reactos/dll/3rdparty/libtiff/tif_next.c

   1 /* $Id: tif_next.c,v 1.8.2.1 2010-06-08 18:50:42 bfriesen Exp $ */
   2
   3 /*
   4  * Copyright (c) 1988-1997 Sam Leffler
   5  * Copyright (c) 1991-1997 Silicon Graphics, Inc.
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and
   8  * its documentation for any purpose is hereby granted without fee, provided
   9  * that (i) the above copyright notices and this permission notice appear in
  10  * all copies of the software and related documentation, and (ii) the names of
  11  * Sam Leffler and Silicon Graphics may not be used in any advertising or
  12  * publicity relating to the software without the specific, prior written
  13  * permission of Sam Leffler and Silicon Graphics.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  17  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  20  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  21  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  22  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  23  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  24  * OF THIS SOFTWARE.
  25  */
  26
  27 #include "tiffiop.h"
  28 #ifdef NEXT_SUPPORT
  29 /*
  30  * TIFF Library.
  31  *
  32  * NeXT 2-bit Grey Scale Compression Algorithm Support
  33  */
  34
  35 #define SETPIXEL(op, v) {                       \
  36         switch (npixels++ & 3) {                \
  37         case 0: op[0]  = (unsigned char) ((v) << 6); break;     \
  38         case 1: op[0] |= (v) << 4; break;       \
  39         case 2: op[0] |= (v) << 2; break;       \
  40         case 3: *op++ |= (v);      break;       \
  41         }                                       \
  42 }
  43
  44 #define LITERALROW      0x00
  45 #define LITERALSPAN     0x40
  46 #define WHITE           ((1<<2)-1)
  47
  48 static int
  49 NeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
  50 {
  51         unsigned char *bp, *op;
  52         tsize_t cc;
  53         tidata_t row;
  54         tsize_t scanline, n;
  55
  56         (void) s;
  57         /*
  58          * Each scanline is assumed to start off as all
  59          * white (we assume a PhotometricInterpretation
  60          * of ``min-is-black'').
  61          */
  62         for (op = buf, cc = occ; cc-- > 0;)
  63                 *op++ = 0xff;
  64
  65         bp = (unsigned char *)tif->tif_rawcp;
  66         cc = tif->tif_rawcc;
  67         scanline = tif->tif_scanlinesize;
  68         for (row = buf; occ > 0; occ -= scanline, row += scanline) {
  69                 n = *bp++, cc--;
  70                 switch (n) {
  71                 case LITERALROW:
  72                         /*
  73                          * The entire scanline is given as literal values.
  74                          */
  75                         if (cc < scanline)
  76                                 goto bad;
  77                         _TIFFmemcpy(row, bp, scanline);
  78                         bp += scanline;
  79                         cc -= scanline;
  80                         break;
  81                 case LITERALSPAN: {
  82                         tsize_t off;
  83                         /*
  84                          * The scanline has a literal span that begins at some
  85                          * offset.
  86                          */
  87                         off = (bp[0] * 256) + bp[1];
  88                         n = (bp[2] * 256) + bp[3];
  89                         if (cc < 4+n || off+n > scanline)
  90                                 goto bad;
  91                         _TIFFmemcpy(row+off, bp+4, n);
  92                         bp += 4+n;
  93                         cc -= 4+n;
  94                         break;
  95                 }
  96                 default: {
  97                         uint32 npixels = 0, grey;
  98                         uint32 imagewidth = tif->tif_dir.td_imagewidth;
  99
 100                         /*
 101                          * The scanline is composed of a sequence of constant
 102                          * color ``runs''.  We shift into ``run mode'' and
 103                          * interpret bytes as codes of the form
 104                          * <color><npixels> until we've filled the scanline.
 105                          */
 106                         op = row;
 107                         for (;;) {
 108                                 grey = (n>>6) & 0x3;
 109                                 n &= 0x3f;
 110                                 /*
 111                                  * Ensure the run does not exceed the scanline
 112                                  * bounds, potentially resulting in a security
 113                                  * issue.
 114                                  */
 115                                 while (n-- > 0 && npixels < imagewidth)
 116                                         SETPIXEL(op, grey);
 117                                 if (npixels >= imagewidth)
 118                                         break;
 119                                 if (cc == 0)
 120                                         goto bad;
 121                                 n = *bp++, cc--;
 122                         }
 123                         break;
 124                 }
 125                 }
 126         }
 127         tif->tif_rawcp = (tidata_t) bp;
 128         tif->tif_rawcc = cc;
 129         return (1);
 130 bad:
 131         TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "NeXTDecode: Not enough data for scanline %ld",
 132             (long) tif->tif_row);
 133         return (0);
 134 }
 135
 136 int
 137 TIFFInitNeXT(TIFF* tif, int scheme)
 138 {
 139         (void) scheme;
 140         tif->tif_decoderow = NeXTDecode;
 141         tif->tif_decodestrip = NeXTDecode;
 142         tif->tif_decodetile = NeXTDecode;
 143         return (1);
 144 }
 145 #endif /* NEXT_SUPPORT */
 146
 147 /* vim: set ts=8 sts=8 sw=8 noet: */
 148 /*
 149  * Local Variables:
 150  * mode: c
 151  * c-basic-offset: 8
 152  * fill-column: 78
 153  * End:
 154  */