/// <summary>
/// Exhaustive search to update neighbor pointers
/// </summary>
/// <param name="t"></param>
public void MarkNeighbor(Triangle t)
{
if (t.Contains(Points[1], Points[2]))
{
_neighbours[0] = t;
t.MarkNeighbor(Points[1], Points[2], this);
}
else if (t.Contains(Points[0], Points[2]))
{
_neighbours[1] = t;
t.MarkNeighbor(Points[0], Points[2], this);
}
else if (t.Contains(Points[0], Points[1]))
{
_neighbours[2] = t;
t.MarkNeighbor(Points[0], Points[1], this);
}
}
private void Fill(SweepContext tcx, Node node)
{
Triangle triangle = new Triangle(node.Prev.Point, node.Point, node.Next.Point);
triangle.MarkNeighbor(node.Prev.Triangle);
triangle.MarkNeighbor(node.Triangle);
tcx.AddToMap(triangle);
// Update the advancing front
node.Prev.Next = node.Next;
node.Next.Prev = node.Prev;
// If it was legalized the triangle has already been mapped
if (!Legalize(tcx, triangle))
{
tcx.MapTriangleToNodes(triangle);
}
}
private Node NewFrontTriangle(SweepContext tcx, TriPoint point, Node node)
{
Triangle triangle = new Triangle(point, node.Point, node.Next.Point);
triangle.MarkNeighbor(node.Triangle);
tcx.AddToMap(triangle);
Node new_node = new Node(point);
_nodes.Add(new_node);
new_node.Next = node.Next;
new_node.Prev = node;
node.Next.Prev = new_node;
node.Next = new_node;
if (!Legalize(tcx, triangle))
{
tcx.MapTriangleToNodes(triangle);
}
return(new_node);
}
/**
* Rotates a triangle pair one vertex CW
*<pre>
* n2 n2
* P +-----+ P +-----+
* | t /| |\ t |
* | / | | \ |
* n1| / |n3 n1| \ |n3
* | / | after CW | \ |
* |/ oT | | oT \|
* +-----+ oP +-----+
* n4 n4
* </pre>
*/
private void RotateTrianglePair(Triangle t, TriPoint p, Triangle ot, TriPoint op)
{
Triangle n1, n2, n3, n4;
n1 = t.NeighborCCW(p);
n2 = t.NeighborCW(p);
n3 = ot.NeighborCCW(op);
n4 = ot.NeighborCW(op);
bool ce1, ce2, ce3, ce4;
ce1 = t.GetConstrainedEdgeCCW(p);
ce2 = t.GetConstrainedEdgeCW(p);
ce3 = ot.GetConstrainedEdgeCCW(op);
ce4 = ot.GetConstrainedEdgeCW(op);
bool de1, de2, de3, de4;
de1 = t.GetDelaunayEdgeCCW(p);
de2 = t.GetDelaunayEdgeCW(p);
de3 = ot.GetDelaunayEdgeCCW(op);
de4 = ot.GetDelaunayEdgeCW(op);
t.Legalize(p, op);
ot.Legalize(op, p);
// Remap delaunay_edge
ot.SetDelunayEdgeCCW(p, de1);
t.SetDelunayEdgeCW(p, de2);
t.SetDelunayEdgeCCW(op, de3);
ot.SetDelunayEdgeCW(op, de4);
// Remap constrained_edge
ot.SetConstrainedEdgeCCW(p, ce1);
t.SetConstrainedEdgeCW(p, ce2);
t.SetConstrainedEdgeCCW(op, ce3);
ot.SetConstrainedEdgeCW(op, ce4);
// Remap neighbors
// XXX: might optimize the markNeighbor by keeping track of
// what side should be assigned to what neighbor after the
// rotation. Now mark neighbor does lots of testing to find
// the right side.
t.ClearNeighbors();
ot.ClearNeighbors();
if (n1 != null)
{
ot.MarkNeighbor(n1);
}
if (n2 != null)
{
t.MarkNeighbor(n2);
}
if (n3 != null)
{
t.MarkNeighbor(n3);
}
if (n4 != null)
{
ot.MarkNeighbor(n4);
}
t.MarkNeighbor(ot);
}