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["Laurent Rineau (GeometryFactory)" <>]

On lundi 23 mai 2011 03:00:28 魏华祎 wrote:
> int main(){
> 
> 
>   int n = 4, m = 2, d = 2;
>   std::vector<Point> P(4);
>   P[0] = Point(0,0);
>   P[1] = Point(1,0);
>   P[2] = Point(1,1);
>   P[3] = Point(0,1);
> 
>   std::vector<Vertex_handle> V(n+1);
>   std::vector<Face_handle> F(m);
> 
>   Triangulation tri;
>   tri.tds().set_dimension(d);
>  // if I comment the following two lines, there will four finite vertices,
> but still three faces
>   V[0] = tri.tds().create_vertex();
>   tri.set_infinite_vertex(V[0]); // set the infinite vertex of tri
> 
>  // create the vertex_handles
>   for(int i = 1; i< 5;i++){
>     V[i] = tri.tds().create_vertex();
>     V[i]->set_point(P[i-1]);
>   }

Forget those low level functions! You do not know what they do. Just use the 
insert() function:

// [... skipped the #include and typedef, please recopy them...]

int main(){
   int n = 4;
   std::vector<Point> P(4);
   P[0] = Point(0,0);
   P[1] = Point(1,0);
   P[2] = Point(1,1);
   P[3] = Point(0,1);
   Triangulation tri;
   for(int i = 1; i< 4;i++){
     tri.insert(P[i]);
  }

  std::cout << tri.number_of_vertices() << std::endl
            << tri.number_of_faces() << std:endl;
}

Then after 'tri' is filled, you can navigate into it using the query 
functions. See 
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Triangulation_2_ref/Class_Triangulation_2.html

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/