"Fossies" - the Fresh Open Source Software archive

Member "spectemu-0.99.3/compr.c" of archive spectemu-0.99.3.tar.gz:

/* 
 * Copyright (C) 1996-2004 Szeredi Miklos
 * Email: mszeredi@inf.bme.hu
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version. See the file COPYING. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include "compr.h"

void compr(void) 
{
    int j, c, lc, lled, rep, num;

    rep = 0;
  
    c = compr_read_byte();
    lc = 0;
    num = 0;

    while(c >= 0) {
        if(lc == 0xED) lled = 1;
        else lled = 0;

        lc = c;
        c = compr_read_byte();
        if(c == lc && num != 255 && (!lled || rep)) {
            if(!rep) {
                num = 1;
                rep = 1;
            }
            num++;
        }
        else {
            if(rep) {
                if(num < 5 && lc != 0xED) for(j = 0; j < num; j++)
                    compr_put_byte(lc);
                else{
                    compr_put_byte(0xED);
                    compr_put_byte(0xED);
                    compr_put_byte(num);
                    compr_put_byte(lc);
                    num = 0;
                }
                rep = 0;
            }
            else compr_put_byte(lc);
        }
    }

    compr_put_byte(0x00);
    compr_put_byte(0xED);
    compr_put_byte(0xED);
    compr_put_byte(0x00);
}