CGAL users discussion list

[Andreas Fabri <>]

Hello,

What programming language do you use? I ask because

int main(array<System::String ^> ^args)

and

System.NullReferenceException

don't look like C++

andreas


naresh wrote:
> Hi
>  
> Can you change kernel for Vertex_base_for_ssr class as 
> Exact_predicates_inexact_constructions_kernel  ?
> I donot anything wrong in code it should work try to match similar kernel .
>  
>
>     ----- Original Message -----
>     *From:* Query Cgal 
> <mailto:>
>     *To:* 
>
>     
> <mailto:>
>     *Sent:* Monday, March 23, 2009 10:13 AM
>     *Subject:* Re: [cgal-discuss] incident_facets function of a Delaunay
>     triangulation
>
>     Hi, Sorry that I have sent an empty reply before because I have hot
>     the wrong button.
>
>     The line that I got the exception is the line
>
>     Dt.incident_facets(start, back_inserter(f));
>
>     and after I have chnaged the vector to a list, the exception still
>     occur..
>
>     Thanks
>
>     --- *2009年3月23日 星期一，Query Cgal 
> /<
>     
> <mailto:>>/*
>  寫道﹕
>
>
>         寄件人: Query Cgal 
> <
>         
> <mailto:>>
>         主題: Re: [cgal-discuss] incident_facets function of a Delaunay
>         triangulation
>         收件人: 
>
>         日期: 2009 3 23 星期一 上午 4:41
>
>
>
>         --- *2009年3月23日 星期一，naresh 
> /<alexdowson@hotmail..com>/*
>         寫道﹕
>
>
>             寄件人: naresh 
> <>
>             主題: Re: [cgal-discuss] incident_facets function of a
>             Delaunay triangulation
>             收件人: 
>
>             日期: 2009 3 23 星期一 上午 4:33
>
>             
>             Hi
>              
>             in Which line you are getting System.NullReferenceException
>             of code ?
>              
>             Hmmm... You can try this instead of this
>              
>              
>             vector<Delaunay_triangulation::Facet> f;  with
>             list<Delaunay_triangulation::Facet> f;
>              
>             try list instead of vector.
>              
>              
>              
>
>                 ----- Original Message -----
>                 *From:* Query Cgal
>                 *To:* 
>
>                 *Sent:* Monday, March 23, 2009 9:47 AM
>                 *Subject:* Re: [cgal-discuss] incident_facets function
>                 of a Delaunay triangulation
>
>                 Hi.
>
>                 Thank you for your reply.
>
>                 Finally, I have tried with the following code to use the
>                 incident_facets function.
>
>                 int main(array<System::String ^> ^args)
>                 {
>                     Delaunay_triangulation Dt;
>
>                     Dt.insert(Point(0,0,0));
>                     Dt.insert(Point(10,0,0));
>                     Dt.insert(Point(5,10,0));
>                     Dt.insert(Point(8,8,0));
>                     Dt..insert(Point(-3, -20, 0));
>                     Dt.insert(Point(-5,10,0));
>
>
>                     Finite_vertices_iterator start =
>                 Dt.finite_vertices_begin();
>
>                     vector<Delaunay_triangulation::Facet> f;
>
>                     Dt.incident_facets(start, back_inserter(f));
>
>                 }
>
>                 However, when it has "System.NullReferenceException'
>                 May I ask is it due to the nature of the points that I
>                 have inserted into the triangulation?
>
>                 I am using CGAL-3.3.1 and Visual C++ 2005
>                 And I am using the triangulation with the following
>                 declaration.
>                 Thank you very much for your help.
>
>
>
>                 typedef CGAL::Cartesian<double> Rep_class;
>                 typedef CGAL::Vector_3<Rep_class> Vector;
>                 typedef CGAL::Point_3<Rep_class> Point_3;
>
>                 typedef CGAL::Object CGAL_object;
>
>
>
>                 template < class GT, class Vb =
>                 CGAL::Triangulation_vertex_base_3<GT> >
>                 class Vertex_base_for_ssr
>                   : public Vb
>                 {
>                 public:
>                   typedef typename Vb::Vertex_handle  Vertex_handle;
>                   typedef typename Vb::Cell_handle    Cell_handle;
>                   typedef typename Vb::Point          Point;
>
>                   template < class TDS2 >
>                   struct Rebind_TDS {
>                     typedef typename Vb::template
>                 Rebind_TDS<TDS2>::Other  Vb2;
>                     typedef Vertex_base_for_ssr<GT,
>                 Vb2>                        Other;
>                   };
>
>
>                   Vector surface_normal;
>                   vector<Vertex_base_for_ssr<GT, Vb> *>
>                 neighbor_vertex_handle;
>                   double fifth_nearest_dist;
>
>
>                   int surface_label;
>                   bool is_safe;
>
>
>
>                   Vertex_base_for_ssr() : Vb()
>                   {
>                       surface_label = -1;
>                       is_safe = false;
>                   }
>
>                   Vertex_base_for_ssr(const Point& p)
>                     : Vb(p)
>                   {
>                       coordinate[0] = p.x();
>                       coordinate[1] = p.y();
>                       coordinate[2] = p.z();
>                       surface_label = -1;
>                       is_safe = false;
>                   }
>
>
>                   Vertex_base_for_ssr(const Point& p, Cell_handle c)
>                     : Vb(p, c)
>                   {
>                       surface_label = -1;
>                       is_safe = false;
>                   }
>
>                   void set_surface_normal(double x_i, double y_i, double
>                 z_i)
>                   {
>                       surface_normal = Vector(x_i, y_i, z_i);
>                   }
>
>                   Vector get_surface_normal()
>                   {
>                      return surface_normal;
>                   }
>
>                   Point get_point()
>                   {
>                       return Vb::point();
>                   }
>
>                   double coordinate[3];
>
>                   void set_coordiante()
>                   {
>                      coordinate[0] = point().x();
>                      coordinate[1] = point().y();
>                      coordinate[2] = point().z();
>                   }
>                 };
>
>                 typedef
>                 CGAL::Exact_predicates_inexact_constructions_kernel K;
>                 typedef
>                 CGAL::Triangulation_data_structure_3<Vertex_base_for_ssr<K>
>                  > Tds;
>                 typedef CGAL::Delaunay_triangulation_3<K, Tds>
>                 Delaunay_triangulation;
>
>
>
>
>
>                 --- 2009年3月21日 星期六，naresh
>                 
> <>
>  寫道﹕
>
>
>                     寄件人: naresh 
> <>
>                     主題: Re: [cgal-discuss] incident_facets function of
>                 a Delaunay triangulation
>                     收件人: 
>
>                     日期: 2009 3 21 星期六 下午 1:47
>
>                     
>                     Hi
>                     
>                     >>In fact, I am dealing with a 3D triangulation
>                 (sorry that I forgot to mention that it is 3D in the
>                  >>previous post.)
>                     >>and therefore, I cannot use Facet since Facet is
>                 not represented in 3D triangulation.
>                     >>So, what should I do to use incident_facets() of a
>                 3D triangulation.
>                     
>                     I donot know which triangulation are you using. for
>                 simple triangulation here there you can define Facet
>                 easily . here is code..
>                     try to modifiy with ur code
>                     
>                     typedef
>                 CGAL::Exact_predicates_inexact_constructions_kernel K;
>
>                     typedef CGAL::Triangulation_3<K> Triangulation;
>
>                     typedef Triangulation::Facet Facet;
>
>                     If there is still confusion post some code . But i
>                 will not able reply today because saturday now and i am
>                 off. :)   I can reply on monday.
>
>                     
>
>                     Hope this helps
>
>                     Alex
>
>                     
>                     
>                     
>                     
>
>                         ----- Original Message -----
>                         From: Query Cgal
>                         To: 
>
>                         Sent: Saturday, March 21, 2009 6:46 PM
>                         Subject: Re: [cgal-discuss] incident_facets
>                 function of a Delaunay triangulation
>
>                         THank you for your reply.
>
>                         In fact, I am dealing with a 3D triangulation
>                 (sorry that I forgot to mention that it is 3D in the
>                 previous post.)
>                         and therefore, I cannot use Facet since Facet is
>                 not represented in 3D triangulation.
>                         So, what should I do to use incident_facets() of
>                 a 3D triangulation.
>
>                         Thank you
>
>
>
>                         --- 2009年3月21日 星期六，naresh
>                 
> <>
>  寫道﹕
>
>
>                             寄件人: naresh 
> <>
>                             主題: Re: [cgal-discuss] incident_facets
>                 function of a Delaunay triangulation
>                             收件人: 
>
>                             日期: 2009 3 21 星期六 下午 1:07
>
>                             
>                             Hi
>                             
>                             I think you should try like this
>                             
>                             typedef Trianluation_2::Facet Facet;   //
>                 something here that you had used in ur programme may
>                 different i had showed only example
>                             
>                             vector<Facet> f;
>                             Dt.incident_facets(start, back_inserter(f));
>                             
>                             
>
>                                 ----- Original Message -----
>                                 From: Query Cgal
>                                 To: 
>
>                                 Sent: Saturday, March 21, 2009 5:45 PM
>                                 Subject: [cgal-discuss] incident_facets
>                 function of a Delaunay triangulation
>
>                                 Hi, I have tried to use the function below
>
>                                 template <class OutputIterator>
>                                 OutputIterator     t.incident_facets (
>                 Vertex_handle v, OutputIterator facets)
>
>                                    
>                                     Copies all Facets incident to v to
>                 the output iterator facets. Returns the resulting output
>                 iterator.
>                                 Precondition:      t..dimension() >1 , v
>                 Vertex_handle(), t.is_vertex(v)..
>                                 
>                                 When I tried to used it in the following
>                 way but it didn't work,
>
>                                 vector<Finite_facets_iterator> f;
>                                 Dt.incident_facets(start, back_inserter(f));
>
>                                 May I ask in what other way should I use
>                 the Output iterator then ?
>
>                                 Thank you
>
>
>
>
>
>
>
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