long.c

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#include "raster3d_intern.h"

/*---------------------------------------------------------------------------*/

int Rast3d_long_encode(long *source, unsigned char *dst, int nofNums)
{
    long *src, d;
    int eltLength, nBytes;
    unsigned char *dstStop, tmp;

    eltLength = RASTER3D_LONG_LENGTH;
    nBytes = 8;

    d = 1;

    while (eltLength--) {
        dstStop = dst + nofNums;
        src = source;

        while (dst != dstStop) {
            tmp = ((*src++ / d) % 256);
            if (tmp != 0)
                nBytes = RASTER3D_MIN(nBytes, eltLength);
            *dst++ = tmp;
        }

        d *= 256;
    }

    return RASTER3D_LONG_LENGTH - nBytes;
}

/*---------------------------------------------------------------------------*/

void
Rast3d_long_decode(unsigned char *source, long *dst, int nofNums, int longNbytes)
{
    long *dest;
    int eltLength;
    unsigned char *srcStop;

    eltLength = longNbytes;

    source += nofNums * eltLength - 1;

    eltLength--;
    srcStop = source - nofNums;
    dest = dst;
    dest += nofNums - 1;
    while (source != srcStop) {
        *dest = *source--;
        if ((eltLength >= RASTER3D_LONG_LENGTH) && (*dest != 0))
            Rast3d_fatal_error("Rast3d_long_decode: decoded long too long");
        dest--;
    }

    while (eltLength--) {
        srcStop = source - nofNums;
        dest = dst;
        dest += nofNums - 1;
        while (source != srcStop) {
            *dest *= 256;
            *dest += *source--;
            if ((eltLength >= RASTER3D_LONG_LENGTH) && (*dest != 0))
                Rast3d_fatal_error("Rast3d_long_decode: decoded long too long");
            dest--;
        }
    }
}