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