foamgridleafiterator.hh

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#ifndef DUNE_FOAMGRID_LEAFITERATOR_HH
#define DUNE_FOAMGRID_LEAFITERATOR_HH
 
namespace Dune {
 
template<int codim, PartitionIteratorType pitype, class GridImp>
class FoamGridLeafIterator
{
    enum {dimgrid  = GridImp::dimension};
    enum {dimworld = GridImp::dimensionworld};
 
public:
 
    using Entity = typename GridImp::template Codim<codim>::Entity;
    enum { codimension = codim };
 
    FoamGridLeafIterator(const GridImp& grid)
    : grid_(&grid)
    {
 
        const int fullRefineLevel = 0;
 
        const auto& entities = std::get<dimgrid-codim>(grid_->entityImps_[fullRefineLevel]);
        levelIterator_ = entities.begin();
 
        if (levelIterator_ != entities.end())
        {
 
          // The &* turns an iterator into a plain pointer
          virtualEntity_.impl().setToTarget(&*entities.begin());
 
          if (!virtualEntity_.impl().target_->isLeaf())
            increment();
        }
 
        // grid doesn't contain entities of this codimension
        else
            virtualEntity_.impl().setToTarget(nullptr);
    }
 
    FoamGridLeafIterator()
    : grid_(nullptr)
    {
        virtualEntity_.impl().setToTarget(nullptr);
    }
 
    void increment() {
        // Increment until you find a leaf entity
        do {
            globalIncrement();
 
        } while (levelIterator_!=std::get<dimgrid-codim>(grid_->entityImps_[grid_->maxLevel()]).end()
                 && !virtualEntity_.impl().target_->isLeaf());
    }
 
    const Entity& dereference() const { return virtualEntity_; }
 
    bool equals(const FoamGridLeafIterator<codim, pitype, GridImp>& other) const {
      return virtualEntity_ == other.virtualEntity_;
    }
 
private:
 
    void globalIncrement() {
 
        // Backup current level because it may not be accessible anymore after
        // setting the pointer to the next entity.
        const int oldLevel = virtualEntity_.level();
 
        // Increment on this level
        ++levelIterator_;
        virtualEntity_.impl().setToTarget(&(*levelIterator_));
        if (levelIterator_==std::get<dimgrid-codim>(grid_->entityImps_[oldLevel]).end())
            virtualEntity_.impl().setToTarget(nullptr);
 
        // If beyond the end of this level set to first of next level
        if (levelIterator_==std::get<dimgrid-codim>(grid_->entityImps_[oldLevel]).end() && oldLevel < grid_->maxLevel()) {
 
            const std::list<FoamGridEntityImp<dimgrid-codim, dimgrid, dimworld, typename GridImp::ctype> >& entities = std::get<dimgrid-codim>(grid_->entityImps_[oldLevel+1]);
            levelIterator_ = entities.begin();
            virtualEntity_.impl().setToTarget(&*entities.begin());
 
        }
 
    }
 
    // /////////////////////////////////////
    //   Data members
    // /////////////////////////////////////
    const GridImp* grid_;
 
    Entity virtualEntity_;
 
    typename std::list<FoamGridEntityImp<dimgrid-codim, dimgrid, dimworld, typename GridImp::ctype> >::const_iterator levelIterator_;
};
 
 
}  // namespace Dune
 
#endif