virtual bool accept(CBsimplex* s) const {
if (!is_edge(s)) // reject if non-edge
return false;
Bedge* e = (Bedge*)s;
if (e->sil_stamp() == _stamp) // reject if previously checked
return 0;
e->set_sil_stamp(_stamp); // mark as checked this frame
if (_skip_secondary && e->is_secondary()) // reject secondary edges as needed
return false;
return e->is_sil(); // accept if silhouette
}
Bsimplex*
Bface::ndc_walk(
CNDCpt& target,
CWvec &passed_bc,
CNDCpt &nearest,
int is_on_tri,
bool use_passed_in_params) const
{
// just like local_search, but in NDC space
//
// start from this face, move in NDC space
// across the mesh to reach the target
//
// if reached, return the simplex that contains
// the target point.
// we only move if it will get us closer to the goal. Hence, we
// can never wander off forever.
// if can't reach it, return 0
NDCpt y (nearest);
Wvec bc(passed_bc);
if (!use_passed_in_params) {
y = nearest_pt_ndc(target, bc, is_on_tri);
}
Bsimplex* sim = bc2sim(bc);
if (is_on_tri) {
// target is on this triangle
// return the lowest-dimensional
// simplex on which it lies
return sim;
}
if (is_edge(sim)) {
Bedge* e = (Bedge*)sim;
Bface* f = e->is_sil() ? nullptr : e->other_face(this);
if (f) {
Wvec new_bc;
int new_on_tri;
NDCpt new_best = f->nearest_pt_ndc(target, new_bc, new_on_tri);
if (new_best.dist_sqrd(target) < y.dist_sqrd(target))
return f->ndc_walk(target, new_bc, new_best, new_on_tri, true);
else
return nullptr;
} else {
return nullptr;
}
}
// better be a vertex
assert(is_vert(sim));
Bvert* v = (Bvert*)sim;
if (v->degree(SilEdgeFilter()) > 0)
return nullptr;
Bface_list nbrs(16);
((Bvert*)sim)->get_faces(nbrs);
double dist_sqrd = 1e50;
Bface* best = nullptr;
Wvec best_bc;
NDCpt best_nearest;
int best_on_tri = 0;
Wvec curr_bc;
NDCpt curr_nearest;
int curr_on_tri=0;
for (Bface_list::size_type k = 0; k < nbrs.size(); k++) {
if (nbrs[k] != this) {
curr_nearest = nbrs[k]->nearest_pt_ndc(target, curr_bc, curr_on_tri);
if (curr_nearest.dist_sqrd(target) < dist_sqrd ) {
dist_sqrd = curr_nearest.dist_sqrd(target);
best_bc = curr_bc;
best_on_tri = curr_on_tri;
best_nearest = curr_nearest;
best = nbrs[k];
}
}
}
if (dist_sqrd < y.dist_sqrd(target)) {
return best->ndc_walk(target, best_bc, best_nearest, best_on_tri, true);
}
return nullptr;
}