extract a member function `detect_edges_and_cells_intersecting_region`

This commit is contained in:
Laurent Rineau 2025-09-24 16:59:32 +02:00
parent 5e80ca60bb
commit f6ebe208e9
1 changed files with 177 additions and 158 deletions

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@ -2020,174 +2020,21 @@ private:
facets_of_upper_cavity, facets_of_lower_cavity] = outputs; facets_of_upper_cavity, facets_of_lower_cavity] = outputs;
// to avoid "warning: captured structured bindings are a C++20 extension [-Wc++20-extensions]"" // to avoid "warning: captured structured bindings are a C++20 extension [-Wc++20-extensions]""
auto& intersecting_edges_ = intersecting_edges;
auto& vertices_of_upper_cavity_ = vertices_of_upper_cavity; auto& vertices_of_upper_cavity_ = vertices_of_upper_cavity;
auto& vertices_of_lower_cavity_ = vertices_of_lower_cavity; auto& vertices_of_lower_cavity_ = vertices_of_lower_cavity;
std::set<std::pair<Vertex_handle, Vertex_handle>> non_intersecting_edges_set; std::set<std::pair<Vertex_handle, Vertex_handle>> non_intersecting_edges_set;
// marker for already visited elements
std::set<Vertex_handle> visited_vertices;
std::map<std::pair<Vertex_handle, Vertex_handle>, bool> visited_edges;
std::set<Cell_handle> visited_cells;
auto make__new_element_functor = [](auto& visited_set) {
return [&visited_set](auto... e) {
const auto [_, not_already_visited] = visited_set.emplace(e...);
return not_already_visited;
};
};
auto new_vertex = make__new_element_functor(visited_vertices);
auto new_cell = make__new_element_functor(visited_cells);
auto new_edge = [&](Vertex_handle v0, Vertex_handle v1, bool does_intersect) {
CGAL_assertion(v0 != Vertex_handle{});
return visited_edges.emplace(CGAL::make_sorted_pair(v0, v1), does_intersect);
};
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) { if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
debug_dump_tetrahedra_intersect_region(face_index, region_index, cdt_2, fh_region); debug_dump_tetrahedra_intersect_region(face_index, region_index, cdt_2, fh_region);
} }
intersecting_edges.push_back(first_intersecting_edge); detect_edges_and_cells_intersecting_region(face_index, region_index, cdt_2, fh_region, region_border_vertices,
const auto [v0, v1] = tr().vertices(first_intersecting_edge); first_intersecting_edge, intersecting_edges, intersecting_cells,
(void)new_edge(v0, v1, true); non_intersecting_edges_set);
for(std::size_t i = 0; i < intersecting_edges.size(); ++i) {
const auto intersecting_edge = intersecting_edges[i];
const auto [v_above, v_below] = tr().vertices(intersecting_edge);
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
debug_dump_edge_region_intersection(face_index, region_index, fh_region, i, v_above, v_below, intersecting_edge);
}
auto test_edge = [&](Cell_handle cell, Vertex_handle v0, int index_v0, Vertex_handle v1, int index_v1,
int expected) {
auto value_returned = [this](bool b) {
CGAL_USE(this);
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
std::cerr << cdt_3_format(" return {}\n", b);
}
return b;
};
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
std::cerr << cdt_3_format(" test_edge {} {} ", IO::oformat(v0, with_point_and_info),
IO::oformat(v1, with_point_and_info));
}
auto [cached_value_it, not_visited] = new_edge(v0, v1, false);
if(!not_visited) return value_returned(cached_value_it->second);
int v0v1_intersects_region = (is_marked(v0, Vertex_marker::REGION_INSIDE) ||
is_marked(v1, Vertex_marker::REGION_INSIDE))
? expected
: does_edge_intersect_region(cell, index_v0, index_v1, cdt_2, fh_region);
if(v0v1_intersects_region != 0) {
if(this->use_older_cavity_algorithm()) {
if(v0v1_intersects_region != expected) {
throw PLC_error{"PLC error: v0v1_intersects_region != expected" ,
__FILE__, __LINE__, face_index, region_index};
}
}
// report the edge with first vertex above the region
if(v0v1_intersects_region < 0) {
std::swap(index_v0, index_v1);
}
intersecting_edges_.emplace_back(cell, index_v0, index_v1);
cached_value_it->second = true;
return value_returned(true);
} else {
non_intersecting_edges_set.insert(make_sorted_pair(v0, v1));
cached_value_it->second = false;
return value_returned(false);
}
};
if(this->use_older_cavity_algorithm()) {
CGAL_assertion(0 == region_border_vertices.count(v_above));
CGAL_assertion(0 == region_border_vertices.count(v_below));
if(new_vertex(v_above)) {
vertices_of_upper_cavity.push_back(v_above);
}
if(new_vertex(v_below)) {
vertices_of_lower_cavity.push_back(v_below);
}
}
auto facet_circ = this->incident_facets(intersecting_edge);
const auto facet_circ_end = facet_circ;
do { // loop facets around [v_above, v_below]
CGAL_assertion(false == this->is_infinite(*facet_circ));
const auto cell = facet_circ->first;
const auto facet_index = facet_circ->second;
CGAL_assertion_msg(!cell->ccdt_3_data().is_facet_constrained(facet_index),
std::invoke([&]() {
this->dump_triangulation_to_off();
return std::string("intersecting polygons!");
}).c_str());
if(new_cell(cell)) {
intersecting_cells.insert(cell);
}
const auto index_v_above = cell->index(v_above);
const auto index_v_below = cell->index(v_below);
const auto index_vc = 6 - index_v_above - index_v_below - facet_index;
const auto vc = cell->vertex(index_vc);
if(region_border_vertices.count(vc) > 0) continue; // intersecting edges cannot touch the border
if(!test_edge(cell, v_above, index_v_above, vc, index_vc, 1) &&
!test_edge(cell, v_below, index_v_below, vc, index_vc, -1) &&
this->use_older_cavity_algorithm())
{
dump_triangulation();
dump_region(face_index, region_index, cdt_2);
{
std::ofstream out(std::string("dump_two_edges_") + std::to_string(face_index) + ".polylines.txt");
out.precision(17);
write_segment(out, Edge{cell, index_v_above, index_vc});
write_segment(out, Edge{cell, index_v_below, index_vc});
}
throw PLC_error{"PLC error: !test_edge(v_above..) && !test_edge(v_below..)" ,
__FILE__, __LINE__, face_index, region_index};
}
} while(++facet_circ != facet_circ_end);
if(this->use_newer_cavity_algorithm() && i + 1 == intersecting_edges.size()) {
for(auto ch: intersecting_cells) {
if(this->debug_regions()) {
std::cerr << "tetrahedron #" << ch->time_stamp() << " intersects the region\n";
}
for(int i = 0; i < 4; ++i) {
for(int j = i + 1; j < 4; ++j) {
test_edge(ch, ch->vertex(i), i, ch->vertex(j), j, 1);
}
}
for(int i = 0; i < 4; ++i) {
auto n_ch = ch->neighbor(i);
if(tr().is_infinite(n_ch))
continue;
if(new_cell(n_ch)) {
const auto tetrahedron = tr().tetrahedron(n_ch);
const auto tet_bbox = tetrahedron.bbox();
if(std::any_of(fh_region.begin(), fh_region.end(), [&](auto fh) {
const auto triangle = cdt_2.triangle(fh);
const auto tri_bbox = triangle.bbox();
return CGAL::do_overlap(tet_bbox, tri_bbox) &&
does_tetrahedron_intersect_triangle_interior(tetrahedron, triangle, tr().geom_traits());
}))
{
intersecting_cells.insert(n_ch);
if(this->debug_regions()) {
std::cerr << "tetrahedron #" << n_ch->time_stamp() << " intersects the region\n";
}
} else if(this->debug_regions()) {
std::cerr << "NO, tetrahedron #" << n_ch->time_stamp() << " does not intersect the region\n";
}
for(int i = 0; i < 4; ++i) {
for(int j = i + 1; j < 4; ++j) {
test_edge(n_ch, n_ch->vertex(i), i, n_ch->vertex(j), j, 1);
}
}
}
}
}
} // last intersecting edge, and new algorithm
} // end loop on intersecting_edges
if(this->use_older_cavity_algorithm()) { if(this->use_older_cavity_algorithm()) {
process_older_cavity_algorithm(intersecting_edges, intersecting_cells, facets_of_upper_cavity, facets_of_lower_cavity); process_older_cavity_algorithm(intersecting_edges, intersecting_cells, vertices_of_upper_cavity,
vertices_of_lower_cavity, facets_of_upper_cavity, facets_of_lower_cavity);
} // older algorithm } // older algorithm
// those facets are viewed from the outside of the cavity // those facets are viewed from the outside of the cavity
@ -3600,12 +3447,23 @@ public:
void process_older_cavity_algorithm(const std::vector<Edge>& intersecting_edges, void process_older_cavity_algorithm(const std::vector<Edge>& intersecting_edges,
const std::set<Cell_handle>& intersecting_cells, const std::set<Cell_handle>& intersecting_cells,
std::vector<Vertex_handle>& vertices_of_upper_cavity,
std::vector<Vertex_handle>& vertices_of_lower_cavity,
std::vector<Facet>& facets_of_upper_cavity, std::vector<Facet>& facets_of_upper_cavity,
std::vector<Facet>& facets_of_lower_cavity) std::vector<Facet>& facets_of_lower_cavity)
{ {
auto new_vertex = make__new_element_functor<Vertex_handle>();
for(auto intersecting_edge: intersecting_edges) { for(auto intersecting_edge: intersecting_edges) {
const auto [v_above, v_below] = tr().vertices(intersecting_edge); const auto [v_above, v_below] = tr().vertices(intersecting_edge);
if(new_vertex(v_above)) {
vertices_of_upper_cavity.push_back(v_above);
}
if(new_vertex(v_below)) {
vertices_of_lower_cavity.push_back(v_below);
}
auto cell_circ = this->incident_cells(intersecting_edge), end = cell_circ; auto cell_circ = this->incident_cells(intersecting_edge), end = cell_circ;
CGAL_assume(cell_circ != nullptr); CGAL_assume(cell_circ != nullptr);
do { do {
@ -3624,6 +3482,167 @@ public:
} }
} }
template <typename Element_type>
static auto make__new_element_functor() {
return [visited_set = std::set<Element_type>()](auto... e) mutable {
const auto [_, not_already_visited] = visited_set.emplace(e...);
return not_already_visited;
};
};
template <typename Fh_region, typename Vertices_container>
void detect_edges_and_cells_intersecting_region(
CDT_3_signed_index face_index,
int region_index,
const CDT_2& cdt_2,
const Fh_region& fh_region,
const Vertices_container& region_border_vertices,
Edge first_intersecting_edge,
std::vector<Edge>& intersecting_edges,
std::set<Cell_handle>& intersecting_cells,
std::set<std::pair<Vertex_handle, Vertex_handle>>& non_intersecting_edges_set)
{
// Create visitor functors
auto new_cell = make__new_element_functor<Cell_handle>();
std::map<std::pair<Vertex_handle, Vertex_handle>, bool> visited_edges;
auto new_edge = [&](Vertex_handle v0, Vertex_handle v1, bool does_intersect) {
CGAL_assertion(v0 != Vertex_handle{});
return visited_edges.emplace(CGAL::make_sorted_pair(v0, v1), does_intersect);
};
// Alias for C++20 extension warning workaround
auto& intersecting_edges_ = intersecting_edges;
intersecting_edges.push_back(first_intersecting_edge);
const auto [v0, v1] = tr().vertices(first_intersecting_edge);
(void)new_edge(v0, v1, true);
for(std::size_t i = 0; i < intersecting_edges.size(); ++i) {
const auto intersecting_edge = intersecting_edges[i];
const auto [v_above, v_below] = tr().vertices(intersecting_edge);
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
debug_dump_edge_region_intersection(face_index, region_index, fh_region, i, v_above, v_below, intersecting_edge);
}
auto test_edge = [&](Cell_handle cell, Vertex_handle v0, int index_v0, Vertex_handle v1, int index_v1,
int expected) {
auto value_returned = [this](bool b) {
CGAL_USE(this);
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
std::cerr << cdt_3_format(" return {}\n", b);
}
return b;
};
if constexpr (cdt_3_can_use_cxx20_format()) if(this->debug_regions()) {
std::cerr << cdt_3_format(" test_edge {} {} ", IO::oformat(v0, with_point_and_info),
IO::oformat(v1, with_point_and_info));
}
auto [cached_value_it, not_visited] = new_edge(v0, v1, false);
if(!not_visited) return value_returned(cached_value_it->second);
int v0v1_intersects_region = (is_marked(v0, Vertex_marker::REGION_INSIDE) ||
is_marked(v1, Vertex_marker::REGION_INSIDE))
? expected
: does_edge_intersect_region(cell, index_v0, index_v1, cdt_2, fh_region);
if(v0v1_intersects_region != 0) {
if(this->use_older_cavity_algorithm()) {
if(v0v1_intersects_region != expected) {
throw PLC_error{"PLC error: v0v1_intersects_region != expected" ,
__FILE__, __LINE__, face_index, region_index};
}
}
// report the edge with first vertex above the region
if(v0v1_intersects_region < 0) {
std::swap(index_v0, index_v1);
}
intersecting_edges_.emplace_back(cell, index_v0, index_v1);
cached_value_it->second = true;
return value_returned(true);
} else {
non_intersecting_edges_set.insert(make_sorted_pair(v0, v1));
cached_value_it->second = false;
return value_returned(false);
}
};
auto facet_circ = this->incident_facets(intersecting_edge);
const auto facet_circ_end = facet_circ;
do { // loop facets around [v_above, v_below]
CGAL_assertion(false == this->is_infinite(*facet_circ));
const auto cell = facet_circ->first;
const auto facet_index = facet_circ->second;
CGAL_assertion_msg(!cell->ccdt_3_data().is_facet_constrained(facet_index),
std::invoke([&]() {
this->dump_triangulation_to_off();
return std::string("intersecting polygons!");
}).c_str());
if(new_cell(cell)) {
intersecting_cells.insert(cell);
}
const auto index_v_above = cell->index(v_above);
const auto index_v_below = cell->index(v_below);
const auto index_vc = 6 - index_v_above - index_v_below - facet_index;
const auto vc = cell->vertex(index_vc);
if(region_border_vertices.count(vc) > 0) continue; // intersecting edges cannot touch the border
if(!test_edge(cell, v_above, index_v_above, vc, index_vc, 1) &&
!test_edge(cell, v_below, index_v_below, vc, index_vc, -1) &&
this->use_older_cavity_algorithm())
{
if(this->debug_regions()) {
dump_triangulation();
dump_region(face_index, region_index, cdt_2);
std::ofstream out(std::string("dump_two_edges_") + std::to_string(face_index) + ".polylines.txt");
out.precision(17);
write_segment(out, Edge{cell, index_v_above, index_vc});
write_segment(out, Edge{cell, index_v_below, index_vc});
}
throw PLC_error{"PLC error: !test_edge(v_above..) && !test_edge(v_below..)" ,
__FILE__, __LINE__, face_index, region_index};
}
} while(++facet_circ != facet_circ_end);
if(this->use_newer_cavity_algorithm() && i + 1 == intersecting_edges.size()) {
for(auto ch: intersecting_cells) {
if(this->debug_regions()) {
std::cerr << "tetrahedron #" << ch->time_stamp() << " intersects the region\n";
}
for(int i = 0; i < 4; ++i) {
for(int j = i + 1; j < 4; ++j) {
test_edge(ch, ch->vertex(i), i, ch->vertex(j), j, 1);
}
}
for(int i = 0; i < 4; ++i) {
auto n_ch = ch->neighbor(i);
if(tr().is_infinite(n_ch))
continue;
if(new_cell(n_ch)) {
const auto tetrahedron = tr().tetrahedron(n_ch);
const auto tet_bbox = tetrahedron.bbox();
if(std::any_of(fh_region.begin(), fh_region.end(), [&](auto fh) {
const auto triangle = cdt_2.triangle(fh);
const auto tri_bbox = triangle.bbox();
return CGAL::do_overlap(tet_bbox, tri_bbox) &&
does_tetrahedron_intersect_triangle_interior(tetrahedron, triangle, tr().geom_traits());
}))
{
intersecting_cells.insert(n_ch);
if(this->debug_regions()) {
std::cerr << "tetrahedron #" << n_ch->time_stamp() << " intersects the region\n";
}
} else if(this->debug_regions()) {
std::cerr << "NO, tetrahedron #" << n_ch->time_stamp() << " does not intersect the region\n";
}
for(int i = 0; i < 4; ++i) {
for(int j = i + 1; j < 4; ++j) {
test_edge(n_ch, n_ch->vertex(i), i, n_ch->vertex(j), j, 1);
}
}
}
}
}
} // last intersecting edge, and new algorithm
} // end loop on intersecting_edges
}
void debug_dump_cavity_outputs(CDT_3_signed_index face_index, void debug_dump_cavity_outputs(CDT_3_signed_index face_index,
int region_index, int region_index,
const std::vector<Edge>& intersecting_edges, const std::vector<Edge>& intersecting_edges,