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[memecs <>]

Hi, 

I am trying to generate a bounded (by a rectangle) voronoi diagram. Here is
my code: 


        DT dt; 
        dt.insert(points.begin(), points.end()); 

        typedef typename K::Point_2 Point_2; 
        typename K::Ray_2 ray; 
        typename K::Line_2 line; 
        typename K::Segment_2 segment; 

        vector<Polygon_2> bounded_voronoi_faces; 


        // Find to which voronoi face the boundary points belong to. 
        list<std::pair&lt;DT::Vertex_handle, Point_2> > nearest_vertices; 
        for(int j = 0; j < 4; ++j) { 
                DT::Vertex_handle nearest =
dt.nearest_vertex(bbox.vertex(j)); 
                nearest_vertices.push_back(std::pair<DT::Vertex_handle,
Point_2>(nearest, bbox.vertex(j))); 
        } 

        // Iterate over all delaunay vertices. Each vertex is a site of a
voronoi face. 
        unsigned i = 0; 
        for(DT::Finite_vertices_iterator fvit = dt.finite_vertices_begin(); 
                        fvit != dt.finite_vertices_end(); ++fvit, ++i) { 

                
                // Circulate over all edges incident to the current vertex. 
                vector<Point_2> unique_points; 
                DT::Edge_circulator ec = dt.incident_edges(fvit); 
                do { 
                        if(!dt.is_infinite(ec)) { 
                                CGAL::Object voronoi_obj, intersection_obj; 
                                voronoi_obj = dt.dual(ec); 
                                if(CGAL::assign(segment,voronoi_obj)) { 
                                        intersection_obj =
CGAL::intersection(segment,bbox); 
                                } 
                                else if(CGAL::assign(ray,voronoi_obj)) { 
                                        intersection_obj =
CGAL::intersection(ray,bbox); 
                                } 

                                else if(CGAL::assign(line,voronoi_obj)) { 
                                        intersection_obj =
CGAL::intersection(line,bbox); 
                                } 
                                else { 
                                        // Something is wrong??? 
                                        assert(false); 
                                } 
                                typename K::Segment_2 intersected_segment; 
                                Point_2 intersected_point; 
                               
if(CGAL::assign(intersected_segment,intersection_obj)) { 
                                        // The object intersected 
                                       
unique_points.push_back(intersected_segment.source()); 
                                       
unique_points.push_back(intersected_segment.target()); 
                                } 
                                else { 
                                        // If it's a point or didn't
intersect do nothing... 
                                } 
                        } 
                } while(++ec != dt.incident_edges(fvit));     

The problem is: 

sometimes I get  voronoi segments with source or target points equals to
NaN. 

For example: 

if(CGAL::assign(segment,voronoi_obj)) { 
  Delaunay segment: 490 39 495 29 
  Voronoi segment: 493.5 34.5 -nan -nan 
} 





I really don't understand how is this possible. The input points I use to
construct the delaunay triangulation don't overlap. 

Does someone have an idea? 

Thanks

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