void LoopSubdiv::weightOneRing(SDVertex *destVert, SDVertex *vert,
float beta) const
{
// Put _vert_ one-ring in _Pring_
u_int valence = vert->valence();
SDVertex **Vring = (SDVertex **)alloca(valence * sizeof(SDVertex *));
SDVertex **VR = Vring;
// Get one ring vertices for interior vertex
SDFace *face = vert->startFace;
bool uvSplit = false;
do {
SDVertex *v = face->v[face->vnum(vert->P)];
if (v->u != vert->u || v->v != vert->v)
uvSplit = true;
SDVertex *v2 = face->nextVert(vert->P);
float vu = v2->u;
float vv = v2->v;
*VR++ = v2;
face = face->nextFace(vert->P);
v2 = face->prevVert(vert->P);
if (vu != v2->u || vv != v2->v)
uvSplit = true;
} while (face != vert->startFace);
Point P((1 - valence * beta) * vert->P);
float u = (1 - valence * beta) * vert->u;
float v = (1 - valence * beta) * vert->v;
Normal N((1 - valence * beta) * vert->n);
for (u_int i = 0; i < valence; ++i) {
P += beta * Vring[i]->P;
u += beta * Vring[i]->u;
v += beta * Vring[i]->v;
N += beta * Vring[i]->n;
}
destVert->P = P;
if (uvSplit) {
destVert->u = vert->u;
destVert->v = vert->v;
} else {
destVert->u = u;
destVert->v = v;
}
destVert->n = N;
}
void SDVertex::oneRing(PbrtPoint *P) {
if (!boundary) {
// Get one-ring vertices for interior vertex
SDFace *face = startFace;
do {
*P++ = face->nextVert(this)->P;
face = face->nextFace(this);
} while (face != startFace);
}
else {
// Get one-ring vertices for boundary vertex
SDFace *face = startFace, *f2;
while ((f2 = face->nextFace(this)) != NULL)
face = f2;
*P++ = face->nextVert(this)->P;
do {
*P++ = face->prevVert(this)->P;
face = face->prevFace(this);
} while (face != NULL);
}
}
void LoopSubdiv::weightBoundary(SDVertex *destVert, SDVertex *vert,
float beta) const
{
// Put _vert_ one-ring in _Pring_
u_int valence = vert->valence();
if (displacementMapSharpBoundary) {
destVert->P = vert->P;
destVert->u = vert->u;
destVert->v = vert->v;
destVert->n = vert->n;
return;
}
SDVertex **Vring = (SDVertex **)alloca(valence * sizeof(SDVertex *));
SDVertex **VR = Vring;
// Get one ring vertices for boundary vertex
SDFace *face = vert->startFace, *f2;
// Go to the last face in the list
while ((f2 = face->nextFace(vert->P)) != NULL)
face = f2;
// Add the last vertex (on the boundary)
*VR++ = face->nextVert(vert->P);
// Add all vertices up to the first one (on the boundary)
bool uvSplit = false;
do {
SDVertex *v = face->v[face->vnum(vert->P)];
if (v->u != vert->u || v->v != vert->v)
uvSplit = true;
SDVertex *v2 = face->prevVert(vert->P);
float vu = v2->u;
float vv = v2->v;
*VR++ = v2;
face = face->prevFace(vert->P);
if (face) {
v2 = face->nextVert(vert->P);
if (vu != v2->u || vv != v2->v)
uvSplit = true;
}
} while (face != NULL);
Point P((1 - 2 * beta) * vert->P);
P += beta * Vring[0]->P;
P += beta * Vring[valence - 1]->P;
destVert->P = P;
if (uvSplit) {
destVert->u = vert->u;
destVert->v = vert->v;
} else {
float u = (1.f - 2.f * beta) * vert->u;
float v = (1.f - 2.f * beta) * vert->v;
u += beta * (Vring[0]->u + Vring[valence - 1]->u);
v += beta * (Vring[0]->v + Vring[valence - 1]->v);
destVert->u = u;
destVert->v = v;
}
Normal N((1 - 2 * beta) * vert->n);
N += beta * Vring[0]->n;
N += beta * Vring[valence - 1]->n;
destVert->n = N;
}
