rle_rawrow.c

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/* 
 * rle_rawrow.c - Convert RLE "raw" input to "row" input.
 * 
 * Author:  Spencer W. Thomas
 *      EECS Dept.
 *      University of Michigan
 * Date:    Mon Jun 18 1990
 * Copyright (c) 1990, University of Michigan
 */

#include "rle.h"
#include "rle_raw.h"

/*****************************************************************
 * TAG( rle_rawtorow )
 * 
 * Convert a "raw" scanline to a row format.
 * Inputs:
 *  the_hdr:    RLE header describing the image.
 *  raw:        Pointer to pointers to vectors of "raw" data.
 *  nraw:       Pointer to vector of lengths of raw data vectors.
 * Outputs:
 *  outrows:    Pointer to pointers to scanline data for
 *          this scanline.
 * Algorithm:
 *  Interpret successive "op codes", filling in scanline array.
 *  Scanline between xmin and xmax is prefilled with background
 *  color, if one is given.
 */
void
rle_rawtorow(the_hdr, raw, nraw, outrows)
rle_hdr * the_hdr;
rle_op ** raw;
int * nraw;
rle_pixel ** outrows;
{
    register int i, j;
    register rle_pixel * outptr;
    int chan;

    for (chan = -the_hdr->alpha; chan < the_hdr->ncolors; chan++)
    if ( RLE_BIT( *the_hdr, chan ) )
    {
        if ( chan >= 0 && the_hdr->background == 2 && the_hdr->bg_color &&
         the_hdr->bg_color[chan] != 0 )
        {
        j = the_hdr->bg_color[chan];
        for ( i = the_hdr->xmin,
              outptr = &outrows[chan][the_hdr->xmin];
              i <= the_hdr->xmax;
              i++, outptr++ )
            *outptr = j;
        }
        else
        bzero( (char *)&outrows[chan][the_hdr->xmin],
               the_hdr->xmax - the_hdr->xmin + 1 );

        for( i = 0; i < nraw[chan]; i++ )
        {
        outptr = &(outrows[chan][raw[chan][i].xloc]);
        switch (raw[chan][i].opcode)
        {
        case RByteDataOp:
            bcopy( (char *)raw[chan][i].u.pixels, (char *)outptr,
               raw[chan][i].length );
            break;

        case RRunDataOp:
            for ( j = raw[chan][i].length; j > 0; j--)
            *(outptr++) = (rle_pixel) raw[chan][i].u.run_val;
            break;
        }
        }
    }
}