| private ContainsVertex ( Vector3D, p ) : bool | ||
| p | Vector3D, | |
| return | bool | |
// Bowyer-Watson algorithm
public IList <Triangle> Triangulate(Vector3[] pointList)
{
List <Triangle> triangulation = new List <Triangle>();
Triangle superTriangle = CreateBoundingTriangle(pointList);
triangulation.Add(superTriangle);
for (int i = 0; i < pointList.Length; i++)
{
List <Triangle> badTriangles = new List <Triangle>();
for (int j = 0; j < triangulation.Count; j++)
{
Triangle triangle = triangulation[j];
if (triangle.IsInsideCircumcircle(pointList[i]))
{
badTriangles.Add(triangle);
}
}
ICollection <Edge> polygon = new HashSet <Edge>();
if (badTriangles.Count == 1)
{
Triangle triangle = badTriangles[0];
IList <Edge> edges = triangle.GetEdges();
foreach (Edge edge in edges)
{
polygon.Add(edge);
}
}
for (int j = 0; j < badTriangles.Count; j++)
{
Triangle triangle = badTriangles[j];
foreach (Edge edge in triangle.GetEdges())
{
ICollection <Triangle> triangleList = new HashSet <Triangle>(badTriangles);
triangleList.Remove(triangle);
if (edge.IsEdgeUnshared(triangleList))
{
polygon.Add(edge);
}
}
}
//remove each triangle in badTriangles from triangulation
foreach (Triangle triangle in badTriangles)
{
//remove triangle from triangulation
triangulation.Remove(triangle);
}
foreach (Edge edge in polygon)
{
Triangle newTri = new Triangle(pointList[i], edge.A, edge.B);
if (newTri.IsValid() && !triangulation.Contains(newTri))
{
triangulation.Add(newTri);
}
}
}
triangulation = triangulation.FindAll(triangle => triangle.ContainsVertex(pointList));
return(triangulation);
}
public List <Triangle> Triangulate(List <Vector2> vertices)
{
List <Triangle> triangles = new List <Triangle>();
if (0 == vertices.Count)
{
return(triangles);
}
float minX = vertices[0].x;
float minY = vertices[0].y;
float maxX = minX;
float maxY = minY;
for (int i = 0, imax = vertices.Count; i < imax; i++)
{
float x = vertices[i].x;
float y = vertices[i].y;
if (x < minX)
{
minX = x;
}
else if (x > maxX)
{
maxX = x;
}
if (y < minY)
{
minY = y;
}
else if (y > maxY)
{
maxY = y;
}
}
float dx = maxX - minX;
float dy = maxY - minY;
float deltaMax = Mathf.Max(dx, dy);
float midX = (minX + maxX) / 2;
float midY = (minY + maxY) / 2;
Vector2 p1 = new Vector2(midX - 20 * deltaMax, midY - deltaMax);
Vector2 p2 = new Vector2(midX, midY + 20 * deltaMax);
Vector2 p3 = new Vector2(midX + 20 * deltaMax, midY - deltaMax);
triangles.Add(new Triangle(p1, p2, p3));
for (int i = 0, imax = vertices.Count; i < imax; i++)
{
Vector2 p = vertices[i];
List <Edge> polygon = new List <Edge>();
for (int j = 0, jmax = triangles.Count; j < jmax; j++)
{
Triangle t = triangles[j];
if (t.circumCircleContains(p))
{
t.IsBad = true;
polygon.Add(t.E0);
polygon.Add(t.E1);
polygon.Add(t.E2);
triangles[j] = t;
}
}
triangles.RemoveAll((t) => t.IsBad);
for (int j = 0, jmax = polygon.Count; j < jmax; j++)
{
Edge e = polygon[j];
for (int k = j + 1; k < jmax; k++)
{
Edge e2 = polygon[k];
if (e.AlmostEqual(e2))
{
e.IsBad = true;
e2.IsBad = true;
polygon[j] = e;
polygon[k] = e2;
}
}
}
polygon.RemoveAll((e) => e.IsBad);
foreach (Edge e in polygon)
{
triangles.Add(new Triangle(e.V0, e.V1, p));
}
}
triangles.RemoveAll((t) => t.ContainsVertex(p1) || t.ContainsVertex(p2) || t.ContainsVertex(p3));
return(triangles);
}
