void geometryUtils::subdivide(Polyhedron& P) { if (P.size_of_facets() == 0) return; // We use that new vertices/halfedges/facets are appended at the end. std::size_t nv = P.size_of_vertices(); Vertex_iterator last_v = P.vertices_end(); --last_v; // the last of the old vertices Edge_iterator last_e = P.edges_end(); --last_e; // the last of the old edges Facet_iterator last_f = P.facets_end(); --last_f; // the last of the old facets Facet_iterator f = P.facets_begin(); // create new center vertices do { geometryUtils::subdivide_create_center_vertex(P, f); } while (f++ != last_f); std::vector<Point_3> pts; // smooth the old vertices pts.reserve(nv); // get intermediate space for the new points ++last_v; // make it the past-the-end position again std::transform(P.vertices_begin(), last_v, std::back_inserter(pts), Smooth_old_vertex()); std::copy(pts.begin(), pts.end(), P.points_begin()); Edge_iterator e = P.edges_begin(); // flip the old edges ++last_e; // make it the past-the-end position again while (e != last_e) { Halfedge_handle h = e; ++e; // careful, incr. before flip since flip destroys current edge geometryUtils::subdivide_flip_edge(P, h); }; CGAL_postcondition(P.is_valid()); };
bool is_weakly_convex(Polyhedron const& p) { for (typename Polyhedron::Edge_const_iterator i = p.edges_begin(); i != p.edges_end(); ++i) { typename Polyhedron::Plane_3 p(i->opposite()->vertex()->point(), i->vertex()->point(), i->next()->vertex()->point()); if (p.has_on_positive_side(i->opposite()->next()->vertex()->point()) && CGAL::squared_distance(p, i->opposite()->next()->vertex()->point()) > 1e-8) { return false; } } // Also make sure that there is only one shell: boost::unordered_set<typename Polyhedron::Facet_const_handle, typename CGAL::Handle_hash_function> visited; // c++11 // visited.reserve(p.size_of_facets()); std::queue<typename Polyhedron::Facet_const_handle> to_explore; to_explore.push(p.facets_begin()); // One arbitrary facet visited.insert(to_explore.front()); while (!to_explore.empty()) { typename Polyhedron::Facet_const_handle f = to_explore.front(); to_explore.pop(); typename Polyhedron::Facet::Halfedge_around_facet_const_circulator he, end; end = he = f->facet_begin(); CGAL_For_all(he,end) { typename Polyhedron::Facet_const_handle o = he->opposite()->facet(); if (!visited.count(o)) { visited.insert(o); to_explore.push(o); } } }
void SetEdgeWeightsEuclidean(Polyhedron& P) { edge_descriptor e(P.edges_begin()); edge_descriptor e_end(P.edges_end()); for(; e!=e_end; e=e.next()) { e.halfedge()->weight (sqrt( (e.halfedge()->vertex()->point() - e.opposite().halfedge()->vertex()->point()).squared_length() )); e.opposite().halfedge()->weight(e.halfedge()->weight()); } }
void subdiv_border( Polyhedron& P) { if ( P.size_of_facets() == 0) return; // We use that new halfedges are appended at the end. Edge_iterator last_e = P.edges_end(); -- last_e; // the last of the old edges Edge_iterator e = P.edges_begin(); // create trisected border edges do { if ( e->opposite()->is_border()) trisect_border_halfedge( P, e->opposite()); else if ( e->is_border()) trisect_border_halfedge( P, e); } while ( e++ != last_e); e = P.edges_begin(); // smooth points on border edges std::vector<Point> pts; // store new smoothed points temporarily do { if ( e->opposite()->is_border()) smooth_border_vertices( e->opposite(), std::back_inserter(pts)); else if ( e->is_border()) smooth_border_vertices( e, std::back_inserter(pts)); } while ( e++ != last_e); e = P.edges_begin(); // copy smoothed points back std::vector<Point>::iterator i = pts.begin(); do { if ( e->opposite()->is_border()) { e->vertex()->point() = *i++; e->opposite()->vertex()->point() = *i++; e->opposite()->next()->vertex()->point() = *i++; } else if ( e->is_border()) { e->opposite()->vertex()->point() = *i++; e->vertex()->point() = *i++; e->next()->vertex()->point() = *i++; } } while ( e++ != last_e); CGAL_assertion( i == pts.end()); CGAL_postcondition( P.is_valid()); }
// a helper method for running different iterators void running_iterators( Polyhedron& P) { if ( P.size_of_facets() == 0) return; std::size_t nv = P.size_of_vertices(); std::cout << "The number of vertices in the Polyhedron: " << nv << std::endl; std::cout << "The number of facets in the Polyhedron: " << P.size_of_facets() << std::endl; std::cout << "The number of half edges in the Polyhedron: " << P.size_of_halfedges() << std::endl; std::cout << std:: endl; Polyhedron::Vertex_iterator last_v = P.vertices_end(); -- last_v; // the last of the old vertices Polyhedron::Edge_iterator last_e = P.edges_end(); -- last_e; // the last of the old edges Polyhedron::Facet_iterator last_f = P.facets_end(); -- last_f; // the last of the old facets int k = 0; Polyhedron::Facet_iterator f = P.facets_begin(); do { std::cout << "Printing a facet index: " << k++ << std::endl; f->halfedge(); } while ( f++ != last_f); std::cout << std::endl; // ------------------------------------------------- // traverse the vertices // ------------------------------------------------- std::cout << "Printing the vertex indices: " << std::endl; int n=0; for (Polyhedron::Vertex_iterator vi = P.vertices_begin(); vi != P.vertices_end(); ++vi) { Kernel::Point_3 p; p = vi->point(); std::cout << "Vertex index: " << n++ << std::endl; std::cout << "p.x() = " << p.x() << std::endl; std::cout << "p.y() = " << p.y() << std::endl; std::cout << "p.z() = " << p.z() << std::endl; } std::cout << std::endl; // ------------------------------------------------- // traverse the edges // ------------------------------------------------- std::cout << "Iterating over the edges.... " << std::endl; n=0; for (Polyhedron::Edge_iterator ei = P.edges_begin(); ei != P.edges_end(); ++ei) { ei->next(); Kernel::Point_3 p; p = ei->vertex()->point(); std::cout << "For edge index: " << n++ << std::endl; std::cout << "p.x() = " << p.x() << std::endl; std::cout << "p.y() = " << p.y() << std::endl; std::cout << "p.z() = " << p.z() << std::endl; } std::cout << std::endl; // ----------------------------------------------- // Do something else with the edge iterators // ----------------------------------------------- Polyhedron::Edge_iterator e = P.edges_begin(); ++ last_e; // make it the past-the-end position again while ( e != last_e) { Polyhedron::Halfedge_handle h = e; ++e; }; CGAL_postcondition( P.is_valid()); }