//------------------------------------------------------------------------------
double Area(OutRec outRec, bool UseFull64BitRange)
{
OutPt op = outRec.pts;
if (UseFull64BitRange)
{
Int128 a = new Int128(0);
do
{
a += Int128.Int128Mul(op.prev.pt.X, op.pt.Y) -
Int128.Int128Mul(op.pt.X, op.prev.pt.Y);
op = op.next;
} while (op != outRec.pts);
return a.ToDouble() / 2;
}
else
{
double a = 0;
do {
a += (op.prev.pt.X * op.pt.Y) - (op.pt.X * op.prev.pt.Y);
op = op.next;
} while (op != outRec.pts);
return a/2;
}
}
//------------------------------------------------------------------------------
private void CheckHoleLinkages1(OutRec outRec1, OutRec outRec2)
{
//when a polygon is split into 2 polygons, make sure any holes the original
//polygon contained link to the correct polygon ...
for (int i = 0; i < m_PolyOuts.Count; ++i)
{
if (m_PolyOuts[i].isHole && m_PolyOuts[i].bottomPt != null &&
m_PolyOuts[i].FirstLeft == outRec1 &&
!PointInPolygon(m_PolyOuts[i].bottomPt.pt,
outRec1.pts, m_UseFullRange))
m_PolyOuts[i].FirstLeft = outRec2;
}
}
//----------------------------------------------------------------------
private void CheckHoleLinkages2(OutRec outRec1, OutRec outRec2)
{
//if a hole is owned by outRec2 then make it owned by outRec1 ...
for (int i = 0; i < m_PolyOuts.Count; ++i)
if (m_PolyOuts[i].isHole && m_PolyOuts[i].bottomPt != null &&
m_PolyOuts[i].FirstLeft == outRec2)
m_PolyOuts[i].FirstLeft = outRec1;
}
//------------------------------------------------------------------------------
private bool Orientation(OutRec outRec, bool UseFull64BitRange)
{
//first make sure bottomPt is correctly assigned ...
OutPt opBottom = outRec.pts, op = outRec.pts.next;
while (op != outRec.pts)
{
if (op.pt.Y >= opBottom.pt.Y)
{
if (op.pt.Y > opBottom.pt.Y || op.pt.X < opBottom.pt.X)
opBottom = op;
}
op = op.next;
}
outRec.bottomPt = opBottom;
opBottom.idx = outRec.idx;
op = opBottom;
//find vertices either side of bottomPt (skipping duplicate points) ....
OutPt opPrev = op.prev;
OutPt opNext = op.next;
while (op != opPrev && PointsEqual(op.pt, opPrev.pt))
opPrev = opPrev.prev;
while (op != opNext && PointsEqual(op.pt, opNext.pt))
opNext = opNext.next;
IntPoint vec1 = new IntPoint(op.pt.X - opPrev.pt.X, op.pt.Y - opPrev.pt.Y);
IntPoint vec2 = new IntPoint(opNext.pt.X - op.pt.X, opNext.pt.Y - op.pt.Y);
if (UseFull64BitRange)
{
Int128 cross = Int128.Int128Mul(vec1.X, vec2.Y) - Int128.Int128Mul(vec2.X, vec1.Y);
return !cross.IsNegative();
}
else
return (vec1.X * vec2.Y - vec2.X * vec1.Y) > 0;
}
//------------------------------------------------------------------------------
private void FixupOutPolygon(OutRec outRec)
{
//FixupOutPolygon() - removes duplicate points and simplifies consecutive
//parallel edges by removing the middle vertex.
OutPt lastOK = null;
outRec.pts = outRec.bottomPt;
OutPt pp = outRec.bottomPt;
for (;;)
{
if (pp.prev == pp || pp.prev == pp.next)
{
DisposeOutPts(pp);
outRec.pts = null;
outRec.bottomPt = null;
return;
}
//test for duplicate points and for same slope (cross-product) ...
if (PointsEqual(pp.pt, pp.next.pt) ||
SlopesEqual(pp.prev.pt, pp.pt, pp.next.pt, m_UseFullRange))
{
lastOK = null;
if (pp == outRec.bottomPt)
outRec.bottomPt = null; //flags need for updating
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;
}
}
if (outRec.bottomPt == null)
{
outRec.bottomPt = GetBottomPt(pp);
outRec.bottomPt.idx = outRec.idx;
outRec.pts = outRec.bottomPt;
}
}
//------------------------------------------------------------------------------
private void SetHoleState(TEdge e, OutRec outRec)
{
bool isHole = false;
TEdge e2 = e.prevInAEL;
while (e2 != null)
{
if (e2.outIdx >= 0)
{
isHole = !isHole;
if (outRec.FirstLeft == null)
outRec.FirstLeft = m_PolyOuts[e2.outIdx];
}
e2 = e2.prevInAEL;
}
if (isHole) outRec.isHole = true;
}
//------------------------------------------------------------------------------
private OutRec GetLowermostRec(OutRec outRec1, OutRec outRec2)
{
//work out which polygon fragment has the correct hole state ...
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;
}
//------------------------------------------------------------------------------
private OutRec CreateOutRec()
{
OutRec result = new OutRec();
result.idx = -1;
result.isHole = false;
result.FirstLeft = null;
result.AppendLink = null;
result.pts = null;
result.bottomPt = null;
result.bottomFlag = null;
result.sides = EdgeSide.esNeither;
return result;
}
//------------------------------------------------------------------------------
void DisposeBottomPt(OutRec outRec)
{
OutPt next = outRec.bottomPt.next;
OutPt prev = outRec.bottomPt.prev;
if (outRec.pts == outRec.bottomPt) outRec.pts = next;
outRec.bottomPt = null;
next.prev = prev;
prev.next = next;
outRec.bottomPt = next;
}
//------------------------------------------------------------------------------
internal void FixHoleLinkage(OutRec outRec)
{
OutRec tmp;
if (outRec.bottomPt != null)
tmp = m_PolyOuts[outRec.bottomPt.idx].FirstLeft;
else
tmp = outRec.FirstLeft;
if (outRec == tmp) throw new ClipperException("HoleLinkage error");
if (tmp != null)
{
if (tmp.AppendLink != null) tmp = FindAppendLinkEnd(tmp);
if (tmp == outRec) tmp = null;
else if (tmp.isHole)
{
FixHoleLinkage(tmp);
tmp = tmp.FirstLeft;
}
}
outRec.FirstLeft = tmp;
if (tmp == null) outRec.isHole = false;
outRec.AppendLink = null;
}
//------------------------------------------------------------------------------
internal OutRec FindAppendLinkEnd(OutRec outRec)
{
while (outRec.AppendLink != null) outRec = outRec.AppendLink;
return outRec;
}
//------------------------------------------------------------------------------
internal int PolySort(OutRec or1, OutRec or2)
{
if (or1 == or2) return 0;
else if (or1.pts == null || or2.pts == null)
{
if ((or1.pts == null) != (or2.pts == null))
{
return or1.pts == null ? 1 : -1;
}
else return 0;
}
int i1, i2;
if (or1.isHole)
i1 = or1.FirstLeft.idx; else
i1 = or1.idx;
if (or2.isHole)
i2 = or2.FirstLeft.idx; else
i2 = or2.idx;
int result = i1 - i2;
if (result == 0 && (or1.isHole != or2.isHole))
{
return or1.isHole ? 1 : -1;
}
return result;
}