compression.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 MADS_COMPRESSION_H
#define MADS_COMPRESSION_H

#include "common/memstream.h"
#include "common/stream.h"

#include "mads/mads.h"

namespace MADS {

enum CompressionType { COMPRESS_NONE = 0, COMPRESS_FAB = 1 };

struct MadsPackEntry {
public:
    CompressionType _type;
    byte _priority;
    uint32 _size;
    uint32 _compressedSize;
    byte *_data;
};

class MadsPack {
private:
    MadsPackEntry *_items;
    int _count;
    int _dataOffset;

    void initialize(Common::SeekableReadStream *stream);
public:
    static bool isCompressed(Common::SeekableReadStream *stream);
    MadsPack(Common::SeekableReadStream *stream);
    MadsPack(const Common::Path &resourceName, MADSEngine *_vm);
    ~MadsPack();

    int getCount() const { return _count; }
    MadsPackEntry &getItem(int index) const {
        assert(index < _count);
        return _items[index]; }
    MadsPackEntry &operator[](int index) const {
        assert(index < _count);
        return _items[index];
    }
    Common::MemoryReadStream *getItemStream(int index) {
        assert(index < _count);
        return new Common::MemoryReadStream(_items[index]._data, _items[index]._size,
            DisposeAfterUse::NO);
    }
    int getDataOffset() const { return _dataOffset; }
};

class FabDecompressor {
private:
    int _bitsLeft;
    uint32 _bitBuffer;
    const byte *_srcData, *_srcP;
    int _srcSize;

    int getBit();
public:
    void decompress(const byte *srcData, int srcSize, byte *destData, int destSize);
};

} // End of namespace MADS

#endif