//------------------------------------------------------------------------------
double Area(OutRec outRec, bool UseFull64BitRange)
{
OutPt op = outRec.pts;
if (op == null) return 0;
if (UseFull64BitRange)
{
Int128 a = new Int128(0);
do
{
a += Int128.Int128Mul(op.pt.X + op.prev.pt.X, op.prev.pt.Y - op.pt.Y);
op = op.next;
} while (op != outRec.pts);
return a.ToDouble() / 2;
}
else
{
double a = 0;
do
{
a = a + (op.pt.X + op.prev.pt.X) * (op.prev.pt.Y - op.pt.Y);
op = op.next;
} while (op != outRec.pts);
return a / 2;
}
}
//----------------------------------------------------------------------
private void FixupFirstLefts2(OutRec OldOutRec, OutRec NewOutRec)
{
foreach (OutRec outRec in m_PolyOuts)
if (outRec.FirstLeft == OldOutRec) outRec.FirstLeft = NewOutRec;
}
//------------------------------------------------------------------------------
private void UpdateOutPtIdxs(OutRec outrec)
{
OutPt op = outrec.pts;
do
{
op.idx = outrec.idx;
op = op.prev;
}
while (op != outrec.pts);
}
//------------------------------------------------------------------------------
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;
for (; ; )
{
if (pp.prev == pp || pp.prev == pp.next)
{
DisposeOutPts(pp);
outRec.pts = 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;
OutPt tmp = pp;
pp.prev.next = pp.next;
pp.next.prev = pp.prev;
pp = pp.prev;
tmp = null;
}
else if (pp == lastOK) break;
else
{
if (lastOK == null) lastOK = pp;
pp = pp.next;
}
}
outRec.pts = pp;
}
//----------------------------------------------------------------------
private void FixupFirstLefts1(OutRec OldOutRec, OutRec NewOutRec)
{
for (int i = 0; i < m_PolyOuts.Count; i++)
{
OutRec outRec = m_PolyOuts[i];
if (outRec.pts != null && outRec.FirstLeft == OldOutRec)
{
if (Poly2ContainsPoly1(outRec.pts, NewOutRec.pts, m_UseFullRange))
outRec.FirstLeft = NewOutRec;
}
}
}
//------------------------------------------------------------------------------
bool Param1RightOfParam2(OutRec outRec1, OutRec outRec2)
{
do
{
outRec1 = outRec1.FirstLeft;
if (outRec1 == outRec2) return true;
} while (outRec1 != null);
return false;
}
//------------------------------------------------------------------------------
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;
}
//------------------------------------------------------------------------------
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 CreateOutRec()
{
OutRec result = new OutRec();
result.idx = -1;
result.isHole = 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 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;
}
