//generate bitboard of moves
public static ulong PseudomoveBitboard(int piece, int[] board)
{
bool isWhite = Util.IsWhite(piece);
int position = Util.GetPieceOffset(piece);
int positionX = Util.GetXForPosition(position);
int positionY = Util.GetYForPosition(position);
ulong result = 0;
ulong one = 1;
if (isWhite)
{
if (positionY < 6)
{
if (board[position + 8] == 0)
{
result |= (one << (position + 8));
}
//captures
if (positionX > 0)
{
result |= (one << (position + 7));
}
if (positionX < 7)
{
result |= (one << (position + 9));
}
//initial double move
if (positionY == 1)
{
result |= (one << (position + (2 * 8)));
}
}
else if (positionY == 6)
{
//pawn promotion
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('Q') + position + 8));
if (positionX > 0)
{
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('Q') + position + 7));
}
if (positionX < 7)
{
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('Q') + position + 9));
}
}
}
else
{
if (positionY > 1)
{
if (board[position - 8] == 0)
{
result |= (one << (position - 8));
}
//captures
if (positionX < 7)
{
result |= (one << (position - 7));
}
if (positionX > 0)
{
result |= (one << (position - 9));
}
//initial double move
if (positionY == 6)
{
result |= (one << (position - (2 * 8)));
}
}
else if (positionY == 1)
{
//pawn promotion
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('q') + position - 8));
if (positionX < 7)
{
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('q') + position - 7));
}
if (positionX > 0)
{
result |= QueenMoveGenerator.PseudomoveBitboard((PieceTypeFENMap.PieceValue('q') + position - 9));
}
}
}
return(result);
}
public Game(string fen)
{
_theBoard = new int[64];
history = new Stack <Move>();
//split the sections of the FEN string with spaces
string[] fenParts = fen.Trim().Split(' ');
//first part is for piece positions
if (fenParts.Length > 0)
{
int[] positions = new int[64];
int index = 0;
//rows are delimited by /
//Row order reversed because the convention I am using is bottom-left=0,0, but FEN starts with rank 8 for some stupid reason
string[] positionRows = fenParts[0].Trim().Split('/').Reverse().ToArray();
for (int y = 0; y < 8; y++)
{
string row = positionRows[y];
//and we have to reverse the row itself too.
char[] charArray = row.ToCharArray();
row = new string(charArray);
for (int x = 0; x < row.Length; x++)
{
//if we see a number, that means n spots are empty in this row, skip over them
if (char.IsNumber(row[x]))
{
//-'0' char trick to offset ascii number
index += row[x] - '0';
}
else
{
positions[index] = (PieceTypeFENMap.PieceValue(row[x]) + index);
index++;
}
}
}
_theBoard = positions;
}
if (fenParts.Length > 1)
{
if (fenParts[1] == "b")
{
_whiteToMove = false;
}
}
if (fenParts.Length > 2)
{
if (!fenParts[2].Contains("K"))
{
_whiteOOCastle = false;
}
if (!fenParts[2].Contains("Q"))
{
_whiteOOOCastle = false;
}
if (!fenParts[2].Contains("k"))
{
_blackOOCastle = false;
}
if (!fenParts[2].Contains("q"))
{
_blackOOOCastle = false;
}
}
if (fenParts.Length > 3 && fenParts[3][0] != '-')
{
//file + (8 * rank)
//ascii offset -'1' instead of -'0' because FEN is 1 indexed instead of 0 indexed
_enPassantSquare = (Util.FileToInt(fenParts[3][0]) + (8 * (fenParts[3][1] - '1')));
}
foreach (int p in _theBoard)
{
if (Util.IsWhiteKing(p))
{
whiteKing = p;
}
else if (Util.IsBlackKing(p))
{
blackKing = p;
}
}
}
//generate real moves based on board state
public static List <int> PossiblePositions(int piece, int[] board)
{
bool isWhite = Util.IsWhite(piece);
List <int> tempResult = new List <int>();
List <int> result = new List <int>();
int position = Util.GetPieceOffset(piece);
int depositionedPiece = Util.DepositionPiece(piece);
int positionX = Util.GetXForPosition(position);
int positionY = Util.GetYForPosition(position);
if (isWhite)
{
if (positionY < 6)
{
if (board[position + 8] == 0)
{
result.Add((piece + 8));
}
//captures
if (positionX > 0 && board[position + 7] > 0 && Util.IsWhite(board[position + 7]) != isWhite)
{
result.Add((piece + 7));
}
if (positionX < 7 && board[position + 9] > 0 && Util.IsWhite(board[position + 9]) != isWhite)
{
result.Add((piece + 9));
}
if (positionY == 1)
{
if (board[position + 8] == 0 && board[position + (2 * 8)] == 0)
{
result.Add((piece + (2 * 8)));
}
}
}
else if (positionY == 6)
{
//pawn promotion
if (board[position + 8] == 0)
{
result.Add((PieceTypeFENMap.PieceValue('Q') + position + 8));
}
if (positionX > 0 && board[position + 7] > 0 && Util.IsWhite(board[position + 7]) != isWhite)
{
result.Add((PieceTypeFENMap.PieceValue('Q') + position + 7));
}
if (positionX < 7 && board[position + 7] > 0 && Util.IsWhite(board[position + 9]) != isWhite)
{
result.Add((PieceTypeFENMap.PieceValue('Q') + position + 9));
}
}
}
else
{
if (positionY > 1)
{
if (board[position - 8] == 0)
{
result.Add((piece - 8));
}
if (positionX < 7 && board[position - 7] > 0 && Util.IsWhite(board[position - 7]) != isWhite)
{
result.Add((piece - 7));
}
if (positionX > 0 && board[position - 9] > 0 && Util.IsWhite(board[position - 9]) != isWhite)
{
result.Add((piece - 9));
}
if (positionY == 6)
{
if (board[position - 8] == 0 && board[position - (2 * 8)] == 0)
{
result.Add((piece - (2 * 8)));
}
}
}
else if (positionY == 1)
{
//pawn promotion
if (board[position - 8] == 0)
{
result.Add((PieceTypeFENMap.PieceValue('q') + position - 8));
}
if (positionX < 7 && board[position - 7] > 0 && Util.IsWhite(board[position - 7]) != isWhite)
{
result.Add((PieceTypeFENMap.PieceValue('q') + position - 7));
}
if (positionX > 0 && board[position - 9] > 0 && Util.IsWhite(board[position - 9]) != isWhite)
{
result.Add((PieceTypeFENMap.PieceValue('q') + position - 9));
}
}
}
return(result);
}