radialfilter.hh

#ifndef DUNE_FEM_GRIDPART_FILTER_RADIALFILTER_HH
#define DUNE_FEM_GRIDPART_FILTER_RADIALFILTER_HH
 
#include <dune/common/fvector.hh>
 
namespace Dune
{
 
  namespace Fem
  {
 
    // RadialFilter
    // ------------
 
    template < typename ct, int dimw >
    class RadialFilter
    {
    public:
      typedef ct ctype;
 
      static constexpr int dimensionworld = dimw;
 
      typedef Dune::FieldVector< ct, dimw > GlobalCoordinateType;
 
      RadialFilter( const GlobalCoordinateType & center = GlobalCoordinateType( 0 ),
                    ctype radius = 0.25)
      : center_( center ),
        radius_( radius )
      { }
 
      template< class Entity >
      bool contains ( const Entity & entity ) const
      {
        constexpr int cc = Entity::codimension;
        if( cc != 0 )
          DUNE_THROW( InvalidStateException, "RadialFilter::contains only available for codim 0 entities" );
        ctype dist = (entity.geometry().center() - center_).two_norm();
        return (dist > radius_);
      }
 
      template< class Intersection >
      bool interiorIntersection( const Intersection &intersection ) const
      {
        return contains( intersection.outside() );
      }
 
      //         which is either it.boundary == true or contains (it.ouside()) == false
      //         so here true is a good choice
      template < class Intersection >
      bool intersectionBoundary( const Intersection & ) const
      {
        return true;
      }
      //          which is either it.boundary == true or contains (it.ouside()) == false
      template < class Intersection >
      int intersectionBoundaryId(const Intersection & ) const
      {
        return 1;
      }
 
      template <class Intersection>
      bool intersectionNeighbor( const Intersection &  ) const
      {
        return false;
      }
 
    private:
      const GlobalCoordinateType center_;
      const ctype radius_;
 
    }; // end RadialFilter
 
  }  // namespace Fem
 
}  // namespace Dune
 
#endif // #ifndef DUNE_FEM_GRIDPART_FILTER_RADIALFILTER_HH