mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-16 14:50:17 +00:00
103 lines
2.6 KiB
C
103 lines
2.6 KiB
C
|
/* 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 2
|
||
|
|
* 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, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
// Based on eos' BitStream implementation
|
||
|
|
|
||
|
|
#ifndef COMMON_BITSTREAM_H
|
||
|
|
#define COMMON_BITSTREAM_H
|
||
|
|
|
||
|
|
#include "common/scummsys.h"
|
||
|
|
|
||
|
|
namespace Common {
|
||
|
|
|
||
|
|
class SeekableReadStream;
|
||
|
|
|
||
|
|
/** A bit stream. */
|
||
|
|
class BitStream {
|
||
|
|
public:
|
||
|
|
BitStream();
|
||
|
|
virtual ~BitStream();
|
||
|
|
|
||
|
|
/** Read a bit. */
|
||
|
|
virtual uint32 getBit() = 0;
|
||
|
|
|
||
|
|
/** Read a number of bits. */
|
||
|
|
virtual uint32 getBits(uint32 n) = 0;
|
||
|
|
|
||
|
|
/** Adding another bit. */
|
||
|
|
virtual void addBit(uint32 &x, uint32 n) = 0;
|
||
|
|
|
||
|
|
/** Skip a number of bits. */
|
||
|
|
void skip(uint32 n);
|
||
|
|
|
||
|
|
/** Get the current position. */
|
||
|
|
virtual uint32 pos() const = 0;
|
||
|
|
/** Return the number of bits in the stream. */
|
||
|
|
virtual uint32 size() const = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
/** A big endian bit stream. */
|
||
|
|
class BitStreamBE : public BitStream {
|
||
|
|
public:
|
||
|
|
BitStreamBE(SeekableReadStream &stream, uint32 bitCount);
|
||
|
|
BitStreamBE(const byte *data, uint32 bitCount);
|
||
|
|
~BitStreamBE();
|
||
|
|
|
||
|
|
uint32 getBit();
|
||
|
|
uint32 getBits(uint32 n);
|
||
|
|
void addBit(uint32 &x, uint32 n);
|
||
|
|
|
||
|
|
uint32 pos() const;
|
||
|
|
uint32 size() const;
|
||
|
|
|
||
|
|
private:
|
||
|
|
SeekableReadStream *_stream;
|
||
|
|
|
||
|
|
byte _value; ///< Current byte.
|
||
|
|
uint8 _inValue; ///< Position within the current byte.
|
||
|
|
};
|
||
|
|
|
||
|
|
/** A 32bit little endian bit stream. */
|
||
|
|
class BitStream32LE : public BitStream {
|
||
|
|
public:
|
||
|
|
BitStream32LE(SeekableReadStream &stream, uint32 bitCount);
|
||
|
|
BitStream32LE(const byte *data, uint32 bitCount);
|
||
|
|
~BitStream32LE();
|
||
|
|
|
||
|
|
uint32 getBit();
|
||
|
|
uint32 getBits(uint32 n);
|
||
|
|
void addBit(uint32 &x, uint32 n);
|
||
|
|
|
||
|
|
uint32 pos() const;
|
||
|
|
uint32 size() const;
|
||
|
|
|
||
|
|
private:
|
||
|
|
SeekableReadStream *_stream;
|
||
|
|
|
||
|
|
uint32 _value; ///< Current 32bit value.
|
||
|
|
uint8 _inValue; ///< Position within the current 32bit value.
|
||
|
|
};
|
||
|
|
|
||
|
|
} // End of namespace Common
|
||
|
|
|
||
|
|
#endif // COMMON_BITSTREAM_H
|