CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Hello,

the example you need to look at is the following:

http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Mesh_2/Chapter_main.html#Subsection_45.2.7

You need to seed each hole of your polygon.

If you need to have an index to each vertex, you need to use a 
vertex_with_info:
Instead of :
typedef CGAL::Triangulation_vertex_base_2<K> Vb;
use:
typedef CGAL::Triangulation_vertex_base_2<K> Vbase;
typedef CGAL::Triangulation_vertex_base_with_info_2<int,K,Vbase> Vb;
as describe here:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2_ref/Class_Triangulation_vertex_base_with_info_2.html#Cross_link_anchor_1300

Then when you insert a point use the info() method to set and get the 
index of your point.

ex:
Vertex_handle va = cdt.insert(Point(2,0));
va->info()=1;

Have a look here for the infinite and finite facet definition:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2/Chapter_main.html#Section_35.2

S.

Aurélien .... wrote:
> Hello everyone,
>
> I'm totally lost and I need some help.
>
> I have outer points which define an outer polygon. Then, I have inner 
> point which define holes.
>
> I need to triangulation this 2D form.
>
> I tried a delaunay triangulation like this :
>
> #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
> #include <CGAL/Constrained_Delaunay_triangulation_2.h>
> #include <CGAL/Delaunay_mesher_2.h>
> #include <CGAL/Delaunay_mesh_face_base_2.h>
> #include <CGAL/Delaunay_mesh_size_criteria_2.h>
>
> typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
> typedef CGAL::Triangulation_vertex_base_2<K> Vb;
> typedef CGAL::Delaunay_mesh_face_base_2<K> Fb;
> typedef CGAL::Triangulation_data_structure_2<Vb, Fb> Tds;
> typedef CGAL::Constrained_Delaunay_triangulation_2<K, Tds> CDT;
> typedef CGAL::Delaunay_mesh_size_criteria_2<CDT> Criteria;
> typedef CGAL::Delaunay_mesher_2<CDT, Criteria> Mesher;
> typedef CDT::Vertex_handle Vertex_handle;
> typedef CDT::Point Point;
> typedef CDT::Face_iterator Face_iterator;
>
> CDT cdt;
> // Insert point by point with cdt.insert
>
> Mesher mesher(cdt); mesher.refine_mesh();
>
> for(Face_iterator oFaceIt = cdt.faces_begin(); oFaceIt != 
> cdt.faces_end(); ++oFaceIt)
> {
>     // Add vertex 0, 1, 2 to the vertex array
>     // Add 0, 1, 2 to the face indices array
> }
>
> The graphic result is not correct.
>
> First of all, I have 212 faces for 145 vertices. Is there is a 
> possibility to have the index of the vertices instead their coords ? In 
> order to enter to the graphic engine 145 vertices and not 212 * 3 ?
>
> After, what's the diferences between faces, finite_faces and all_faces ?
>
> Is their an xample to show these problematics solved together ?
>
> Thank you very much,
>
> Aurélien