blob: 524e127c13dcbb17b149f5a77b1532959e9ba9c0
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 "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, uint8* buf, tmsize_t occ, uint16 s) |
50 | { |
51 | static const char module[] = "NeXTDecode"; |
52 | unsigned char *bp, *op; |
53 | tmsize_t cc; |
54 | uint8* row; |
55 | tmsize_t scanline, n; |
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 = (unsigned char*) buf, cc = occ; cc-- > 0;) |
64 | *op++ = 0xff; |
65 | |
66 | bp = (unsigned char *)tif->tif_rawcp; |
67 | cc = tif->tif_rawcc; |
68 | scanline = tif->tif_scanlinesize; |
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) { |
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: { |
88 | tmsize_t off; |
89 | /* |
90 | * The scanline has a literal span that begins at some |
91 | * offset. |
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: { |
103 | uint32 npixels = 0, grey; |
104 | uint32 imagewidth = tif->tif_dir.td_imagewidth; |
105 | |
106 | /* |
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. |
111 | */ |
112 | op = row; |
113 | for (;;) { |
114 | grey = (uint32)((n>>6) & 0x3); |
115 | n &= 0x3f; |
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) |
122 | SETPIXEL(op, grey); |
123 | if (npixels >= imagewidth) |
124 | break; |
125 | if (cc == 0) |
126 | goto bad; |
127 | n = *bp++, cc--; |
128 | } |
129 | break; |
130 | } |
131 | } |
132 | } |
133 | tif->tif_rawcp = (uint8*) bp; |
134 | tif->tif_rawcc = cc; |
135 | return (1); |
136 | bad: |
137 | TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld", |
138 | (long) tif->tif_row); |
139 | return (0); |
140 | } |
141 | |
142 | int |
143 | TIFFInitNeXT(TIFF* tif, int scheme) |
144 | { |
145 | (void) scheme; |
146 | tif->tif_decoderow = NeXTDecode; |
147 | tif->tif_decodestrip = NeXTDecode; |
148 | tif->tif_decodetile = NeXTDecode; |
149 | return (1); |
150 | } |
151 | #endif /* NEXT_SUPPORT */ |
152 | |
153 | /* vim: set ts=8 sts=8 sw=8 noet: */ |
154 | /* |
155 | * Local Variables: |
156 | * mode: c |
157 | * c-basic-offset: 8 |
158 | * fill-column: 78 |
159 | * End: |
160 | */ |
161 |