decompress.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/>.
 *
 */

#ifndef DGDS_DECOMPRESS_H
#define DGDS_DECOMPRESS_H

#include "common/scummsys.h"

namespace Common {
class SeekableReadStream;
}

namespace Dgds {

class RleDecompressor {
public:
    uint32 decompress(byte *dest, uint32 sz, Common::SeekableReadStream &input);
};

class LzwDecompressor {
public:
    LzwDecompressor();
    uint32 decompress(byte *dest, uint32 sz, Common::SeekableReadStream &input);

protected:
    void reset();
    uint32 getCode(uint32 totalBits, Common::SeekableReadStream &input);

private:
    struct {
        byte str[256];
        uint8 len;
    } _codeTable[0x4000];

    byte _codeCur[256];

    uint32 _bitsData;
    uint32 _bitsSize;

    uint32 _codeSize;
    uint32 _codeLen;
    uint32 _cacheBits;

    uint32 _tableSize;
    uint32 _tableMax;
    bool _tableFull;
};

class Decompressor {
public:
    Decompressor();
    virtual ~Decompressor();

    byte *decompress(Common::SeekableReadStream *input, int size, uint32 &uncompressedSize);

private:
    RleDecompressor _rleDecompressor;
    LzwDecompressor _lzwDecompressor;
};

} // End of namespace Dgds

#endif // DGDS_DECOMPRESS_H