public void SubmitNullMove()
{
states.Push(new BoardState
{
lastMove = null,
positionKey = positionKey,
enPassentSquare = EnPassentSquare,
castelingRights = CastelingRights,
materialKey = materialKey,
WhitePawnBitboard = WhitePawnBitboard,
BlackPawnBitboard = BlackPawnBitboard,
WhitePiecesBitboard = WhitePiecesBitboard,
BlackPiecesBitboard = BlackPiecesBitboard
});
//No EnPassent in NullMovePruning
EnPassentSquare = -1;
Ply++;
Us = Them;
Them = Piece.OtherColor(Us);
ZobristKey.ColorChanged(ref positionKey);
}
//We assume the submitted move is legal
public void SubmitMove(Move move)
{
states.Push(new BoardState //Save the current state to the history
{
lastMove = move,
positionKey = positionKey,
materialKey = materialKey,
enPassentSquare = EnPassentSquare,
castelingRights = CastelingRights,
WhitePawnBitboard = WhitePawnBitboard,
BlackPawnBitboard = BlackPawnBitboard,
WhitePiecesBitboard = WhitePiecesBitboard,
BlackPiecesBitboard = BlackPiecesBitboard
});
Ply++;
board[move.Start] = Piece.NONE;
pieceList[move.MovedPiece].Remove(move.Start);
if (move.Promotion != Piece.NONE)
{
var promotedPiece = (Piece.COLOR_MASK & move.MovedPiece) | move.Promotion;
board[move.Target] = promotedPiece;
pieceList[promotedPiece].Add(move.Target);
//Update material key
MaterialKey.RemovePiece(move.MovedPiece, ref materialKey);
MaterialKey.AddPiece(promotedPiece, ref materialKey);
//Update Zobrist key
ZobristKey.PieceMoved(move.MovedPiece, move.Start, -1, ref positionKey);
ZobristKey.PieceMoved(promotedPiece, move.Target, -1, ref positionKey);
//Update piece and pawn Bitboards
if (Us == Piece.WHITE)
{
WhitePawnBitboard &= ~(1ul << move.Start);
WhitePiecesBitboard |= 1ul << move.Target;
}
else // Us == Piece.BLACK
{
BlackPawnBitboard &= ~(1ul << move.Start);
BlackPiecesBitboard |= 1ul << move.Target;
}
}
else
{
board[move.Target] = move.MovedPiece;
pieceList[move.MovedPiece].Add(move.Target);
//material key need not be updated, piece just moved
//Update Zobrist key
ZobristKey.PieceMoved(move.MovedPiece, move.Start, move.Target, ref positionKey);
//Update Pawn and pieces Bitboards
if (move.MovedPiece == (Piece.WHITE | Piece.PAWN))
{
WhitePawnBitboard &= ~(1ul << move.Start);
WhitePawnBitboard |= 1ul << move.Target;
}
else if (move.MovedPiece == (Piece.BLACK | Piece.PAWN))
{
BlackPawnBitboard &= ~(1ul << move.Start);
BlackPawnBitboard |= 1ul << move.Target;
}
else if (Us == Piece.WHITE)
{
WhitePiecesBitboard &= ~(1ul << move.Start);
WhitePiecesBitboard |= 1ul << move.Target;
}
else
{
BlackPiecesBitboard &= ~(1ul << move.Start);
BlackPiecesBitboard |= 1ul << move.Target;
}
}
if (move.CapturedPiece != Piece.NONE)
{
pieceList[move.CapturedPiece].Remove(move.Target);
//Update material key
MaterialKey.RemovePiece(move.CapturedPiece, ref materialKey);
//Update Zobrist Key
ZobristKey.PieceMoved(move.CapturedPiece, move.Target, -1, ref positionKey);
//Update pawn bitboards
if (move.CapturedPiece == (Piece.BLACK | Piece.PAWN))
{
BlackPawnBitboard &= ~(1ul << move.Target);
}
else if (move.CapturedPiece == (Piece.WHITE | Piece.PAWN))
{
WhitePawnBitboard &= ~(1ul << move.Target);
}
else if (Us == Piece.WHITE)
{
BlackPiecesBitboard &= ~(1ul << move.Target);
}
else
{
WhitePiecesBitboard &= ~(1ul << move.Target);
}
}
//EnPassent related stuff
if (move.IsDoublePawnMove)
{
//set the enPassent square to the square behind the target
EnPassentSquare = Us == Piece.WHITE ? move.Target - 8 : move.Target + 8;
}
else
{
//reset the enPassent square
EnPassentSquare = -1;
}
if (move.IsEnPassent)
{
//Remove the pawn on the advanced square
var captureSquare = Us == Piece.WHITE ? move.Target - 8 : move.Target + 8; //rank of start + file of target
pieceList[Piece.PAWN | Them].Remove(captureSquare);
board[captureSquare] = Piece.NONE;
//Update material key
MaterialKey.RemovePiece(Piece.PAWN | Them, ref materialKey);
//Update Zobrist key
ZobristKey.PieceMoved(Piece.PAWN | Them, captureSquare, -1, ref positionKey);
//Update pawn bitboards
if (Us == Piece.WHITE)
{
BlackPawnBitboard &= ~(1ul << captureSquare);
}
else //Us == BLACK
{
WhitePawnBitboard &= ~(1ul << captureSquare);
}
}
//Casteling related stuff
if (move.MovedPiece == (Piece.WHITE | Piece.KING))
{
//Revoke whites casteling rights after a king move
CastelingRights &= BLACK_KINGSIDE_CASTLE | BLACK_QUEENSIDE_CASTLE;
}
else if (move.MovedPiece == (Piece.BLACK | Piece.KING))
{
//Revoke blacks casteling rights after a king move
CastelingRights &= WHITE_KINGSIDE_CASTLE | WHITE_QUEENSIDE_CASTLE;
}
else
{
//Revoke whites casteling rights if the correpsonding rook moved or was captured
if (move.Start == 0 || move.Target == 0) //A1
{
CastelingRights &= ~WHITE_QUEENSIDE_CASTLE;
}
if (move.Start == 7 || move.Target == 7) //H1
{
CastelingRights &= ~WHITE_KINGSIDE_CASTLE;
}
//Revoke blacks casteling rights if the correpsonding rook moved or was captured
if (move.Start == 7 * 8 || move.Target == 7 * 8) //A8
{
CastelingRights &= ~BLACK_QUEENSIDE_CASTLE;
}
if (move.Start == 7 * 8 + 7 || move.Target == 7 * 8 + 7) //H8
{
CastelingRights &= ~BLACK_KINGSIDE_CASTLE;
}
}
if (move.IsCasteling)
{
//We need not revoke casteling rights after castle, this has already happend
//We only need to move the rook
int rookStart, rookEnd;
switch (move.Target)
{
case 2: //C1
rookStart = 0; //A1
rookEnd = 3; //D1
break;
case 6: //G1
rookStart = 7; //H1
rookEnd = 5; //F1
break;
case 7 * 8 + 2: //C8
rookStart = 7 * 8; //A8
rookEnd = 7 * 8 + 3; //D8
break;
case 7 * 8 + 6: //G8
rookStart = 7 * 8 + 7; //H8
rookEnd = 7 * 8 + 5; //F8
break;
default:
throw new Exception("Illegal casteling move: " + move.ToAlgebraicNotation());
}
var pieceType = Piece.ROOK | Us;
board[rookStart] = Piece.NONE;
board[rookEnd] = pieceType;
pieceList[pieceType].Remove(rookStart);
pieceList[pieceType].Add(rookEnd);
ZobristKey.PieceMoved(pieceType, rookStart, rookEnd, ref positionKey);
if (Us == Piece.WHITE)
{
WhitePiecesBitboard &= ~(1ul << rookStart);
WhitePiecesBitboard |= 1ul << rookEnd;
}
else
{
BlackPiecesBitboard &= ~(1ul << rookStart);
BlackPiecesBitboard |= 1ul << rookEnd;
}
}
Us = Them;
Them = Piece.OtherColor(Us);
ZobristKey.ColorChanged(ref positionKey);
}