CGAL users discussion list

[Monique Teillaud <>]

Hi Ben,

Your 4 points are the vertices of a square, which is a degenerate case 
since the 4 points are cocircular.
The triangulation consists in two triangles, both having the center of 
the square, ie the origin, as circumcenter.
So, the dual segment to the common edge of these two triangles (a 
diagonal of the square) has the origin as its two equal endpoints.

Best,
        Monique Teillaud

Ben Strasser wrote:
> Hello,
>
> I'm trying to iterator over the boundaries of the facets of a Voronoi
> diagram and have run into a CGAL behavior I can not explain. I build the
> diagram of the points (1, 1), (-1, 1), (-1, -1) and (1, -1). Then I just
> print out what objects CGAL gives me.
>
> seg:-0 -0 -0 -0
> ray:-0 -0 4 -0
> ray:-0 -0 -0 4
>  --- 
> ray:-0 -0 -4 -0
> ray:-0 -0 -0 4
>  --- 
> ray:-0 -0 -0 -4
> seg:-0 -0 -0 -0
> ray:-0 -0 -4 -0
>  --- 
> ray:-0 -0 -0 -4
> ray:-0 -0 4 -0
>  --- 

--
Monique Teillaud
INRIA Sophia Antipolis - Méditerranée
http://www.inria.fr/sophia/members/Monique.Teillaud/