CGAL users discussion list

[Andreas Fabri <>]

When you insert the points one by one you can associate the index
to each vertex just after its insertion.

When you use the insert function with the iterator range, the points
get reordered in order that the insertion is fast. The reordering uses
spatial sorting documented here:
http://www.cgal.org/Manual/3.4/doc_html/cgal_manual/Spatial_sorting/Chapter_main.html


To combine spatial sorting to get it fast with your order you should have a
look at CGAL-3.4/examples/Spatial_sort/sort_indices.cpp

There you find the ingredients to insert the points one by one in an order
that makes it fast, and as you insert them one by one you can give them
the correct index according to your indexing scheme.

The rest is left as an exercise to the reader ===:>-

andreas





 wrote:
> Hmm. When the insertion has no order how can i ensure i keep my input order of
> my points?
> If i want read out the vertices or faces of the finished triangulation is this
> in a non-changing order?
> Because if the input is random and the output how can i ensure reliability?
>
> coord.push_back(Point(x,y,z));
> //How do i assign an index to the point which is put in the "coord" list?
>
> at the moment i do that after the triangulation because i thought it was in
> order.
> // Loop through faces of triangulation and assign index to vertices
> int q = 0;
> for (Finite_vertices_iterator fvi = Delaunay.finite_vertices_begin();
>                                         fvi !=
> Delaunay.finite_vertices_end();++fvi){
>                 fvi->info()= q++;
> }