public void Reset()
{
for (var depth = 0; depth < _killerMoves.Length; depth++)
{
var killerMoves = _killerMoves[depth];
killerMoves[0] = new KillerMove(Piece.None, Square.Illegal);
killerMoves[1] = new KillerMove(Piece.None, Square.Illegal);
}
}
public int GetValue(int depth, ulong move)
{
var killerMove = KillerMove.Parse(move);
if (killerMove == _killerMoves[depth][0])
{
return(2);
}
return(killerMove == _killerMoves[depth][1] ? 1 : 0);
}
public void Update(int depth, ulong move)
{
var killerMove = KillerMove.Parse(move);
if (killerMove == _killerMoves[depth][0])
{
return; // Move already is the best killer move.
}
// Shift and update killer move.
_killerMoves[depth][1] = _killerMoves[depth][0];
_killerMoves[depth][0] = killerMove;
}
public void Shift(int depth)
{
// Shift killer moves closer to root position.
var lastDepth = _killerMoves.Length - depth - 1;
for (var depthIndex = 0; depthIndex <= lastDepth; depthIndex++)
{
_killerMoves[depthIndex][0] = _killerMoves[depthIndex + depth][0];
_killerMoves[depthIndex][1] = _killerMoves[depthIndex + depth][1];
}
// Reset killer moves far from root position.
for (var depthIndex = lastDepth + 1; depthIndex < _killerMoves.Length; depthIndex++)
{
_killerMoves[depthIndex][0] = new KillerMove(Piece.None, Square.Illegal);
_killerMoves[depthIndex][1] = new KillerMove(Piece.None, Square.Illegal);
}
}
// ReSharper disable once MemberCanBePrivate.Global public bool Equals(KillerMove otherKillerMove) => (_piece == otherKillerMove._piece) && (_toSquare == otherKillerMove._toSquare);
