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
NeXTDecode(TIFF * tif,uint8 * buf,tmsize_t occ,uint16 s)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
TIFFInitNeXT(TIFF * tif,int scheme)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