Boolean_set_operations_2/simple_join_intersect.cpp

#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Boolean_set_operations_2.h>
#include <list>

typedef CGAL::Exact_predicates_exact_constructions_kernel Kernel;
typedef Kernel::Point_2                                   Point_2;
typedef CGAL::Polygon_2<Kernel>                           Polygon_2;
typedef CGAL::Polygon_with_holes_2<Kernel>                Polygon_with_holes_2;
typedef std::list<Polygon_with_holes_2>                   Pwh_list_2;

#include "print_utils.h"

int main ()
{
  // Construct the two input polygons.
  Polygon_2 P;
  P.push_back (Point_2 (0, 0));
  P.push_back (Point_2 (5, 0));
  P.push_back (Point_2 (3.5, 1.5));
  P.push_back (Point_2 (2.5, 0.5));
  P.push_back (Point_2 (1.5, 1.5));

  std::cout << "P = "; print_polygon (P);

  Polygon_2 Q;
  Q.push_back (Point_2 (0, 2));
  Q.push_back (Point_2 (1.5, 0.5));
  Q.push_back (Point_2 (2.5, 1.5));
  Q.push_back (Point_2 (3.5, 0.5));
  Q.push_back (Point_2 (5, 2));

  std::cout << "Q = "; print_polygon (Q);

  // Compute the union of P and Q.
  Polygon_with_holes_2 unionR;

  if (CGAL::Boolean_set_operations_2::join (P, Q, unionR)) {
    std::cout << "The union: ";
    print_polygon_with_holes (unionR);
  } else
    std::cout << "P and Q are disjoint and their union is trivial."
              << std::endl;
  std::cout << std::endl;

  // Compute the intersection of P and Q.
  Pwh_list_2                  intR;
  Pwh_list_2::const_iterator  it;

  CGAL::Boolean_set_operations_2::intersection (P, Q, std::back_inserter(intR));

  std::cout << "The intersection:" << std::endl;
  for (it = intR.begin(); it != intR.end(); ++it) {
    std::cout << "--> ";
    print_polygon_with_holes (*it);
  }

  return 0;
}