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8414a40c VZ |
1 | /* $Id$ */ |
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 | |
80ed523f | 49 | NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) |
8414a40c | 50 | { |
80ed523f VZ |
51 | static const char module[] = "NeXTDecode"; |
52 | unsigned char *bp, *op; | |
53 | tmsize_t cc; | |
54 | uint8* row; | |
55 | tmsize_t scanline, n; | |
8414a40c VZ |
56 | |
57 | (void) s; | |
58 | /* | |
59 | * Each scanline is assumed to start off as all | |
60 | * white (we assume a PhotometricInterpretation | |
61 | * of ``min-is-black''). | |
62 | */ | |
80ed523f | 63 | for (op = (unsigned char*) buf, cc = occ; cc-- > 0;) |
8414a40c VZ |
64 | *op++ = 0xff; |
65 | ||
66 | bp = (unsigned char *)tif->tif_rawcp; | |
67 | cc = tif->tif_rawcc; | |
68 | scanline = tif->tif_scanlinesize; | |
80ed523f VZ |
69 | if (occ % scanline) |
70 | { | |
71 | TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read"); | |
72 | return (0); | |
73 | } | |
74 | for (row = buf; occ > 0; occ -= scanline, row += scanline) { | |
8414a40c VZ |
75 | n = *bp++, cc--; |
76 | switch (n) { | |
77 | case LITERALROW: | |
78 | /* | |
79 | * The entire scanline is given as literal values. | |
80 | */ | |
81 | if (cc < scanline) | |
82 | goto bad; | |
83 | _TIFFmemcpy(row, bp, scanline); | |
84 | bp += scanline; | |
85 | cc -= scanline; | |
86 | break; | |
87 | case LITERALSPAN: { | |
80ed523f | 88 | tmsize_t off; |
8414a40c | 89 | /* |
80ed523f VZ |
90 | * The scanline has a literal span that begins at some |
91 | * offset. | |
8414a40c VZ |
92 | */ |
93 | off = (bp[0] * 256) + bp[1]; | |
94 | n = (bp[2] * 256) + bp[3]; | |
95 | if (cc < 4+n || off+n > scanline) | |
96 | goto bad; | |
97 | _TIFFmemcpy(row+off, bp+4, n); | |
98 | bp += 4+n; | |
99 | cc -= 4+n; | |
100 | break; | |
101 | } | |
102 | default: { | |
80ed523f VZ |
103 | uint32 npixels = 0, grey; |
104 | uint32 imagewidth = tif->tif_dir.td_imagewidth; | |
8414a40c VZ |
105 | |
106 | /* | |
80ed523f VZ |
107 | * The scanline is composed of a sequence of constant |
108 | * color ``runs''. We shift into ``run mode'' and | |
109 | * interpret bytes as codes of the form | |
110 | * <color><npixels> until we've filled the scanline. | |
8414a40c VZ |
111 | */ |
112 | op = row; | |
113 | for (;;) { | |
80ed523f | 114 | grey = (uint32)((n>>6) & 0x3); |
8414a40c | 115 | n &= 0x3f; |
80ed523f VZ |
116 | /* |
117 | * Ensure the run does not exceed the scanline | |
118 | * bounds, potentially resulting in a security | |
119 | * issue. | |
120 | */ | |
121 | while (n-- > 0 && npixels < imagewidth) | |
8414a40c | 122 | SETPIXEL(op, grey); |
80ed523f | 123 | if (npixels >= imagewidth) |
8414a40c VZ |
124 | break; |
125 | if (cc == 0) | |
126 | goto bad; | |
127 | n = *bp++, cc--; | |
128 | } | |
129 | break; | |
130 | } | |
131 | } | |
132 | } | |
80ed523f | 133 | tif->tif_rawcp = (uint8*) bp; |
8414a40c VZ |
134 | tif->tif_rawcc = cc; |
135 | return (1); | |
136 | bad: | |
80ed523f | 137 | TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld", |
8414a40c VZ |
138 | (long) tif->tif_row); |
139 | return (0); | |
140 | } | |
141 | ||
142 | int | |
143 | TIFFInitNeXT(TIFF* tif, int scheme) | |
144 | { | |
145 | (void) scheme; | |
80ed523f VZ |
146 | tif->tif_decoderow = NeXTDecode; |
147 | tif->tif_decodestrip = NeXTDecode; | |
8414a40c VZ |
148 | tif->tif_decodetile = NeXTDecode; |
149 | return (1); | |
150 | } | |
151 | #endif /* NEXT_SUPPORT */ | |
152 | ||
153 | /* vim: set ts=8 sts=8 sw=8 noet: */ | |
80ed523f VZ |
154 | /* |
155 | * Local Variables: | |
156 | * mode: c | |
157 | * c-basic-offset: 8 | |
158 | * fill-column: 78 | |
159 | * End: | |
160 | */ |