/*
* Motif
*
* Copyright (c) 1987-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these librararies and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*
* HISTORY
*/
#ifdef REV_INFO
#ifndef lint
static char rcsid[] = "$XConsortium: DcompresRead.c /main/7 1995/07/14 11:49:24 drk $"
#endif
#endif
/***********************************************************************
@(#)DcompresRead.c 1.6.1.1 Date:1/22/91
Author: TAT
History:
05/24/90 SJS add to SCCS
Calls:
Summary:
This function reads in information about visual images
that was previously written to the data file. This information
was in compressed form and needs to be decompressed
************************************************************************/
#include "vislib.h"
void mvsDecompressRead(fp,buffer,size)
FILE *fp;
unsigned char buffer[];
int size;
{
unsigned char *bp = buffer;
unsigned char byte,curchar;
long cnt;
unsigned char cnt_comp[10];
short num_cnt_comps;
unsigned char *end_of_buffer = &buffer[size];
unsigned char inbuf[INBUF_SIZE];
int i,j;
mvsGetCh((FILE *)0, (unsigned char *)0,
(unsigned char *)0); /* initialize mvsGetCh */
/* Loop to read one byte at a time from buffer until 'size' bytes read */
while ((bp < end_of_buffer) && (mvsGetCh(fp,inbuf,&curchar))) {
/* New character read in while loop above */
/* Now read the variable length count below */
cnt = 0;
if (mvsGetCh(fp,inbuf,&byte)) {
num_cnt_comps = 0;
/* Repeatedly read bytes int cnt_comp[] until MSBit is 0 */
do {
cnt_comp[num_cnt_comps++] = (byte & 0x7f);
} while ((byte & 0x80) && (mvsGetCh(fp,inbuf,&byte)));
/* Reconstruct count; start with MSbyte last back to LSbyte first */
for (j=num_cnt_comps-1; j>=0; j--) {
cnt <<=7;
cnt |= cnt_comp[j];
}
}
/* Now output that many instances of curchar in the image buffer */
for (i=0; i<cnt; i++) {
*bp++ = curchar;
}
} /* End while() */
} /* End mvsDecompressRead() */