grid_key_dx_iterator_hilbert.hpp

/*
 * grid_key_dx_iterator_hilbert.hpp
 *
 *  Created on: Feb 24, 2016
 *      Author: yaroslav
 */

#ifndef OPENFPM_DATA_SRC_GRID_GRID_KEY_DX_ITERATOR_HILBERT_HPP_
#define OPENFPM_DATA_SRC_GRID_GRID_KEY_DX_ITERATOR_HILBERT_HPP_

extern "C"
{
#include "hilbertKey.h"
}


/*
 *
 * Grid key class iterator, iterate through the grid elements following an
 * hilbert space filling curve
 *
 * \param dim dimensionality of the grid
 *
 * ### Grid iterator declaration and usage
 * \snippet grid_unit_tests.hpp Grid iterator test usage
 *
 */

template<unsigned int dim>
class grid_key_dx_iterator_hilbert
{
#ifdef SE_CLASS1
    bool initialized = false;
#endif

    uint64_t hkey = 0;

    size_t m;

    grid_sm<dim,void> grid_base;

protected:

    grid_key_dx<dim> gk;

public:

    grid_key_dx_iterator_hilbert(int32_t m)
    :m(m)
    {
        // create from m the correct grid_sm

        size_t dims[dim];

        //Set the 2^m value to the each elements of dims[]
        for (size_t i = 0 ; i < dim ; i++)
            dims[i] = 1 << m;

        //Set grid_sm dimensions
        grid_base.setDimensions(dims);

        reset();

#ifdef SE_CLASS1
        initialized = true;
#endif
    }

    grid_key_dx_iterator_hilbert<dim> & operator++()
    {
        //An integer to handle errors
        int err;

        hkey++;

        //Array to handle output
        uint64_t nextCoord[dim];

        //Get the coordinates of the next cell
        getIntCoordFromHKey(nextCoord, m, dim, hkey, &err);

        //Set the new coordinates
        for (size_t i = 0; i < dim; i++)
            gk.set_d(i, nextCoord[i]);

        return *this;
    }

    bool isNext()
    {
        if ( hkey < (size_t)1 << (m*dim))
        {

            return true;
        }

        return false;
    }

    const grid_key_dx<dim> & get()
    {
        return gk;
    }


    void reset()
    {
        for (size_t i = 0 ; i < dim ; i++)
            gk.set_d(i,0);
    }
};


#endif /* OPENFPM_DATA_SRC_GRID_GRID_KEY_DX_ITERATOR_HILBERT_HPP_ */