CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

This is a problem in the demo only.
Try patching include/CGAL/Qt/PainterOstream.h

like this:
@@ -156,6 +156,7 @@
   {
     const Point_2 proj_source = line.projection(source);
     const Point_2 proj_target = line.projection(target);
+    if (CGAL::collinear(proj_source,proj_target,center)) return;
     const Point_2 intersection = circumcenter(proj_source,
                                                 proj_target,
                                                 center);

Sebastien.

Hailong Yao wrote:
> Dear all,
>  
> It seems I have not received any reply on this thread.
>  
> I thecked the CGAL manual, is there a constraint for segment Voronoi 
> diagrams that no four points are co-circular? If so, is it difficult to 
> solve this issue? In my inputs, there are many cases where four points 
> are co-circular. How can I solve this problem? Any comments or 
> suggestions? Thanks very much!
>  
> Thanks,
> Hailong
> On Mon, Oct 31, 2011 at 10:04 PM, Hailong Yao < 
> <mailto:>> wrote:
>
>     Dear all,
>      
>     I am trying a demo of the CGAL in "Segment_Delaunay_graph_2", I can
>     launch the demo and draw segments in the window to get the correct
>     segment voronoi graphs for most cases. But when I draw three
>     parallel vertical segments, the program crashes. Anyone has met with
>     this problem? Thanks very much!
>      
>     Thanks,
>     Hailong
>