foamgridhierarchiciterator.hh

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#ifndef DUNE_FOAMGRID_HIERARCHIC_ITERATOR_HH
#define DUNE_FOAMGRID_HIERARCHIC_ITERATOR_HH
 
#include <stack>
 
namespace Dune {
 
 
//**********************************************************************
//
template<class GridImp>
class FoamGridHierarchicIterator
{
    static constexpr int dimworld = GridImp::dimensionworld;
    static constexpr int dimgrid = GridImp::dimension;
 
    using EntityImpPointer = const FoamGridEntityImp<
        dimgrid, dimgrid, dimworld, typename GridImp::ctype
    >*;
 
public:
    using Entity = typename GridImp::template Codim<0>::Entity;
 
    enum { codimension = 0 };
 
    FoamGridHierarchicIterator(EntityImpPointer target, int maxLevel)
    : maxLevel_(maxLevel)
    {
        // Load sons of target onto the iterator stack
        stackChildren_(target);
 
        // Set entity target to the next child if exists
        resetEntity_();
    }
 
    FoamGridHierarchicIterator(int maxLevel)
    : maxLevel_(maxLevel)
    {
        resetEntity_();
    }
 
    void increment()
    {
        if (elemStack_.empty())
            return;
 
        auto target = elemStack_.top();
        elemStack_.pop();
 
        // Load sons of previous target onto the iterator stack
        stackChildren_(target);
 
        // Set entity target to the next stacked element if exists
        resetEntity_();
    }
 
    const Entity& dereference() const { return virtualEntity_; }
 
    bool equals(const FoamGridHierarchicIterator<GridImp>& other) const
    { return virtualEntity_ == other.virtualEntity_; }
 
private:
    void stackChildren_(EntityImpPointer target)
    {
        // Load sons of target onto the iterator stack
        if (target->level() < maxLevel_ && !target->isLeaf())
            for (std::size_t i = 0; i < target->nSons(); i++)
                elemStack_.push(target->sons_[i]);
    }
 
    void resetEntity_()
    {
        virtualEntity_.impl().setToTarget(
            elemStack_.empty() ? nullptr : elemStack_.top()
        );
    }
 
    Entity virtualEntity_;
 
    int maxLevel_;
 
    std::stack<EntityImpPointer> elemStack_;
};
 
 
}  // end namespace Dune
 
#endif