CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 06/02/2015 03:20 PM, Clement Roux-Langlois wrote:
> Hello,
>
> I am wandering if it is possible to use the AABB Tree algorithm to
> compute the intersection of a Sphere_3 and a (AABB) tree of Line_arc_3.
> It seems that the intersection function for a spherical kernel does not
> have the same number of arguments as that of a cartesian kernel. When I
> try to refer to AABBTree::Intersection_and_primitive_id<Sphere_3>::Type,
> I get the following compilation error :
>
> /usr/local/include/CGAL/Circular_kernel_3/function_objects_polynomial_sphere.h:1182:67:
> error: no type named ‘result_type’ in ‘struct
> CGAL::Intersection_traits<CGAL::Spherical_kernel_3<CGAL::Simple_cartesian<double>,
> CGAL::Algebraic_kernel_for_spheres_2_3<double> >,
> CGAL::Sphere_3<CGAL::Spherical_kernel_3<CGAL::Simple_cartesian<double>,
> CGAL::Algebraic_kernel_for_spheres_2_3<double> > >,
> CGAL::Line_arc_3<CGAL::Spherical_kernel_3<CGAL::Simple_cartesian<double>, 
> CGAL::Algebraic_kernel_for_spheres_2_3<double>
>  > > >’
>       { typedef typename Intersection_traits<SK, A, B>::result_type
> type; };
>
> I found a workaround for the intersection function alone on
> http://stackoverflow.com/questions/26246381/how-to-calculate-the-intersection-of-a-line-segment-and-circle-with-cgal,
> but I don't see how I can apply that to the AABB tree module.
>
> Thanks for your help,
> Best regards,
>
> Clément
The intersection functor does not have the same API as required by the 
concepts in the AABB-tree:

http://doc.cgal.org/latest/Kernel_23/group__intersection__spherical__grp.html
vs.
http://doc.cgal.org/latest/Kernel_23/group__intersection__linear__grp.html

As documented here:
http://doc.cgal.org/latest/AABB_tree/classAABBTraits.html#a70e323d8c5dd12580bdf06433373b21c
it's the second form that is required.

It should be doable to define a custom traits.

Sebastien