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/*
* The Progressive Graphics File; http://www.libpgf.org
*
* $Date: 2006-06-04 22:05:59 +0200 (So, 04 Jun 2006) $
* $Revision: 229 $
*
* This file Copyright (C) 2006 xeraina GmbH, Switzerland
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU LESSER GENERAL PUBLIC LICENSE
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//////////////////////////////////////////////////////////////////////
/// @file Bitstream.h
/// @brief PGF bit-stream operations
/// @author C. Stamm
#ifndef PGF_BITSTREAM_H
#define PGF_BITSTREAM_H
#include "PGFtypes.h"
//////////////////////////////////////////////////////////////////////
// constants
//static const WordWidth = 32;
//static const WordWidthLog = 5;
static const UINT32 Filled = 0xFFFFFFFF;
/// @brief Make 64 bit unsigned integer from two 32 bit unsigned integers
#define MAKEU64(a, b) ((UINT64) (((UINT32) (a)) | ((UINT64) ((UINT32) (b))) << 32))
/*
static UINT8 lMask[] = {
0x00, // 00000000
0x80, // 10000000
0xc0, // 11000000
0xe0, // 11100000
0xf0, // 11110000
0xf8, // 11111000
0xfc, // 11111100
0xfe, // 11111110
0xff, // 11111111
};
*/
// these procedures have to be inlined because of performance reasons
//////////////////////////////////////////////////////////////////////
/// Set one bit of a bit stream to 1
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
inline void SetBit(UINT32* stream, UINT32 pos) {
stream[pos >> WordWidthLog] |= (1 << (pos%WordWidth));
}
//////////////////////////////////////////////////////////////////////
/// Set one bit of a bit stream to 0
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
inline void ClearBit(UINT32* stream, UINT32 pos) {
stream[pos >> WordWidthLog] &= ~(1 << (pos%WordWidth));
}
//////////////////////////////////////////////////////////////////////
/// Return one bit of a bit stream
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @return bit at position pos of bit stream stream
inline bool GetBit(UINT32* stream, UINT32 pos) {
return (stream[pos >> WordWidthLog] & (1 << (pos%WordWidth))) > 0;
}
//////////////////////////////////////////////////////////////////////
/// Compare k-bit binary representation of stream at position pos with val
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param k Number of bits to compare
/// @param val Value to compare with
/// @return true if equal
inline bool CompareBitBlock(UINT32* stream, UINT32 pos, UINT32 k, UINT32 val) {
const UINT32 iLoInt = pos >> WordWidthLog;
const UINT32 iHiInt = (pos + k - 1) >> WordWidthLog;
ASSERT(iLoInt <= iHiInt);
const UINT32 mask = (Filled >> (WordWidth - k));
if (iLoInt == iHiInt) {
// fits into one integer
val &= mask;
val <<= (pos%WordWidth);
return (stream[iLoInt] & val) == val;
} else {
// must be splitted over integer boundary
UINT64 v1 = MAKEU64(stream[iLoInt], stream[iHiInt]);
UINT64 v2 = UINT64(val & mask) << (pos%WordWidth);
return (v1 & v2) == v2;
}
}
//////////////////////////////////////////////////////////////////////
/// Store k-bit binary representation of val in stream at position pos
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param val Value to store in stream at position pos
/// @param k Number of bits of integer representation of val
inline void SetValueBlock(UINT32* stream, UINT32 pos, UINT32 val, UINT32 k) {
const UINT32 offset = pos%WordWidth;
const UINT32 iLoInt = pos >> WordWidthLog;
const UINT32 iHiInt = (pos + k - 1) >> WordWidthLog;
ASSERT(iLoInt <= iHiInt);
const UINT32 loMask = Filled << offset;
const UINT32 hiMask = Filled >> (WordWidth - 1 - ((pos + k - 1)%WordWidth));
if (iLoInt == iHiInt) {
// fits into one integer
stream[iLoInt] &= ~(loMask & hiMask); // clear bits
stream[iLoInt] |= val << offset; // write value
} else {
// must be splitted over integer boundary
stream[iLoInt] &= ~loMask; // clear bits
stream[iLoInt] |= val << offset; // write lower part of value
stream[iHiInt] &= ~hiMask; // clear bits
stream[iHiInt] |= val >> (WordWidth - offset); // write higher part of value
}
}
//////////////////////////////////////////////////////////////////////
/// Read k-bit number from stream at position pos
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param k Number of bits to read: 1 <= k <= 32
inline UINT32 GetValueBlock(UINT32* stream, UINT32 pos, UINT32 k) {
UINT32 count, hiCount;
const UINT32 iLoInt = pos >> WordWidthLog; // integer of first bit
const UINT32 iHiInt = (pos + k - 1) >> WordWidthLog; // integer of last bit
const UINT32 loMask = Filled << (pos%WordWidth);
const UINT32 hiMask = Filled >> (WordWidth - 1 - ((pos + k - 1)%WordWidth));
if (iLoInt == iHiInt) {
// inside integer boundary
count = stream[iLoInt] & (loMask & hiMask);
count >>= pos%WordWidth;
} else {
// overlapping integer boundary
count = stream[iLoInt] & loMask;
count >>= pos%WordWidth;
hiCount = stream[iHiInt] & hiMask;
hiCount <<= WordWidth - (pos%WordWidth);
count |= hiCount;
}
return count;
}
//////////////////////////////////////////////////////////////////////
/// Clear block of size at least len at position pos in stream
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param len Number of bits set to 0
inline void ClearBitBlock(UINT32* stream, UINT32 pos, UINT32 len) {
ASSERT(len > 0);
const UINT32 iFirstInt = pos >> WordWidthLog;
const UINT32 iLastInt = (pos + len - 1) >> WordWidthLog;
const UINT32 startMask = Filled << (pos%WordWidth);
// const UINT32 endMask=Filled>>(WordWidth-1-((pos+len-1)%WordWidth));
if (iFirstInt == iLastInt) {
stream[iFirstInt] &= ~(startMask /*& endMask*/);
} else {
stream[iFirstInt] &= ~startMask;
for (UINT32 i = iFirstInt + 1; i <= iLastInt; i++) { // changed <=
stream[i] = 0;
}
//stream[iLastInt] &= ~endMask;
}
}
//////////////////////////////////////////////////////////////////////
/// Set block of size at least len at position pos in stream
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param len Number of bits set to 1
inline void SetBitBlock(UINT32* stream, UINT32 pos, UINT32 len) {
ASSERT(len > 0);
const UINT32 iFirstInt = pos >> WordWidthLog;
const UINT32 iLastInt = (pos + len - 1) >> WordWidthLog;
const UINT32 startMask = Filled << (pos%WordWidth);
// const UINT32 endMask=Filled>>(WordWidth-1-((pos+len-1)%WordWidth));
if (iFirstInt == iLastInt) {
stream[iFirstInt] |= (startMask /*& endMask*/);
} else {
stream[iFirstInt] |= startMask;
for (UINT32 i = iFirstInt + 1; i <= iLastInt; i++) { // changed <=
stream[i] = Filled;
}
//stream[iLastInt] &= ~endMask;
}
}
//////////////////////////////////////////////////////////////////////
/// Returns the distance to the next 1 in stream at position pos.
/// If no 1 is found within len bits, then len is returned.
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param len size of search area (in bits)
/// return The distance to the next 1 in stream at position pos
inline UINT32 SeekBitRange(UINT32* stream, UINT32 pos, UINT32 len) {
UINT32 count = 0;
UINT32 testMask = 1 << (pos%WordWidth);
UINT32* word = stream + (pos >> WordWidthLog);
while (((*word & testMask) == 0) && (count < len)) {
count++;
testMask <<= 1;
if (!testMask) {
word++; testMask = 1;
// fast steps if all bits in a word are zero
while ((count + WordWidth <= len) && (*word == 0)) {
word++;
count += WordWidth;
}
}
}
return count;
}
//////////////////////////////////////////////////////////////////////
/// Returns the distance to the next 0 in stream at position pos.
/// If no 0 is found within len bits, then len is returned.
/// @param stream A bit stream stored in array of unsigned integers
/// @param pos A valid zero-based position in the bit stream
/// @param len size of search area (in bits)
/// return The distance to the next 0 in stream at position pos
inline UINT32 SeekBit1Range(UINT32* stream, UINT32 pos, UINT32 len) {
UINT32 count = 0;
UINT32 testMask = 1 << (pos%WordWidth);
UINT32* word = stream + (pos >> WordWidthLog);
while (((*word & testMask) != 0) && (count < len)) {
count++;
testMask <<= 1;
if (!testMask) {
word++; testMask = 1;
// fast steps if all bits in a word are one
while ((count + WordWidth <= len) && (*word == Filled)) {
word++;
count += WordWidth;
}
}
}
return count;
}
/*
//////////////////////////////////////////////////////////////////////
/// BitCopy: copies k bits from source to destination
/// Note: only 8 bits are copied at a time, if speed is an issue, a more
/// complicated but faster 64 bit algorithm should be used.
inline void BitCopy(const UINT8 *sStream, UINT32 sPos, UINT8 *dStream, UINT32 dPos, UINT32 k) {
ASSERT(k > 0);
div_t divS = div(sPos, 8);
div_t divD = div(dPos, 8);
UINT32 sOff = divS.rem;
UINT32 dOff = divD.rem;
INT32 tmp = div(dPos + k - 1, 8).quot;
const UINT8 *sAddr = sStream + divS.quot;
UINT8 *dAddrS = dStream + divD.quot;
UINT8 *dAddrE = dStream + tmp;
UINT8 eMask;
UINT8 destSB = *dAddrS;
UINT8 destEB = *dAddrE;
UINT8 *dAddr;
UINT8 prec;
INT32 shiftl, shiftr;
if (dOff > sOff) {
prec = 0;
shiftr = dOff - sOff;
shiftl = 8 - dOff + sOff;
} else {
prec = *sAddr << (sOff - dOff);
shiftr = 8 - sOff + dOff;
shiftl = sOff - dOff;
sAddr++;
}
for (dAddr = dAddrS; dAddr < dAddrE; dAddr++, sAddr++) {
*dAddr = prec | (*sAddr >> shiftr);
prec = *sAddr << shiftl;
}
if ((sPos + k)%8 == 0) {
*dAddr = prec;
} else {
*dAddr = prec | (*sAddr >> shiftr);
}
eMask = lMask[dOff];
*dAddrS = (destSB & eMask) | (*dAddrS & (~eMask));
INT32 mind = (dPos + k) % 8;
eMask = (mind) ? lMask[mind] : lMask[8];
*dAddrE = (destEB & (~eMask)) | (*dAddrE & eMask);
}
*/
//////////////////////////////////////////////////////////////////////
/// Compute bit position of the next 32-bit word
/// @param pos current bit stream position
/// @return bit position of next 32-bit word
inline UINT32 AlignWordPos(UINT32 pos) {
// return ((pos + WordWidth - 1) >> WordWidthLog) << WordWidthLog;
return DWWIDTHBITS(pos);
}
//////////////////////////////////////////////////////////////////////
/// Compute number of the 32-bit words
/// @param pos Current bit stream position
/// @return Number of 32-bit words
inline UINT32 NumberOfWords(UINT32 pos) {
return (pos + WordWidth - 1) >> WordWidthLog;
}
#endif //PGF_BITSTREAM_H