max_cover_example.cpp

File contents

#include <fstream>
#include <sstream>
#include <ostream>

#include <boost/timer.hpp>

#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Arr_circle_segment_traits_2.h>
#include <CGAL/Arrangement_2.h>

typedef CGAL::Exact_predicates_exact_constructions_kernel  Kernel;
typedef Kernel::FT                                         Number_type;
typedef CGAL::Arr_circle_segment_traits_2<Kernel>          Traits;
typedef Traits::CoordNT                                    CoordNT;
typedef Traits::Point_2                                    Point;
typedef Traits::Curve_2                                    Curve;
typedef Traits::Rational_point_2                           Rational_point;
typedef Traits::Rational_segment_2                         Segment;
typedef Traits::Rational_circle_2                          Circle;
typedef CGAL::Arrangement_2<Traits>                        Arrangement;

/*! Export a coordinate of type square-root extension to the standard output.
 */
std::ostream& operator<<(std::ostream& os, const CoordNT& c)
{
  CGAL::Rational_traits<Number_type> rt;
  std::cout << "("
            << rt.numerator(c.a0()) << "/" << rt.denominator(c.a0()) << ","
            << rt.numerator(c.a1()) << "/" << rt.denominator(c.a1()) << ","
            << rt.numerator(c.root()) << "/" << rt.denominator(c.root()) << ")";
  return os;
}

/*! Export a point of two coordinates of type square-root extension to the
 * standard output.
 */
std::ostream& operator<<(std::ostream& os, const Point& p)
{
  std::cout << "(" << p.x() << "," << p.y() << ")";
  return os;
}

int main(int argc, char* argv[])
{
  Kernel::FT r_square;
  if (argc < 2) {
    std::cerr << "The radius is missing!" << std::endl;
    return 1;
  }
  std::istringstream r_square_stream(argv[1]);
  r_square_stream >> r_square;

  const char* filename = (argc > 2) ? argv[2] : "points.txt";
  std::ifstream is;
  is.open(filename);
  if (!is.is_open()) {
    std::cerr << "Failed to open " << filename << "!" << std::endl;
    return 1;
  }
  size_t n;
  is >> n;
  std::vector<Curve> curves(n);
  for (auto i = 0; i < n; ++i) {
    Kernel::FT x, y;
    is >> x >> y;
    curves[i] = Curve(Circle(Rational_point(x, y), r_square));
  }

  Arrangement arr;
  boost::timer timer;
  insert(arr, curves.begin(), curves.end());
  double secs = timer.elapsed();

  // Print the number of cells:
  std::cout << "Execution time: " << secs << std::endl;
  std::cout << "# vertices: " << arr.number_of_vertices() << std::endl
            << "# halfedges: " << arr.number_of_halfedges()  << std::endl
            << "# faces: " << arr.number_of_faces() << std::endl;

  // Print one point:
  if (arr.number_of_vertices() > 0)
    std::cout << "1st point: " << arr.vertices_begin()->point() << std::endl;

  return 0;
}