CGAL 6.2 - Triangulated Surface Mesh Shortest Paths: Surface_mesh_shortest_path/shortest_paths_multiple_sources.cpp

CGAL 6.2 - Triangulated Surface Mesh Shortest Paths

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Surface_mesh_shortest_path/shortest_paths_multiple_sources.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Random.h>
#include <CGAL/Surface_mesh_shortest_path.h>
#include <boost/lexical_cast.hpp>
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <iterator>
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef CGAL::Surface_mesh<Kernel::Point_3> Triangle_mesh;
typedef CGAL::Surface_mesh_shortest_path_traits<Kernel, Triangle_mesh> Traits;
typedef CGAL::Surface_mesh_shortest_path<Traits> Surface_mesh_shortest_path;
typedef Surface_mesh_shortest_path::Face_location Face_location;
typedef boost::graph_traits<Triangle_mesh> Graph_traits;
typedef Graph_traits::vertex_iterator vertex_iterator;
typedef Graph_traits::face_iterator face_iterator;
typedef Graph_traits::face_descriptor face_descriptor;
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) ||
!CGAL::is_triangle_mesh(tmesh))
{
std::cerr << "Invalid input file." << std::endl;
return EXIT_FAILURE;
}
// pick up some source points inside faces,
const unsigned int randSeed = argc > 2 ? boost::lexical_cast<unsigned int>(argv[2]) : 7915421;
CGAL::Random rand(randSeed);
// by copying the faces in a vector to get a direct access to faces
std::size_t nb_faces=num_faces(tmesh);
face_iterator fit, fit_end;
std::tie(fit, fit_end) = faces(tmesh);
std::vector<face_descriptor> face_vector(fit, fit_end);
// and creating a vector of Face_location objects
const std::size_t nb_source_points = 30;
Traits::Barycentric_coordinates face_location = {{0.25, 0.5, 0.25}};
std::vector<Face_location> faceLocations(nb_source_points, Face_location(face_descriptor(), face_location));
for (std::size_t i = 0; i < nb_source_points; ++i)
{
faceLocations[i].first=face_vector[rand.get_int(0, static_cast<int>(nb_faces))];
}
// construct a shortest path query object and add a range of source points
Surface_mesh_shortest_path shortest_paths(tmesh);
shortest_paths.add_source_points(faceLocations.begin(), faceLocations.end());
// 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 Tmesh demo
std::ofstream output("shortest_paths_multiple_sources.polylines.txt");
vertex_iterator vit, vit_end;
for ( std::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;
}
Surface_mesh_shortest_path.h
Convenience header file only including CGAL/Surface_mesh_shortest_path/Surface_mesh_shortest_path....
CGAL::Exact_predicates_inexact_constructions_kernel
CGAL::Surface_mesh_shortest_path_traits
A model of the concept SurfaceMeshShortestPathTraits as required by the Surface_mesh_shortest_path cl...
Definition: Surface_mesh_shortest_path_traits.h:43
CGAL::Surface_mesh_shortest_path
Computes shortest surface paths from one or more source points on a surface mesh.
Definition: Surface_mesh_shortest_path.h:73
CGAL::Surface_mesh
CGAL::is_triangle_mesh
bool is_triangle_mesh(const FaceGraph &g)
CGAL::IO::read_polygon_mesh
bool read_polygon_mesh(const std::string &fname, Graph &g, const NamedParameters &np=parameters::default_values())
Kernel