public static Edge SupportEdgeForPoly(cpPolyShape poly, cpVect n)
{
ulong count = (ulong)poly.Count;
ulong i1 = cpCollision.PolySupportPointIndex(poly.Count, poly.planes, n);
// TODO get rid of mod eventually, very expensive on ARM
ulong i0 = (ulong)((i1 - 1 + count) % count);
ulong i2 = (ulong)((i1 + 1) % count);
cpSplittingPlane[] planes = poly.planes;
ulong hashid = poly.hashid;
if (cpVect.cpvdot(n, planes[i1].n) > cpVect.cpvdot(n, planes[i2].n))
{
Edge edge = new Edge(
new EdgePoint(planes[i0].v0, cp.CP_HASH_PAIR(hashid, i0)),
new EdgePoint(planes[i1].v0, cp.CP_HASH_PAIR(hashid, i1)),
poly.r, poly.planes[i1].n);
return(edge);
}
else
{
Edge edge = new Edge(
new EdgePoint(planes[i1].v0, cp.CP_HASH_PAIR(hashid, i1)),
new EdgePoint(planes[i2].v0, cp.CP_HASH_PAIR(hashid, i2)),
poly.r, poly.planes[i2].n);
return(edge);
}
}
public static SupportPoint PolySupportPoint(cpPolyShape poly, cpVect n)
{
ulong i = PolySupportPointIndex(poly.Count, poly.planes, n);
return(new SupportPoint(poly.planes[i].v0, i));
}