packfile.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 PACKFILE_H
#define PACKFILE_H

namespace Common {
class SeekableReadStream;
}

namespace Grim {

class PackFile : public Common::SeekableReadStream {
public:
    PackFile(Common::SeekableReadStream *data);
    ~PackFile();

    bool err() const;
    void clearErr();
    uint32 read(void *dataPtr, uint32 dataSize);
    bool eos() const;
    int64 pos() const;
    int64 size() const;
    bool seek(int64 offset, int whence = SEEK_SET);

private:
    Common::SeekableReadStream *_orgStream;
    int32 _offset, _size;

    uint16 *_codeTable;
    const uint32 _kCodeTableSize;

    void createCodeTable(uint32 key);
    void decode(uint8 *data, uint32 size, uint32 start_point);

    static const uint32 _knownOffsets[5];
};

} // end of namespace Grim

#endif