/// <summary>
/// Verifies if a piece attacks a square. This method does not check if the piece on "from"
/// on the board is of the same type as this FlyweightPiece represents.
/// </summary>
/// <param name="board">Board to check attacking on.</param>
/// <param name="from">Square on which attacking piece is placed.</param>
/// <param name="to">The square to check if attacked.</param>
/// <returns>True if a FlyweightPiece placed on "from" square attacks the "to" square. False otherwise.</returns>
public bool Attacks(Board board, Square from, Square to)
{
if (Math.Abs(Board.File(from) - Board.File(to)) == Math.Abs(Board.Rank(from) - Board.Rank(to)))
{
return(board.IsPathClear(from, to));
}
return(false);
}
/// <summary>
/// Verifies if a piece attacks a square. This method does not check if the piece on "from"
/// on the board is of the same type as this FlyweightPiece represents.
/// </summary>
/// <param name="board">Board to check attacking on.</param>
/// <param name="from">Square on which attacking piece is placed.</param>
/// <param name="to">The square to check if attacked.</param>
/// <returns>True if a FlyweightPiece placed on "from" square attacks the "to" square. False otherwise.</returns>
public bool Attacks(Board board, Square from, Square to)
{
if (Board.File(from) != Board.File(to) &&
Board.Rank(from) != Board.Rank(to) &&
(Math.Abs(Board.File(from) - Board.File(to)) + Math.Abs(Board.Rank(from) - Board.Rank(to))) == 3)
{
return(true);
}
return(false);
}
/// <summary>
/// Updates if the board has a pawn that can be hit En-Passant after the move has been performed.
/// </summary>
/// <param name="afterState">The "BoardState" to update.</param>
protected void SetEnPassentTarget(ref BoardState afterState)
{
if ((Board.Rank(m_from) == 1 && Board.Rank(m_to) == 3 && m_piece == Piece.WhitePawn) ||
(Board.Rank(m_from) == 6 && Board.Rank(m_to) == 4 && m_piece == Piece.BlackPawn))
{
afterState.EnPassantTarget = m_to;
}
else
{
afterState.EnPassantTarget = Square.None;
}
}
/// <summary>
/// Updates if the board has a pawn that can be hit En-Passant after the move has been performed.
/// </summary>
/// <param name="afterState">The "BoardState" to update.</param>
private void SetEnPassentTarget(ref BoardState afterState)
{
if ((Board.Rank(From) == 1 && Board.Rank(To) == 3 && Piece == Piece.WhitePawn) ||
(Board.Rank(From) == 6 && Board.Rank(To) == 4 && Piece == Piece.BlackPawn))
{
afterState.EnPassantTarget = To;
}
else
{
afterState.EnPassantTarget = Square.None;
}
}
/// <summary>
/// XOR's an En-Passant target into the Zobrist key.
/// </summary>
public void HashFlipEnPassantTarget(Square square)
{
if (Board.Rank(square) == 3)
{
m_key ^= ZobristValues.Keys[1541 + Board.File(square)];
m_lock ^= ZobristValues.Locks[1541 + Board.File(square)];
}
if (Board.Rank(square) == 4)
{
m_key ^= ZobristValues.Keys[1549 + Board.File(square)];
m_lock ^= ZobristValues.Locks[1549 + Board.File(square)];
}
}
/// <summary>
/// Verifies if a piece attacks a square. This method does not check if the piece on "from"
/// on the board is of the same type as this FlyweightPiece represents.
/// </summary>
/// <param name="board">Board to check attacking on.</param>
/// <param name="from">Square on which attacking piece is placed.</param>
/// <param name="to">The square to check if attacked.</param>
/// <returns>True if a FlyweightPiece placed on "from" square attacks the "to" square. False otherwise.</returns>
public bool Attacks(Board board, Square from, Square to)
{
if ((m_color == PieceColor.White && Board.Rank(to) == Board.Rank(from) + 1) ||
(m_color == PieceColor.Black && Board.Rank(to) == Board.Rank(from) - 1))
{
if ((Math.Abs(Board.File(to) - Board.File(from)) == 1) &&
(board.GetPieceColor(to) != m_color))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Sets the hash value according to a board.
/// </summary>
/// <param name="board">The board a hash value will be generated for.</param>
public void HashSet(Board board)
{
m_key = 0;
m_lock = 0;
if (board != null)
{
foreach (Square square in board)
{
if (board[square] != Piece.None)
{
m_key ^= ZobristValues.Keys[((int)board[square] * 128) + (int)square];
m_lock ^= ZobristValues.Locks[((int)board[square] * 128) + (int)square];
}
}
if (board.State.ColorToPlay == PieceColor.White)
{
m_key ^= ZobristValues.Keys[1536];
m_lock ^= ZobristValues.Locks[1536];
}
if (board.State.WhiteCanCastleLong)
{
m_key ^= ZobristValues.Keys[1537];
m_lock ^= ZobristValues.Locks[1537];
}
if (board.State.WhiteCanCastleShort)
{
m_key ^= ZobristValues.Keys[1538];
m_lock ^= ZobristValues.Locks[1538];
}
if (board.State.BlackCanCastleLong)
{
m_key ^= ZobristValues.Keys[1539];
m_lock ^= ZobristValues.Locks[1539];
}
if (board.State.BlackCanCastleShort)
{
m_key ^= ZobristValues.Keys[1540];
m_lock ^= ZobristValues.Locks[1540];
}
if (board.State.EnPassantTarget != Square.None)
{
if (Board.Rank(board.State.EnPassantTarget) == 3)
{
m_key ^= ZobristValues.Keys[1541 + Board.File(board.State.EnPassantTarget)];
m_lock ^= ZobristValues.Locks[1541 + Board.File(board.State.EnPassantTarget)];
}
if (Board.Rank(board.State.EnPassantTarget) == 4)
{
m_key ^= ZobristValues.Keys[1549 + Board.File(board.State.EnPassantTarget)];
m_lock ^= ZobristValues.Locks[1549 + Board.File(board.State.EnPassantTarget)];
}
}
}
}
/// <summary>
/// Generate moves a FlyweightPiece can make.
/// This method does not varifies if a move puts its own king in check.
/// This is done in MoveOrganizer when adding a move.
/// </summary>
/// <param name="board">Board to generate moves for.</param>
/// <param name="location">Location of the piece.</param>
/// <param name="moves">Container class to which all generated moves are added.</param>
public void GenerateMoves(Board board, Square location, MoveOrganizer moves)
{
if (m_color == board.State.ColorToPlay)
{
for (int i = 0; i < m_directions.Length; i++)
{
m_iterator.Reset(board, location, m_directions[i]);
if (m_iterator.Next())
{
if (m_iterator.CurrentPiece() == Piece.None &&
(m_iterator.CurrentDirection() == Direction.Up || m_iterator.CurrentDirection() == Direction.Down))
{
//Non hitting moves
switch (Board.Rank(m_iterator.CurrentSquare()))
{
case 0:
//Black non hitting promotion move
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackBishop));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackKnight));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackQueen));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackRook));
break;
case 7:
//White non hitting promotion move
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteBishop));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteKnight));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteQueen));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteRook));
break;
default:
//Basic non hitting move
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
break;
}
if ((Board.Rank(m_iterator.CurrentSquare()) == 2 && m_iterator.CurrentDirection() == Direction.Up) ||
(Board.Rank(m_iterator.CurrentSquare()) == 5 && m_iterator.CurrentDirection() == Direction.Down))
{ //Two squares forward opening move
m_iterator.Next();
if (m_iterator.CurrentPiece() == Piece.None)
{
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
}
}
}
else if (m_iterator.CurrentPiece() != Piece.None && m_iterator.CurrentPieceColor() != m_color &&
m_iterator.CurrentDirection() != Direction.Up && m_iterator.CurrentDirection() != Direction.Down)
{
//Hitting moves
switch (Board.Rank(m_iterator.CurrentSquare()))
{
case 0:
//Black hitting promotion move
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackBishop));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackKnight));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackQueen));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.BlackRook));
break;
case 7:
//White hitting promotion move
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteBishop));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteKnight));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteQueen));
moves.Add(new PawnPromotionMove(board, location, m_iterator.CurrentSquare(), Piece.WhiteRook));
break;
default:
//Basic hitting move
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
break;
}
}
}
}
//EnPassant moves
if (board.State.EnPassantTarget != Square.None &&
Math.Abs(board.State.EnPassantTarget - location) == 1 &&
Board.Rank(board.State.EnPassantTarget) == Board.Rank(location))
{
switch (m_color)
{
case PieceColor.White:
moves.Add(new EnPassantCaptureMove(board, location, Board.Position(Board.File(board.State.EnPassantTarget), Board.Rank(location) + 1)));
break;
case PieceColor.Black:
moves.Add(new EnPassantCaptureMove(board, location, Board.Position(Board.File(board.State.EnPassantTarget), Board.Rank(location) - 1)));
break;
}
}
}
}
/// <summary>
/// Moves the iterator to the next square.
/// </summary>
/// <returns>True if if the new square is a valid and existing square. False otherwise.</returns>
public bool Next()
{
switch (m_direction)
{
case Direction.Up:
if (Board.Rank(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1)
{
return(false);
}
m_currentSquare += 8;
return(true);
case Direction.UpRight:
if (Board.Rank(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1 ||
Board.File(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1)
{
return(false);
}
m_currentSquare += 9;
return(true);
case Direction.Right:
if (Board.File(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1)
{
return(false);
}
m_currentSquare += 1;
return(true);
case Direction.DownRight:
if (Board.Rank(m_currentSquare) == 0 ||
Board.File(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1)
{
return(false);
}
m_currentSquare -= 7;
return(true);
case Direction.Down:
if (Board.Rank(m_currentSquare) == 0)
{
return(false);
}
m_currentSquare -= 8;
return(true);
case Direction.DownLeft:
if (Board.Rank(m_currentSquare) == 0 ||
Board.File(m_currentSquare) == 0)
{
return(false);
}
m_currentSquare -= 9;
return(true);
case Direction.Left:
if (Board.File(m_currentSquare) == 0)
{
return(false);
}
m_currentSquare -= 1;
return(true);
case Direction.UpLeft:
if (Board.Rank(m_currentSquare) == Board.NOF_SIDE_SQUARS - 1 ||
Board.File(m_currentSquare) == 0)
{
return(false);
}
m_currentSquare += 7;
return(true);
case Direction.NoDirection:
default:
return(false);
}
}
/// <summary>
/// Generate moves a FlyweightPiece can make.
/// This method does not varifies if a move puts its own king in check.
/// This is done by a move when its carried out.
/// </summary>
/// <param name="board">Board to generate moves for.</param>
/// <param name="location">Location of the piece.</param>
/// <param name="moves">Container class to which all generated moves are added.</param>
public void GenerateMoves(Board board, Square location, MoveOrganizer moves)
{
if (m_color == board.State.ColorToPlay)
{
//Non hitting moves
m_iterator.Reset(board, location, m_directions[0]);
if (m_iterator.Next())
{
if (m_iterator.CurrentPiece() == Piece.None)
{
switch (Board.Rank(m_iterator.CurrentSquare()))
{
case 0:
//Black non hitting promotion move
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackBishop));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackKnight));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackQueen));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackRook));
break;
case 7:
//White non hitting promotion move
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteBishop));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteKnight));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteQueen));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteRook));
break;
default:
//Basic non hitting move
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
break;
}
//Two squares forward opening move
if (Board.Rank(m_iterator.CurrentSquare()) == moveAgainRow)
{
m_iterator.Next();
if (m_iterator.CurrentPiece() == Piece.None)
{
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
}
}
}
}
//Hitting moves to the left and right
for (int i = 1; i < m_directions.Length; ++i)
{
m_iterator.Reset(board, location, m_directions[i]);
if (m_iterator.Next())
{
if (m_iterator.CurrentPieceColor() == m_opponentColor)
{
switch (Board.Rank(m_iterator.CurrentSquare()))
{
case 0:
//Black hitting promotion move
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackBishop));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackKnight));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackQueen));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.BlackRook));
break;
case 7:
//White hitting promotion move
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteBishop));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteKnight));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteQueen));
moves.Add(new Move(board, location, m_iterator.CurrentSquare(), Piece.WhiteRook));
break;
default:
//Basic hitting move
moves.Add(new Move(board, location, m_iterator.CurrentSquare()));
break;
}
}
}
}
//EnPassant moves
if (Math.Abs(board.State.EnPassantTarget - location) == 1)
{
switch (m_color)
{
case PieceColor.White:
moves.Add(new Move(board, location, Board.Position(Board.File(board.State.EnPassantTarget), Board.Rank(location) + 1), board.State.EnPassantTarget));
break;
case PieceColor.Black:
moves.Add(new Move(board, location, Board.Position(Board.File(board.State.EnPassantTarget), Board.Rank(location) - 1), board.State.EnPassantTarget));
break;
}
}
}
}