public static void InitializeHoles(List <Contour> holes, ITriangulatable parent, ConstrainedPointSet cps)
{
int numHoles = holes.Count;
int holeIdx = 0;
// pass 1 - remove duplicates
while (holeIdx < numHoles)
{
int hole2Idx = holeIdx + 1;
while (hole2Idx < numHoles)
{
bool bSamePolygon = PolygonUtil.PolygonsAreSame2D(holes[holeIdx], holes[hole2Idx]);
if (bSamePolygon)
{
// remove one of them
holes.RemoveAt(hole2Idx);
--numHoles;
}
else
{
++hole2Idx;
}
}
++holeIdx;
}
// pass 2: Intersections and Containment
holeIdx = 0;
while (holeIdx < numHoles)
{
bool bIncrementHoleIdx = true;
int hole2Idx = holeIdx + 1;
while (hole2Idx < numHoles)
{
if (PolygonUtil.PolygonContainsPolygon(holes[holeIdx], holes[holeIdx].Bounds, holes[hole2Idx], holes[hole2Idx].Bounds, false))
{
holes[holeIdx].AddHole(holes[hole2Idx]);
holes.RemoveAt(hole2Idx);
--numHoles;
}
else if (PolygonUtil.PolygonContainsPolygon(holes[hole2Idx], holes[hole2Idx].Bounds, holes[holeIdx], holes[holeIdx].Bounds, false))
{
holes[hole2Idx].AddHole(holes[holeIdx]);
holes.RemoveAt(holeIdx);
--numHoles;
bIncrementHoleIdx = false;
break;
}
else
{
bool bIntersect = PolygonUtil.PolygonsIntersect2D(holes[holeIdx], holes[holeIdx].Bounds, holes[hole2Idx], holes[hole2Idx].Bounds);
if (bIntersect)
{
// this is actually an error condition
// fix by merging hole1 and hole2 into hole1 (including the holes inside hole2!) and delete hole2
// Then, because hole1 is now changed, restart it's check.
PolygonOperationContext ctx = new PolygonOperationContext();
if (!ctx.Init(PolygonUtil.PolyOperation.Union | PolygonUtil.PolyOperation.Intersect, holes[holeIdx], holes[hole2Idx]))
{
if (ctx.mError == PolygonUtil.PolyUnionError.Poly1InsidePoly2)
{
holes[hole2Idx].AddHole(holes[holeIdx]);
holes.RemoveAt(holeIdx);
--numHoles;
bIncrementHoleIdx = false;
break;
}
else
{
throw new Exception("PolygonOperationContext.Init had an error during initialization");
}
}
PolygonUtil.PolyUnionError pue = PolygonUtil.PolygonOperation(ctx);
if (pue == PolygonUtil.PolyUnionError.None)
{
Point2DList union = ctx.Union;
Point2DList intersection = ctx.Intersect;
// create a new contour for the union
Contour c = new Contour(parent);
c.AddRange(union);
c.Name = "(" + holes[holeIdx].Name + " UNION " + holes[hole2Idx].Name + ")";
c.WindingOrder = Point2DList.WindingOrderType.Default;
// add children from both of the merged contours
int numChildHoles = holes[holeIdx].GetNumHoles();
for (int i = 0; i < numChildHoles; ++i)
{
c.AddHole(holes[holeIdx].GetHole(i));
}
numChildHoles = holes[hole2Idx].GetNumHoles();
for (int i = 0; i < numChildHoles; ++i)
{
c.AddHole(holes[hole2Idx].GetHole(i));
}
// make sure we preserve the contours of the intersection
Contour cInt = new Contour(c);
cInt.AddRange(intersection);
cInt.Name = "(" + holes[holeIdx].Name + " INTERSECT " + holes[hole2Idx].Name + ")";
cInt.WindingOrder = Point2DList.WindingOrderType.Default;
c.AddHole(cInt);
// replace the current contour with the merged contour
holes[holeIdx] = c;
// toss the second contour
holes.RemoveAt(hole2Idx);
--numHoles;
// current hole is "examined", so move to the next one
hole2Idx = holeIdx + 1;
}
else
{
throw new Exception("PolygonOperation had an error!");
}
}
else
{
++hole2Idx;
}
}
}
if (bIncrementHoleIdx)
{
++holeIdx;
}
}
numHoles = holes.Count;
holeIdx = 0;
while (holeIdx < numHoles)
{
int numPoints = holes[holeIdx].Count;
for (int i = 0; i < numPoints; ++i)
{
int j = holes[holeIdx].NextIndex(i);
uint constraintCode = TriangulationConstraint.CalculateContraintCode(holes[holeIdx][i], holes[holeIdx][j]);
TriangulationConstraint tc = null;
if (!cps.TryGetConstraint(constraintCode, out tc))
{
tc = new TriangulationConstraint(holes[holeIdx][i], holes[holeIdx][j]);
cps.AddConstraint(tc);
}
// replace the points in the holes with valid points
if (holes[holeIdx][i].VertexCode == tc.P.VertexCode)
{
holes[holeIdx][i] = tc.P;
}
else if (holes[holeIdx][j].VertexCode == tc.P.VertexCode)
{
holes[holeIdx][j] = tc.P;
}
if (holes[holeIdx][i].VertexCode == tc.Q.VertexCode)
{
holes[holeIdx][i] = tc.Q;
}
else if (holes[holeIdx][j].VertexCode == tc.Q.VertexCode)
{
holes[holeIdx][j] = tc.Q;
}
}
++holeIdx;
}
}
protected void AddHole(Contour c)
{
// no checking is done here as we rely on InitializeHoles for that
c.mParent = this;
mHoles.Add(c);
}