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Merge fd178ca9e0 into 26a5fc70e4

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Mael 2025-12-03 14:01:24 +01:00 committed by GitHub
parent 26a5fc70e4 fd178ca9e0
commit 797eb4f2c7
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1 changed files with 67 additions and 13 deletions
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Constrained_triangulation_3/include/CGAL/Conforming_constrained_Delaunay_triangulation_3.h
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@ -4804,23 +4804,77 @@ auto get_remeshing_triangulation(Conforming_constrained_Delaunay_triangulation_3
} }
} else { } else {
for(auto ch : tr.all_cell_handles()) { for(auto ch : tr.all_cell_handles()) {
ch->set_subdomain_index(1); ch->set_subdomain_index(-1);
} }
std::stack<decltype(tr.infinite_cell())> stack; // Use a flood algorithm to mark constrained connected components.
stack.push(tr.infinite_cell()); // The connected component containing the infinite vertex is marked with index 0.
while(!stack.empty()) { // Nested components are marked with increasing indices.
auto ch = stack.top(); // Disconnected components that have the same nesting level get the same index parity:
stack.pop(); // for example two cubes within a larger bounding box will be index 2 and 4.
ch->set_subdomain_index(0); std::list<typename Tr::Facet> border;
for(int i = 0; i < 4; ++i) { int next_even_subdomain = 0;
if(ch->ccdt_3_data().is_facet_constrained(i)) int next_odd_subdomain = 1;
continue;
auto n = ch->neighbor(i); // Function to flood-fill a connected component with a given subdomain index
if(n->subdomain_index() == 1) { auto flood_component = [&tr, &border](typename Tr::Cell_handle start, int subdomain_index) {
stack.push(n); if(start->subdomain_index() != -1)
return;
std::list<typename Tr::Cell_handle> queue;
queue.push_back(start);
while(!queue.empty()) {
auto ch = queue.front();
queue.pop_front();
if(ch->subdomain_index() == -1) {
ch->set_subdomain_index(subdomain_index);
for(int i = 0; i < 4; i++) {
typename Tr::Facet f(ch, i);
auto n = ch->neighbor(i);
if(n->subdomain_index() == -1) {
if(ch->ccdt_3_data().is_facet_constrained(i))
border.push_back(f);
else
queue.push_back(n);
}
}
} }
} }
};
// Start with the infinite cell's component using index 0
flood_component(tr.infinite_cell(), next_even_subdomain);
next_even_subdomain += 2;
for (;;) { // while there are unvisited cells
while(!border.empty()) {
auto f = border.front();
border.pop_front();
auto n = f.first->neighbor(f.second);
if(n->subdomain_index() == -1) {
// If we are coming from an even subdomain, use next odd, and vice versa
bool from_even = (f.first->subdomain_index() % 2 == 0);
int next_index = from_even ? next_odd_subdomain : next_even_subdomain;
flood_component(n, next_index);
if(from_even)
next_odd_subdomain += 2;
else
next_even_subdomain += 2;
}
}
bool found_unvisited = false;
for(auto ch : tr.finite_cell_handles()) {
if(ch->subdomain_index() == -1) {
flood_component(ch, next_even_subdomain);
next_even_subdomain += 2;
found_unvisited = true;
break;
}
}
if(!found_unvisited)
break;
} }
for(auto f : tr.finite_facets()) for(auto f : tr.finite_facets())