Files
CypherCore/Source/Game/DataStorage/ClientReader/BitReader.cs
T
2020-01-09 11:35:00 -05:00

69 lines
2.2 KiB
C#

/*
* Copyright (C) 2012-2020 CypherCore <http://github.com/CypherCore>
*
* 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/>.
*/
using System.Runtime.CompilerServices;
using System.Text;
namespace Game.DataStorage
{
public class BitReader
{
public int Position { get; set; }
public int Offset { get; set; }
public byte[] Data { get; set; }
public BitReader(byte[] data)
{
Data = data;
}
public BitReader(byte[] data, int offset)
{
Data = data;
Offset = offset;
}
public T Read<T>(int numBits) where T : unmanaged
{
ulong result = Unsafe.As<byte, ulong>(ref Data[Offset + (Position >> 3)]) << (64 - numBits - (Position & 7)) >> (64 - numBits);
Position += numBits;
return Unsafe.As<ulong, T>(ref result);
}
public T ReadSigned<T>(int numBits) where T : unmanaged
{
ulong result = Unsafe.As<byte, ulong>(ref Data[Offset + (Position >> 3)]) << (64 - numBits - (Position & 7)) >> (64 - numBits);
Position += numBits;
ulong signedShift = (1UL << (numBits - 1));
result = (signedShift ^ result) - signedShift;
return Unsafe.As<ulong, T>(ref result);
}
public string ReadCString()
{
int start = Position;
while (Data[Offset + (Position >> 3)] != 0)
Position += 8;
string result = Encoding.UTF8.GetString(Data, Offset + (start >> 3), (Position - start) >> 3);
Position += 8;
return result;
}
}
}