/// <summary>
/// Returns the other triangle than the given triangle on the graph
/// Returns null if no such triangle could be found.
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public Triangle GetOtherTriangle(Triangle t)
{
var otherVertexOfTriangle = t.GetVertices().Single(o => o != v1 && o != v2);
var triangleMembers = GetTriangleMembers();
//if (triangleMembers.Count() > 2)
//throw new InvalidOperationException("Edge with more than two triangles?");
//TODO: Something goes wrong here! This should never be larger than 1!!!
var otherTriangleMember = triangleMembers.FirstOrDefault(o => o != otherVertexOfTriangle);
if (otherTriangleMember == null)
return null;
var edges = new List<Edge>() { this };
otherTriangleMember.Edges.ForEach(o =>
{
if ((o.v1 == v1 || o.v1 == v2 || o.v2 == v1 || o.v2 == v2))
edges.Add(o);
});
if (edges.Count != 3)
throw new InvalidOperationException("Triangle with no 3 edges");
var triangle = new Triangle() { Edges = edges};
return triangle;
}
/// <summary>
/// Retriangulate the given triangle with P
/// Basically removes the conflicting edge from the graph and introduces a new one from the vertex that was not on the removed edge and P
/// </summary>
/// <param name="triangle"></param>
/// <param name="P"></param>
private void Retriangulate(Triangle triangle, Vertex P)
{
var otherVertex = triangle.GetVertices().Single(o => o != triangle.conflictingEdge.v1 && o != triangle.conflictingEdge.v2);
GM.DestroyEdge(triangle.conflictingEdge);
GM.CreateOrGet(otherVertex, P);
}
