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#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/boost/graph/Dual.h>
#include <CGAL/boost/graph/helpers.h>
#include <iostream>
#include <fstream>
#include <boost/graph/filtered_graph.hpp>
#include <boost/graph/connected_components.hpp>
typedef CGAL::Simple_cartesian<double> Kernel;
typedef Kernel::Point_3 Point;
typedef CGAL::Surface_mesh<Point> Mesh;
typedef CGAL::Dual<Mesh> Dual;
typedef boost::graph_traits<Dual>::edge_descriptor edge_descriptor;
template <typename G>
struct noborder {
noborder() : g(nullptr) {} // default-constructor required by filtered_graph
noborder(G& g) : g(&g) {}
bool operator()(const edge_descriptor& e) const
{ return !is_border(e,*g); }
G* g;
};
// A dual border edge has a null_face as the source or target "vertex"
// BGL algorithms won't like that, so we remove border edges through a
// boost::filtered_graph.
typedef boost::filtered_graph<Dual, noborder<Mesh> > FiniteDual;
typedef boost::graph_traits<Mesh>::vertex_descriptor vertex_descriptor;
typedef boost::graph_traits<Mesh>::face_descriptor face_descriptor;
typedef boost::graph_traits<Mesh>::edge_descriptor edge_descriptor;
int main(int argc, char* argv[])
{
const std::string filename = (argc > 1) ? argv[1] : CGAL::data_file_path("meshes/prim.off");
Mesh primal;
if(!CGAL::IO::read_polygon_mesh(filename, primal))
{
std::cerr << "Invalid input." << std::endl;
return 1;
}
Dual dual(primal);
FiniteDual finite_dual(dual,noborder<Mesh>(primal));
std::cout << "dual has " << num_vertices(dual) << " vertices" << std::endl;
std::cout << "The vertices of dual are faces in primal"<< std::endl;
for(boost::graph_traits<Dual>::vertex_descriptor dvd : vertices(dual)) {
std::cout << dvd << std::endl;
}
std::cout << "The edges in primal and dual with source and target" << std::endl;
for(edge_descriptor e : edges(dual)) {
std::cout << e << " in primal: " << source(e,primal) << " -- " << target(e,primal) << " "
<< " in dual : " << source(e,finite_dual) << " -- " << target(e,finite_dual) << std::endl;
}
std::cout << "edges of the finite dual graph" << std::endl;
for(boost::graph_traits<FiniteDual>::edge_descriptor e : CGAL::make_range(edges(finite_dual))) {
std::cout << e << " " << source(e,primal) << " " << source(e,finite_dual) << std::endl;
}
// the storage of a property map is in primal
Mesh::Property_map<face_descriptor,int> fccmap;
fccmap = primal.add_property_map<face_descriptor,int>("f:CC").first;
int num = connected_components(finite_dual, fccmap);
std::cout << "The graph has " << num << " connected components (face connectivity)" << std::endl;
for(face_descriptor f : faces(primal)) {
std::cout << f << " in connected component " << fccmap[f] << std::endl;
}
Mesh::Property_map<vertex_descriptor,int> vccmap;
vccmap = primal.add_property_map<vertex_descriptor,int>("v:CC").first;
num = connected_components(primal, vccmap);
std::cout << "The graph has " << num << " connected components (edge connectvity)" << std::endl;
for(vertex_descriptor v : vertices(primal)) {
std::cout << v << " in connected component " << vccmap[v] << std::endl;
}
return 0;
}
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