public void MakeNullMove()
{
IrrevState irrevState = GetIrrevState().CopyBeforeMove();
IrrevStates.Add(irrevState);
ChangeTurn();
ZobristHashUtils.UpdateTurn(ref GetIrrevState().ZobristHash);
irrevState.PliesFromNull = 0;
}
public void Reset()
{
Pieces = new ulong[2, 6];
Occupancy = new ulong[2];
IrrevState irrevState = new IrrevState(ZobristHashUtils);
IrrevStates = new List <IrrevState>()
{
irrevState
};
}
public bool IsCheck()
{
IrrevState irrevState = GetIrrevState();
if (irrevState.IsCheck == null)
{
ulong king = Pieces[Turn, (int)PieceType.King];
irrevState.IsCheck = IsAttacked(Turn, king, false);
}
return(irrevState.IsCheck.Value);
}
public bool IsThreefoldRepetition()
{
int repetitions = 0;
IrrevState irrevState = GetIrrevState();
int maxMovesBack = Math.Min(irrevState.HalfmoveClock, irrevState.PliesFromNull);
int lastMove = Math.Max(IrrevStates.Count - 1 - maxMovesBack, 0);
ulong hash = GetIrrevState().ZobristHash;
for (int i = IrrevStates.Count - 5; i >= lastMove && repetitions < 2; i -= 2)
{
if (IrrevStates[i].ZobristHash == hash)
{
repetitions++;
}
}
return(repetitions == 2);
}