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1 | /* $Header$ */ |
2 | ||
3 | /* | |
4 | * Copyright (c) 1988-1997 Sam Leffler | |
5 | * Copyright (c) 1991-1997 Silicon Graphics, Inc. | |
6 | * | |
615a9936 | 7 | * Permission to use, copy, modify, distribute, and sell this software and |
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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. | |
615a9936 DW |
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 | * | |
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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, | |
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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 | |
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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] = (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 | ||
615a9936 | 48 | static int LINKAGEMODE |
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49 | NeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s) |
50 | { | |
51 | register u_char *bp, *op; | |
52 | register tsize_t cc; | |
53 | register int n; | |
54 | tidata_t row; | |
55 | tsize_t scanline; | |
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 | */ | |
63 | for (op = buf, cc = occ; cc-- > 0;) | |
64 | *op++ = 0xff; | |
65 | ||
66 | bp = (u_char *)tif->tif_rawcp; | |
67 | cc = tif->tif_rawcc; | |
68 | scanline = tif->tif_scanlinesize; | |
69 | for (row = buf; (long)occ > 0; occ -= scanline, row += scanline) { | |
70 | n = *bp++, cc--; | |
71 | switch (n) { | |
72 | case LITERALROW: | |
73 | /* | |
74 | * The entire scanline is given as literal values. | |
75 | */ | |
76 | if (cc < scanline) | |
77 | goto bad; | |
78 | _TIFFmemcpy(row, bp, scanline); | |
79 | bp += scanline; | |
80 | cc -= scanline; | |
81 | break; | |
82 | case LITERALSPAN: { | |
83 | int off; | |
84 | /* | |
85 | * The scanline has a literal span | |
86 | * that begins at some offset. | |
87 | */ | |
88 | off = (bp[0] * 256) + bp[1]; | |
89 | n = (bp[2] * 256) + bp[3]; | |
90 | if (cc < 4+n) | |
91 | goto bad; | |
92 | _TIFFmemcpy(row+off, bp+4, n); | |
93 | bp += 4+n; | |
94 | cc -= 4+n; | |
95 | break; | |
96 | } | |
97 | default: { | |
98 | register int npixels = 0, grey; | |
99 | u_long imagewidth = tif->tif_dir.td_imagewidth; | |
100 | ||
101 | /* | |
102 | * The scanline is composed of a sequence | |
103 | * of constant color ``runs''. We shift | |
104 | * into ``run mode'' and interpret bytes | |
105 | * as codes of the form <color><npixels> | |
106 | * until we've filled the scanline. | |
107 | */ | |
108 | op = row; | |
109 | for (;;) { | |
110 | grey = (n>>6) & 0x3; | |
111 | n &= 0x3f; | |
112 | while (n-- > 0) | |
113 | SETPIXEL(op, grey); | |
114 | if (npixels >= imagewidth) | |
115 | break; | |
116 | if (cc == 0) | |
117 | goto bad; | |
118 | n = *bp++, cc--; | |
119 | } | |
120 | break; | |
121 | } | |
122 | } | |
123 | } | |
124 | tif->tif_rawcp = (tidata_t) bp; | |
125 | tif->tif_rawcc = cc; | |
126 | return (1); | |
127 | bad: | |
128 | TIFFError(tif->tif_name, "NeXTDecode: Not enough data for scanline %ld", | |
129 | (long) tif->tif_row); | |
130 | return (0); | |
131 | } | |
132 | ||
133 | int | |
134 | TIFFInitNeXT(TIFF* tif, int scheme) | |
135 | { | |
136 | (void) scheme; | |
137 | tif->tif_decoderow = NeXTDecode; | |
138 | tif->tif_decodestrip = NeXTDecode; | |
139 | tif->tif_decodetile = NeXTDecode; | |
140 | return (1); | |
141 | } | |
142 | #endif /* NEXT_SUPPORT */ |