/// <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);
}
