CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 03/21/2017 02:16 PM, Ch'Gans wrote:
> On 21 March 2017 at 15:34, Ch'Gans 
> <>
>  wrote:
> > Hi there,
> [...]
> > Actually it looks like i cannot use graph_traits_Triangulation_2.h or
> > graph_traits_Delaunay_Triangulation_2.h, i would need to write my own
> > version for CDT, do I?
>
> Indeed, I had to copy and adapt
> graph_traits_Delaunay_Triangulation_2.h, first to add support for the
> Constrained_Delaunay_Triangulation, and as well for the intersection
> tag. On top of that I've modified the weight_map to return 0 for
> constrained weight. Surprisingly, it was quite easy.
> I just wondered why there's no generic graph_traits that could be used
> for the whole (or part of) the triangulation family.
> As well, I have the feeling that the weight map is sub-optimal in term
> of CPU usage, it doesn't cache the weight value, tho I haven't
> verified if the operator[] get called more than once for a given
> edge... One might argue that caching is user choice, a decision that
> should be based on trade off b/w time and space requirement.

I guess you only have to make the specialization of graph_traits inherit 
from the one from Delaunay and leave it empty, right?

Sebastien.

> Chris
>
> > Any clarification or point out are very welcome,
> > Chris