CGAL users discussion list

[<>]

Hi all,
I am a newbie to cgal and I have a problem concerning voronoi Diagrams.

I created voronoi Diagrams  and I am able to write the Points of each Edge 
(x,y
) to the output stream.

But how can I get the boundary segments of one Face containing a Point of
interest. I need this to calculate the area of the corresponding face.

So far I used the the code from the CGAL Homepage
By transforming the edges to  segments I get the two Points (x,y) describing
one edge.


#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_2.h>

#include <fstream>

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

typedef CGAL::Delaunay_triangulation_2<K>  Triangulation;
typedef Triangulation::Edge_iterator  Edge_iterator;
typedef Triangulation::Point          Point;

int main( )
{
  std::ifstream in("data/voronoi.cin");
  std::istream_iterator<Point> begin(in);
  std::istream_iterator<Point> end;
  Triangulation T;
  T.insert(begin, end);

  int ns = 0;
  int nr = 0;
  Edge_iterator eit =T.edges_begin();
  for ( ; eit !=T.edges_end(); ++eit) {
    CGAL::Object o = T.dual(eit);
    if (CGAL::object_cast<K::Segment_2>(&o)) {++ns;}
    else if (CGAL::object_cast<K::Ray_2>(&o)) {++nr;}
  }
  std::cout << "The Voronoi diagram has " << ns << " finite edges "
            << " and " << nr << " rays" << std::endl;
  return 0;
}



Thank you very much in advance.

Andi