public void InitializeHoles(ConstrainedPointSet cps)
 {
     Contour.InitializeHoles(mHoles, this, cps);
     foreach (Contour c in mHoles)
     {
         c.InitializeHoles(cps);
     }
 }
        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;
            }
        }