Surface_mesh_topology/path_homotopy_with_symbols.cpp

#include <CGAL/Polygonal_schema.h>
#include <CGAL/Path_on_surface.h>
#include <CGAL/Curves_on_surface_topology.h>
#include <iostream>
#include <cstdlib>
 
using namespace CGAL::Surface_mesh_topology;
typedef Polygonal_schema_with_combinatorial_map<> PS;
 
int main()
{
  PS ps;
  ps.add_facet("a b -a -b c d -c -d");
 
  Path_on_surface<PS> p1(ps); p1.push_back_by_label("a");
  Path_on_surface<PS> p2(ps); p2.push_back_by_label("b c a -c -b");
 
  Curves_on_surface_topology<PS> cst(ps);
 
  bool res1=cst.are_freely_homotopic(p1, p2);
  std::cout<<"Paths p1 and p2 "<<(res1?"ARE":"ARE NOT")
           <<" freely homotopic."<<std::endl;
 
  bool res2=cst.are_base_point_homotopic(p1, p2);
  std::cout<<"Paths p1 and p2 "<<(res2?"ARE":"ARE NOT")
           <<" base point homotopic."<<std::endl;
 
  return EXIT_SUCCESS;
}