CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

It is not documented but if you are at the infinite vertex it will be
cw, and ccw otherwise.

Sebastien.

On 06/20/2013 06:24 PM, Raul Gallegos wrote:
> Hello,
>
> I am getting the voronoi cell (a Polygon_2) from a Vertex_handle, on a
> constrained Delaunay Triangulation.
>
> Getting the points of the Polygon is easy when all the faces aren't
> constrained (blind), because you only use a Circulator to get all the
> faces incident to the Vertex_handle and get their circumcenters.
>
> When there is Constrained it becomes a pain, because you need to
> calculate the points of that polygon that intersect with the constraint.
>
> I got this points by using the middle point of the current Vertex_handle
> comparing it with the vertex_handle on the current face of the
> circulator, and it works, I get the points.
>
> I have a problem understanding which is the order of a circulator, is it
> cw? ccw?, because to get a Polygon_2 I have to get the points in order,
> if not it becomes a totally different Polygon.
>
> Can someone help me with this? first let me understand which is the
> order of a Circulator (for 2D meshes) and maybe if there is an easier
> way to get the voronoi cell from a Vertex_handle for Constrained
> Delaunay Triangulations.
>
> Thank you.
> --
> Raul O. Gallegos Hidalgo