| 1 | /* $Header$ */ |
| 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] = (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 LINKAGEMODE |
| 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 */ |