/*
* /// <summary>
* /// Applies a single iteration of Catmull-Clark subdivision to the given mesh.
* /// http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
* /// http://w3.impa.br/~lcruz/courses/cma/surfaces.html
* /// </summary>
* /// <typeparam name="V"></typeparam>
* /// <typeparam name="E"></typeparam>
* /// <typeparam name="F"></typeparam>
* /// <param name="mesh"></param>
* /// <param name="position"></param>
* /// <param name="boundaryType"></param>
* public static void CatmullClark<V, E, F>(HeMesh<V, E, F> mesh, Property<V, Vec3d> position, SmoothBoundaryType boundaryType, bool parallel)
* where V : HeVertex<V, E, F>
* where E : Halfedge<V, E, F>
* where F : HeFace<V, E, F>
* {
* CatmullClarkGeometry(mesh, position, boundaryType, parallel);
* QuadSplitTopology(mesh);
* }
*
*
* /// <summary>
* ///
* /// </summary>
* private static void CatmullClarkGeometry<V, E, F>(HeMesh<V, E, F> mesh, Property<V, Vec3d> position, SmoothBoundaryType boundaryType, bool parallel)
* where V : HeVertex<V, E, F>
* where E : Halfedge<V, E, F>
* where F : HeFace<V, E, F>
* {
* var verts = mesh.Vertices;
* var edges = mesh.Edges;
* var faces = mesh.Faces;
*
* int fv0 = verts.Count; // index of first face vertex
* int ev0 = verts.Count + faces.Count;
*
* // add all new vertices
* mesh.AddVertices(faces.Count);
* mesh.AddVertices(edges.Count);
*
* // set attributes of face vertices
* Action<Tuple<int, int>> setFaceVerts = range =>
* {
* for (int i = range.Item1; i < range.Item2; i++)
* {
* var f = faces[i];
*
* if (!f.IsRemoved)
* position.Set(verts[i + fv0], f.Vertices.Mean(position.Get));
* }
* };
*
* // set attributes of edge vertices
* Action<Tuple<int, int>> setEdgeVerts = range =>
* {
* for (int i = range.Item1; i < range.Item2; i++)
* {
* var he0 = edges[i];
* if (he0.IsRemoved) continue;
*
* if (he0.IsBoundary)
* {
* position.Set(verts[i + ev0], he0.Lerp(position.Get, 0.5));
* continue;
* }
*
* var he1 = he0.Twin;
* var p0 = position.Get(he0.Start);
* var p1 = position.Get(he1.Start);
* var p2 = position.Get(verts[he0.Face.Index + fv0]);
* var p3 = position.Get(verts[he1.Face.Index + fv0]);
* position.Set(verts[i + ev0], (p0 + p1 + p2 + p3) * 0.25);
* }
* };
*
* // set attributes of old vertices
* //CatmullClarkSmooth(mesh, position, boundaryType);
* Action<Tuple<int, int>> setOldVerts = range =>
* {
* for (int i = range.Item1; i < range.Item2; i++)
* {
* var v = verts[i];
* if (v.IsRemoved) continue;
*
* if (v.IsBoundary)
* {
* var he0 = v.FirstOut;
* var he1 = he0.PrevInFace;
* var p0 = position.Get(verts[(he0.Index >> 1) + ev0]);
* var p1 = position.Get(verts[(he1.Index >> 1) + ev0]);
* position.Set(v, position.Get(v) * 0.5 + (p0 + p1) * 0.25);
* }
* else
* {
* Vec3d fsum = new Vec3d();
* Vec3d esum = new Vec3d();
* int n = 0;
*
* foreach (var he in v.OutgoingHalfedges)
* {
* fsum += position.Get(verts[he.Face.Index + fv0]);
* esum += position.Get(verts[(he.Index >> 1) + ev0]);
* n++;
* }
*
* double t = 1.0 / n;
* position.Set(v, (position.Get(v) * (n - 3) + fsum * t + 2 * esum * t) * t);
* }
* }
* };
*
*
* if (parallel)
* {
* Parallel.ForEach(Partitioner.Create(0, faces.Count), setFaceVerts);
* Parallel.ForEach(Partitioner.Create(0, edges.Count), setEdgeVerts);
* Parallel.ForEach(Partitioner.Create(0, verts.Count), setOldVerts);
* }
* else
* {
* setFaceVerts(Tuple.Create(0, faces.Count));
* setEdgeVerts(Tuple.Create(0, edges.Count));
* setOldVerts(Tuple.Create(0, verts.Count));
* }
* }
*/
#endregion
/// <summary>
/// If using external buffers to store vertex attributes, the number of vertices after subdivision equals the sum of the number of vertices and faces in the initial mesh.
/// </summary>
/// <typeparam name="V"></typeparam>
/// <typeparam name="E"></typeparam>
/// <typeparam name="F"></typeparam>
/// <param name="mesh"></param>
/// <param name="position"></param>
/// <param name="skipBoundary"></param>
public static void Diagonalize <V, E, F>(HeMeshBase <V, E, F> mesh, Property <V, Vec3d> position, bool skipBoundary)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
var edges = mesh.Edges;
var faces = mesh.Faces;
int ne = edges.Count;
int nf = faces.Count;
// stellate faces
for (int i = 0; i < nf; i++)
{
var f = faces[i];
if (f.IsRemoved)
{
continue;
}
var v = mesh.AddVertex();
position.Set(v, f.GetBarycenter(position.Get));
mesh.PokeFaceImpl(f.First, v);
}
// merge faces
if (skipBoundary)
{
for (int i = 0; i < ne; i++)
{
var he = edges[i];
if (he.IsRemoved || he.IsBoundary)
{
continue;
}
mesh.MergeFaces(he);
}
}
else
{
for (int i = 0; i < ne; i++)
{
var he = edges[i];
if (he.IsRemoved)
{
continue;
}
mesh.MergeFaces(he);
}
}
}
