/*
* Returns true if a move results in a caputre for a given
* position
*/
public static Boolean isMoveCapture(Move move, Position position)
{
if (position.getPiece(move.destination) == PieceType.Empty)
{
//Deal with En Passant capture
PieceType piece = position.getPiece(move.origin);
if ((piece == (position.whiteMove ? PieceType.P : PieceType.p)) && (move.destination == position.getEpSquare()))
{
return true;
}
else
{
return false;
}
}
else
{
return true;
}
}
/*
* Return a Forsyth-Edwards Notation string corresponding to a Position object
*/
public static String convertPositionToFEN(Position position)
{
StringBuilder feNotation = new StringBuilder();
//Piece placement
for (int rank = 7; rank >= 0; rank--)
{
int emptySquares = 0;
for (int file = 0; file < 8; file++)
{
PieceType piece = position.getPiece(Position.getSquare(file, rank));
if (piece == PieceType.Empty)
{
emptySquares++;
}
else
{
if (emptySquares > 0)
{
feNotation.Append(emptySquares);
emptySquares = 0;
}
switch (piece)
{
case PieceType.K: feNotation.Append('K'); break;
case PieceType.Q: feNotation.Append('Q'); break;
case PieceType.R: feNotation.Append('R'); break;
case PieceType.B: feNotation.Append('B'); break;
case PieceType.N: feNotation.Append('N'); break;
case PieceType.P: feNotation.Append('P'); break;
case PieceType.k: feNotation.Append('k'); break;
case PieceType.q: feNotation.Append('q'); break;
case PieceType.r: feNotation.Append('r'); break;
case PieceType.b: feNotation.Append('b'); break;
case PieceType.n: feNotation.Append('n'); break;
case PieceType.p: feNotation.Append('p'); break;
default: throw new ParserError("Error creating FEN String");
}
}
}
if (emptySquares > 0)
{
feNotation.Append(emptySquares);
}
if (rank > 0)
{
feNotation.Append("/");
}
}
//Active Colour
feNotation.Append(position.whiteMove ? " w " : " b ");
//Castling Rights
Boolean anyCastle = false;
if (position.h1Castle())
{
feNotation.Append('K');
anyCastle = true;
}
if (position.a1Castle())
{
feNotation.Append('Q');
anyCastle = true;
}
if (position.h8Castle())
{
feNotation.Append('k');
anyCastle = true;
}
if (position.a8Castle())
{
feNotation.Append('q');
anyCastle = true;
}
if (!anyCastle)
{
feNotation.Append('-');
}
//En Passant Target Square
{
feNotation.Append(" ");
if (position.getEpSquare() >= 0)
{
int file = Position.getFile(position.getEpSquare());
int rank = Position.getRank(position.getEpSquare());
feNotation.Append((char)(file + 'a'));
feNotation.Append((char)(rank + '1'));
}
else
{
feNotation.Append('-');
}
}
//Move Counters
feNotation.Append(' ');
feNotation.Append(position.halfMoveClock);
feNotation.Append(' ');
feNotation.Append(position.fullMoveCounter);
return feNotation.ToString();
}
/*
* Remove EPSquare from position if it is not legal
*/
private static void fixupEPSquare(Position position)
{
int epSquare = position.getEpSquare();
if (epSquare >= 0)
{
ArrayList moves = MoveGenerator.mgInstance.legalMoves(position);
Boolean epValid = false;
foreach (Move move in moves)
{
if (move.destination == epSquare)
{
if (position.getPiece(move.origin) == (position.whiteMove ? PieceType.P : PieceType.p))
{
epValid = true;
break;
}
}
}
if (!epValid)
{
position.setEpSquare(-1);
}
}
}
/*
* Generate and return a list of psuedo-legal moves.
* Pseudo-legal moves are those that don't necessarily defend
* from check threats.
*/
public ArrayList psuedoLegalMoves(Position position)
{
ArrayList moveList = getMoveListObject();
Boolean whiteToMove = position.whiteMove;
for (int file = 0; file < 8; file++)
{
for (int rank = 0; rank < 8; rank++)
{
int square = Position.getSquare(file, rank);
PieceType piece = position.getPiece(square);
if ((piece == PieceType.Empty) || (((int)piece < 6) != whiteToMove))
{
continue;
}
if ((piece == PieceType.R) || (piece == PieceType.r) || (piece == PieceType.Q) || (piece == PieceType.q))
{
if (addDirection(moveList, position, square, 7 - file, 1)) return moveList;
if (addDirection(moveList, position, square, 7 - rank, 8)) return moveList;
if (addDirection(moveList, position, square, file, -1)) return moveList;
if (addDirection(moveList, position, square, rank, -8)) return moveList;
}
if ((piece == PieceType.B) || (piece == PieceType.b) || (piece == PieceType.Q) || (piece == PieceType.q))
{
if (addDirection(moveList, position, square, Math.Min(7 - file, 7 - rank), 9)) return moveList;
if (addDirection(moveList, position, square, Math.Min(file, 7 - rank), 7)) return moveList;
if (addDirection(moveList, position, square, Math.Min(file, rank), -9)) return moveList;
if (addDirection(moveList, position, square, Math.Min(7 - file, rank), -7)) return moveList;
}
if ((piece == PieceType.N) || (piece == PieceType.n))
{
if (file < 6 && rank < 7 && addDirection(moveList, position, square, 1, 10)) return moveList;
if (file < 7 && rank < 6 && addDirection(moveList, position, square, 1, 17)) return moveList;
if (file > 0 && rank < 6 && addDirection(moveList, position, square, 1, 15)) return moveList;
if (file > 1 && rank < 7 && addDirection(moveList, position, square, 1, 6)) return moveList;
if (file > 1 && rank > 0 && addDirection(moveList, position, square, 1, -10)) return moveList;
if (file > 0 && rank > 1 && addDirection(moveList, position, square, 1, -17)) return moveList;
if (file < 7 && rank > 1 && addDirection(moveList, position, square, 1, -15)) return moveList;
if (file < 6 && rank > 0 && addDirection(moveList, position, square, 1, -6)) return moveList;
}
if ((piece == PieceType.K) || (piece == PieceType.k))
{
if (file < 7 && addDirection(moveList, position, square, 1, 1)) return moveList;
if (file < 7 && rank < 7 && addDirection(moveList, position, square, 1, 9)) return moveList;
if (rank < 7 && addDirection(moveList, position, square, 1, 8)) return moveList;
if (file > 0 && rank < 7 && addDirection(moveList, position, square, 1, 7)) return moveList;
if (file > 0 && addDirection(moveList, position, square, 1, -1)) return moveList;
if (file > 0 && rank > 0 && addDirection(moveList, position, square, 1, -9)) return moveList;
if (rank > 0 && addDirection(moveList, position, square, 1, -8)) return moveList;
if (file < 7 && rank > 0 && addDirection(moveList, position, square, 1, -7)) return moveList;
int kingOrigin = whiteToMove ? Position.getSquare(4, 0) : Position.getSquare(4, 7);
if (Position.getSquare(file, rank) == kingOrigin)
{
int aCastle = whiteToMove ? Position.A1_CASTLE : Position.A8_CASTLE;
int hCastle = whiteToMove ? Position.H1_CASTLE : Position.H8_CASTLE;
PieceType rook = whiteToMove ? PieceType.R : PieceType.r;
if (((position.getCastleMask() & (1 << hCastle)) != 0) &&
(position.getPiece(kingOrigin + 1) == PieceType.Empty) &&
(position.getPiece(kingOrigin + 2) == PieceType.Empty) &&
(position.getPiece(kingOrigin + 3) == rook) &&
!squareAttacked(position, kingOrigin) &&
!squareAttacked(position, kingOrigin + 1) &&
!squareAttacked(position, kingOrigin + 2))
{
moveList.Add(getMoveObject(kingOrigin, kingOrigin + 2, PieceType.Empty));
}
if (((position.getCastleMask() & (1 << aCastle)) != 0) &&
(position.getPiece(kingOrigin - 1) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 2) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 3) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 4) == rook) &&
!squareAttacked(position, kingOrigin) &&
!squareAttacked(position, kingOrigin - 1) &&
!squareAttacked(position, kingOrigin - 2))
{
moveList.Add(getMoveObject(kingOrigin, kingOrigin - 2, PieceType.Empty));
}
}
}
if ((piece == PieceType.P) || (piece == PieceType.p))
{
int rankDir = whiteToMove ? 8 : -8;
if (position.getPiece(square + rankDir) == PieceType.Empty)
{
//non capture moves
addPawnMoves(moveList, square, square + rankDir);
if ((rank == (whiteToMove ? 1 : 6)) &&
(position.getPiece(square + 2 * rankDir) == PieceType.Empty))
{
//double step moves
addPawnMoves(moveList, square, square + rankDir * 2);
}
}
//Capture to the left
if (file > 0)
{
int toSquare = square + rankDir - 1;
PieceType captured = position.getPiece(toSquare);
if (captured != PieceType.Empty)
{
if (((int)captured < 6) != whiteToMove)
{
if (captured == (whiteToMove ? PieceType.k : PieceType.K))
{
returnMoveList(moveList);
moveList = getMoveListObject();
moveList.Add(getMoveObject(square, toSquare, PieceType.Empty));
return moveList;
}
else
{
addPawnMoves(moveList, square, toSquare);
}
}
}
else if (toSquare == position.getEpSquare())
{
addPawnMoves(moveList, square, toSquare);
}
}
//Capture to the right
if (file < 7)
{
int toSquare = square + rankDir + 1;
PieceType captured = position.getPiece(toSquare);
if (captured != PieceType.Empty)
{
if (((int)captured < 6) != whiteToMove)
{
if (captured == (whiteToMove ? PieceType.k : PieceType.K))
{
returnMoveList(moveList);
moveList = getMoveListObject();
moveList.Add(getMoveObject(square, toSquare, PieceType.Empty));
return moveList;
}
else
{
addPawnMoves(moveList, square, toSquare);
}
}
}
else if (toSquare == position.getEpSquare())
{
addPawnMoves(moveList, square, toSquare);
}
}
}
}
}
return moveList;
}
