[Dune] [Dune-Commit] dune-grid r6566 - trunk/dune/grid/genericgeometry

[Oliver Sander]

Hi Martin!
Sorry for screwing up.  However, I must say that I don't feel much guilt.
I did run a few tests (UGGrid among them), and everything worked fine.
Requiring Alberta to test for correctness of the GenericGeometries seems
a bit far-fetched to me.  Also, putting comments in the code now and
then would really help people understand the design decisions.

For example: What does the template parameter of

template< bool > struct AllTypes;

do?  It doesn't even have a name. 

best,
Oliver

mnolte at dune-project.org schrieb:
> Author: mnolte
> Date: 2010-04-06 07:58:08 +0200 (Tue, 06 Apr 2010)
> New Revision: 6566
>
> Modified:
>    trunk/dune/grid/genericgeometry/mappingprovider.hh
> Log:
> revert patch 6565
>
> I agree with Oliver, that the code would look nicer. The problem with static
> ifs, though, is that both branches have to be instanciated. Conversion< prism, 0 >
> then instanciates Conversion< simplex, -1 > and so on.
>
> In my opinion, we should discuss the future of the GeometryType before we start
> discussing how the geometry type conversion stuff can be beautified.
>
> Oh, yes, and thanks for extensive testing. The bug could have been found by
> configurung with ALBERTA.
>
>
> Modified: trunk/dune/grid/genericgeometry/mappingprovider.hh
> ===================================================================
> --- trunk/dune/grid/genericgeometry/mappingprovider.hh	2010-04-05 07:30:38 UTC (rev 6565)
> +++ trunk/dune/grid/genericgeometry/mappingprovider.hh	2010-04-06 05:58:08 UTC (rev 6566)
> @@ -46,6 +46,8 @@
>        typedef HybridMapping< dim, GeometryTraits > Mapping;
>  
>      private:
> +      template< bool > struct AllTypes;
> +      template< bool > struct OnlySimplexCube;
>  
>        template< GeometryType :: BasicType type, class CoordVector >
>        static Mapping *virtualMapping ( const CoordVector &coords )
> @@ -60,49 +62,66 @@
>        mapping ( const GeometryType &type, const CoordVector &coords )
>        {
>          assert( type.dim() == Mapping :: dimension );
> +        typedef typename SelectType< (Mapping :: dimension >= 3), AllTypes<true>, OnlySimplexCube<false> >::Type Switch;
> +        return Switch :: mapping( type.basicType(), coords );
> +      }
> +    };
>  
> -        if (Mapping :: dimension >= 3) {  // static if: can be evaluated at compile time
>  
> -            // If our dimension is at least 3 there are four possible types of elements
> -            switch( type.basicType() )
> -                {
> -                case GeometryType :: simplex:
> -                    return virtualMapping< GeometryType :: simplex, CoordVector >( coords );
> -                    
> -                case GeometryType :: cube:
> -                    return virtualMapping< GeometryType :: cube, CoordVector >( coords );
> -                    
> -                case GeometryType :: prism:
> -                    return virtualMapping< GeometryType :: prism, CoordVector >( coords );
> -                    
> -                case GeometryType :: pyramid:
> -                    return virtualMapping< GeometryType :: pyramid, CoordVector >( coords );
> -                    
> -                default:
> -                    DUNE_THROW( RangeError, "Unknown basic geometry type: " << type );
> -                }
> +    template< unsigned int dim, class GeometryTraits >
> +    template< bool >
> +    struct VirtualMappingFactory< dim, GeometryTraits > :: AllTypes
> +    {
> +      template< class CoordVector >
> +      static Mapping *
> +      mapping ( GeometryType :: BasicType type, const CoordVector &coords )
> +      {
> +        switch( type )
> +        {
> +        case GeometryType :: simplex:
> +          return virtualMapping< GeometryType :: simplex, CoordVector >( coords );
>  
> +        case GeometryType :: cube:
> +          return virtualMapping< GeometryType :: cube, CoordVector >( coords );
> +        
> +        case GeometryType :: prism:
> +          return virtualMapping< GeometryType :: prism, CoordVector >( coords );
> +
> +        case GeometryType :: pyramid:
> +          return virtualMapping< GeometryType :: pyramid, CoordVector >( coords );
> +        
> +        default:
> +          DUNE_THROW( RangeError, "Unknown basic geometry type: " << type );
>          }
> +      }
> +    };
>  
> -        // Our dimension is less than 3.  There can be only triangles or quadrilaterals.
> -        /** \todo The case dim=1 is actually missing */
> -        switch( type.basicType() )
> -            {
> -            case GeometryType :: simplex:
> -                return virtualMapping< GeometryType :: simplex, CoordVector >( coords );
> -                
> -            case GeometryType :: cube:
> -                return virtualMapping< GeometryType :: cube, CoordVector >( coords );
> -                
> -            default:
> -                DUNE_THROW( RangeError, "Unknown basic geometry type: " << type );
> -            }
>  
> +    template< unsigned int dim, class GeometryTraits >
> +    template< bool >
> +    struct VirtualMappingFactory< dim, GeometryTraits > :: OnlySimplexCube
> +    {
> +      template< class CoordVector >
> +      static Mapping *
> +      mapping ( GeometryType :: BasicType type, const CoordVector &coords )
> +      {
> +        switch( type )
> +        {
> +        case GeometryType :: simplex:
> +          return virtualMapping< GeometryType :: simplex, CoordVector >( coords );
> +
> +        case GeometryType :: cube:
> +          return virtualMapping< GeometryType :: cube, CoordVector >( coords );
> +        
> +        default:
> +          DUNE_THROW( RangeError, "Unknown basic geometry type: " << type );
> +        }
>        }
>      };
>  
>  
>  
> +
>      // MappingProvider
>      // ---------------
>  
>
>
> _______________________________________________
> Dune-Commit mailing list
> Dune-Commit at dune-project.org
> http://lists.dune-project.org/mailman/listinfo/dune-commit
>   


-- 
************************************************************************
* Oliver Sander                ** email: sander at mi.fu-berlin.de        *
* Freie Universität Berlin     ** phone: + 49 (30) 838 75348           *
* Institut für Mathematik      ** URL  : page.mi.fu-berlin.de/~sander  *
* Arnimallee 6                 ** -------------------------------------*
* 14195 Berlin, Germany        ** Member of MATHEON (www.matheon.de)   *
************************************************************************