/// <summary>
/// Merge coincident vertices where possible, optimizing the vertex count of a UnityEngine.Mesh.
/// </summary>
/// <param name="mesh">The mesh to optimize.</param>
/// <param name="vertices">
/// If provided these values are used in place of extracting attributes from the Mesh.
/// <br />
/// This is a performance optimization for when this array already exists. If not provided this array will be
/// automatically generated for you.
/// </param>
public static void CollapseSharedVertices(Mesh mesh, Vertex[] vertices = null)
{
if (mesh == null)
{
throw new System.ArgumentNullException("mesh");
}
bool hasCollapsedVertices = vertices != null;
if (vertices == null)
{
vertices = mesh.GetVertices();
}
int smc = mesh.subMeshCount;
List <Dictionary <Vertex, int> > subVertices = new List <Dictionary <Vertex, int> >();
int[][] tris = new int[smc][];
int subIndex = 0;
for (int i = 0; i < smc; ++i)
{
tris[i] = mesh.GetTriangles(i);
Dictionary <Vertex, int> newVertices = new Dictionary <Vertex, int>();
for (int n = 0; n < tris[i].Length; n++)
{
Vertex v = vertices[tris[i][n]];
int index;
if (newVertices.TryGetValue(v, out index))
{
tris[i][n] = index;
}
else
{
tris[i][n] = subIndex;
newVertices.Add(v, subIndex);
subIndex++;
}
}
subVertices.Add(newVertices);
}
Vertex[] collapsed = subVertices.SelectMany(x => x.Keys).ToArray();
//Check if new vertices have been collapsed
hasCollapsedVertices |= (collapsed.Length != vertices.Length);
if (hasCollapsedVertices)
{
Vertex.SetMesh(mesh, collapsed);
mesh.subMeshCount = smc;
for (int i = 0; i < smc; i++)
{
mesh.SetTriangles(tris[i], i);
}
}
}
/// <summary>
/// Create an array of @"UnityEngine.ProBuilder.Vertex" values that are ordered as individual triangles. This modifies the source mesh to match the new individual triangles format.
/// </summary>
/// <param name="mesh">The mesh to extract vertices from, and apply per-triangle topology to.</param>
/// <returns>A @"UnityEngine.ProBuilder.Vertex" array of the per-triangle vertices.</returns>
internal static Vertex[] GeneratePerTriangleMesh(Mesh mesh)
{
if (mesh == null)
{
throw new ArgumentNullException("mesh");
}
Vertex[] vertices = mesh.GetVertices();
int smc = mesh.subMeshCount;
Vertex[] tv = new Vertex[mesh.triangles.Length];
int[][] triangles = new int[smc][];
int triIndex = 0;
for (int s = 0; s < smc; s++)
{
triangles[s] = mesh.GetTriangles(s);
int tl = triangles[s].Length;
for (int i = 0; i < tl; i++)
{
tv[triIndex++] = new Vertex(vertices[triangles[s][i]]);
triangles[s][i] = triIndex - 1;
}
}
Vertex.SetMesh(mesh, tv);
mesh.subMeshCount = smc;
for (int s = 0; s < smc; s++)
{
mesh.SetTriangles(triangles[s], s);
}
return(tv);
}
