\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.7 - CGAL and the Boost Graph Library
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BGL_surface_mesh/surface_mesh_dual.cpp
#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>
#include <boost/foreach.hpp>
typedef Kernel::Point_3 Point;
typedef CGAL::Dual<Mesh> Dual;
typedef boost::graph_traits<Dual>::edge_descriptor edge_descriptor;
template <typename G>
struct noborder {
noborder() { }
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 source or target "vertex"
// BGL algorithms won't like that
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>::halfedge_descriptor halfedge_descriptor;
int main(int argc, char* argv[])
{
Mesh primal;
const char* filename = (argc > 1) ? argv[1] : "data/prim.off";
std::ifstream in(filename);
in >> primal;
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;
BOOST_FOREACH(boost::graph_traits<Dual>::vertex_descriptor dvd , vertices(dual)){
std::cout << dvd << std::endl;
}
std::cerr << "The halfedges in primal and dual with source and target"<< std::endl;
BOOST_FOREACH(halfedge_descriptor h , halfedges(dual)){
std::cout << h << " in primal: " << source(h,primal) << " -- " << target(h,primal) << " "
<< " in dual : " << source(h,finite_dual)<< " -- " << target(h,finite_dual) << std::endl;
}
std::cout << "edges of the finite dual graph" << std::endl;
BOOST_FOREACH(boost::graph_traits<FiniteDual>::edge_descriptor e , 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::cerr << "The graph has " << num << " connected components (face connectivity)" << std::endl;
BOOST_FOREACH(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::cerr << "The graph has " << num << " connected components (edge connectvity)" << std::endl;
BOOST_FOREACH(vertex_descriptor v , vertices(primal)){
std::cout << v << " in connected component " << vccmap[v] << std::endl;
}
return 0;
}