gen/libsaio/unpackbits.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1988, 1989, 1990, 1991 Sam Leffler
  26  * Copyright (c) 1991 Silicon Graphics, Inc.
  27  *
  28  * Permission to use, copy, modify, distribute, and sell this software and
  29  * its documentation for any purpose is hereby granted without fee, provided
  30  * that (i) the above copyright notices and this permission notice appear in
  31  * all copies of the software and related documentation, and (ii) the names of
  32  * Sam Leffler and Silicon Graphics may not be used in any advertising or
  33  * publicity relating to the software without the specific, prior written
  34  * permission of Sam Leffler and Silicon Graphics.
  35  *
  36  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  37  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  38  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  39  *
  40  * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  41  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  42  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  43  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  44  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  45  * OF THIS SOFTWARE.
  46  */
  47
  48 /*
  49  * TIFF Library.
  50  *
  51  * PackBits Compression Algorithm Support
  52  */
  53 #import "bitmap.h"
  54 #import "libsa.h"
  55
  56 typedef unsigned int u_int;
  57 typedef unsigned char u_char;
  58
  59 int
  60 PackBitsDecode(tif, op, occ, s)
  61         TIFF *tif;
  62         register u_char *op;
  63         register int occ;
  64         u_int s;
  65 {
  66         register char *bp;
  67         register int n, b;
  68         register int cc;
  69
  70         bp = tif->tif_rawcp; cc = tif->tif_rawcc;
  71         while (cc > 0 && occ > 0) {
  72                 n = (int) *bp++; cc--;
  73                 /*
  74                  * Watch out for compilers that
  75                  * don't sign extend chars...
  76                  */
  77                 if (n >= 128)
  78                         n -= 256;
  79                 if (n < 0) {            /* replicate next byte -n+1 times */
  80                         cc--;
  81                         if (n == -128)  /* nop */
  82                                 continue;
  83                         n = -n + 1;
  84                         occ -= n;
  85                         for (b = *bp++; n-- > 0;)
  86                                 *op++ = b;
  87                 } else {                /* copy next n+1 bytes literally */
  88                         bcopy(bp, op, ++n);
  89                         op += n; occ -= n;
  90                         bp += n; cc -= n;
  91                 }
  92         }
  93         tif->tif_rawcp = bp;
  94         tif->tif_rawcc = cc;
  95         if (occ > 0) {
  96 //              TIFFError(tif->tif_name,
  97 //                  "PackBitsDecode: Not enough data for scanline %d",
  98 //                  tif->tif_row);
  99 //              reallyPrint("Not enough data\n");
 100                 return (0);
 101         }
 102         /* check for buffer overruns? */
 103         return (1);
 104 }