Combinatorial_map/map_3_marks.cpp

#include <CGAL/Combinatorial_map.h>
#include <iostream>
#include <cstdlib>

typedef CGAL::Combinatorial_map<3> CMap_3;
typedef CMap_3::Dart_descriptor Dart_descriptor;
typedef CMap_3::size_type size_type;

int main()
{
  CMap_3 cm;

  // 1) Reserve a mark.
  size_type amark;
  try
  {
    amark = cm.get_new_mark();
  }
  catch (CMap_3::Exception_no_more_available_mark)
  {
    std::cerr<<"No more free mark, exit."<<std::endl;
    exit(-1);
  }

  // 2) Create two tetrahedra.
  Dart_descriptor d1 = cm.make_combinatorial_tetrahedron();
  Dart_descriptor d2 = cm.make_combinatorial_tetrahedron();

  // 3) 3-sew them.
  cm.sew<3>(d1, d2);

  // 4) Mark the darts belonging to the first tetrahedron.
  for  (CMap_3::Dart_of_cell_range<3>::iterator
          it(cm.darts_of_cell<3>(d1).begin()),
          itend(cm.darts_of_cell<3>(d1).end()); it!=itend; ++it)
    cm.mark(it, amark);

  // 4) Remove the common 2-cell between the two cubes:
  //    the two tetrahedra are merged.
  cm.remove_cell<2>(d1);

  // 5) Thanks to the mark, we know which darts come from the first tetrahedron.
  unsigned int res=0;
  for (CMap_3::Dart_range::iterator it(cm.darts().begin()),
         itend(cm.darts().end()); it!=itend; ++it)
  {
    if ( cm.is_marked(it, amark) )
      ++res;
  }

  std::cout<<"Number of darts from the first tetrahedron: "<<res<<std::endl;
  cm.free_mark(amark);

  return EXIT_SUCCESS;
}