Merge branch 'feature/add-subentities-to-all-codims' into 'master'

add method Entity::subEntities to all codimensions

For polyhedral grids, it is not clear how many vertices a face (i.e., a
general polygon) has. For elements, this information is provided by the
(redundant) method Entity::subEntities. This patch add this usually
redundant method to entities of all codimensions.

See merge request !103

dune/grid/albertagrid/entity.hh

@@ -98,6 +98,29 @@ namespace Dune
     //! obtain entity seed
     EntitySeed seed () const { return EntitySeed( AlbertaGridEntitySeed< codim, Grid >( elementInfo(), subEntity() ) ); }
 
+    /** \brief Obtain the number of subentities of a given codimension
+     *
+     * That number is ((mydimension+1) over (dim-cd+1))
+     *
+     *  \param  cd  codimension
+     *
+     *  \returns the number of subentities of the given codimension
+     */
+    unsigned int subEntities ( unsigned int cd ) const
+    {
+      int n = mydimension+1;
+      int k = dimension-cd+1;
+
+      // binomial: n over k
+      int binomial=1;
+      for (int i=n-k+1; i<=n; i++)
+        binomial *= i;
+      for (long i=2; i<=k; i++)
+        binomial /= i;
+
+      return binomial;
+    }
+
     //***********************************************
     // end of interface methods
     //***********************************************
@@ -233,16 +256,16 @@ namespace Dune
 
     /** \brief Obtain the number of subentities of a given codimension
      *
-     * That number is ((dim+1) over (dim-codim+1))
+     * That number is ((mydimension+1) over (dim-cd+1))
      *
-     *  \param  codim  codimension
+     *  \param  cd  codimension
      *
      *  \returns the number of subentities of the given codimension
      */
-    unsigned int subEntities (unsigned int codim) const
+    unsigned int subEntities ( unsigned int cd ) const
     {
-      int n = dimension+1;
-      int k = dimension-codim+1;
+      int n = mydimension+1;
+      int k = dimension-cd+1;
 
       // binomial: n over k
       int binomial=1;

dune/grid/common/entity.hh

@@ -3,10 +3,13 @@
 #ifndef DUNE_GRID_ENTITY_HH
 #define DUNE_GRID_ENTITY_HH
 
+#include <type_traits>
+
 #include <dune/common/iteratorrange.hh>
 #include <dune/common/typetraits.hh>
 
 #include <dune/geometry/dimension.hh>
+#include <dune/geometry/referenceelements.hh>
 
 #include "grid.hh"
 #include "entitypointer.hh"
@@ -146,6 +149,22 @@ namespace Dune
      */
     GeometryType type () const { return realEntity.type(); }
 
+    /**
+     * \brief Number of subentities for a given codimension
+     *
+     * \param  codim  codimension to obtain number of subentities for
+     *
+     * \note The codimension is specified with respect to the grid dimension.
+     *
+     * \note Unless the geometry type is None, this method is redundant and
+     *       the same information can be obtained from the corresponding
+     *       reference element.
+     **/
+    unsigned int subEntities ( unsigned int codim ) const
+    {
+      return realEntity.subEntities(codim);
+    }
+
     /** \brief Return the entity seed which contains sufficient information
      *  to generate the entity again and uses as little memory as possible
      */
@@ -318,6 +337,22 @@ namespace Dune
     //! @copydoc Dune::Entity::geometry()
     Geometry geometry () const { return realEntity.geometry(); }
 
+    /**
+     * \brief Number of subentities for a given codimension
+     *
+     * \param  codim  codimension to obtain number of subentities for
+     *
+     * \note The codimension is specified with respect to the grid dimension.
+     *
+     * \note Unless the geometry type is None, this method is redundant and
+     *       the same information can be obtained from the corresponding
+     *       reference element.
+     **/
+    unsigned int subEntities ( unsigned int codim ) const
+    {
+      return realEntity.subEntities(codim);
+    }
+
     /** \brief Return the name of the reference element. The type can
         be used to access the Dune::ReferenceElement.
      */
@@ -375,16 +410,6 @@ namespace Dune
     //@{
     //===========================================================
 
-    /**\brief Number of subentities with codimension <tt>codim</tt>.
-     *
-     * Strictly speaking this method is redundant, because the same information can be obtained
-     * from the corresponding reference element. It is here for efficiency reasons only.
-     */
-    unsigned int subEntities(unsigned int codim) const
-    {
-      return realEntity.subEntities(codim);
-    }
-
     /** \brief Obtain a subentity
      *
      *  \tparam  codim  codimension of the desired subentity
@@ -555,6 +580,23 @@ namespace Dune
     //! \brief The corresponding entity seed (for storage of entities)
     typedef typename GridImp::template Codim<cd>::EntitySeed EntitySeed;
 
+    /**
+     * \brief Number of subentities for a given codimension
+     *
+     * \param  codim  codimension to obtain number of subentities for
+     *
+     * \note The codimension is specified with respect to the grid dimension.
+     *
+     * \note Unless the geometry type is None, this method is redundant and
+     *       the same information can be obtained from the corresponding
+     *       reference element.
+     **/
+    unsigned int subEntities ( unsigned int codim ) const
+    {
+      typedef typename std::remove_const< GridImp >::type::ctype ctype;
+      return ReferenceElements< ctype, mydimension >::general( asImp().type() ).size( codim - codimension );
+    }
+
     /** \brief Return the name of the reference element. The type can
         be used to access the Dune::ReferenceElement.
      */
@@ -604,6 +646,23 @@ namespace Dune
      */
     bool isRegular() const { return true; }
 
+    /**
+     * \brief Number of subentities for a given codimension
+     *
+     * \param  codim  codimension to obtain number of subentities for
+     *
+     * \note The codimension is specified with respect to the grid dimension.
+     *
+     * \note Unless the geometry type is None, this method is redundant and
+     *       the same information can be obtained from the corresponding
+     *       reference element.
+     **/
+    unsigned int subEntities ( unsigned int codim ) const
+    {
+      typedef typename std::remove_const< GridImp >::type::ctype ctype;
+      return ReferenceElements< ctype, mydimension >::general( asImp().type() ).size( codim - codimension );
+    }
+
     /** \brief Return the name of the reference element. The type can
         be used to access the Dune::ReferenceElement.
      */

dune/grid/geometrygrid/entity.hh

@@ -256,6 +256,11 @@ namespace Dune
         return Geometry( geo_ );
       }
 
+      unsigned int subEntities ( unsigned int cc ) const
+      {
+        return hostEntity().subEntities( cc );
+      }
+
       /** \brief return EntitySeed of host grid entity */
       EntitySeed seed () const { return typename EntitySeed::Implementation( hostEntity().seed() ); }
       /** \} */
@@ -569,6 +574,13 @@ namespace Dune
         return Geometry( geo_ );
       }
 
+      unsigned int subEntities ( unsigned int cc ) const
+      {
+        const ReferenceElement< ctype, dimension > &refElement
+          = ReferenceElements< ctype, dimension >::general( hostElement().type() );
+        return refElement.size( subEntity_, codimension, cc );
+      }
+
       /** \brief return EntitySeed of host grid entity */
       EntitySeed seed () const { return typename EntitySeed::Implementation( hostElement().seed(), subEntity_ ); }
       /** \} */
@@ -772,17 +784,6 @@ namespace Dune
         assert( i == 0 );
       }
 
-      template< int codim >
-      int count () const
-      {
-        return hostEntity().template count< codim >();
-      }
-
-      unsigned int subEntities (unsigned int codim) const
-      {
-        return hostEntity().subEntities(codim);
-      }
-
       template< int codim >
       typename Grid::template Codim< codim >::Entity
       subEntity ( int i ) const

dune/grid/identitygrid/identitygridentity.hh

@@ -168,6 +168,12 @@ namespace Dune {
       return hostEntity_.template count<cc>();
     }
 
+    /** \brief Return the number of subEntities of codimension codim.
+     */
+    unsigned int subEntities (unsigned int cc) const
+    {
+      return hostEntity_.subEntities(cc);
+    }
 
     //! geometry of this entity
     Geometry geometry () const

dune/grid/onedgrid/onedgridentity.hh

@@ -230,6 +230,14 @@ namespace Dune {
     //! return the element type identifier (segment)
     GeometryType type () const {return GeometryType(0);}
 
+    /** \brief Return the number of subentities of codimension codim.
+     */
+    unsigned int subEntities (unsigned int codim) const
+    {
+      assert(codim==1);
+      return 1;
+    }
+
     //! geometry of this entity
     Geometry geometry () const { return Geometry(GeometryImpl(target_->pos_)); }
 

dune/grid/uggrid/uggridentity.hh

@@ -9,6 +9,8 @@
 
 #include <memory>
 
+#include <dune/geometry/referenceelements.hh>
+
 #include <dune/grid/common/gridenums.hh>
 
 
@@ -177,6 +179,13 @@ namespace Dune {
     /** \brief Get the seed corresponding to this entity */
     EntitySeed seed () const { return EntitySeed( *this ); }
 
+    /** \brief Return the number of subEntities of codimension codim.
+     */
+    unsigned int subEntities (unsigned int cd) const
+    {
+      return ReferenceElements<UGCtype, dim-codim>::general(type()).size(cd-codim);
+    }
+
     typename UG_NS<dim>::template Entity<codim>::T* getTarget() const
     {
       return target_;
@@ -261,6 +270,13 @@ namespace Dune {
       return GeometryType(1);
     }
 
+    /** \brief Return the number of subEntities of codimension codim.
+     */
+    unsigned int subEntities (unsigned int cd) const
+    {
+      return ReferenceElements<UGCtype, dim-codim>::general(type()).size(cd-codim);
+    }
+
     /** \brief The partition type for parallel computing
      */
     PartitionType partitionType () const
@@ -521,6 +537,13 @@ namespace Dune {
       return EntitySeed( *this );
     }
 
+    /** \brief Return the number of subEntities of codimension codim.
+     */
+    unsigned int subEntities (unsigned int cd) const
+    {
+      return ReferenceElements<UGCtype, dim-codim>::general(type()).size(cd-codim);
+    }
+
     /** \brief Set to a UG side vector object
         \param target The UG side vector to point to
         \param gridImp Dummy argument, only for consistency with codim-0 entities

dune/grid/yaspgrid/yaspgridentity.hh

@@ -270,6 +270,15 @@ namespace Dune {
       return Geometry(_geometry);
     }
 
+    /*! Return number of subentities with codimension cc.
+     *
+     * That number is (dim over (dim-codim)) times 2^codim
+     */
+    unsigned int subEntities (unsigned int cc) const
+    {
+      return Dune::Yasp::subEnt<dim>(dim-codim,cc-codim);
+    }
+
     //! return partition type attribute
     PartitionType partitionType () const
     {
@@ -821,6 +830,15 @@ namespace Dune {
       return EntitySeed(YaspEntitySeed<dim,GridImp>(_g->level(), _it.coord(), _it.which()));
     }
 
+    /*! Return number of subentities with codimension cc.
+     *
+     * That number is (dim over (dim-codim)) times 2^codim
+     */
+    unsigned int subEntities (unsigned int cc) const
+    {
+      return Dune::Yasp::subEnt<dim>(dim-dim,cc-dim);
+    }
+
     //! geometry of this entity
     Geometry geometry () const {
       GeometryImpl _geometry((_it).lowerleft());