// TODO: Add Validation
public static Move FromLongAlgebraic(Position position, string move)
{
int[] squares = position.GetPieceSquares();
int originSquare = Bitboards.GetSquareFromName(move.Substring(0, 2));
int destinationSquare = Bitboards.GetSquareFromName(move.Substring(2, 2));
int capturePiece = squares[destinationSquare];
int movedPiece = squares[originSquare];
// Castle Moves
if (movedPiece == Position.KING && Bitboards.SquareDistance[originSquare, destinationSquare] > 1)
{
int castleDirection = Bitboards.GetColumn(destinationSquare) == 6 ? Position.KING : Position.QUEEN;
return(new Move(originSquare, destinationSquare, movedPiece, false, true, castleDirection));
}
// En Passent and Promotion
if (movedPiece == Position.PAWN)
{
// En Passent
if (Bitboards.GetColumn(originSquare) != Bitboards.GetColumn(destinationSquare) &&
capturePiece == Position.EMPTY)
{
return(new Move(originSquare, destinationSquare, movedPiece, true, false));
}
else if (move.Length > 4)
{
const string promotionMap = "-qrbn";
int promotionPiece = promotionMap.IndexOf(move[4]);
return(new Move(originSquare, destinationSquare, movedPiece, capturePiece, promotionPiece));
}
}
// Everything else
return(new Move(originSquare, destinationSquare, movedPiece, capturePiece));
}
public static int[] GenerateOffsets(Bitboard bitboard)
{
int[] result = new int[Bitboards.CountBits(bitboard)];
int cnt = 0;
while (bitboard != 0)
{
result[cnt++] = Bitboards.BitScanForward(bitboard);
Bitboards.PopLsb(ref bitboard);
}
return(result);
}
public override string ToString()
{
string pieceStr = "KQRBNP";
StringBuilder sb = new StringBuilder();
sb.Append(Bitboards.GetNameFromSquare(OriginSquare()));
sb.Append(Bitboards.GetNameFromSquare(DestinationSquare()));
if (PromotionType() != Position.EMPTY)
{
sb.Append('=');
sb.Append(pieceStr[PromotionType()]);
}
return(sb.ToString());
}
public static Bitboard[] GeneratePermutations(Bitboard occupancyBitboard)
{
int numBits = Bitboards.CountBits(occupancyBitboard);
int numPossibilities = (int)Math.Pow(2, numBits);
int[] offsets = GenerateOffsets(occupancyBitboard);
Bitboard[] result = new Bitboard[numPossibilities];
for (int i = 0; i < numPossibilities; i++)
{
for (int bit = 0; bit < numBits; bit++)
{
bool bitIsSet = (i & (1 << bit)) != 0;
if (bitIsSet)
{
result[i] |= Bitboards.SquareBitboards[offsets[bit]];
}
}
}
return(result);
}
