CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 06/18/2017 11:41 AM, 王少东 wrote:
> Hi,
>
> I want to write generic algorithms on top of cgal's halfedge data
> structures. So I wonder is there a way to get the FieldType of
> kernel from a Surface_mesh as well as Polyhedron_3 using the bgl interface?
>
> Cheers,
> Shaodong

The best way to do it is to ask a geometric traits class template
parameter in addition in your algorithm. From this traits class
you can extract the FT.

The hacking way is to get a Kernel from the point type and then
get the FT.

for example

typedef boost::property_map<boost::vertex_point, TriangleMesh>::type 
Vpm; // the default vertex point map
typedef typename boost::property_traits<Vpm>::value_type Point_3; // the 
point type
typedef  CGAL::Kernel_traits<Point_3>::Kernel::FT FT;

Sebastien.