private static void flipEdgeEvent(DTSweepContext tcx,
TriangulationPoint ep,
TriangulationPoint eq,
DelaunayTriangle t,
TriangulationPoint p)
{
TriangulationPoint op, newP;
DelaunayTriangle ot;
bool _inScanArea;
ot = t.neighborAcross(p);
op = ot.oppositePoint(t, p);
if (ot == null)
{
// If we want to integrate the fillEdgeEvent do it here
// With current implementation we should never get here
throw new Exception("[BUG:FIXME] FLIP failed due to missing triangle");
}
if (t.getConstrainedEdgeAcross(p))
{
throw new Exception("Intersecting Constraints");
}
if (tcx.isDebugEnabled())
{
tcx.getDebugContext().setPrimaryTriangle(t);
tcx.getDebugContext().setSecondaryTriangle(ot);
} // TODO: remove
_inScanArea = inScanArea(p,
t.pointCCW(p),
t.pointCW(p),
op);
if (_inScanArea)
{
// Lets rotate shared edge one vertex CW
rotateTrianglePair(t, p, ot, op);
tcx.mapTriangleToNodes(t);
tcx.mapTriangleToNodes(ot);
if (p == eq && op == ep)
{
if (eq == tcx.edgeEvent.constrainedEdge.getQ() &&
ep == tcx.edgeEvent.constrainedEdge.getP())
{
if (tcx.isDebugEnabled())
{
Console.Out.WriteLine("[FLIP] - constrained edge done");
} // TODO: remove
t.markConstrainedEdge(ep, eq);
ot.markConstrainedEdge(ep, eq);
legalize(tcx, t);
legalize(tcx, ot);
}
else
{
if (tcx.isDebugEnabled())
{
Console.Out.WriteLine("[FLIP] - subedge done");
} // TODO: remove
// XXX: I think one of the triangles should be legalized here?
}
}
else
{
if (tcx.isDebugEnabled())
{
Console.Out.WriteLine("[FLIP] - flipping and continuing with triangle still crossing edge");
} // TODO: remove
Orientation o = orient2d(eq, op, ep);
t = nextFlipTriangle(tcx, o, t, ot, p, op);
flipEdgeEvent(tcx, ep, eq, t, p);
}
}
else
{
newP = nextFlipPoint(ep, eq, ot, op);
flipScanEdgeEvent(tcx, ep, eq, t, ot, newP);
edgeEvent(tcx, ep, eq, t, p);
}
}