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

   1 /* $Id: tif_next.c,v 1.13 2010-03-10 18:56:48 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 <precomp.h>
  28
  29 #ifdef NEXT_SUPPORT
  30 /*
  31  * TIFF Library.
  32  *
  33  * NeXT 2-bit Grey Scale Compression Algorithm Support
  34  */
  35
  36 #define SETPIXEL(op, v) {                       \
  37         switch (npixels++ & 3) {                \
  38         case 0: op[0]  = (unsigned char) ((v) << 6); break;     \
  39         case 1: op[0] |= (v) << 4; break;       \
  40         case 2: op[0] |= (v) << 2; break;       \
  41         case 3: *op++ |= (v);      break;       \
  42         }                                       \
  43 }
  44
  45 #define LITERALROW      0x00
  46 #define LITERALSPAN     0x40
  47 #define WHITE           ((1<<2)-1)
  48
  49 static int
  50 NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
  51 {
  52         static const char module[] = "NeXTDecode";
  53         unsigned char *bp, *op;
  54         tmsize_t cc;
  55         uint8* row;
  56         tmsize_t scanline, n;
  57
  58         (void) s;
  59         /*
  60          * Each scanline is assumed to start off as all
  61          * white (we assume a PhotometricInterpretation
  62          * of ``min-is-black'').
  63          */
  64         for (op = (unsigned char*) buf, cc = occ; cc-- > 0;)
  65                 *op++ = 0xff;
  66
  67         bp = (unsigned char *)tif->tif_rawcp;
  68         cc = tif->tif_rawcc;
  69         scanline = tif->tif_scanlinesize;
  70         if (occ % scanline)
  71         {
  72                 TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read");
  73                 return (0);
  74         }
  75         for (row = buf; occ > 0; occ -= scanline, row += scanline) {
  76                 n = *bp++, cc--;
  77                 switch (n) {
  78                 case LITERALROW:
  79                         /*
  80                          * The entire scanline is given as literal values.
  81                          */
  82                         if (cc < scanline)
  83                                 goto bad;
  84                         _TIFFmemcpy(row, bp, scanline);
  85                         bp += scanline;
  86                         cc -= scanline;
  87                         break;
  88                 case LITERALSPAN: {
  89                         tmsize_t off;
  90                         /*
  91                          * The scanline has a literal span that begins at some
  92                          * offset.
  93                          */
  94                         off = (bp[0] * 256) + bp[1];
  95                         n = (bp[2] * 256) + bp[3];
  96                         if (cc < 4+n || off+n > scanline)
  97                                 goto bad;
  98                         _TIFFmemcpy(row+off, bp+4, n);
  99                         bp += 4+n;
 100                         cc -= 4+n;
 101                         break;
 102                 }
 103                 default: {
 104                         uint32 npixels = 0, grey;
 105                         uint32 imagewidth = tif->tif_dir.td_imagewidth;
 106
 107                         /*
 108                          * The scanline is composed of a sequence of constant
 109                          * color ``runs''.  We shift into ``run mode'' and
 110                          * interpret bytes as codes of the form
 111                          * <color><npixels> until we've filled the scanline.
 112                          */
 113                         op = row;
 114                         for (;;) {
 115                                 grey = (uint32)((n>>6) & 0x3);
 116                                 n &= 0x3f;
 117                                 /*
 118                                  * Ensure the run does not exceed the scanline
 119                                  * bounds, potentially resulting in a security
 120                                  * issue.
 121                                  */
 122                                 while (n-- > 0 && npixels < imagewidth)
 123                                         SETPIXEL(op, grey);
 124                                 if (npixels >= imagewidth)
 125                                         break;
 126                                 if (cc == 0)
 127                                         goto bad;
 128                                 n = *bp++, cc--;
 129                         }
 130                         break;
 131                 }
 132                 }
 133         }
 134         tif->tif_rawcp = (uint8*) bp;
 135         tif->tif_rawcc = cc;
 136         return (1);
 137 bad:
 138         TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld",
 139             (long) tif->tif_row);
 140         return (0);
 141 }
 142
 143 int
 144 TIFFInitNeXT(TIFF* tif, int scheme)
 145 {
 146         (void) scheme;
 147         tif->tif_decoderow = NeXTDecode;
 148         tif->tif_decodestrip = NeXTDecode;
 149         tif->tif_decodetile = NeXTDecode;
 150         return (1);
 151 }
 152 #endif /* NEXT_SUPPORT */
 153
 154 /* vim: set ts=8 sts=8 sw=8 noet: */
 155 /*
 156  * Local Variables:
 157  * mode: c
 158  * c-basic-offset: 8
 159  * fill-column: 78
 160  * End:
 161  */