/src/FreeImage/Source/LibTIFF/tif_swab.c

  1/* $Id: tif_swab.c,v 1.37 2011/04/10 17:14:09 drolon 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/*
 28 * TIFF Library Bit & Byte Swapping Support.
 29 *
 30 * XXX We assume short = 16-bits and long = 32-bits XXX
 31 */
 32#include "tiffiop.h"
 33
 34#ifndef TIFFSwabShort
 35void
 36TIFFSwabShort(uint16* wp)
 37{
 38	register unsigned char* cp = (unsigned char*) wp;
 39	unsigned char t;
 40
 41	t = cp[1]; cp[1] = cp[0]; cp[0] = t;
 42}
 43#endif
 44
 45#ifndef TIFFSwabLong
 46void
 47TIFFSwabLong(uint32* lp)
 48{
 49	register unsigned char* cp = (unsigned char*) lp;
 50	unsigned char t;
 51
 52	t = cp[3]; cp[3] = cp[0]; cp[0] = t;
 53	t = cp[2]; cp[2] = cp[1]; cp[1] = t;
 54}
 55#endif
 56
 57#ifndef TIFFSwabArrayOfShort
 58void
 59TIFFSwabArrayOfShort(uint16* wp, register unsigned long n)
 60{
 61	register unsigned char* cp;
 62	register unsigned char t;
 63
 64	/* XXX unroll loop some */
 65	while (n-- > 0) {
 66		cp = (unsigned char*) wp;
 67		t = cp[1]; cp[1] = cp[0]; cp[0] = t;
 68		wp++;
 69	}
 70}
 71#endif
 72
 73#ifndef TIFFSwabArrayOfTriples
 74void
 75TIFFSwabArrayOfTriples(uint8* tp, unsigned long n)
 76{
 77	unsigned char* cp;
 78	unsigned char t;
 79
 80	/* XXX unroll loop some */
 81	while (n-- > 0) {
 82		cp = (unsigned char*) tp;
 83		t = cp[2]; cp[2] = cp[0]; cp[0] = t;
 84		tp += 3;
 85	}
 86}
 87#endif
 88
 89#ifndef TIFFSwabArrayOfLong
 90void
 91TIFFSwabArrayOfLong(register uint32* lp, register unsigned long n)
 92{
 93	register unsigned char *cp;
 94	register unsigned char t;
 95
 96	/* XXX unroll loop some */
 97	while (n-- > 0) {
 98		cp = (unsigned char *)lp;
 99		t = cp[3]; cp[3] = cp[0]; cp[0] = t;
100		t = cp[2]; cp[2] = cp[1]; cp[1] = t;
101		lp++;
102	}
103}
104#endif
105
106#ifndef TIFFSwabDouble
107void
108TIFFSwabDouble(double *dp)
109{
110        register uint32* lp = (uint32*) dp;
111        uint32 t;
112
113	TIFFSwabArrayOfLong(lp, 2);
114	t = lp[0]; lp[0] = lp[1]; lp[1] = t;
115}
116#endif
117
118#ifndef TIFFSwabArrayOfDouble
119void
120TIFFSwabArrayOfDouble(double* dp, register unsigned long n)
121{
122	register uint32* lp = (uint32*) dp;
123        register uint32 t;
124
125	TIFFSwabArrayOfLong(lp, n + n);
126        while (n-- > 0) {
127		t = lp[0]; lp[0] = lp[1]; lp[1] = t;
128                lp += 2;
129        }
130}
131#endif
132
133/*
134 * Bit reversal tables.  TIFFBitRevTable[<byte>] gives
135 * the bit reversed value of <byte>.  Used in various
136 * places in the library when the FillOrder requires
137 * bit reversal of byte values (e.g. CCITT Fax 3
138 * encoding/decoding).  TIFFNoBitRevTable is provided
139 * for algorithms that want an equivalent table that
140 * do not reverse bit values.
141 */
142static const unsigned char TIFFBitRevTable[256] = {
143    0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
144    0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
145    0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
146    0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
147    0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
148    0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
149    0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
150    0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
151    0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
152    0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
153    0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
154    0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
155    0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
156    0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
157    0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
158    0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
159    0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
160    0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
161    0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
162    0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
163    0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
164    0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
165    0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
166    0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
167    0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
168    0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
169    0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
170    0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
171    0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
172    0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
173    0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
174    0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
175};
176static const unsigned char TIFFNoBitRevTable[256] = {
177    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
178    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 
179    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 
180    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 
181    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 
182    0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 
183    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 
184    0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 
185    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 
186    0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 
187    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 
188    0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 
189    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 
190    0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 
191    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 
192    0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 
193    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 
194    0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 
195    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 
196    0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 
197    0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 
198    0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 
199    0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 
200    0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 
201    0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 
202    0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 
203    0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 
204    0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 
205    0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 
206    0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 
207    0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 
208    0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, 
209};
210
211const unsigned char*
212TIFFGetBitRevTable(int reversed)
213{
214	return (reversed ? TIFFBitRevTable : TIFFNoBitRevTable);
215}
216
217void
218TIFFReverseBits(register unsigned char* cp, register unsigned long n)
219{
220	for (; n > 8; n -= 8) {
221		cp[0] = TIFFBitRevTable[cp[0]];
222		cp[1] = TIFFBitRevTable[cp[1]];
223		cp[2] = TIFFBitRevTable[cp[2]];
224		cp[3] = TIFFBitRevTable[cp[3]];
225		cp[4] = TIFFBitRevTable[cp[4]];
226		cp[5] = TIFFBitRevTable[cp[5]];
227		cp[6] = TIFFBitRevTable[cp[6]];
228		cp[7] = TIFFBitRevTable[cp[7]];
229		cp += 8;
230	}
231	while (n-- > 0)
232		*cp = TIFFBitRevTable[*cp], cp++;
233}
234
235/* vim: set ts=8 sts=8 sw=8 noet: */
236/*
237 * Local Variables:
238 * mode: c
239 * c-basic-offset: 8
240 * fill-column: 78
241 * End:
242 */