g2_unpack6.c

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#include <stdio.h>
#include <stdlib.h>
#include "grib2_int.h"
 
g2int
g2_unpack6(unsigned char *cgrib, g2int *iofst, g2int ngpts, g2int *ibmap,
           g2int **bmap)
{
    g2int j, isecnum;
    g2int *lbmap = 0;
    g2int *intbmap;
 
    *bmap = NULL;
 
    *iofst = *iofst + 32;    /* skip Length of Section */
    gbit(cgrib, &isecnum, *iofst, 8);         /* Get Section Number */
    *iofst = *iofst + 8;
 
    if (isecnum != 6)
    {
        fprintf(stderr, "g2_unpack6: Not Section 6 data.\n");
        return G2_UNPACK_BAD_SEC;
    }
 
    gbit(cgrib, ibmap, *iofst, 8);    /* Get bit-map indicator */
    *iofst = *iofst + 8;
 
    if (*ibmap == 0)
    {               /* Unpack bitmap */
        if (ngpts > 0)
            lbmap = calloc(ngpts, sizeof(g2int));
        if (!lbmap)
            return G2_UNPACK_NO_MEM;
 
        *bmap = lbmap;
        intbmap = calloc(ngpts, sizeof(g2int));
        gbits(cgrib, intbmap, *iofst, 1, 0, ngpts);
        *iofst = *iofst + ngpts;
        for (j = 0; j < ngpts; j++)
            lbmap[j] = (g2int)intbmap[j];
        free(intbmap);
    }
 
    return G2_NO_ERROR;
}