CGAL 5.5.2 - Surface Mesh Topology
Surface_mesh_topology/open_path_homotopy.cpp
#include <CGAL/Surface_mesh.h>
#include <CGAL/Curves_on_surface_topology.h>
#include <CGAL/Path_on_surface.h>
#include <CGAL/draw_face_graph_with_paths.h>
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::Point_3 Point_3;
void create_path_1(Path_on_surface<SM>& p)
{
p.push_back_by_index(88); // Its starting dart
for (int i=0; i<3; ++i)
{ p.extend_positive_turn(2); } // Extend the path
}
void create_path_2(Path_on_surface<SM>& p)
{
p.push_back_by_index(300); // Its starting dart
for (int i=0; i<3; ++i)
{ p.extend_negative_turn(2); } // Extend the path
}
void create_path_3(Path_on_surface<SM>& p)
{
p.push_back_by_index(87); // Its starting dart
p.extend_positive_turn(1); // Extend the path
for (int i=0; i<3; ++i)
}
int main(int argc, char* argv[])
{
bool draw=(argc>1?std::string(argv[1])=="-draw":false);
std::ifstream in(CGAL::data_file_path("meshes/double-torus-example.off"));
if (!in.is_open())
{
std::cout<<"ERROR reading file data/double-torus.off"<<std::endl;
exit(EXIT_FAILURE);
}
SM sm;
in>>sm;
Path_on_surface<SM> p1(sm), p2(sm), p3(sm);
create_path_1(p1);
create_path_2(p2);
create_path_3(p3);
bool res1=cst.are_base_point_homotopic(p1, p2);
std::cout<<"Path p1 (pink) "<<(res1?"IS":"IS NOT")
<<" base point homotopic with path p2 (green)."<<std::endl;
bool res2=cst.are_base_point_homotopic(p2, p3);
std::cout<<"Path p2 (green) "<<(res2?"IS":"IS NOT")
<<" base point homotopic with path p3 (orange)."<<std::endl;
if (draw)
{ CGAL::draw(sm, {p1, p2, p3}); }
return EXIT_SUCCESS;
}