doom3-bfg/neo/sys/LightweightCompression.cpp
Daniel Gibson d949bc9410 Fix compiler warnings and errors in MinGW
many of the warnings -Wreorder and #includes with invalid path because of
case-errors (windows may not care, but linux does)
2012-12-03 09:29:14 +01:00

571 lines
No EOL
12 KiB
C++

/*
===========================================================================
Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").
Doom 3 BFG Edition Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 BFG Edition Source Code 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 Doom 3 BFG Edition Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#pragma hdrstop
#include "../idlib/precompiled.h"
#include "LightweightCompression.h"
/*
========================
HashIndex
========================
*/
static int HashIndex( int w, int k )
{
return ( w ^ k ) & idLZWCompressor::HASH_MASK;
}
/*
========================
idLZWCompressor::Start
========================
*/
void idLZWCompressor::Start( uint8* data_, int maxSize_, bool append )
{
// Clear hash
ClearHash();
if( append )
{
assert( lzwData->nextCode > LZW_FIRST_CODE );
int originalNextCode = lzwData->nextCode;
lzwData->nextCode = LZW_FIRST_CODE;
// If we are appending, then fill up the hash
for( int i = LZW_FIRST_CODE; i < originalNextCode; i++ )
{
AddToDict( lzwData->dictionaryW[i], lzwData->dictionaryK[i] );
}
assert( originalNextCode == lzwData->nextCode );
}
else
{
for( int i = 0; i < LZW_FIRST_CODE; i++ )
{
lzwData->dictionaryK[i] = ( uint8 )i;
lzwData->dictionaryW[i] = 0xFFFF;
}
lzwData->nextCode = LZW_FIRST_CODE;
lzwData->codeBits = LZW_START_BITS;
lzwData->codeWord = -1;
lzwData->tempValue = 0;
lzwData->tempBits = 0;
lzwData->bytesWritten = 0;
}
oldCode = -1; // Used by DecompressBlock
data = data_;
blockSize = 0;
blockIndex = 0;
bytesRead = 0;
maxSize = maxSize_;
overflowed = false;
savedBytesWritten = 0;
savedCodeWord = 0;
saveCodeBits = 0;
savedTempValue = 0;
savedTempBits = 0;
}
/*
========================
idLZWCompressor::ReadBits
========================
*/
int idLZWCompressor::ReadBits( int bits )
{
int bitsToRead = bits - lzwData->tempBits;
while( bitsToRead > 0 )
{
if( bytesRead >= maxSize )
{
return -1;
}
lzwData->tempValue |= ( uint64 )data[bytesRead++] << lzwData->tempBits;
lzwData->tempBits += 8;
bitsToRead -= 8;
}
int value = ( int )lzwData->tempValue & ( ( 1 << bits ) - 1 );
lzwData->tempValue >>= bits;
lzwData->tempBits -= bits;
return value;
}
/*
========================
idLZWCompressor::WriteBits
========================
*/
void idLZWCompressor::WriteBits( uint32 value, int bits )
{
// Queue up bits into temp value
lzwData->tempValue |= ( uint64 )value << lzwData->tempBits;
lzwData->tempBits += bits;
// Flush 8 bits (1 byte) at a time ( leftovers will get caught in idLZWCompressor::End() )
while( lzwData->tempBits >= 8 )
{
if( lzwData->bytesWritten >= maxSize )
{
overflowed = true;
return;
}
data[lzwData->bytesWritten++] = ( uint8 )( lzwData->tempValue & 255 );
lzwData->tempValue >>= 8;
lzwData->tempBits -= 8;
}
}
/*
========================
idLZWCompressor::WriteChain
The chain is stored backwards, so we have to write it to a buffer then output the buffer in
reverse.
========================
*/
int idLZWCompressor::WriteChain( int code )
{
byte chain[lzwCompressionData_t::LZW_DICT_SIZE];
int firstChar = 0;
int i = 0;
do
{
assert( i < lzwCompressionData_t::LZW_DICT_SIZE && code < lzwCompressionData_t::LZW_DICT_SIZE && code >= 0 );
chain[i++] = ( byte )lzwData->dictionaryK[code];
code = lzwData->dictionaryW[code];
}
while( code != 0xFFFF );
firstChar = chain[--i];
for( ; i >= 0; i-- )
{
block[blockSize++] = chain[i];
}
return firstChar;
}
/*
========================
idLZWCompressor::DecompressBlock
========================
*/
void idLZWCompressor::DecompressBlock()
{
assert( blockIndex == blockSize ); // Make sure we've read all we can
blockIndex = 0;
blockSize = 0;
int firstChar = -1;
while( blockSize < LZW_BLOCK_SIZE - lzwCompressionData_t::LZW_DICT_SIZE )
{
assert( lzwData->codeBits <= lzwCompressionData_t::LZW_DICT_BITS );
int code = ReadBits( lzwData->codeBits );
if( code == -1 )
{
break;
}
if( oldCode == -1 )
{
assert( code < 256 );
block[blockSize++] = ( uint8 )code;
oldCode = code;
firstChar = code;
continue;
}
if( code >= lzwData->nextCode )
{
assert( code == lzwData->nextCode );
firstChar = WriteChain( oldCode );
block[blockSize++] = ( uint8 )firstChar;
}
else
{
firstChar = WriteChain( code );
}
AddToDict( oldCode, firstChar );
if( BumpBits() )
{
oldCode = -1;
}
else
{
oldCode = code;
}
}
}
/*
========================
idLZWCompressor::ReadByte
========================
*/
int idLZWCompressor::ReadByte( bool ignoreOverflow )
{
if( blockIndex == blockSize )
{
DecompressBlock();
}
if( blockIndex == blockSize ) //-V581 DecompressBlock() updates these values, the if() isn't redundant
{
if( !ignoreOverflow )
{
overflowed = true;
assert( !"idLZWCompressor::ReadByte overflowed!" );
}
return -1;
}
return block[blockIndex++];
}
/*
========================
idLZWCompressor::WriteByte
========================
*/
void idLZWCompressor::WriteByte( uint8 value )
{
int code = Lookup( lzwData->codeWord, value );
if( code >= 0 )
{
lzwData->codeWord = code;
}
else
{
WriteBits( lzwData->codeWord, lzwData->codeBits );
if( !BumpBits() )
{
AddToDict( lzwData->codeWord, value );
}
lzwData->codeWord = value;
}
if( lzwData->bytesWritten >= maxSize - ( lzwData->codeBits + lzwData->tempBits + 7 ) / 8 )
{
overflowed = true; // At any point, if we can't perform an End call, then trigger an overflow
return;
}
}
/*
========================
idLZWCompressor::Lookup
========================
*/
int idLZWCompressor::Lookup( int w, int k )
{
if( w == -1 )
{
return k;
}
else
{
int i = HashIndex( w, k );
for( int j = hash[i]; j != 0xFFFF; j = nextHash[j] )
{
assert( j < lzwCompressionData_t::LZW_DICT_SIZE );
if( lzwData->dictionaryK[j] == k && lzwData->dictionaryW[j] == w )
{
return j;
}
}
}
return -1;
}
/*
========================
idLZWCompressor::AddToDict
========================
*/
int idLZWCompressor::AddToDict( int w, int k )
{
assert( w < 0xFFFF - 1 );
assert( k < 256 );
assert( lzwData->nextCode < lzwCompressionData_t::LZW_DICT_SIZE );
lzwData->dictionaryK[lzwData->nextCode] = ( uint8 )k;
lzwData->dictionaryW[lzwData->nextCode] = ( uint16 )w;
int i = HashIndex( w, k );
nextHash[lzwData->nextCode] = hash[i];
hash[i] = ( uint16 )lzwData->nextCode;
return lzwData->nextCode++;
}
/*
========================
idLZWCompressor::BumpBits
Possibly increments codeBits.
return: bool - true, if the dictionary was cleared.
========================
*/
bool idLZWCompressor::BumpBits()
{
if( lzwData->nextCode == ( 1 << lzwData->codeBits ) )
{
lzwData->codeBits ++;
if( lzwData->codeBits > lzwCompressionData_t::LZW_DICT_BITS )
{
lzwData->nextCode = LZW_FIRST_CODE;
lzwData->codeBits = LZW_START_BITS;
ClearHash();
return true;
}
}
return false;
}
/*
========================
idLZWCompressor::End
========================
*/
int idLZWCompressor::End()
{
assert( lzwData->tempBits < 8 );
assert( lzwData->bytesWritten < maxSize - ( lzwData->codeBits + lzwData->tempBits + 7 ) / 8 );
assert( ( Length() > 0 ) == ( lzwData->codeWord != -1 ) );
if( lzwData->codeWord != -1 )
{
WriteBits( lzwData->codeWord, lzwData->codeBits );
}
if( lzwData->tempBits > 0 )
{
if( lzwData->bytesWritten >= maxSize )
{
overflowed = true;
return -1;
}
data[lzwData->bytesWritten++] = ( uint8 )lzwData->tempValue & ( ( 1 << lzwData->tempBits ) - 1 );
}
return Length() > 0 ? Length() : -1; // Total bytes written (or failure)
}
/*
========================
idLZWCompressor::Save
========================
*/
void idLZWCompressor::Save()
{
assert( !overflowed );
// Check and make sure we are at a good spot (can call End)
assert( lzwData->bytesWritten < maxSize - ( lzwData->codeBits + lzwData->tempBits + 7 ) / 8 );
savedBytesWritten = lzwData->bytesWritten;
savedCodeWord = lzwData->codeWord;
saveCodeBits = lzwData->codeBits;
savedTempValue = lzwData->tempValue;
savedTempBits = lzwData->tempBits;
}
/*
========================
idLZWCompressor::Restore
========================
*/
void idLZWCompressor::Restore()
{
lzwData->bytesWritten = savedBytesWritten;
lzwData->codeWord = savedCodeWord;
lzwData->codeBits = saveCodeBits;
lzwData->tempValue = savedTempValue;
lzwData->tempBits = savedTempBits;
}
/*
========================
idLZWCompressor::ClearHash
========================
*/
void idLZWCompressor::ClearHash()
{
memset( hash, 0xFF, sizeof( hash ) );
}
/*
========================
idZeroRunLengthCompressor
Simple zero based run length encoder/decoder
========================
*/
void idZeroRunLengthCompressor::Start( uint8* dest_, idLZWCompressor* comp_, int maxSize_ )
{
zeroCount = 0;
dest = dest_;
comp = comp_;
compressed = 0;
maxSize = maxSize_;
}
bool idZeroRunLengthCompressor::WriteRun()
{
if( zeroCount > 0 )
{
assert( zeroCount <= 255 );
if( compressed + 2 > maxSize )
{
maxSize = -1;
return false;
}
if( comp != NULL )
{
comp->WriteByte( 0 );
comp->WriteByte( ( uint8 )zeroCount );
}
else
{
*dest++ = 0;
*dest++ = ( uint8 )zeroCount;
}
compressed += 2;
zeroCount = 0;
}
return true;
}
bool idZeroRunLengthCompressor::WriteByte( uint8 value )
{
if( value != 0 || zeroCount >= 255 )
{
if( !WriteRun() )
{
maxSize = -1;
return false;
}
}
if( value != 0 )
{
if( compressed + 1 > maxSize )
{
maxSize = -1;
return false;
}
if( comp != NULL )
{
comp->WriteByte( value );
}
else
{
*dest++ = value;
}
compressed++;
}
else
{
zeroCount++;
}
return true;
}
byte idZeroRunLengthCompressor::ReadByte()
{
// See if we need to possibly read more data
if( zeroCount == 0 )
{
int value = ReadInternal();
if( value == -1 )
{
assert( 0 );
}
if( value != 0 )
{
return ( byte )value; // Return non zero values immediately
}
// Read the number of zeroes
zeroCount = ReadInternal();
}
assert( zeroCount > 0 );
zeroCount--;
return 0;
}
void idZeroRunLengthCompressor::ReadBytes( byte* dest, int count )
{
for( int i = 0; i < count; i++ )
{
*dest++ = ReadByte();
}
}
void idZeroRunLengthCompressor::WriteBytes( uint8* src, int count )
{
for( int i = 0; i < count; i++ )
{
WriteByte( *src++ );
}
}
int idZeroRunLengthCompressor::End()
{
WriteRun();
if( maxSize == -1 )
{
return -1;
}
return compressed;
}
int idZeroRunLengthCompressor::ReadInternal()
{
compressed++;
if( comp != NULL )
{
return comp->ReadByte();
}
return *dest++;
}