internal CommonEdge(int _x, int _y, int _cx, int _cy)
{
this.edge = new PolyEdge(_x, _y);
this.common = new PolyEdge(_cx, _cy);
}
/// <summary>
/// Returns a dictionary where each PolyEdge is mapped to a list of triangle indices that share that edge.
/// To translate triangle list to vertex indices, multiply by 3 and take those indices (ex, triangles[index+{0,1,2}])
/// </summary>
/// <param name="mesh">mesh to use</param>
/// <returns>see summary</returns>
internal static Dictionary <PolyEdge, List <int> > GetAdjacentTriangles(PolyMesh mesh)
{
//null checks
if (mesh == null)
{
return(null);
}
int len = mesh.GetTriangles().Length;
if (len % 3 != 0 || len / 3 == mesh.vertexCount)
{
return(new Dictionary <PolyEdge, List <int> >());
}
Dictionary <PolyEdge, List <int> > lookup = null;
// @todo - should add some checks to make sure triangle structure hasn't changed
if (adjacentTrianglesCache.TryGetValue(mesh, out lookup) && lookup.Count == mesh.vertexCount)
{
return(lookup);
}
if (adjacentTrianglesCache.ContainsKey(mesh))
{
adjacentTrianglesCache.Remove(mesh);
}
int subMeshCount = mesh.subMeshCount;
lookup = new Dictionary <PolyEdge, List <int> >();
List <int> connections;
for (int n = 0; n < subMeshCount; n++)
{
int[] tris = mesh.subMeshes[n].indexes;
for (int i = 0; i < tris.Length; i += 3)
{
int index = i / 3;
PolyEdge a = new PolyEdge(tris[i], tris[i + 1]);
PolyEdge b = new PolyEdge(tris[i + 1], tris[i + 2]);
PolyEdge c = new PolyEdge(tris[i + 2], tris[i]);
if (lookup.TryGetValue(a, out connections))
{
connections.Add(index);
}
else
{
lookup.Add(a, new List <int>()
{
index
});
}
if (lookup.TryGetValue(b, out connections))
{
connections.Add(index);
}
else
{
lookup.Add(b, new List <int>()
{
index
});
}
if (lookup.TryGetValue(c, out connections))
{
connections.Add(index);
}
else
{
lookup.Add(c, new List <int>()
{
index
});
}
}
}
adjacentTrianglesCache.Add(mesh, lookup);
return(lookup);
}
