vsa_meshing_manifold_test.cpp

#include <iostream>
#include <fstream>

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Surface_mesh.h>

#include <CGAL/Variational_shape_approximation.h>

typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::FT FT;
typedef CGAL::Surface_mesh<Kernel::Point_3> Mesh;
typedef boost::property_map<Mesh, boost::vertex_point_t>::type Vertex_point_map;

typedef CGAL::Variational_shape_approximation<Mesh, Vertex_point_map> L21_approx;
typedef L21_approx::Error_metric L21_metric;


int main()
{
  const char* file_name = "sphere_remeshed.off";
  const FT drop = FT(1e-2);

  Mesh mesh;
  std::ifstream input(file_name);
  if (!input || !(input >> mesh) || !CGAL::is_triangle_mesh(mesh)) {
    std::cout << "Invalid input file." << std::endl;
    return false;
  }

  std::cout << "Testing \"" << file_name << '\"' << std::endl;
  // algorithm instance
  L21_metric error_metric(mesh,
    get(boost::vertex_point, const_cast<Mesh &>(mesh)));
  L21_approx approx(mesh,
    get(boost::vertex_point, const_cast<Mesh &>(mesh)),
    error_metric);

  // approximation, seeding from error, drop to the target error incrementally
  const std::size_t num_iterations = 20;
  const std::size_t inner_iterations = 5;
  approx.initialize_seeds(
    CGAL::parameters::seeding_method(CGAL::Surface_mesh_approximation::RANDOM)
    .min_error_drop(drop)
    .number_of_relaxations(inner_iterations));
  approx.run(num_iterations);
  std::cout << "#proxies " << approx.number_of_proxies() << std::endl;

  // meshing
  if (approx.extract_mesh(CGAL::parameters::subdivision_ratio(5.0))) {
    std::cout << "Succeeded." << std::endl;
    return EXIT_SUCCESS;
  }

  std::cout << "Failed." << std::endl;
  return EXIT_FAILURE;
}