resample.c

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#include <stdio.h>
#include <grass/gis.h>
#include "raster3d_intern.h"
 
/*--------------------------------------------------------------------------*/
 
/*!
 * \brief
 *
 * The default resampling function which uses nearest
 * neighbor resampling. This method converts the window coordinates
 * x, y, and z into region coordinates and returned the nearest neighbor.
 *
 *  \param map
 *  \param x
 *  \param y
 *  \param z
 *  \param value
 *  \param type
 *  \return void
 */
void Rast3d_nearest_neighbor(RASTER3D_Map *map, int x, int y, int z,
                             void *value, int type)
{
    double north, east, top;
    int row, col, depth;
 
    /* convert (x, y, z) window coordinates into (north, east, top) */
    Rast3d_coord2location(&(map->window), (double)x + 0.5, (double)y + 0.5,
                          (double)z + 0.5, &north, &east, &top);
 
    /* convert (north, east, top) into map region coordinates (row, col, depth)
     */
    Rast3d_location2coord(&(map->region), north, east, top, &col, &row, &depth);
 
    /* Get the value from the map in map-region resolution */
    Rast3d_get_value_region(map, col, row, depth, value, type);
}
 
/*--------------------------------------------------------------------------*/
 
/*!
 * \brief
 *
 * Sets the resampling function to be used by
 * Rast3d_get_value () (cf.{g3d:G3d.getValue}). This function is defined
 * as follows:
 * \param map
 * \param resampleFun
 * \return void
 */
void Rast3d_set_resampling_fun(RASTER3D_Map *map,
                               void (*resampleFun)(RASTER3D_Map *, int, int,
                                                   int, void *, int))
{
    map->resampleFun = resampleFun;
}
 
/*--------------------------------------------------------------------------*/
 
/*!
 * \brief
 *
 *
 * Returns in <em>resampleFun</em> a pointer to the resampling function used by
 * <em>map</em>.
 *
 *  \return void
 */
void Rast3d_get_resampling_fun(RASTER3D_Map *map,
                               void (**resampleFun)(RASTER3D_Map *, int, int,
                                                    int, void *, int))
{
    *resampleFun = map->resampleFun;
}
 
/*--------------------------------------------------------------------------*/
 
/*!
 * \brief
 *
 *  Returns
 * in <em>nnFunPtr</em> a pointer to Rast3d_nearest_neighbor ()
 * (cf.{g3d:G3d.nearestNeighbor}).
 *
 *  \return void
 */
void Rast3d_get_nearest_neighbor_fun_ptr(void (**nnFunPtr)(RASTER3D_Map *, int,
                                                           int, int, void *,
                                                           int))
{
    *nnFunPtr = Rast3d_nearest_neighbor;
}