root/3rdparty/libtiff/tif_swab.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. TIFFSwabShort
  2. TIFFSwabLong
  3. TIFFSwabLong8
  4. TIFFSwabArrayOfShort
  5. TIFFSwabArrayOfTriples
  6. TIFFSwabArrayOfLong
  7. TIFFSwabArrayOfLong8
  8. TIFFSwabFloat
  9. TIFFSwabArrayOfFloat
  10. TIFFSwabDouble
  11. TIFFSwabArrayOfDouble
  12. TIFFGetBitRevTable
  13. TIFFReverseBits

/* $Id: tif_swab.c,v 1.13 2010-03-10 18:56:49 bfriesen 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;
    assert(sizeof(uint16)==2);
    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;
    assert(sizeof(uint32)==4);
    t = cp[3]; cp[3] = cp[0]; cp[0] = t;
    t = cp[2]; cp[2] = cp[1]; cp[1] = t;
}
#endif

#ifndef TIFFSwabLong8
void
TIFFSwabLong8(uint64* lp)
{
    register unsigned char* cp = (unsigned char*) lp;
    unsigned char t;
    assert(sizeof(uint64)==8);
    t = cp[7]; cp[7] = cp[0]; cp[0] = t;
    t = cp[6]; cp[6] = cp[1]; cp[1] = t;
    t = cp[5]; cp[5] = cp[2]; cp[2] = t;
    t = cp[4]; cp[4] = cp[3]; cp[3] = t;
}
#endif

#ifndef TIFFSwabArrayOfShort
void
TIFFSwabArrayOfShort(register uint16* wp, tmsize_t n)
{
    register unsigned char* cp;
    register unsigned char t;
    assert(sizeof(uint16)==2);
    /* 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(register uint8* tp, tmsize_t 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, tmsize_t n)
{
    register unsigned char *cp;
    register unsigned char t;
    assert(sizeof(uint32)==4);
    /* 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 TIFFSwabArrayOfLong8
void
TIFFSwabArrayOfLong8(register uint64* lp, tmsize_t n)
{
    register unsigned char *cp;
    register unsigned char t;
    assert(sizeof(uint64)==8);
    /* XXX unroll loop some */
    while (n-- > 0) {
        cp = (unsigned char *)lp;
        t = cp[7]; cp[7] = cp[0]; cp[0] = t;
        t = cp[6]; cp[6] = cp[1]; cp[1] = t;
        t = cp[5]; cp[5] = cp[2]; cp[2] = t;
        t = cp[4]; cp[4] = cp[3]; cp[3] = t;
        lp++;
    }
}
#endif

#ifndef TIFFSwabFloat
void
TIFFSwabFloat(float* fp)
{
    register unsigned char* cp = (unsigned char*) fp;
    unsigned char t;
    assert(sizeof(float)==4);
    t = cp[3]; cp[3] = cp[0]; cp[0] = t;
    t = cp[2]; cp[2] = cp[1]; cp[1] = t;
}
#endif

#ifndef TIFFSwabArrayOfFloat
void
TIFFSwabArrayOfFloat(register float* fp, tmsize_t n)
{
    register unsigned char *cp;
    register unsigned char t;
    assert(sizeof(float)==4);
    /* XXX unroll loop some */
    while (n-- > 0) {
        cp = (unsigned char *)fp;
        t = cp[3]; cp[3] = cp[0]; cp[0] = t;
        t = cp[2]; cp[2] = cp[1]; cp[1] = t;
        fp++;
    }
}
#endif

#ifndef TIFFSwabDouble
void
TIFFSwabDouble(double *dp)
{
    register unsigned char* cp = (unsigned char*) dp;
    unsigned char t;
    assert(sizeof(double)==8);
    t = cp[7]; cp[7] = cp[0]; cp[0] = t;
    t = cp[6]; cp[6] = cp[1]; cp[1] = t;
    t = cp[5]; cp[5] = cp[2]; cp[2] = t;
    t = cp[4]; cp[4] = cp[3]; cp[3] = t;
}
#endif

#ifndef TIFFSwabArrayOfDouble
void
TIFFSwabArrayOfDouble(double* dp, tmsize_t n)
{
    register unsigned char *cp;
    register unsigned char t;
    assert(sizeof(double)==8);
    /* XXX unroll loop some */
    while (n-- > 0) {
        cp = (unsigned char *)dp;
        t = cp[7]; cp[7] = cp[0]; cp[0] = t;
        t = cp[6]; cp[6] = cp[1]; cp[1] = t;
        t = cp[5]; cp[5] = cp[2]; cp[2] = t;
        t = cp[4]; cp[4] = cp[3]; cp[3] = t;
        dp++;
    }
}
#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(uint8* cp, tmsize_t 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: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */

/* [<][>][^][v][top][bottom][index][help] */