CGAL users discussion list

[gerth <>]

Hi!
Thanks for your answers so far! My code snip was a little messy, so I'd like
to post it once again. JuanLu, the difference between v1 and vc1 was just a
typo (I had to copy the code snips from several files). The following code
snip should work unmodified though.

In my last example I forgot to specify an Itag. This time I did, but I still
get an error if I try to insert constraint lines that are *very close* to an
existing vertex. Can you please check the code and verify this error. The
error I get is:

Unhandled exception at 0x7c812afb in gui.exe: Microsoft C++ exception:
CGAL::Assertion_exception at memory location 0x010ec2dc..

Code:

//Includes
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Cartesian.h>
#include <CGAL/Delaunay_triangulation_2.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>
#include <CGAL/Triangulation_face_base_2.h>
#include <CGAL/Triangulation_face_base_with_info_2.h>
#include <CGAL/Polygon_2.h>
#include <CGAL/Triangulation_2.h>
#include <CGAL/Vector_3.h>
#include <CGAL/Triangulation_conformer_2.h>
#include <CGAL/Triangulation_utils_2.h>
#include <CGAL/number_utils.h>
#include <CGAL/bounding_box.h>

//General
typedef CGAL::Exact_predicates_inexact_constructions_kernel                   
  K;
typedef CGAL::Triangulation_vertex_base_2<K>                                  
          Vb;
typedef K::Point_2                                                            
                  Point_2;

//Fine mesh
typedef CGAL::Delaunay_mesh_face_base_2<K>                                    
  Fb_fine;  
typedef CGAL::Triangulation_data_structure_2<Vb, Fb_fine>                     
  TDS_fine;
typedef CGAL::Exact_predicates_tag                                            
          Itag_fine;
typedef CGAL::Constrained_Delaunay_triangulation_2<K, TDS_fine, Itag_fine>
CDT_fine;
typedef CGAL::Delaunay_mesh_size_criteria_2<CDT_fine>                         
  Criteria_fine;
typedef CGAL::Delaunay_mesher_2<CDT_fine, Criteria_fine>                      
         
Mesher_fine;
typedef CDT_fine::Point                                                       
          Point_fine;
typedef CDT_fine::Vertex_handle                                               
          Vertex_handle_fine;
typedef CDT_fine::Vertex_iterator                                             
                  Vertex_iterator_fine;
typedef CDT_fine::Face_handle                                                 
          Face_handle_fine;
typedef CDT_fine::Triangle                                                    
                  Triangle_fine;
typedef CDT_fine::Vertex                                                      
                  Vertex_fine;

int main()
{
        //Insert initial points and constraints (closed polygon)        
        CDT_fine cdt_fine;
        Vertex_handle_fine v_act, v_next;
        v_act = cdt_fine.insert(Point_fine(0.0, 0.0));
        v_next = cdt_fine.insert(Point_fine(-15.636358459247276,
-17.832801345735788));
        cdt_fine.insert_constraint(v_act, v_next);

        v_act = cdt_fine.insert(Point_fine(-15.636358459247276,
-17.832801345735788));
        v_next = cdt_fine.insert(Point_fine(-30.793984547723085,
-4.6360093057155609));
        cdt_fine.insert_constraint(v_act, v_next);

        v_act = cdt_fine.insert(Point_fine(-30.793984547723085,
-4.6360093057155609));
        v_next = cdt_fine.insert(Point_fine(-22.687070030719042,
4.6138969026505947));
        cdt_fine.insert_constraint(v_act, v_next);

        v_act = cdt_fine.insert(Point_fine(-22.687070030719042,
4.6138969026505947));
        v_next = cdt_fine.insert(Point_fine(-18.531077503692359,
1.0006236322224140));
        cdt_fine.insert_constraint(v_act, v_next);

        v_act = cdt_fine.insert(Point_fine(-18.531077503692359,
1.0006236322224140));
        v_next = cdt_fine.insert(Point_fine(-11.001624230295420,
9.5834844978526235));
        cdt_fine.insert_constraint(v_act, v_next);

        v_act = cdt_fine.insert(Point_fine(-11.001624230295420,
9.5834844978526235));
        v_next = cdt_fine.insert(Point_fine(0.0, 0.0));
        cdt_fine.insert_constraint(v_act, v_next);
        


        //Insert additional points and constraints (does not work)
        Vertex_handle_fine vc_act, vc_next;
        vc_act =
cdt_fine.insert(Point_fine(-18.530322841197869,0.99996751895902314));
        vc_next =
cdt_fine.insert(Point_fine(-7.5181155150824690,-8.5741869389974159));
        cdt_fine.insert_constraint(vc_act, vc_next);
        vc_act =
cdt_fine.insert(Point_fine(18.531736972623872,0.99987190033978390));
        vc_next =
cdt_fine.insert(Point_fine(-26.644896901557836,-8.2483590564386784));
        cdt_fine.insert_constraint(vc_act, vc_next);


        //Mesh it
        Mesher_fine mesher_fine(cdt_fine);
        mesher_fine.refine_mesh();      
        mesher_fine.set_criteria(Criteria_fine(0.125, 1));  
        mesher_fine.refine_mesh();      //Exception is thrown here
}

I appreciate your help!
Gert



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