protected TriangleTree GetContainingTriangle(GraphNode node)
{
TriangleTree tri_within = tris;
bool outside_triangles = true;
while (!tri_within.IsLeaf())
{
foreach (TriangleTree sub_tri in tri_within.GetChildren())
{
if (sub_tri.IsInTriangle(node))
{
tri_within = sub_tri;
outside_triangles = false;
break;
}
}
if (outside_triangles)
{
return(null);
}
outside_triangles = true;
}
return(tri_within);
}
protected void ReworkTriangle(TriangleTree containing_tri, GraphNode node, GraphNode[] dummies)
{
List <TriangleTree> new_tris = containing_tri.SubDivide(node, dummies);
foreach (TriangleTree tri_tree in new_tris)
{
EnsureEdge(tri_tree, node);
}
}
protected void EnsureEdge(TriangleTree triangle, GraphNode node)
{
TriangleTree adjacent = GetContainingTriangle(triangle.GetAdjacentDummy(node));
if (adjacent != null && adjacent.IsLeaf() && adjacent.IsInCircle(node))
{
List <TriangleTree> new_tris = FlipEdge(triangle, adjacent);
foreach (TriangleTree new_tri in new_tris)
{
EnsureEdge(new_tri, node);
}
}
}
public List <GraphEdge> Triangulate(float x_low_bound, float x_high_bound, float y_low_bound, float y_high_bound)
{
tris = InitTris(x_low_bound, x_high_bound, y_low_bound, y_high_bound);
GraphNode[] dummy_verts = tris.GetVertices();
foreach (GraphNode node in nodes)
{
AddNode(node, dummy_verts);
}
List <Triangle> tri_list = tris.AsList();
List <GraphEdge> edges = new List <GraphEdge>();
foreach (Triangle tri in tri_list)
{
if (!TriangleContains(tri, tris.GetVertices()))
{
float area = tri.Area() / 3;
GraphNode[] vertices = tri.GetVertices();
vertices[0].Voronoi += area;
vertices[1].Voronoi += area;
vertices[2].Voronoi += area;
GraphEdge edge = vertices[0].AddEdgeFromNode(vertices[1]);
edges.Add(edge);
vertices[1].AddEdge(edge);
edge = vertices[0].AddEdgeFromNode(vertices[2]);
edges.Add(edge);
vertices[2].AddEdge(edge);
edge = vertices[1].AddEdgeFromNode(vertices[2]);
edges.Add(edge);
vertices[2].AddEdge(edge);
}
}
return(edges);
}
protected List <TriangleTree> FlipEdge(TriangleTree tri, TriangleTree adj)
{
List <GraphNode> shared_verts = new List <GraphNode>();
List <GraphNode> separate_verts = new List <GraphNode>();
separate_verts.AddRange(tri.GetVertices());
foreach (GraphNode vertex_a in adj.GetVertices())
{
bool separate = true;
foreach (GraphNode vertex_b in separate_verts)
{
if (vertex_a.X == vertex_b.X && vertex_a.Y == vertex_b.Y)
{
separate_verts.Remove(vertex_b);
shared_verts.Add(vertex_b);
separate = false;
break;
}
}
if (separate)
{
separate_verts.Add(vertex_a);
}
}
List <TriangleTree> new_tris = new List <TriangleTree>();
new_tris.Add(new TriangleTree(new Triangle(separate_verts[0], separate_verts[1], shared_verts[0])));
new_tris.Add(new TriangleTree(new Triangle(separate_verts[0], separate_verts[1], shared_verts[1])));
// TODO: Bugfix!! Sometimes, very rarely, shared_verts[1] doesn't exist????????
tri.GetChildren().AddRange(new_tris);
adj.GetChildren().AddRange(new_tris);
return(new_tris);
}
protected void AddNode(GraphNode node, GraphNode[] dummies)
{
TriangleTree containing_tri = GetContainingTriangle(node);
ReworkTriangle(containing_tri, node, dummies);
}