1 /* PDFlib GmbH cvsid: $Id: tif_next.c,v 1.11 2005/12/21 14:12:52 rjs 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,tidata_t buf,tsize_t occ,tsample_t s)49 NeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
50 {
51 register unsigned 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 = (unsigned 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 || off+n > scanline)
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 unsigned 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 >= (int) 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->tif_name,
129 "NeXTDecode: Not enough data for scanline %ld",
130 (long) tif->tif_row);
131 return (0);
132 }
133
134 int
TIFFInitNeXT(TIFF * tif,int scheme)135 TIFFInitNeXT(TIFF* tif, int scheme)
136 {
137 (void) scheme;
138 tif->tif_decoderow = NeXTDecode;
139 tif->tif_decodestrip = NeXTDecode;
140 tif->tif_decodetile = NeXTDecode;
141 return (1);
142 }
143 #endif /* NEXT_SUPPORT */
144
145 /* vim: set ts=8 sts=8 sw=8 noet: */
146