/// <summary> /// Creates a new front triangle and legalize it /// </summary> private static AdvancingFrontNode NewFrontTriangle(DTSweepContext tcx, TriangulationPoint point, AdvancingFrontNode node) { AdvancingFrontNode newNode; DelaunayTriangle triangle; triangle = new DelaunayTriangle(point, node.Point, node.Next.Point); triangle.MarkNeighbor(node.Triangle); tcx.Triangles.Add(triangle); newNode = new AdvancingFrontNode(point); newNode.Next = node.Next; newNode.Prev = node; node.Next.Prev = newNode; node.Next = newNode; tcx.AddNode(newNode); // XXX: BST if (tcx.IsDebugEnabled) { tcx.DTDebugContext.ActiveNode = newNode; } 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, newNode; node = tcx.LocateNode(point); if (tcx.IsDebugEnabled) { tcx.DTDebugContext.ActiveNode = node; } 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); }