kc3-lang/libqrencode/bitstream.c

Branch : - branch - master - tag -

• Show log

  Commit

• Author : fukuchi
  Date : 2006-11-02 12:31:40
  Hash : 3f3f4d1e
  Message :

• bitstream.c

• /*
   * qrencode - QR-code encoder
   *
   * Originally written by Y.Swetake
   * Copyright (c)2003-2005 Y.Swetake
   *
   * Ported to C and modified by Kentaro Fukuchi
   * Copyright (c) 2006 Kentaro Fukuchi
   *
   * 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
   * any later version.
   *
   * 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.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <assert.h>
  
  #include "bitstream.h"
  
  BitStream *BitStream_new(int size)
  {
  	BitStream *bstream;
  	div_t d;
  	int byte;
  
  	d = div(size, 8);
  	byte = d.quot + (d.rem?1:0);
  
  	bstream = (BitStream *)malloc(sizeof(BitStream));
  	bstream->size = size;
  	bstream->data = (unsigned char *)malloc(byte);
  	bstream->head = bstream->data;
  	bstream->remain = 0;
  
  	return bstream;
  }
  
  void BitStream_append(BitStream *bstream, int size, unsigned char *data)
  {
  	int sb;
  	int shift;
  
  	sb = size / 8;
  
  	if(bstream->remain == 0) {
  		memcpy(bstream->head, data, sb);
  		bstream->head += sb;
  		if(size & 7) {
  			*bstream->head = data[sb];
  			bstream->remain = 8 - (size - sb * 8);
  		}
  	} else {
  		shift = 8 - bstream->remain;
  		while(size > 7) {
  			*bstream->head++ |= *data << shift;
  			*bstream->head = *data++ >> bstream->remain;
  			size -= 8;
  		}
  		if(size > 0) {
  			*bstream->head |= *data << shift;
  			if(size > bstream->remain) {
  				bstream->head++;
  				*bstream->head = *data >> bstream->remain;
  				bstream->remain += 8 - size;
  			} else {
  				bstream->remain -= size;
  				if(bstream->remain == 0) {
  					bstream->head++;
  					bstream->remain = 8;
  				}
  			}
  		}
  	}
  }
  
  void BitStream_free(BitStream *bstream)
  {
  	free(bstream->data);
  	free(bstream);
  }