auto_mask.c

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#include <stdlib.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include "G.h"


int G__check_for_auto_masking(void)
{
    struct Cell_head cellhd;

    /* if mask is switched off (-2) return -2
       if G__.auto_mask is not set (-1) or set (>=0) recheck the MASK */

    if (G__.auto_mask < -1)
        return G__.auto_mask;

    /* if(G__.mask_fd > 0) G_free (G__.mask_buf); */

    /* look for the existence of the MASK file */
    G__.auto_mask = (G_find_cell("MASK", G_mapset()) != 0);

    if (G__.auto_mask <= 0)
        return 0;

    /* check MASK projection/zone against current region */
    if (G_get_cellhd("MASK", G_mapset(), &cellhd) >= 0) {
        if (cellhd.zone != G_zone() || cellhd.proj != G_projection()) {
            G__.auto_mask = 0;
            return 0;
        }
    }

    G_unopen_cell(G__.mask_fd);
    G__.mask_fd = G__open_cell_old("MASK", G_mapset());
    if (G__.mask_fd < 0) {
        G__.auto_mask = 0;
        G_warning(_("Unable to open automatic MASK file"));
        return 0;
    }

    /*    G__.mask_buf = G_allocate_cell_buf(); */

    G__.auto_mask = 1;

    return 1;
}


int G_suppress_masking(void)
{
    if (G__.auto_mask > 0) {
        G_close_cell(G__.mask_fd);
        /* G_free (G__.mask_buf); */
        G__.mask_fd = -1;
    }
    G__.auto_mask = -2;

    return 0;
}


int G_unsuppress_masking(void)
{
    if (G__.auto_mask < -1) {
        G__.mask_fd = -1;
        G__check_for_auto_masking();
    }

    return 0;
}