public ShapeCache Cache(ConvexShape shape)
{
ShapeCache sc=(ShapeCache)shape.GetUserPointer();
if(sc == null)
{
sc=new ShapeCache(shape);
sc.m_shapehull.BuildHull(shape.GetMargin());
m_shapecaches.Add(sc);
shape.SetUserPointer(sc);
/* Build edges */
int ni=sc.m_shapehull.NumIndices();
int nv=sc.m_shapehull.NumVertices();
IList<int> pi=sc.m_shapehull.m_indices;
IList<IndexedVector3> pv=sc.m_shapehull.m_vertices;
IList<Edge> edges = new ObjectArray<Edge>(ni);
for(int i=0;i<ni;i+=3)
{
IndexedVector3 nrm= IndexedVector3.Normalize(IndexedVector3.Cross(pv[pi[i+1]]-pv[pi[i]],pv[pi[i+2]]-pv[pi[i]]));
for(int j=2,k=0;k<3;j=k++)
{
int a=pi[i+j];
int b=pi[i+k];
Edge e=edges[Math.Min(a,b)*nv+Math.Max(a,b)];
if(e != null)
{
sc.m_edges.Add(new Edge());
e=sc.m_edges[sc.m_edges.Count-1];
e.n[0]=nrm;e.n[1]=-nrm;
e.v[0]=a;e.v[1]=b;
}
else
{
e.n[1]=nrm;
}
}
}
}
return(sc);
}
