/// <summary>Creates a new front triangle and legalize it</summary> private static AdvancingFrontNode NewFrontTriangle(DtSweepContext tcx, TriangulationPoint point, AdvancingFrontNode node) { DelaunayTriangle triangle = new DelaunayTriangle(point, node.Point, node.Next.Point); triangle.MarkNeighbor(node.Triangle); tcx.Triangles.Add(triangle); AdvancingFrontNode newNode = new AdvancingFrontNode(point) { Next = node.Next, Prev = node }; node.Next.Prev = newNode; node.Next = newNode; tcx.AddNode(newNode); // XXX: BST if (!Legalize(tcx, triangle)) { tcx.MapTriangleToNodes(triangle); } return(newNode); }
/// <summary> /// Find closes node to the left of the new point and create a new triangle. If needed new holes and basins will /// be filled to. /// </summary> private static AdvancingFrontNode PointEvent(DtSweepContext tcx, TriangulationPoint point) { AdvancingFrontNode node = tcx.LocateNode(point); AdvancingFrontNode newNode = NewFrontTriangle(tcx, point, node); // Only need to check +epsilon since point never have smaller // x value than node due to how we fetch nodes from the front if (point.X <= node.Point.X + TriangulationUtil.Epsilon) { Fill(tcx, node); } tcx.AddNode(newNode); FillAdvancingFront(tcx, newNode); return(newNode); }