mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-04 08:17:40 +00:00
124 lines
2.7 KiB
C++
124 lines
2.7 KiB
C++
/* ScummVM - Scumm Interpreter
|
|
* Copyright (C) 2001 Ludvig Strigeus
|
|
* Copyright (C) 2001/2002 The ScummVM project
|
|
*
|
|
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* $Header$
|
|
*
|
|
*/
|
|
|
|
#ifndef COMMON_STREAM_H
|
|
#define COMMON_STREAM_H
|
|
|
|
#include "stdafx.h"
|
|
#include "common/scummsys.h"
|
|
|
|
|
|
namespace Common {
|
|
|
|
class WriteStream {
|
|
public:
|
|
virtual uint32 write(const void *ptr, uint32 size) = 0;
|
|
|
|
// The remaining methods all have default implementations
|
|
|
|
void writeByte(byte value);
|
|
|
|
void writeUint16LE(uint16 value);
|
|
void writeUint32LE(uint32 value);
|
|
|
|
void writeUint16BE(uint16 value);
|
|
void writeUint32BE(uint32 value);
|
|
|
|
/*
|
|
void writeSint16LE(int16 value);
|
|
void writeSint32LE(int32 value);
|
|
|
|
void writeSint16BE(int16 value);
|
|
void writeSint32BE(int32 value);
|
|
*/
|
|
};
|
|
|
|
|
|
class ReadStream {
|
|
public:
|
|
virtual uint32 read(void *ptr, uint32 size) = 0;
|
|
|
|
// The remaining methods all have default implementations
|
|
|
|
byte readByte();
|
|
|
|
uint16 readUint16LE();
|
|
uint32 readUint32LE();
|
|
|
|
uint16 readUint16BE();
|
|
uint32 readUint32BE();
|
|
|
|
/*
|
|
int16 readSint16LE();
|
|
int32 readSint32LE();
|
|
|
|
int16 readSint16BE();
|
|
int32 readSint32BE();
|
|
*/
|
|
};
|
|
|
|
/**
|
|
* XORReadStream is a wrapper around an arbitrary other ReadStream,
|
|
* which 'decrypts' the data being read by XORing all data bytes with the given
|
|
* encryption 'key'.
|
|
*/
|
|
class XORReadStream : public ReadStream {
|
|
private:
|
|
byte _encbyte;
|
|
ReadStream *_realStream;
|
|
public:
|
|
XORReadStream(ReadStream *in, byte enc = 0) : _realStream(in), _encbyte(enc) {}
|
|
void setEnc(byte value) { _encbyte = value; }
|
|
|
|
uint32 read(void *ptr, uint32 size) {
|
|
uint32 len = _realStream->read(ptr, size);
|
|
if (_encbyte) {
|
|
byte *p = (byte *)ptr;
|
|
byte *end = p + len;
|
|
while (p < end)
|
|
*p++ ^= _encbyte;
|
|
}
|
|
return len;
|
|
}
|
|
};
|
|
|
|
class MemoryReadStream : public ReadStream {
|
|
private:
|
|
const byte *_ptr;
|
|
uint32 _size;
|
|
public:
|
|
MemoryReadStream(const byte *ptr, uint32 size) : _ptr(ptr), _size(size) {}
|
|
|
|
uint32 read(void *ptr, uint32 size) {
|
|
if (size > _size)
|
|
size = _size;
|
|
memcpy(ptr, _ptr, size);
|
|
_size -= size;
|
|
_ptr += size;
|
|
return size;
|
|
}
|
|
};
|
|
|
|
} // End of namespace Common
|
|
|
|
#endif
|