CGAL 5.5 - Triangulated Surface Mesh Shortest Paths
Surface_mesh_shortest_path/shortest_paths.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Random.h>
#include <boost/lexical_cast.hpp>
#include <cstdlib>
#include <iostream>
#include <fstream>
typedef CGAL::Surface_mesh_shortest_path<Traits> Surface_mesh_shortest_path;
typedef boost::graph_traits<Triangle_mesh> Graph_traits;
typedef Graph_traits::vertex_iterator vertex_iterator;
typedef Graph_traits::face_iterator face_iterator;
int main(int argc, char** argv)
{
const std::string filename = (argc>1) ? argv[1] : CGAL::data_file_path("meshes/elephant.off");
Triangle_mesh tmesh;
if(!CGAL::IO::read_polygon_mesh(filename, tmesh) ||
{
std::cerr << "Invalid input file." << std::endl;
return EXIT_FAILURE;
}
// pick up a random face
const unsigned int randSeed = argc > 2 ? boost::lexical_cast<unsigned int>(argv[2]) : 7915421;
CGAL::Random rand(randSeed);
const int target_face_index = rand.get_int(0, static_cast<int>(num_faces(tmesh)));
face_iterator face_it = faces(tmesh).first;
std::advance(face_it,target_face_index);
// ... and define a barycentric coordinates inside the face
Traits::Barycentric_coordinates face_location = {{0.25, 0.5, 0.25}};
// construct a shortest path query object and add a source point
Surface_mesh_shortest_path shortest_paths(tmesh);
shortest_paths.add_source_point(*face_it, face_location);
// For all vertices in the tmesh, compute the points of
// the shortest path to the source point and write them
// into a file readable using the CGAL Polyhedron demo
std::ofstream output("shortest_paths_with_id.polylines.txt");
vertex_iterator vit, vit_end;
for ( boost::tie(vit, vit_end) = vertices(tmesh);
vit != vit_end; ++vit)
{
std::vector<Traits::Point_3> points;
shortest_paths.shortest_path_points_to_source_points(*vit, std::back_inserter(points));
// print the points
output << points.size() << " ";
for (std::size_t i = 0; i < points.size(); ++i)
output << " " << points[i];
output << std::endl;
}
return 0;
}