Polygon_mesh_processing/extrude.cpp

#include <CGAL/Surface_mesh.h>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_mesh_processing/compute_normal.h>
#include <CGAL/Polygon_mesh_processing/extrude.h>
#include <CGAL/boost/graph/IO/polygon_mesh_io.h>
 
#include <iostream>
#include <fstream>
#include <string>
 
typedef CGAL::Exact_predicates_inexact_constructions_kernel  Kernel;
typedef CGAL::Surface_mesh<Kernel::Point_3> SM;
typedef boost::graph_traits<SM>::vertex_descriptor           vertex_descriptor;
 
typedef Kernel::Vector_3                                     Vector;
typedef boost::property_map<SM, CGAL::vertex_point_t>::type  VPMap;
typedef SM::template Property_map<vertex_descriptor, Vector> VNMap;
 
struct Bottom
{
  Bottom(VPMap pmap, VNMap nmap, double vlen)
    : pmap(pmap), nmap(nmap), vlen(vlen)
  {}
 
 
  void operator()(const vertex_descriptor& vin, const vertex_descriptor vout) const
  {
    put(pmap, vout, get(pmap, vout) - vlen* get(nmap, vin));
  }
 
  VPMap pmap;
  VNMap nmap;
  double vlen;
};
 
struct Top
{
  Top(VPMap pmap, VNMap nmap, double vlen)
    : pmap(pmap), nmap(nmap), vlen(vlen)
  {}
 
 
  void operator()(const vertex_descriptor& vin, const vertex_descriptor vout) const
  {
    put(pmap, vout, get(pmap, vout) + vlen* get(nmap, vin));
  }
 
  VPMap pmap;
  VNMap nmap;
  double vlen;
};
 
int main(int argc, char* argv[])
{
  SM in, out;
 
  std::string filename = (argc > 1) ? std::string(argv[1]) : CGAL::data_file_path("meshes/cube-ouvert.off");
  double vlen = (argc > 2) ? std::stod(argv[2]) : 0.1;
 
  CGAL::IO::read_polygon_mesh(filename, in);
 
  VNMap vnormals = in.template add_property_map<vertex_descriptor, Vector>("v:normals", CGAL::NULL_VECTOR).first;
 
  CGAL::Polygon_mesh_processing::compute_vertex_normals(in, vnormals);
  Bottom bottom(get(CGAL::vertex_point,out), vnormals, vlen);
  Top top(get(CGAL::vertex_point,out), vnormals, vlen);
  CGAL::Polygon_mesh_processing::extrude_mesh(in, out, bottom, top);
 
 
  filename = filename.substr(filename.find_last_of("/") + 1, filename.length() - 1);
  filename = filename.substr(0, filename.find_last_of("."));
  filename = filename + "_" + std::to_string(vlen) + ".off";
  CGAL::IO::write_polygon_mesh(filename, out, CGAL::parameters::stream_precision(17));
  return 0;
}