CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 08/29/2012 12:45 PM, Laurent Rineau (CGAL/GeometryFactory) wrote:
> Le mercredi 29 août 2012 03:29:28 gerth a écrit :
> > Hello!
> > I am using a Constrained_Delaunay_triangulation_2 in combination with a
> > Delaunay_mesher_2 to mesh a polygon area.
> > I noticed that I can use the number_of_faces() method to get the number of
> > resulting faces of my mesh. However, some faces are outside of the polygon.
> > When I iterate over the faces with a Finite_faces_iterator, I can use the
> > is_in_domain() function to determine whether the face lies within the
> > polygon or not.
> > I was wondering if there is a function similar to number_of_faces(), that
> > returns only those faces that are within the polygon. Of course I can
> > iterate over the result and count all the faces where is_in_domain() returns
> > true, but that doesn't seem very efficient to me.
>
> You are right that this function does not exist. And it is not plan to add it.
> It could not be a member function, because the object "mesh" is actually a
> Constrained_Delaunay_triangulation_2, and not a type dedicated to meshing.
Note that you could use boost::filter_iterator and std::distance to do that.

Sebastien.