CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 02/06/2012 05:11 PM, Thomas Recouvreux wrote:
> Hi,
>
> Thanks the Delaunay triangulation works well.
> Do you have a piece of code to remove edges ?
Do you mean removing constrained edges?


> And is there an index for each faces or shall I put it in FaceInfo
> structure ?
You need to use Face_with_info.
Note that a Face_handle can be use as a key in a map for example.

Sebastien.

> Thomas
>
>
> 2012/1/18 Mariette Yvinec 
> <
> <mailto:>>
>
>     Starting from the constrained triangulation of your polygons
>     you can appraoch a minimal convex subdivision
>     (I think at most twice the number of parts of the optimal)
>     by pulling out as much as you can
>     of non constrained triangulation edges
>     without forming angles greater than 90 degrees.
>
>     Le 18/01/12 09:27, Sebastien Loriot (GeometryFactory) a écrit :
> >     The input polygon should be simple and without holes.
> >     In you case you might want to try to use a constrained (Delaunay)
> >     triangulation (edges of your polygon are constraints).
> >     The decomposition would be minimal at all but it will be convex.
> >
> >
> >     See:
> >     
> > http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2/Chapter_main.html#Section_36.7
> >
> >
> >     Sebastien.
> >
> >     Thomas Recouvreux wrote:
> > >     Hi,
> > >
> > >     I've have found some examples about partitionning a Polygon_2,
> > >     but I didn't see functions for partitionning a Poly_2 with holes.
> > >     Is there any function to do so or shall I decompose first my
> > >     polygon with holes in polygons without holes and apply the
> > >     partitionning function ?
> > >
> > >     An other question, I tried to use partition function on a polygon
> > >     with tangente edges (see below), and the function return the
> > >     whole polygon without partionning it, did I miss something ?
> > >
> > >     +---------------------------------------+
> > >     |                                       / |
> > >     |                                     /   |
> > >     |                        +----------+   |
> > >     |                         |           |    |
> > >     |                        +----------+   |
> > >     |                                         |
> > >     |                                         |
> > >     +---------------------------------------+
> > >     polygon.push_back(Point_2(0, 0));
> > >     polygon.push_back(Point_2(10, 0));
> > >     polygon.push_back(Point_2(6, 2));
> > >     polygon.push_back(Point_2(2, 2));
> > >     polygon.push_back(Point_2(2, 6));
> > >     polygon.push_back(Point_2(6, 6));
> > >     polygon.push_back(Point_2(6, 2));
> > >     polygon.push_back(Point_2(10, 0));
> > >     polygon.push_back(Point_2(10, 10));
> > >     polygon.push_back(Point_2(0,10));
> > >
> > >
> > >     Best
> > >     Thomas
>
>     --
>     Mariette Yvinec
>     Geometrica project team
>     INRIA  Sophia-Antipolis