/// <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;
}
/// <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) {Next = node.Next, 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;
}