scummvm/engines/ultima/ultima8/misc/stream_util.h

74 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.
*
*/
#ifndef ULTIMA8_MISC_STREAM_H
#define ULTIMA8_MISC_STREAM_H
#include "common/stream.h"
namespace Ultima {
namespace Ultima8 {
// Read a 3-byte value, lsb first.
inline uint32 readUint24LE(Common::ReadStream &rs) {
uint32 val = 0;
val |= static_cast<uint32>(rs.readByte());
val |= static_cast<uint32>(rs.readByte() << 8);
val |= static_cast<uint32>(rs.readByte() << 16);
return val;
}
inline uint32 readX(Common::ReadStream &rs, uint32 num_bytes) {
assert(num_bytes > 0 && num_bytes <= 4);
if (num_bytes == 1) return rs.readByte();
else if (num_bytes == 2) return rs.readUint16LE();
else if (num_bytes == 3) return readUint24LE(rs);
else return rs.readUint32LE();
}
inline int32 readXS(Common::ReadStream &rs, uint32 num_bytes) {
assert(num_bytes > 0 && num_bytes <= 4);
if (num_bytes == 1) return static_cast<int8>(rs.readByte());
else if (num_bytes == 2) return static_cast<int16>(rs.readUint16LE());
else if (num_bytes == 3) return (((static_cast<int32>(readUint24LE(rs))) << 8) >> 8);
else return static_cast<int32>(rs.readUint32LE());
}
inline void writeUint24LE(Common::WriteStream &ws, uint32 val) {
ws.writeByte(static_cast<byte>(val & 0xff));
ws.writeByte(static_cast<byte>((val >> 8) & 0xff));
ws.writeByte(static_cast<byte>((val >> 16) & 0xff));
}
inline void writeX(Common::WriteStream &ws, uint32 val, uint32 num_bytes) {
assert(num_bytes > 0 && num_bytes <= 4);
if (num_bytes == 1) ws.writeByte(static_cast<byte>(val));
else if (num_bytes == 2) ws.writeUint16LE(static_cast<uint16>(val));
else if (num_bytes == 3) writeUint24LE(ws, val);
else ws.writeUint32LE(val);
}
} // End of namespace Ultima8
} // End of namespace Ultima
#endif