public static String AsciiBoard(Board board, List <Move> moves = null, bool displayCount = false)
{
if (moves == null)
{
moves = new List <Move>();
}
moves = moves.Where(move => board.IsLegalMove(move)).ToList();
StringBuilder ascii = new StringBuilder();
ascii.Append("+---------------+\n");
for (int row = 7; row >= 0; row--)
{
ascii.Append("|");
for (int column = 0; column < 8; column++)
{
var position = row * BoardStateOffset.ROW_OFFSET + column;
var piece = board.GetPiece(position);
var movesOnPosition = moves.Count(move => move.targetPosition == position);
if (movesOnPosition > 0)
{
if (movesOnPosition < 10 && displayCount)
{
ascii.Append(movesOnPosition);
}
else
{
ascii.Append("x");
}
}
else
{
ascii.Append(PieceParser.ToChar(piece));
}
if (column != 7)
{
ascii.Append(" ");
}
}
ascii.Append($"| {(row + 1)}\n");
}
ascii.Append("+---------------+\n");
ascii.Append(" A B C D E F G H");
return(ascii.ToString());
}
public static String BoardToFen(Board board, int move = 0)
{
StringBuilder fen = new StringBuilder();
for (int row = 7; row >= 0; row--)
{
int count = 0;
for (int column = 0; column < 8; column++)
{
var position = row * BoardStateOffset.ROW_OFFSET + column;
var piece = board.GetPiece(position);
//var piece = Board.GetPiece(board, position);
char c = PieceParser.ToChar(piece);
if (c == '_')
{
count++;
}
else
{
if (count != 0)
{
fen.Append(count);
count = 0;
}
fen.Append(c);
}
}
if (count != 0)
{
fen.Append(count);
}
if (row != 0)
{
fen.Append("/");
}
}
fen.Append(" ");
fen.Append(board.IsWhiteTurnBool ? "w" : "b");
fen.Append(" ");
CastlingBits castlingBits = board.CastlingBits;
if (castlingBits == CastlingBits.EMPTY)
{
fen.Append("-");
}
else
{
if ((castlingBits & CastlingBits.WHITE_KING_SIDE_CASTLE) != CastlingBits.EMPTY)
{
fen.Append("K");
}
if ((castlingBits & CastlingBits.WHITE_QUEEN_SIDE_CASTLE) != CastlingBits.EMPTY)
{
fen.Append("Q");
}
if ((castlingBits & CastlingBits.BLACK_KING_SIDE_CASTLE) != CastlingBits.EMPTY)
{
fen.Append("k");
}
if ((castlingBits & CastlingBits.BLACK_QUEEN_SIDE_CASTLE) != CastlingBits.EMPTY)
{
fen.Append("q");
}
}
fen.Append(" ");
fen.Append(board.EnPassantTarget != EnPassant.NO_ENPASSANT ? BoardPosition.ReadablePosition(board.EnPassantTarget) : "-");
fen.Append(" ");
fen.Append(board.HalfTurnCounter);
fen.Append(" ");
fen.Append(move);
return(fen.ToString());
}
public static ChessState GameToState(ChessGame game)
{
var chessState = new ChessState();
//var moves = board.GetMoves().Where(move => board.IsLegalMove(move));
var moves = game.Moves();
for (int column = 0; column < 8; column++)
{
for (int row = 0; row < 8 * BoardStateOffset.ROW_OFFSET; row += BoardStateOffset.ROW_OFFSET)
{
var position = row + column;
Piece piece = game.board.GetPiece(position);
if (piece != Piece.EMPTY)
{
var from = BoardPosition.x88PositionToCoordinate(position);
var chessPiece = new ChessPiece()
{
piece = PieceParser.ToChar(piece).ToString(),
row = from.row,
column = from.column,
isWhite = (piece & Piece.IS_WHITE) == Piece.IS_WHITE
};
chessState.pieces.Add(chessPiece);
foreach (var move in moves)
{
if (move.move.fromPosition == position)
{
var to = BoardPosition.x88PositionToCoordinate(move.move.targetPosition);
chessPiece.options.Add(new PieceOption()
{
row = to.row,
column = to.column,
isPromotion = (Piece)move.move.promotion != Piece.EMPTY,
isCastle = ((MoveFlags)move.move.moveFlags & MoveFlags.CASTLING) == MoveFlags.CASTLING,
isEnpassant = (((MoveFlags)move.move.moveFlags & MoveFlags.ENPASSANT) == MoveFlags.ENPASSANT),
san = move.san
});
}
}
}
}
}
var winner = game.Winner();
if (winner == Winner.DRAW)
{
chessState.isDraw = true;
}
else if (winner == Winner.WINNER_BLACK)
{
chessState.blackWins = true;
}
else if (winner == Winner.WINNER_WHITE)
{
chessState.whiteWins = true;
}
chessState.fen = game.FEN;
return(chessState);
}
// based on rules from https://en.wikipedia.org/wiki/Algebraic_notation_(chess)
// Notice the parameter legalMoves only contains legal moves
public string StandardAlgebraicNotation(Move move, List <Move> legalMoves)
{
StringBuilder san = new StringBuilder();
var piece = GetPiece(move.fromPosition);
if (((MoveFlags)move.moveFlags & MoveFlags.CASTLING) == MoveFlags.CASTLING)
{
if (move.targetPosition < move.fromPosition)
{
// castle queen side
san.Append("O-O-O");
}
else
{
// castle king side
san.Append("O-O");
}
}
else
{
var isPawn = (piece & Piece.PIECE_MASK) == Piece.PAWN;
if (!isPawn)
{
// all pieces other pawns display their piece name
var pChar = PieceParser.ToChar(piece);
san.Append(pChar.ToString().ToUpper());
}
int fromRow = move.fromPosition / BoardStateOffset.ROW_OFFSET;
int fromColumn = move.fromPosition - (fromRow * BoardStateOffset.ROW_OFFSET);
bool sameColumns = false;
bool sameRows = false;
bool isAmbigious = false;
foreach (var possibleMove in legalMoves)
{
// check all other moves of the same piece type if they can move to the same position
if (possibleMove.targetPosition == move.targetPosition && // check if it can reach the same square
possibleMove.fromPosition != move.fromPosition && // check if not the same piece
piece == GetPiece(possibleMove.fromPosition)) // check it is the same type of piece
{
isAmbigious = true;
int possibleFromRow = possibleMove.fromPosition / BoardStateOffset.ROW_OFFSET;
int possibleFromColumn = possibleMove.fromPosition - (possibleFromRow * BoardStateOffset.ROW_OFFSET);
if (possibleFromColumn == fromColumn)
{
sameColumns = true;
}
if (possibleFromRow == fromRow)
{
sameRows = true;
}
}
}
if (isPawn)
{
if ((Piece)move.capturedPiece != Piece.EMPTY)
{
// when pawn captures always specify the starting column
san.Append(Convert.ToChar('a' + (fromColumn)));
}
}
else
{
if (isAmbigious)
{
// disambiguating moves
if (sameColumns && sameRows)
{
san.Append(Convert.ToChar('a' + (fromColumn)));
san.Append((fromRow + 1).ToString());
}
else if (sameColumns)
{
san.Append((fromRow + 1).ToString());
}
else
{
san.Append(Convert.ToChar('a' + (fromColumn)));
}
}
}
if ((Piece)move.capturedPiece != Piece.EMPTY)
{
san.Append("x");
}
int targetRow = move.targetPosition / BoardStateOffset.ROW_OFFSET;
int targetColumn = move.targetPosition - (targetRow * BoardStateOffset.ROW_OFFSET);
san.Append(Convert.ToChar('a' + (targetColumn))).Append((targetRow + 1).ToString());
Piece promotion = (Piece)move.promotion;
if (promotion != Piece.EMPTY)
{
san.Append("=").Append(PieceParser.ToChar(promotion).ToString().ToUpper());
}
}
Move(move);
// check for checkmate
// after the move is played check if the current players king is attacked
if (Attacked(GetKingPosition(IsWhiteTurn), IsWhiteTurn))
{
var winner = detectWinner(GetMoves());
if (winner == Winner.WINNER_BLACK || winner == Winner.WINNER_WHITE)
{
//san += "#";
san.Append("#");
}
else
{
//san += "+";
san.Append("+");
}
}
UndoMove(move);
return(san.ToString());
}
// Loads a board from the FEN notation(Forsyth–Edwards Notation)
// Useful for getting to certain chess positions quickly.
// Use the website below to generate positions
// https://lichess.org/editor/8/1QQ2QQ1/QqqQQqqQ/QqqqqqqQ/QqqqqqqQ/1QqqqqQ1/2QqqQ2/3QQ3_b_-_-_0_1
// FEN consists of 6 parts which are sepperated by space
// 1. Position
// - Describes what pieces are at which positions
// - The pieces are described from left to right with a "/" to indicate row changes
// - a single letter is used to represent a piece
// - P = Pawn
// - N = Knight
// - B = Bishop
// - R = Rook
// - Q = Queen
// - K = King
// - Capital letters indicate White pieces, while lowercase letter indicate Black pieces
// 2. active color
// - Either "w" or "b", which indicates whose turn it is.
// 3. castling options
// - stores information if about who is allowed to castle.
// - Capital letters indicate White side lowercase letters are blacks options
// - the letters K and Q mean queen or kingside castle.
// - If no castling options it is marked with a "-"
// 4. En passant target
// - marks which square is current possible to attack with en passant.
// 5. Half move clock
// - Stores how many half moves have been made since the last capture or pawn move
// - This is used for declaring stalemate
// 6. Fullmove number
// - Counts how many full moves have been made
// - full moves are not a part of Board since it is not required to play legal chess, it will be handled by the Chess class
public static Board LoadBoardFromFen(out int move, String fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
{
Board board = new Board(new byte[BoardStateOffset.BOARD_STATE_SIZE]);
var sections = fen.Split(" ");
if (sections.Length != 6)
{
throw new ArgumentException("FEN has to contanin 6 sections");
}
string positions = sections[0];
string activeColor = sections[1];
string castlingOptions = sections[2];
string enPassantAttackedSquare = sections[3];
string halfMoveClock = sections[4];
string fullMoveClock = sections[5];
int square = BoardStateOffset.A8;
for (var i = 0; i < positions.Length; i++)
{
char piece = positions[i];
if (piece == '/')
{
square -= 24;
}
else if (Char.IsDigit(piece))
{
square += int.Parse(piece.ToString());
}
else
{
Piece parsedPiece = PieceParser.FromChar(piece);
//Board.PutPiece(board, square, parsedPiece);
board.SetPiece(square, parsedPiece);
if ((parsedPiece & Piece.PIECE_MASK) == Piece.KING)
{
//Board.SetKingPosition(board, (parsedPiece & Piece.IS_WHITE) == Piece.IS_WHITE, square);
board.SetKingPosition((int)(parsedPiece & Piece.IS_WHITE), (byte)square);
}
square++;
}
}
//Board.SetIsWhitesTurn(board, activeColor == "w");
board.IsWhiteTurnBool = activeColor == "w";
if (castlingOptions.Contains("K") && board.WhiteKingPosition == BoardStateOffset.E1 && board.GetPiece(BoardStateOffset.H1) == (Piece.ROOK | Piece.IS_WHITE))
{
//Board.SetCastleBit(board, CastlingBits.WHITE_KING_SIDE_CASTLE, true);
board.CastlingBits |= CastlingBits.WHITE_KING_SIDE_CASTLE;
}
if (castlingOptions.Contains("Q") && board.WhiteKingPosition == BoardStateOffset.E1 && board.GetPiece(BoardStateOffset.A1) == (Piece.ROOK | Piece.IS_WHITE))
{
//Board.SetCastleBit(board, CastlingBits.WHITE_QUEEN_SIDE_CASTLE, true);
board.CastlingBits |= CastlingBits.WHITE_QUEEN_SIDE_CASTLE;
}
if (castlingOptions.Contains("k") && board.BlackKingPosition == BoardStateOffset.E8 && board.GetPiece(BoardStateOffset.H8) == Piece.ROOK)
{
//Board.SetCastleBit(board, CastlingBits.BLACK_KING_SIDE_CASTLE, true);
board.CastlingBits |= CastlingBits.BLACK_KING_SIDE_CASTLE;
}
if (castlingOptions.Contains("q") && board.BlackKingPosition == BoardStateOffset.E8 && board.GetPiece(BoardStateOffset.A8) == Piece.ROOK)
{
//Board.SetCastleBit(board, CastlingBits.BLACK_QUEEN_SIDE_CASTLE, true);
board.CastlingBits |= CastlingBits.BLACK_QUEEN_SIDE_CASTLE;
}
if (enPassantAttackedSquare == "-")
{
//Board.SetEnPassantAttackedSquare(board, EnPassant.NO_ENPASSANT);
board.EnPassantTarget = EnPassant.NO_ENPASSANT;
}
else
{
//Board.SetEnPassantAttackedSquare(board, Board.AlgebraicPosition(enPassantAttackedSquare));
board.EnPassantTarget = (byte)BoardPosition.ArrayPosition(enPassantAttackedSquare);
}
//Board.SetHalfTurnCounter(board, int.Parse(halfMoveClock));
board.HalfTurnCounter = (byte)int.Parse(halfMoveClock);
//Board.SetFullMoveClock(board, int.Parse(fullMoveClock));
move = (short)int.Parse(fullMoveClock);
return(board);
}
