private bool ExistsIncludedVertex(VertexContract vertex)
{
var a = vertex.Position.ToVector2();
var b = vertex.Previous.Position.ToVector2();
var c = vertex.Next.Position.ToVector2();
var pointer = vertex.Next.Next;
while (pointer.Next.Index != vertex.Index)
{
var o = pointer.Position.ToVector2();
if (VectorUtility.OntheSameSide(o, c, a, b) && VectorUtility.OntheSameSide(o, a, b, c) && VectorUtility.OntheSameSide(o, b, a, c)) { return true; }
pointer = pointer.Next;
}
return false;
}
private List<int> GetTriangles(VertexContract[] vertexes, bool reverse)
{
var pointer = vertexes[0];
var triangles = new List<int>();
for (var i = 0; i < vertexes.Length - 3; i++)
{
var index = pointer.Index;
while (GetIncludeAngle(pointer) >= 180.0f || ExistsIncludedVertex(pointer))
{
pointer = pointer.Next;
if (pointer.Index == index) { break; }
}
if (reverse)
{
triangles.Add(pointer.Next.Index);
triangles.Add(pointer.Index);
triangles.Add(pointer.Previous.Index);
}
else
{
triangles.Add(pointer.Previous.Index);
triangles.Add(pointer.Index);
triangles.Add(pointer.Next.Index);
}
pointer.Next.Previous = pointer.Previous;
pointer.Previous.Next = pointer.Next;
pointer = pointer.Next;
}
if (reverse)
{
triangles.Add(pointer.Next.Index);
triangles.Add(pointer.Index);
triangles.Add(pointer.Previous.Index);
}
else
{
triangles.Add(pointer.Previous.Index);
triangles.Add(pointer.Index);
triangles.Add(pointer.Next.Index);
}
return triangles;
}
private float GetIncludeAngle(VertexContract vertex)
{
return VectorUtility.GetAngle((vertex.Previous.Position - vertex.Position).ToVector2(), (vertex.Next.Position - vertex.Position).ToVector2());
}
public static void Join(this List<SurfaceContract> surfaceContracts, VertexContract[] vertexes, Direction direction)
{
surfaceContracts.Add(new SurfaceContract { Vertexes = vertexes.Link(GetVectexesCount(surfaceContracts)), Direction = direction });
}
