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#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
#include <CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h>
// Simplification function
#include <CGAL/Surface_mesh_simplification/edge_collapse.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_count_stop_predicate.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_length_cost.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Midpoint_placement.h>
#include <iostream>
#include <fstream>
typedef OpenMesh::PolyMesh_ArrayKernelT</* default traits*/> Surface_mesh;
typedef boost::graph_traits<Surface_mesh>::edge_descriptor edge_descriptor;
class Constrained_edge_map
{
public:
typedef boost::read_write_property_map_tag category;
typedef bool value_type;
typedef bool reference;
typedef edge_descriptor key_type;
Constrained_edge_map(Surface_mesh& sm)
: sm_(sm)
{
sm_.add_property(constraint);
}
inline friend value_type get(const Constrained_edge_map& em, key_type e)
{
bool b = em.sm_.property(em.constraint,em.sm_.edge_handle(e.idx()));
return b;
}
inline friend void put(const Constrained_edge_map& em, key_type e, value_type b)
{
em.sm_.property(em.constraint,em.sm_.edge_handle(e.idx())) = b;
}
private:
Surface_mesh& sm_;
OpenMesh::EPropHandleT<bool> constraint;
};
namespace SMS = CGAL::Surface_mesh_simplification;
int main(int argc, char** argv)
{
Surface_mesh surface_mesh;
Constrained_edge_map constraints_map(surface_mesh);
const std::string filename = (argc > 1) ? argv[1] : CGAL::data_file_path("meshes/cube-meshed.off");
OpenMesh::IO::read_mesh(surface_mesh, filename);
if(!CGAL::is_triangle_mesh(surface_mesh)){
std::cerr << "Input geometry is not triangulated." << std::endl;
return EXIT_FAILURE;
}
// For the purpose of the example we mark 100 edges as constrained edges
int count = 0;
for(edge_descriptor e : edges(surface_mesh))
put(constraints_map, e, (count++ < 100));
// This is a stop predicate (defines when the algorithm terminates).
// In this example, the simplification stops when the number of undirected edges
// left in the surface mesh drops below the specified number (1000)
const std::size_t stop_n = (argc > 2) ? std::stoi(argv[2]) : 1000;
SMS::Edge_count_stop_predicate<Surface_mesh> stop(stop_n);
// This the actual call to the simplification algorithm.
// The surface mesh and stop conditions are mandatory arguments.
std::cout << "Collapsing edges of mesh: " << filename << ", aiming for " << stop_n << " final edges..." << std::endl;
int r = SMS::edge_collapse(surface_mesh, stop,
CGAL::parameters::halfedge_index_map(get(CGAL::halfedge_index,surface_mesh))
.vertex_point_map(get(boost::vertex_point, surface_mesh))
.edge_is_constrained_map(constraints_map));
surface_mesh.garbage_collection();
std::cout << "\nFinished!\n" << r << " edges removed.\n"
<< num_edges(surface_mesh) << " final edges.\n";
OpenMesh::IO::write_mesh(surface_mesh, "out.off");
return EXIT_SUCCESS;
}
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