datapacker.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.
 *
 * Additional copyright for this file:
 * Copyright (C) 1999-2000 Revolution Software Ltd.
 * This code is based on source code created by Revolution Software,
 * used with permission.
 *
 * 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 ICB_DATAPACKER_HH
#define ICB_DATAPACKER_HH

#include "common/stream.h"

namespace ICB {

// Pack: 4 values into 4*14 bits = 56-bits = 7 bytes
#define BUFFER_BYTE_SIZE (7)
#define PACK_BIT_SIZE (14)
#define PACK_CHUNK_SIZE (4)

class DataPacker {
public:
    DataPacker();
    ~DataPacker();

    // Copy constructor
    DataPacker(DataPacker &src);

    // Assignment operator
    DataPacker &operator=(DataPacker &b);

    enum ModeEnum { NO_MODE, READ, WRITE };

    enum PackModeEnum { NO_PACKMODE, PACK, DONT_PACK };

    enum ReturnCodes { OK, BAD_POS, BAD_MODE, BAD_PACKMODE, READ_ERROR, WRITE_ERROR, BAD_READFUNC, BAD_WRITEFUNC, BAD_VALUE };

    // Start the bit-packing process : say if we are in READ or WRITE mode
    ReturnCodes open(const ModeEnum mode, const PackModeEnum packMode);

    // Put a value into the bit-stream
    ReturnCodes put(const int32 value, Common::WriteStream *fh);

    // Get a value from the bit-stream
    ReturnCodes Get(int32 &value, Common::SeekableReadStream *stream);

    // Stop the bit-packing process : will output any remaining data
    ReturnCodes close(Common::WriteStream *stream);
    ReturnCodes close(Common::SeekableReadStream *stream);
    // Simple inspectors
    int32 Pos() const { return pos; }
    int32 PackMin() const { return packMin; }
    int32 PackMax() const { return packMax; }

private:
    void ClearBuffer();

    bool readMode;

    ModeEnum iMode;
    PackModeEnum iPackMode;
    int32 pos;
    int32 packMin;
    int32 packMax;

    uint8 buffer[BUFFER_BYTE_SIZE];
};

} // End of namespace ICB

#endif // #ifndef DATAPACKER_HH