2);
if (pos2 == Position.pMiddle)
{
if (pos1 == Position.pMiddle)
{
if (Pt3IsBetweenPt1AndPt2(pp1a.pt, p1.pt, pt2))
p2 = InsertPolyPtBetween(pp1a, p1, pt2); else
p2 = InsertPolyPtBetween(p1, pp1b, pt2);
}
else if (pos2 == Position.pFirst) p2 = pp1a;
else p2 = pp1b;
}
else if (pos2 == Position.pFirst) p2 = pp1a;
else p2 = pp1b;
//get p3 & p4 polypts - the overlap start & endpoints on poly2
pos1 = GetPosition(pp2a.pt, pp2b.pt, pt1);
if (pos1 == Position.pFirst) p3 = pp2a;
else if (pos1 == Position.pSecond) p3 = pp2b;
else p3 = InsertPolyPtBetween(pp2a, pp2b, pt1);
pos2 = GetPosition(pp2a.pt, pp2b.pt, pt2);
if (pos2 == Position.pMiddle)
{
if (pos1 == Position.pMiddle)
{
if (Pt3IsBetweenPt1AndPt2(pp2a.pt, p3.pt, pt2))
p4 = InsertPolyPtBetween(pp2a, p3, pt2); else
p4 = InsertPolyPtBetween(p3, pp2b, pt2);
}
else if (pos2 == Position.pFirst) p4 = pp2a;
else p4 = pp2b;
}
else if (pos2 == Position.pFirst) p4 = pp2a;
else p4 = pp2b;
if (p1.next == p2) p1.next = p3; else p1.prev = p3;
if (p3.next == p4) p3.next = p1; else p3.prev = p1;
if (p2.next == p1) p2.next = p4; else p2.prev = p4;
if (p4.next == p3) p4.next = p2; else p4.prev = p2;
m_PolyPts[j.poly2Idx] = null;
}
}
}
}
//------------------------------------------------------------------------------
private bool IntersectPoint(TEdge4 edge1, TEdge4 edge2, ref IntPoint ip)
{
double b1, b2;
if (SlopesEqual(edge1, edge2)) return false;
else if (edge1.dx == 0)
{
ip.X = edge1.xbot;
if (edge2.dx == horizontal)
{
ip.Y = edge2.ybot;
} else
{
b2 = edge2.ybot - (edge2.xbot/edge2.dx);
ip.Y = Round(ip.X/edge2.dx + b2);
}
}
else if (edge2.dx == 0)
{
ip.X = edge2.xbot;
if (edge1.dx == horizontal)
{
ip.Y = edge1.ybot;
} else
{
b1 = edge1.ybot - (edge1.xbot/edge1.dx);
ip.Y = Round(ip.X/edge1.dx + b1);
}
} else
{
b1 = edge1.xbot - edge1.ybot * edge1.dx;
b2 = edge2.xbot - edge2.ybot * edge2.dx;
b2 = (b2-b1)/(edge1.dx - edge2.dx);
ip.Y = Round(b2);
ip.X = Round(edge1.dx * b2 + b1);
}
return
//can be *so close* to the top of one edge that the rounded Y equals one ytop ...
(ip.Y == edge1.ytop && ip.Y >= edge2.ytop && edge1.tmpX > edge2.tmpX) ||
(ip.Y == edge2.ytop && ip.Y >= edge1.ytop && edge1.tmpX > edge2.tmpX) ||
(ip.Y > edge1.ytop && ip.Y > edge2.ytop);
}
//------------------------------------------------------------------------------
private void AddLocalMinPoly(TEdge4 e1, TEdge4 e2, IntPoint pt)
{
if (e2.dx == horizontal || (e1.dx > e2.dx))
{
AddPolyPt(e1, pt);
e2.outIdx = e1.outIdx;
e1.side = EdgeSide.esLeft;
e2.side = EdgeSide.esRight;
}
else
{
AddPolyPt(e2, pt);
e1.outIdx = e2.outIdx;
e1.side = EdgeSide.esRight;
e2.side = EdgeSide.esLeft;
}
}
//------------------------------------------------------------------------------
internal static Polygon BuildArc(IntPoint pt, double a1, double a2, double r)
{
int steps = Math.Max(6, (int)(Math.Sqrt(Math.Abs(r)) * Math.Abs(a2 - a1)));
Polygon result = new Polygon(steps);
int n = steps - 1;
double da = (a2 - a1) / n;
double a = a1;
for (int i = 0; i < steps; ++i)
{
result.Add(new IntPoint(pt.X + (int)(Math.Cos(a)*r), pt.Y + (int)(Math.Sin(a)*r)));
a += da;
}
return result;
}
//------------------------------------------------------------------------------
private PolyPt AddPolyPt(TEdge4 e, IntPoint pt)
{
bool ToFront = (e.side == EdgeSide.esLeft);
if( e.outIdx < 0 )
{
PolyPt newPolyPt = new PolyPt();
newPolyPt.pt = pt;
newPolyPt.isHole = IsHole(e);
m_PolyPts.Add(newPolyPt);
newPolyPt.next = newPolyPt;
newPolyPt.prev = newPolyPt;
e.outIdx = m_PolyPts.Count-1;
return newPolyPt;
} else
{
PolyPt pp = m_PolyPts[e.outIdx];
if (ToFront && PointsEqual(pt, pp.pt)) return pp;
if (!ToFront && PointsEqual(pt, pp.prev.pt)) return pp.prev;
PolyPt newPolyPt = new PolyPt();
newPolyPt.pt = pt;
newPolyPt.isHole = pp.isHole;
newPolyPt.next = pp;
newPolyPt.prev = pp.prev;
newPolyPt.prev.next = newPolyPt;
pp.prev = newPolyPt;
if (ToFront) m_PolyPts[e.outIdx] = newPolyPt;
return newPolyPt;
}
}
//------------------------------------------------------------------------------
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 DoEdge2(TEdge4 edge1, TEdge4 edge2, IntPoint pt)
{
AddPolyPt(edge2, pt);
SwapSides(edge1, edge2);
SwapPolyIndexes(edge1, edge2);
}
//------------------------------------------------------------------------------
internal Position GetPosition(IntPoint pt1, IntPoint pt2, IntPoint pt)
{
if (PointsEqual(pt1, pt)) return Position.pFirst;
else if (PointsEqual(pt2, pt)) return Position.pSecond;
else return Position.pMiddle;
}
//------------------------------------------------------------------------------
private bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a,
IntPoint pt2b, ref IntPoint pt1, ref IntPoint pt2)
{
//precondition: segments are colinear.
if ( pt1a.Y == pt1b.Y || Math.Abs((pt1a.X - pt1b.X)/(pt1a.Y - pt1b.Y)) > 1 )
{
if (pt1a.X > pt1b.X) SwapPoints(ref pt1a, ref pt1b);
if (pt2a.X > pt2b.X) SwapPoints(ref pt2a, ref pt2b);
if (pt1a.X > pt2a.X) pt1 = pt1a; else pt1 = pt2a;
if (pt1b.X < pt2b.X) pt2 = pt1b; else pt2 = pt2b;
return pt1.X < pt2.X;
} else
{
if (pt1a.Y < pt1b.Y) SwapPoints(ref pt1a, ref pt1b);
if (pt2a.Y < pt2b.Y) SwapPoints(ref pt2a, ref pt2b);
if (pt1a.Y < pt2a.Y) pt1 = pt1a; else pt1 = pt2a;
if (pt1b.Y > pt2b.Y) pt2 = pt1b; else pt2 = pt2b;
return pt1.Y > pt2.Y;
}
}
//------------------------------------------------------------------------------
internal bool Pt3IsBetweenPt1AndPt2(IntPoint pt1, IntPoint pt2, IntPoint pt3)
{
if (PointsEqual(pt1, pt3) || PointsEqual(pt2, pt3)) return true;
else if (pt1.X != pt2.X) return (pt1.X < pt3.X) == (pt3.X < pt2.X);
else return (pt1.Y < pt3.Y) == (pt3.Y < pt2.Y);
}
//---------------------------------------------------------------------
private IntPoint GenerateRandomPoint(int l, int t, int r, int b, Random rand)
{
IntPoint newPt = new IntPoint();
newPt.X = (rand.Next(r / 10) * 10 + l + 10) * scale;
newPt.Y = (rand.Next(b / 10) * 10 + t + 10) * scale;
return newPt;
}
//------------------------------------------------------------------------------
private PolyPt InsertPolyPtBetween(PolyPt p1, PolyPt p2, IntPoint pt)
{
PolyPt result = new PolyPt();
result.pt = pt;
result.isHole = p1.isHole;
if (p2 == p1.next)
{
p1.next = result;
p2.prev = result;
result.next = p2;
result.prev = p1;
} else
{
p2.next = result;
p1.prev = result;
result.next = p1;
result.prev = p2;
}
return result;
}
