lzw.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * Based on the Reverse Engineering work of Christophe Fontanel,
 * maintainer of the Dungeon Master Encyclopaedia (http://dmweb.free.fr/)
 */

#ifndef DM_LZW_H
#define DM_LZW_H

#include "common/file.h"

#include "dm/dm.h"

namespace Common {
    class MemoryReadStream;
}

namespace DM {
class LZWdecompressor {
    bool _repetitionEnabled;
    int16 _codeBitCount;
    int16 _currentMaximumCode;
    int16 _absoluteMaximumCode;
    byte _inputBuffer[12];
    int16 _dictNextAvailableCode;
    bool _dictFlushed;

    byte _leastSignificantBitmasks[9];
    int16 _inputBufferBitIndex;
    int16 _inputBufferBitCount;
    int16 _charToRepeat;

    byte *_tempBuffer;
    int16 *_prefixCode;
    byte *_appendCharacter;

    int16 getNextInputCode(Common::MemoryReadStream &stream, int32 *inputByteCount);
    void outputCharacter(byte character, byte **out);
    void operator=(const LZWdecompressor&); // deleted
public:
    LZWdecompressor();
    ~LZWdecompressor();
    int32 decompress(Common::MemoryReadStream &inputStream, int32 inputByteCount, byte *out);
};

}

#endif