/*
* Return true if the side to move is in check
*/
public static Boolean inCheck(Position position)
{
int kingSquare = position.getKingSquare(position.whiteMove);
if (kingSquare < 0)
{
return false;
}
return squareAttacked(position, kingSquare);
}
/*
* Return true if a square is attacked by the opposite side
*/
public static Boolean squareAttacked(Position position, int square)
{
int file = Position.getFile(square);
int rank = Position.getRank(square);
Boolean isWhiteMove = position.whiteMove;
PieceType opppositeQueen = isWhiteMove ? PieceType.q : PieceType.Q;
PieceType opppositeRook = isWhiteMove ? PieceType.r : PieceType.R;
PieceType opppositeBishop = isWhiteMove ? PieceType.b : PieceType.B;
PieceType opppositeKnight = isWhiteMove ? PieceType.n : PieceType.N;
PieceType piece;
if (rank > 0)
{
piece = checkDirection(position, square, rank, -8);
if ((piece == opppositeQueen) || (piece == opppositeRook)) return true;
piece = checkDirection(position, square, Math.Min(file, rank), -9);
if ((piece == opppositeQueen) || (piece == opppositeBishop)) return true;
piece = checkDirection(position, square, Math.Min(7 - file, rank), -7);
if ((piece == opppositeQueen) || (piece == opppositeBishop)) return true;
if (file > 1)
{
piece = checkDirection(position, square, 1, -10);
if (piece == opppositeKnight) return true;
}
if (file > 0 && rank > 1)
{
piece = checkDirection(position, square, 1, -17);
if (piece == opppositeKnight) return true;
}
if (file < 7 && rank > 1)
{
piece = checkDirection(position, square, 1, -15);
if (piece == opppositeKnight) return true;
}
if (file < 6)
{
piece = checkDirection(position, square, 1, -6);
if (piece == opppositeKnight) return true;
}
if (!isWhiteMove)
{
if (file < 7 && rank > 1)
{
piece = checkDirection(position, square, 1, -7);
if (piece == PieceType.P) return true;
}
if (file > 0 && rank > 1)
{
piece = checkDirection(position, square, 1, -9);
if (piece == PieceType.P) return true;
}
}
}
if (rank < 7)
{
piece = checkDirection(position, square, 7 - rank, 8);
if ((piece == opppositeQueen) || (piece == opppositeRook)) return true;
piece = checkDirection(position, square, Math.Min(7 - file, 7 - rank), 9);
if ((piece == opppositeQueen) || (piece == opppositeBishop)) return true;
piece = checkDirection(position, square, Math.Min(file, 7 - rank), 7);
if ((piece == opppositeQueen) || (piece == opppositeBishop)) return true;
if (rank < 6)
{
piece = checkDirection(position, square, 1, 10);
if (piece == opppositeKnight) return true;
}
if (file < 7 && rank < 6)
{
piece = checkDirection(position, square, 1, 17);
if (piece == opppositeKnight) return true;
}
if (file > 0 && rank < 6)
{
piece = checkDirection(position, square, 1, 15);
if (piece == opppositeKnight) return true;
}
if (file > 1)
{
piece = checkDirection(position, square, 1, 6);
if (piece == opppositeKnight) return true;
}
if (isWhiteMove)
{
if (file < 7 && rank < 6)
{
piece = checkDirection(position, square, 1, 9);
if (piece == PieceType.p) return true;
}
if (file > 0 && rank < 6)
{
piece = checkDirection(position, square, 1, 7);
if (piece == PieceType.p) return true;
}
}
}
piece = checkDirection(position, square, 7 - file, 1);
if ((piece == opppositeQueen) || (piece == opppositeRook)) return true;
piece = checkDirection(position, square, file, -1);
if ((piece == opppositeQueen) || (piece == opppositeRook)) return true;
int opppositeKingSquare = position.getKingSquare(!isWhiteMove);
if (opppositeKingSquare >= 0)
{
int oFile = Position.getFile(opppositeKingSquare);
int oRank = Position.getRank(opppositeKingSquare);
if ((Math.Abs(file - oFile) <= 1) && (Math.Abs(rank - oRank) <= 1))
{
return true;
}
}
return false;
}
