#include <unistd.h>
#include "global.h"

/* Modified to support Grass 5.0 fp format 11 april 2000
 *
 * Pierre de Mouveaux - pmx@audiovu.com
 *
 */

int rectify (char *name, char *mapset, char *result, int order)
{
    struct Cell_head cellhd, win;
    int ncols, nrows;
    int row, col;
    int infd;
    void *rast;
    char buf[2048]="";

    select_current_env();
    if (G_get_cellhd (name, mapset, &cellhd) < 0)
	return 0;

/* open the result file into target window
 * this open must be first since we change the window later
 * cell files open for writing are not affected by window changes
 * but those open for reading are
 *
 * also tell open that cell file will have the same format
 * (ie number of bytes per cell) as the file being rectified
 */

    select_target_env();
    G_set_window (&target_window);
    G_set_cell_format (cellhd.format);
    select_current_env();

/* open the file to be rectified
 * set window to cellhd first to be able to read file exactly
 */
    G_set_window (&cellhd);
    infd = G_open_cell_old (name, mapset);
    if (infd < 0)
    {
	close (infd);
	return 0;
    }
    map_type = G_raster_map_type(name, mapset);
    rast = (void *)  G_calloc (G_window_cols()+1, G_raster_size(map_type));
    G_set_null_value(rast, G_window_cols()+1, map_type);

    G_copy (&win, &target_window, sizeof(win));

    win.west += win.ew_res/2;
    ncols = target_window.cols;
    col = 0;

    temp_fd = 0;

    while (ncols > 0)
    {
	if ((win.cols = ncols) > NCOLS)
	    win.cols = NCOLS;
	win.north = target_window.north - win.ns_res/2;
	nrows = target_window.rows;
	row = 0;

	while (nrows > 0)
	{
	    if ((win.rows = nrows) > NROWS)
		win.rows = NROWS;

		compute_georef_matrix (&cellhd, &win,order);
	    perform_georef (infd, rast);
	    write_matrix (row, col);

	    nrows -= win.rows;
	    row += win.rows;
	    win.north -= (win.ns_res * win.rows);
	}

	ncols -= win.cols;
	col += win.cols;
	win.west += (win.ew_res * win.cols);
	G_percent(col,col+ncols,1);
    }

    select_target_env();

    if (cellhd.proj == 0) { /* x,y imagery */
			cellhd.proj = target_window.proj;
			cellhd.zone = target_window.zone;
	}

    if (target_window.proj != cellhd.proj) {
			cellhd.proj = target_window.proj;
			sprintf(buf,"WARNING %s@%s: projection don't match current settings.\n",name,mapset);
			G_warning(buf);
	}  

    if (target_window.zone != cellhd.zone) {
			cellhd.zone = target_window.zone;
			sprintf(buf,"WARNING %s@%s: zone don't match current settings .\n",name,mapset);
			G_warning(buf);
	}  

    target_window.compressed=cellhd.compressed;
    G_close_cell (infd); /* (pmx) 17 april 2000 */
    write_map(result);
    select_current_env();

    G_free (rast);

    return 1;
}