uggrid.hh

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// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
 
#ifndef DUNE_UGGRID_HH
#define DUNE_UGGRID_HH
 
#include <dune/common/classname.hh>
#include <dune/common/parallel/collectivecommunication.hh>
#include <dune/common/exceptions.hh>
#include <dune/common/parallel/mpihelper.hh>
#include <dune/common/deprecated.hh>
 
#include <dune/grid/common/boundarysegment.hh>
#include <dune/grid/common/capabilities.hh>
#include <dune/grid/common/grid.hh>
 
#if HAVE_UG || DOXYGEN
 
#ifdef ModelP
#include <dune/common/parallel/mpicollectivecommunication.hh>
#endif
 
/* [Before reading the following: the macros UG_DIM_2 and UG_DIM_3 where named
 *  _2 and _3, respectively, up until ug-3.12.0.]
 *
 * The following lines including the necessary UG headers are somewhat
   tricky.  Here's what's happening:
   UG can support two- and three-dimensional grids.  You choose by setting
   either UG_DIM_2 or UG_DIM_3 while compiling.  This changes all sorts of stuff, in
   particular data structures in the headers.
   UG was never supposed to provide 2d and 3d grids at the same time.
   However, when compiling it as c++, the dimension-dependent parts are
   wrapped up cleanly in the namespaces UG::D2 and UG::D3, respectively.  That
   way it is possible to link together the UG lib for 2d and the one for 3d.
   But we also need the headers twice!  Once with UG_DIM_2 set and once with UG_DIM_3!
   So here we go:*/
 
/* The following define tells the UG headers that we want access to a few
   special fields, for example the extra index fields in the element data structures. */
#define FOR_DUNE
 
// Set UG's space-dimension flag to 2d
#ifdef UG_USE_NEW_DIMENSION_DEFINES
#define UG_DIM_2
#else
#define _2
#endif
// And include all necessary UG headers
#include "uggrid/ugincludes.hh"
 
// Wrap a few large UG macros by functions before they get undef'ed away.
// Here: The 2d-version of the macros
#define UG_DIM 2
#include "uggrid/ugwrapper.hh"
#undef UG_DIM
 
// UG defines a whole load of preprocessor macros.  ug_undefs.hh undefines
// them all, so we don't get name clashes.
#include "uggrid/ug_undefs.hh"
#ifdef UG_USE_NEW_DIMENSION_DEFINES
#undef UG_DIM_2
#else
#undef _2
#endif
 
/* Now we're done with 2d, and we can do the whole thing over again for 3d */
 
/* All macros set by UG have been unset.  This includes the macros that ensure
   single inclusion of headers.  We can thus include them again.  However, we
   only want to include those headers again that contain dimension-dependent stuff.
   Therefore, we set a few single-inclusion defines manually before including
   ugincludes.hh again.
 */
#define UGTYPES_H
#define __HEAPS__
#define __UGENV__
#define __DEVICESH__
#ifdef ModelP
#define __PPIF__
#endif
 
#ifdef UG_USE_NEW_DIMENSION_DEFINES
#define UG_DIM_3
#else
#define _3
#endif
 
#include "uggrid/ugincludes.hh"
 
// Wrap a few large UG macros by functions before they get undef'ed away.
// This time it's the 3d-versions.
#define UG_DIM 3
#include "uggrid/ugwrapper.hh"
#undef UG_DIM
 
// undef all macros defined by UG
#include "uggrid/ug_undefs.hh"
 
#ifdef UG_USE_NEW_DIMENSION_DEFINES
#undef UG_DIM_3
#else
#undef _3
#endif
#undef FOR_DUNE
 
// The components of the UGGrid interface
#include "uggrid/uggridgeometry.hh"
#include "uggrid/uggridlocalgeometry.hh"
#include "uggrid/uggridentity.hh"
#include "uggrid/uggridentitypointer.hh"
#include "uggrid/uggridentityseed.hh"
#include "uggrid/uggridintersections.hh"
#include "uggrid/uggridintersectioniterators.hh"
#include "uggrid/uggridleveliterator.hh"
#include "uggrid/uggridleafiterator.hh"
#include "uggrid/uggridhieriterator.hh"
#include "uggrid/uggridindexsets.hh"
#include <dune/grid/uggrid/uggridviews.hh>
#ifdef ModelP
#include "uggrid/ugmessagebuffer.hh"
#include "uggrid/uglbgatherscatter.hh"
#endif
 
// Not needed here, but included for user convenience
#include "uggrid/uggridfactory.hh"
 
#ifdef ModelP
template <class DataHandle, int GridDim, int codim>
DataHandle *Dune::UGMessageBufferBase<DataHandle,GridDim,codim>::duneDataHandle_ = 0;
 
template <class DataHandle, int GridDim, int codim>
int Dune::UGMessageBufferBase<DataHandle,GridDim,codim>::level = -1;
#endif // ModelP
 
namespace Dune {
 
#ifdef ModelP
  template <int dim>
  class CollectiveCommunication<Dune::UGGrid<dim> > :
    public CollectiveCommunication< Dune::MPIHelper::MPICommunicator >
  {
    typedef CollectiveCommunication< Dune::MPIHelper::MPICommunicator > ParentType;
  public:
    CollectiveCommunication()
      : ParentType(MPIHelper::getCommunicator())
    {}
  };
#endif // ModelP
 
  template<int dim>
  struct UGGridFamily
  {
    typedef GridTraits<dim,dim,Dune::UGGrid<dim>,
        UGGridGeometry,
        UGGridEntity,
        UGGridEntityPointer,
        UGGridLevelIterator,
        UGGridLeafIntersection,
        UGGridLevelIntersection,
        UGGridLeafIntersectionIterator,
        UGGridLevelIntersectionIterator,
        UGGridHierarchicIterator,
        UGGridLeafIterator,
        UGGridLevelIndexSet< const UGGrid<dim> >,
        UGGridLeafIndexSet< const UGGrid<dim> >,
        UGGridIdSet< const UGGrid<dim> >,
        typename UG_NS<dim>::UG_ID_TYPE,
        UGGridIdSet< const UGGrid<dim> >,
        typename UG_NS<dim>::UG_ID_TYPE,
        CollectiveCommunication<Dune::UGGrid<dim> >,
        UGGridLevelGridViewTraits,
        UGGridLeafGridViewTraits,
        UGGridEntitySeed,
        UGGridLocalGeometry>
    Traits;
  };
 
 
  //**********************************************************************
  //
  // --UGGrid
  //
  //**********************************************************************
 
  template <int dim>
  class UGGrid : public GridDefaultImplementation  <dim, dim, double, UGGridFamily<dim> >
  {
    typedef GridDefaultImplementation <dim, dim, double, UGGridFamily<dim> > Base;
 
    friend class UGGridGeometry<0,dim,const UGGrid<dim> >;
    friend class UGGridGeometry<dim,dim,const UGGrid<dim> >;
    friend class UGGridGeometry<1,2,const UGGrid<dim> >;
    friend class UGGridGeometry<2,3,const UGGrid<dim> >;
 
    friend class UGGridEntity <0,dim,const UGGrid<dim> >;
    friend class UGGridEntity <dim,dim,const UGGrid<dim> >;
    friend class UGGridHierarchicIterator<const UGGrid<dim> >;
    friend class UGGridLeafIntersection<const UGGrid<dim> >;
    friend class UGGridLevelIntersection<const UGGrid<dim> >;
    friend class UGGridLeafIntersectionIterator<const UGGrid<dim> >;
    friend class UGGridLevelIntersectionIterator<const UGGrid<dim> >;
 
    friend class UGGridLevelIndexSet<const UGGrid<dim> >;
    friend class UGGridLeafIndexSet<const UGGrid<dim> >;
    friend class UGGridIdSet<const UGGrid<dim> >;
    template <class GridImp_, PartitionIteratorType PiType_>
    friend class UGGridLeafGridView;
    template <class GridImp_, PartitionIteratorType PiType_>
    friend class UGGridLevelGridView;
 
    friend class GridFactory<UGGrid<dim> >;
 
#ifdef ModelP
    friend class UGLBGatherScatter;
#endif
 
    template <int codim_, PartitionIteratorType PiType_, class GridImp_>
    friend class UGGridLeafIterator;
    template <int codim_, PartitionIteratorType PiType_, class GridImp_>
    friend class UGGridLevelIterator;
    template <int codim_, class GridImp_>
    friend class UGGridEntityPointer;
 
    static_assert(dim==2 || dim==3, "Use UGGrid only for 2d and 3d!");
 
    // The different instantiations are mutual friends so they can access
    // each others numOfUGGrids field
    friend class UGGrid<2>;
    friend class UGGrid<3>;
 
    //**********************************************************
    // The Interface Methods
    //**********************************************************
  public:
    typedef UGGridFamily<dim>  GridFamily;
 
    // the Traits
    typedef typename UGGridFamily<dim>::Traits Traits;
 
    typedef UG::DOUBLE ctype;
 
    UGGrid();
 
    ~UGGrid()
#if HAVE_NOEXCEPT_SPECIFIER
      noexcept(false)
#endif
      ;
 
    int maxLevel() const;
 
    template<int codim>
    typename Traits::template Codim<codim>::LevelIterator lbegin (int level) const;
 
    template<int codim>
    typename Traits::template Codim<codim>::LevelIterator lend (int level) const;
 
    template<int codim, PartitionIteratorType PiType>
    typename Traits::template Codim<codim>::template Partition<PiType>::LevelIterator lbegin (int level) const;
 
    template<int codim, PartitionIteratorType PiType>
    typename Traits::template Codim<codim>::template Partition<PiType>::LevelIterator lend (int level) const;
 
    template<int codim>
    typename Traits::template Codim<codim>::LeafIterator leafbegin() const {
      return typename Traits::template Codim<codim>::template Partition<All_Partition>::LeafIterator(*this);
    }
 
    template<int codim>
    typename Traits::template Codim<codim>::LeafIterator leafend() const {
      return UGGridLeafIterator<codim,All_Partition, const UGGrid<dim> >();
    }
 
    template<int codim, PartitionIteratorType PiType>
    typename Traits::template Codim<codim>::template Partition<PiType>::LeafIterator leafbegin() const {
      return typename Traits::template Codim<codim>::template Partition<PiType>::LeafIterator(*this);
    }
 
    template<int codim, PartitionIteratorType PiType>
    typename Traits::template Codim<codim>::template Partition<PiType>::LeafIterator leafend() const {
      return UGGridLeafIterator<codim,PiType, const UGGrid<dim> >();
    }
 
    template <typename Seed>
    DUNE_DEPRECATED_MSG("entityPointer() is deprecated and will be removed after the release of dune-grid 2.4. Use entity() instead to directly obtain an Entity object.")
    typename Traits::template Codim<Seed::codimension>::EntityPointer
    entityPointer(const Seed& seed) const
    {
      enum {codim = Seed::codimension};
      return typename Traits::template Codim<codim>::EntityPointer(UGGridEntityPointer<codim,const UGGrid<dim> >(this->getRealImplementation(seed).target(),this));
    }
 
    template <typename Seed>
    typename Traits::template Codim<Seed::codimension>::Entity
    entity(const Seed& seed) const
    {
      const int codim = Seed::codimension;
      return typename Traits::template Codim<codim>::Entity(UGGridEntity<codim,dim,const UGGrid<dim> >(this->getRealImplementation(seed).target(),this));
    }
 
    int size (int level, int codim) const;
 
    int size (int codim) const
    {
      return leafIndexSet().size(codim);
    }
 
    int size (int level, GeometryType type) const
    {
      return this->levelIndexSet(level).size(type);
    }
 
    int size (GeometryType type) const
    {
      return this->leafIndexSet().size(type);
    }
 
    size_t numBoundarySegments() const {
      // The number is stored as a member of UGGrid upon grid creation.
      // The corresponding data structure is not exported by UG.  (It is in ug/dom/std/std_internal.h)
      return numBoundarySegments_;
    }
 
    const typename Traits::GlobalIdSet& globalIdSet() const
    {
      return idSet_;
    }
 
    const typename Traits::LocalIdSet& localIdSet() const
    {
      return idSet_;
    }
 
    const typename Traits::LevelIndexSet& levelIndexSet(int level) const
    {
      if (level<0 || level>maxLevel())
        DUNE_THROW(GridError, "levelIndexSet of nonexisting level " << level << " requested!");
      return *levelIndexSets_[level];
    }
 
    const typename Traits::LeafIndexSet& leafIndexSet() const
    {
      return leafIndexSet_;
    }
 
 
    bool mark(int refCount, const typename Traits::template Codim<0>::Entity & e );
 
    bool mark(const typename Traits::template Codim<0>::Entity & e,
              typename UG_NS<dim>::RefinementRule rule,
              int side=0);
 
    int getMark(const typename Traits::template Codim<0>::Entity& e) const;
 
    bool preAdapt();
 
    bool adapt();
 
    void postAdapt();
    unsigned int overlapSize(int codim) const {
      return 0;
    }
 
    unsigned int ghostSize(int codim) const {
      return (codim==0) ? 1 : 0;
    }
 
    unsigned int overlapSize(int level, int codim) const {
      return 0;
    }
 
    unsigned int ghostSize(int level, int codim) const {
      return (codim==0) ? 1 : 0;
    }
 
    template<class DataHandle>
    bool loadBalance (DataHandle& dataHandle)
    {
#ifdef ModelP
      // gather element data
      //        UGLBGatherScatter::template gather<0>(this->leafGridView(), dataHandle);
 
      // gather node data
      UGLBGatherScatter::template gather<dim>(this->leafGridView(), dataHandle);
#endif
 
      // the load balancing step now also attaches
      // the data to the entities and distributes it
      loadBalance();
 
#ifdef ModelP
      // scatter element data
      //        UGLBGatherScatter::template scatter<0>(this->leafGridView(), dataHandle);
 
      // scatter node data
      UGLBGatherScatter::template scatter<dim>(this->leafGridView(), dataHandle);
#endif
 
      return true;
    }
 
    bool loadBalance(int minlevel=0);
 
    bool loadBalance(const std::vector<unsigned int>& targetProcessors, unsigned int fromLevel);
 
    template<class DataHandle>
    bool loadBalance (const std::vector<unsigned int>& targetProcessors, unsigned int fromLevel, DataHandle& dataHandle)
    {
#ifdef ModelP
      // gather element data
      //        UGLBGatherScatter::template gather<0>(this->leafGridView(), dataHandle);
 
      // gather node data
      UGLBGatherScatter::template gather<dim>(this->leafGridView(), dataHandle);
#endif
 
      // the load balancing step now also attaches
      // the data to the entities and distributes it
      loadBalance(targetProcessors,fromLevel);
 
#ifdef ModelP
      // scatter element data
      //        UGLBGatherScatter::template scatter<0>(this->leafGridView(), dataHandle);
 
      // scatter node data
      UGLBGatherScatter::template scatter<dim>(this->leafGridView(), dataHandle);
#endif
 
      return true;
    }
 
 
    template<class DataHandle>
    void communicate (DataHandle& dataHandle, InterfaceType iftype, CommunicationDirection dir, int level) const
    {
#ifdef ModelP
      typedef typename UGGrid::LevelGridView LevelGridView;
 
      for (int curCodim = 0; curCodim <= dim; ++curCodim) {
        if (!dataHandle.contains(dim, curCodim))
          continue;
 
        if (curCodim == 0)
          communicateUG_<LevelGridView, DataHandle, 0>(this->levelGridView(level), level, dataHandle, iftype, dir);
        else if (curCodim == dim)
          communicateUG_<LevelGridView, DataHandle, dim>(this->levelGridView(level), level, dataHandle, iftype, dir);
        else if (curCodim == dim - 1)
          communicateUG_<LevelGridView, DataHandle, dim-1>(this->levelGridView(level), level, dataHandle, iftype, dir);
        else if (curCodim == 1)
          communicateUG_<LevelGridView, DataHandle, 1>(this->levelGridView(level), level, dataHandle, iftype, dir);
        else
          DUNE_THROW(NotImplemented,
                     className(*this) << "::communicate(): Not "
                     "supported for dim " << dim << " and codim " << curCodim);
      }
#endif // ModelP
    }
 
    template<class DataHandle>
    void communicate(DataHandle& dataHandle, InterfaceType iftype, CommunicationDirection dir) const
    {
#ifdef ModelP
      typedef typename UGGrid::LeafGridView LeafGridView;
 
      for (int curCodim = 0; curCodim <= dim; ++curCodim) {
        if (!dataHandle.contains(dim, curCodim))
          continue;
        int level = -1;
        if (curCodim == 0)
          communicateUG_<LeafGridView, DataHandle, 0>(this->leafGridView(), level, dataHandle, iftype, dir);
        else if (curCodim == dim)
          communicateUG_<LeafGridView, DataHandle, dim>(this->leafGridView(), level, dataHandle, iftype, dir);
        else if (curCodim == dim - 1)
          communicateUG_<LeafGridView, DataHandle, dim-1>(this->leafGridView(), level, dataHandle, iftype, dir);
        else if (curCodim == 1)
          communicateUG_<LeafGridView, DataHandle, 1>(this->leafGridView(), level, dataHandle, iftype, dir);
        else
          DUNE_THROW(NotImplemented,
                     className(*this) << "::communicate(): Not "
                     "supported for dim " << dim << " and codim " << curCodim);
      }
#endif // ModelP
    }
 
    const CollectiveCommunication<UGGrid>& comm () const
    {
      return ccobj_;
    }
 
  protected:
#ifdef ModelP
    template <class GridView, class DataHandle, int codim>
    void communicateUG_(const GridView& gv, int level,
                        DataHandle &dataHandle,
                        InterfaceType iftype,
                        CommunicationDirection dir) const
    {
      typename UG_NS<dim>::DDD_IF_DIR ugIfDir;
      // Translate the communication direction from Dune-Speak to UG-Speak
      if (dir==ForwardCommunication)
        ugIfDir = UG_NS<dim>::IF_FORWARD();
      else
        ugIfDir = UG_NS<dim>::IF_BACKWARD();
 
      typedef UGMessageBuffer<DataHandle,dim,codim> UGMsgBuf;
      UGMsgBuf::duneDataHandle_ = &dataHandle;
 
      UGMsgBuf::level = level;
 
      std::vector<typename UG_NS<dim>::DDD_IF> ugIfs;
      findDDDInterfaces_(ugIfs, iftype, codim);
 
      unsigned bufSize = UGMsgBuf::ugBufferSize_(gv);
      if (!bufSize)
        return;     // we don't need to communicate if we don't have any data!
      for (unsigned i=0; i < ugIfs.size(); ++i)
        UG_NS<dim>::DDD_IFOneway(ugIfs[i],
                                 ugIfDir,
                                 bufSize,
                                 &UGMsgBuf::ugGather_,
                                 &UGMsgBuf::ugScatter_);
    }
 
    void findDDDInterfaces_(std::vector<typename UG_NS<dim>::DDD_IF > &dddIfaces,
                            InterfaceType iftype,
                            int codim) const
    {
      dddIfaces.clear();
      if (codim == 0)
      {
        switch (iftype) {
        case InteriorBorder_InteriorBorder_Interface :
          // do not communicate anything: Elements can not be in
          // the interior of two processes at the same time
          return;
        case InteriorBorder_All_Interface :
          // The communicated elements are in the sender's
          // interior and it does not matter what they are for
          // the receiver
          dddIfaces.push_back(UG_NS<dim>::ElementVHIF());
          return;
        case All_All_Interface :
          // It does neither matter what the communicated
          // elements are for sender nor for the receiver. If
          // they are seen by these two processes, data is send
          // and received.
          dddIfaces.push_back(UG_NS<dim>::ElementSymmVHIF());
          return;
        default :
          DUNE_THROW(GridError,
                     "Element communication not supported for "
                     "interfaces of type  "
                     << iftype);
        }
      }
      else if (codim == dim)
      {
        switch (iftype)
        {
        case InteriorBorder_InteriorBorder_Interface :
          dddIfaces.push_back(UG_NS<dim>::BorderNodeSymmIF());
          return;
        case InteriorBorder_All_Interface :
          dddIfaces.push_back(UG_NS<dim>::BorderNodeSymmIF());
          dddIfaces.push_back(UG_NS<dim>::NodeIF());
          return;
        case All_All_Interface :
          dddIfaces.push_back(UG_NS<dim>::NodeAllIF());
          return;
        default :
          DUNE_THROW(GridError,
                     "Node communication not supported for "
                     "interfaces of type  "
                     << iftype);
        }
      }
      else if (codim == dim-1)
      {
        switch (iftype)
        {
        case InteriorBorder_InteriorBorder_Interface :
          dddIfaces.push_back(UG_NS<dim>::BorderEdgeSymmIF());
          return;
        case InteriorBorder_All_Interface :
          dddIfaces.push_back(UG_NS<dim>::BorderEdgeSymmIF());
          // Is the following line needed or not?
          // dddIfaces.push_back(UG_NS<dim>::EdgeIF());
          return;
        case All_All_Interface :
          dddIfaces.push_back(UG_NS<dim>::EdgeSymmVHIF());
          return;
        default :
          DUNE_THROW(GridError,
                     "Edge communication not supported for "
                     "interfaces of type  "
                     << iftype);
        }
      }
      else if (codim == 1)
      {
        switch (iftype)
        {
        case InteriorBorder_InteriorBorder_Interface :
        case InteriorBorder_All_Interface :
          dddIfaces.push_back(UG_NS<dim>::BorderVectorSymmIF());
          return;
        default :
          DUNE_THROW(GridError,
                     "Face communication not supported for "
                     "interfaces of type  "
                     << iftype);
        }
      }
      else
      {
        DUNE_THROW(GridError,
                   "Communication for codim "
                   << codim
                   << " entities is not yet supported "
                   << " by the DUNE UGGrid interface!");
      }
    };
#endif // ModelP
 
  public:
    // **********************************************************
    // End of Interface Methods
    // **********************************************************
 
#ifdef DOXYGEN
 
    void getChildrenOfSubface(const typename Traits::template Codim<0>::EntityPointer & e,
                              int elementSide,
                              int maxl,
                              std::vector<typename Traits::template Codim<0>::EntityPointer>& childElements,
                              std::vector<unsigned char>& childElementSides) const;
 
#else
 
    // This is the actual implementation of the deprecated method. We need this ugly trick of turning
    // it into a template to avoid triggering a deprecation warning every time UGGrid is used.
    template< typename T >
    DUNE_DEPRECATED_MSG("This version of getChildrenOfSubface() uses EntityPointer and is deprecated. It will be removed after the release of Dune 2.4. Please use the new version with entities instead.")
    typename std::enable_if<
      std::is_same<
        T,
        typename UGGrid<dim>::Traits::template Codim<0>::EntityPointer
        >::value
      >::type
    getChildrenOfSubface(const T & e,
                         int elementSide,
                         int maxl,
                         std::vector<typename Traits::template Codim<0>::EntityPointer>& childElements,
                         std::vector<unsigned char>& childElementSides) const
    {
 
      typedef std::pair<typename UG_NS<dim>::Element*,int> ListEntryType;
 
      SLList<ListEntryType> list;
 
      // //////////////////////////////////////////////////////////////////////
      //   Change the input face number from Dune numbering to UG numbering
      // //////////////////////////////////////////////////////////////////////
 
      elementSide = UGGridRenumberer<dim>::facesDUNEtoUG(elementSide, e->type());
 
      // ///////////////
      //   init list
      // ///////////////
      if (!e->isLeaf()   // Get_Sons_of_ElementSide returns GM_FATAL when called for a leaf !?!
          && e->level() < maxl) {
 
        typename UG_NS<dim>::Element* theElement = this->getRealImplementation(*e).target_;
 
        int Sons_of_Side = 0;
        typename UG_NS<dim>::Element* SonList[UG_NS<dim>::MAX_SONS];
        int SonSides[UG_NS<dim>::MAX_SONS];
 
        int rv = Get_Sons_of_ElementSide(theElement,
                                         elementSide,
                                         &Sons_of_Side,
                                         SonList,          // the output elements
                                         SonSides,         // Output element side numbers
                                         true,            // Element sons are not precomputed
                                         true);            // ioflag: I have no idea what this is supposed to do
        if (rv!=0)
          DUNE_THROW(GridError, "Get_Sons_of_ElementSide returned with error value " << rv);
 
        for (int i=0; i<Sons_of_Side; i++)
          list.push_back(ListEntryType(SonList[i],SonSides[i]));
 
      }
 
      // //////////////////////////////////////////////////
      //   Traverse and collect all children of the side
      // //////////////////////////////////////////////////
 
      typename SLList<ListEntryType>::iterator f = list.begin();
      for (; f!=list.end(); ++f) {
 
        typename UG_NS<dim>::Element* theElement = f->first;
        int side                                  = f->second;
 
        int Sons_of_Side = 0;
        typename UG_NS<dim>::Element* SonList[UG_NS<dim>::MAX_SONS];
        int SonSides[UG_NS<dim>::MAX_SONS];
 
        if (UG_NS<dim>::myLevel(theElement) < maxl) {
 
          Get_Sons_of_ElementSide(theElement,
                                  side,         // Input element side number
                                  &Sons_of_Side,       // Number of topological sons of the element side
                                  SonList,            // Output elements
                                  SonSides,           // Output element side numbers
                                  true,
                                  true);
 
          for (int i=0; i<Sons_of_Side; i++)
            list.push_back(ListEntryType(SonList[i],SonSides[i]));
 
        }
 
      }
 
      // //////////////////////////////
      //   Extract result from stack
      // //////////////////////////////
 
      // Use reserve / push_back since EntityPointer is not default constructable
      childElements.clear();
      childElements.reserve( list.size() );
      childElementSides.resize(list.size());
 
      int i=0;
      for (f = list.begin(); f!=list.end(); ++f, ++i)
        {
 
          // Set element
          typedef typename Traits::template Codim< 0 >::EntityPointer EntityPointer;
          childElements.push_back( EntityPointer( UGGridEntityPointer< 0, const UGGrid< dim > >( f->first, this ) ) );
 
          int side = f->second;
 
          // Dune numbers the faces of several elements differently than UG.
          // The following switch does the transformation
          childElementSides[i] = UGGridRenumberer<dim>::facesUGtoDUNE(side, childElements[i]->type());
 
        }
 
    }
#endif
 
    void getChildrenOfSubface(const typename Traits::template Codim<0>::Entity & e,
                              int elementSide,
                              int maxl,
                              std::vector<typename Traits::template Codim<0>::Entity>& childElements,
                              std::vector<unsigned char>& childElementSides) const;
 
    enum RefinementType {
      LOCAL,
      COPY
    };
 
    enum ClosureType {
      GREEN,
      NONE
    };
 
    void setRefinementType(RefinementType type) {
      refinementType_ = type;
    }
 
    void setClosureType(ClosureType type) {
      closureType_ = type;
    }
 
    static void setDefaultHeapSize(unsigned size) {
      heapSize_ = size;
    }
 
#ifdef DOXYGEN
 
    void setPosition(const typename Traits::template Codim<dim>::EntityPointer& e,
                     const FieldVector<double, dim>& pos);
 
#else
 
    // This is the actual implementation of the deprecated method. We need this ugly trick of turning
    // it into a template to avoid triggering a deprecation warning every time UGGrid is used.
    template< typename T >
    DUNE_DEPRECATED_MSG("This version of setPosition() uses EntityPointer and is deprecated. It will be removed after the release of Dune 2.4. Please use the new version with entities instead.")
    typename std::enable_if<
      std::is_same<
        T,
        typename UGGrid<dim>::Traits::template Codim<dim>::EntityPointer
        >::value
      >::type
    setPosition(const T& e,
                const FieldVector<double, dim>& pos)
{
  typename UG_NS<dim>::Node* target = this->getRealImplementation(*e).target_;
 
  for (int i=0; i<dim; i++)
    target->myvertex->iv.x[i] = pos[i];
}
 
#endif
 
    void setPosition(const typename Traits::template Codim<dim>::Entity& e,
                     const FieldVector<double, dim>& pos);
 
    void globalRefine(int n);
 
    void saveState(const std::string& filename) const;
 
    void loadState(const std::string& filename);
 
  private:
    typename UG_NS<dim>::MultiGrid* multigrid_;
 
    CollectiveCommunication<UGGrid> ccobj_;
 
    void setIndices(bool setLevelZero,
                    std::vector<unsigned int>* nodePermutation);
 
    // Each UGGrid object has a unique name to identify it in the
    // UG environment structure
    std::string name_;
 
    // Our set of level indices
    std::vector<shared_ptr<UGGridLevelIndexSet<const UGGrid<dim> > > > levelIndexSets_;
 
    UGGridLeafIndexSet<const UGGrid<dim> > leafIndexSet_;
 
    // One id set implementation
    // Used for both the local and the global UGGrid id sets
    UGGridIdSet<const UGGrid<dim> > idSet_;
 
    RefinementType refinementType_;
 
    ClosureType closureType_;
 
    static int numOfUGGrids;
 
    bool someElementHasBeenMarkedForRefinement_;
 
    bool someElementHasBeenMarkedForCoarsening_;
 
    static unsigned int heapSize_;
 
    std::vector<shared_ptr<BoundarySegment<dim> > > boundarySegments_;
 
    unsigned int numBoundarySegments_;
 
  }; // end Class UGGrid
 
  namespace Capabilities
  {
    template<int dim>
    struct hasEntity< UGGrid<dim>, 0>
    {
      static const bool v = true;
    };
 
    template<int dim>
    struct hasEntity< UGGrid<dim>, dim>
    {
      static const bool v = true;
    };
 
    template<int dim>
    struct DUNE_DEPRECATED_MSG("Capabilities::isParallel will be removed after dune-grid-2.4.") isParallel< UGGrid<dim> >
    {
#ifdef ModelP
      static const bool DUNE_DEPRECATED_MSG("Capabilities::isParallel will be removed after dune-grid-2.4.") v = true;
#else // !ModelP
      static const bool DUNE_DEPRECATED_MSG("Capabilities::isParallel will be removed after dune-grid-2.4.") v = false;
#endif // !ModelP
    };
 
    template<int dim>
    struct isLevelwiseConforming< UGGrid<dim> >
    {
      static const bool v = true;
    };
 
    template<int dim>
    struct isLeafwiseConforming< UGGrid<dim> >
    {
      static const bool v = false;
    };
 
  }
 
} // namespace Dune
 
#endif   // HAVE_UG || DOXYGEN
#endif   // DUNE_UGGRID_HH