tif_swab.c
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上传日期:2014-07-20
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- /* $Id: tif_swab.c,v 1.4 2005/04/13 14:06:21 dron Exp $ */
- /*
- * Copyright (c) 1988-1997 Sam Leffler
- * Copyright (c) 1991-1997 Silicon Graphics, Inc.
- *
- * Permission to use, copy, modify, distribute, and sell this software and
- * its documentation for any purpose is hereby granted without fee, provided
- * that (i) the above copyright notices and this permission notice appear in
- * all copies of the software and related documentation, and (ii) the names of
- * Sam Leffler and Silicon Graphics may not be used in any advertising or
- * publicity relating to the software without the specific, prior written
- * permission of Sam Leffler and Silicon Graphics.
- *
- * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
- * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
- *
- * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
- * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
- * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
- * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
- * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
- * OF THIS SOFTWARE.
- */
- /*
- * TIFF Library Bit & Byte Swapping Support.
- *
- * XXX We assume short = 16-bits and long = 32-bits XXX
- */
- #include "tiffiop.h"
- #ifndef TIFFSwabShort
- void
- TIFFSwabShort(uint16* wp)
- {
- register unsigned char* cp = (unsigned char*) wp;
- unsigned char t;
- t = cp[1]; cp[1] = cp[0]; cp[0] = t;
- }
- #endif
- #ifndef TIFFSwabLong
- void
- TIFFSwabLong(uint32* lp)
- {
- register unsigned char* cp = (unsigned char*) lp;
- unsigned char t;
- t = cp[3]; cp[3] = cp[0]; cp[0] = t;
- t = cp[2]; cp[2] = cp[1]; cp[1] = t;
- }
- #endif
- #ifndef TIFFSwabArrayOfShort
- void
- TIFFSwabArrayOfShort(uint16* wp, register unsigned long n)
- {
- register unsigned char* cp;
- register unsigned char t;
- /* XXX unroll loop some */
- while (n-- > 0) {
- cp = (unsigned char*) wp;
- t = cp[1]; cp[1] = cp[0]; cp[0] = t;
- wp++;
- }
- }
- #endif
- #ifndef TIFFSwabArrayOfTriples
- void
- TIFFSwabArrayOfTriples(uint8* tp, unsigned long n)
- {
- unsigned char* cp;
- unsigned char t;
- /* XXX unroll loop some */
- while (n-- > 0) {
- cp = (unsigned char*) tp;
- t = cp[2]; cp[2] = cp[0]; cp[0] = t;
- tp += 3;
- }
- }
- #endif
- #ifndef TIFFSwabArrayOfLong
- void
- TIFFSwabArrayOfLong(register uint32* lp, register unsigned long n)
- {
- register unsigned char *cp;
- register unsigned char t;
- /* XXX unroll loop some */
- while (n-- > 0) {
- cp = (unsigned char *)lp;
- t = cp[3]; cp[3] = cp[0]; cp[0] = t;
- t = cp[2]; cp[2] = cp[1]; cp[1] = t;
- lp++;
- }
- }
- #endif
- #ifndef TIFFSwabDouble
- void
- TIFFSwabDouble(double *dp)
- {
- register uint32* lp = (uint32*) dp;
- uint32 t;
- TIFFSwabArrayOfLong(lp, 2);
- t = lp[0]; lp[0] = lp[1]; lp[1] = t;
- }
- #endif
- #ifndef TIFFSwabArrayOfDouble
- void
- TIFFSwabArrayOfDouble(double* dp, register unsigned long n)
- {
- register uint32* lp = (uint32*) dp;
- register uint32 t;
- TIFFSwabArrayOfLong(lp, n + n);
- while (n-- > 0) {
- t = lp[0]; lp[0] = lp[1]; lp[1] = t;
- lp += 2;
- }
- }
- #endif
- /*
- * Bit reversal tables. TIFFBitRevTable[<byte>] gives
- * the bit reversed value of <byte>. Used in various
- * places in the library when the FillOrder requires
- * bit reversal of byte values (e.g. CCITT Fax 3
- * encoding/decoding). TIFFNoBitRevTable is provided
- * for algorithms that want an equivalent table that
- * do not reverse bit values.
- */
- static const unsigned char TIFFBitRevTable[256] = {
- 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
- 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
- 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
- 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
- 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
- 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
- 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
- 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
- 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
- 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
- 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
- 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
- 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
- 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
- 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
- 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
- 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
- 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
- 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
- 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
- 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
- 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
- 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
- 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
- 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
- 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
- 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
- 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
- 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
- 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
- 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
- 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
- };
- static const unsigned char TIFFNoBitRevTable[256] = {
- 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
- 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
- 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
- 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
- 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
- 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
- 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
- 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
- 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
- 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
- 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
- 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
- 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
- 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
- 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
- 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
- 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
- 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
- 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
- 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
- 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
- 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
- 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
- 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
- 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
- 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
- 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
- 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
- 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
- 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
- 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
- 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
- };
- const unsigned char*
- TIFFGetBitRevTable(int reversed)
- {
- return (reversed ? TIFFBitRevTable : TIFFNoBitRevTable);
- }
- void
- TIFFReverseBits(register unsigned char* cp, register unsigned long n)
- {
- for (; n > 8; n -= 8) {
- cp[0] = TIFFBitRevTable[cp[0]];
- cp[1] = TIFFBitRevTable[cp[1]];
- cp[2] = TIFFBitRevTable[cp[2]];
- cp[3] = TIFFBitRevTable[cp[3]];
- cp[4] = TIFFBitRevTable[cp[4]];
- cp[5] = TIFFBitRevTable[cp[5]];
- cp[6] = TIFFBitRevTable[cp[6]];
- cp[7] = TIFFBitRevTable[cp[7]];
- cp += 8;
- }
- while (n-- > 0)
- *cp = TIFFBitRevTable[*cp], cp++;
- }
- /* vim: set ts=8 sts=8 sw=8 noet: */