void
TriStrip::get_strips(
Bface* start,
vector<TriStrip*>& strips
)
{
// if starting face was visited already, stop
if (!is_cleared(start))
return;
// stack is used to record faces adjacent to
// the current strip, in order to build additional
// strips that align with the current one
static Bface_list stack(1024);
stack.clear();
stack.push_back(start);
BMESHptr mesh = start->mesh();
while (!stack.empty()) {
start = stack.back();
stack.pop_back();
if (is_cleared(start)) {
TriStrip* strip = mesh->new_tri_strip();
strip->build(start, stack);
strips.push_back(strip);
}
}
}
inline void
try_append(Bface_list& A, Bface* f)
{
// Helper method used below in try_append();
if (f && !f->flag()) {
f->set_flag();
A.push_back(f);
}
}
inline Bface_list
copy_faces(CBface_list& faces, CVertMapper& vmap, Primitive* p, bool reverse=false)
{
assert(p && vmap.is_valid());
Bface_list ret;
for (Bface_list::size_type i=0; i<faces.size(); i++) {
ret.push_back(copy_face(faces[i], vmap, p, reverse));
}
copy_edges(faces.get_edges(), vmap);
return ret;
}
Bface_list
Bface_list::quad_complete_faces() const
{
// If the list contains any "quad" faces but not their partners,
// returns the "completed" list, containing the missing partners:
mark_faces();
Bface* p=nullptr;
Bface_list ret = *this;
for (Bface_list::size_type i=0; i<size(); i++)
if ((p = check_partner(at(i))))
ret.push_back(p);
return ret;
}
bool
TriStrip::build(
Bface* start, // build a new strip starting here.
Bface_list& stack // used to build nearby parallel strips
)
{
// a set flag means this face is already in a TriStrip
assert(!start->flag());
// start fresh
reset();
// repeat 1st vertex if needed
if (!start->orient_strip())
start->orient_strip(start->v1());
// get the starting vert. i.e., the strip will
// continue onto the next face across the edge
// opposite this vertex.
Bvert *a = start->orient_strip(), *b, *c;
// squash and stretch
start = backup_strip(start,a);
if (!start) {
// should never happen, but can happen
// if there are inconsistently oriented faces
err_msg("TriStrip::build: error: backup_strip() failed");
err_msg("*** check mesh for inconsistently oriented faces ***");
return 0;
}
// claim it
claim_face(start);
// record direction of strip on 1st face:
start->orient_strip(a);
// faces alternate CCW / CW
if (_orientation) {
c = start->next_vert_ccw(a);
b = start->next_vert_ccw(c);
} else {
b = start->next_vert_ccw(a);
c = start->next_vert_ccw(b);
}
add(a,start);
add(b,start);
add(c,start);
Bface* opp;
if ((opp = start->opposite_face(b)) && is_cleared(opp) &&
opp->patch() == start->patch()) {
opp->orient_strip(_orientation ? a : c);
stack.push_back(opp);
}
int i=_orientation;
Bface* cur = start;
while ((cur = cur->next_strip_face()) && !is_claimed(cur)) {
claim_face(cur);
i++;
a = b;
b = c;
c = cur->other_vertex(a,b);
cur->orient_strip(a);
if ((opp = cur->opposite_face(b)) && is_cleared(opp) &&
opp->patch() == start->patch()) {
opp->orient_strip(i % 2 ? a : c);
stack.push_back(opp);
}
add(c,cur);
}
return 1;
}
