private static bool castleSquaresInCheck(Move move, Piece piece, ControlledPositions controlledMoves)
{
if (move.isCastle)
{
UInt64 testMask = castleSquaresBitMask(move, piece);
if ((controlledMoves.ControlledPositionsBitMask & testMask) != 0)
{
return(true);
}
}
return(false);
}
private bool gameOver(ref PieceColor winner)
{
foreach (Square pos in gamestate.getPiecePositions())
{
PossibleMoves moves = new PossibleMoves(gamestate, pos);
if (moves.MoveCount != 0)
{
return(false);
}
}
ControlledPositions control = new ControlledPositions(gamestate, (PieceColor)(1 - gamestate.turnColor));
if (control.Check == null)
{
winner = PieceColor.PieceColor_NB;
}
else
{
winner = (PieceColor)(1 - gamestate.turnColor);
}
return(true);
}
public PossibleMoves(Gamestate board, Square StartPosition)
{
MoveCount = 0;
MoveBitMask = 0;
Piece StartPiece = board.GetPiece(StartPosition);
if (StartPiece == null)
{
return;
}
Moves = StartPiece.getPositionMoves(StartPosition);
MoveDirections skipDirection = MoveDirections.Move_0;
UInt32 mask = 1;
foreach (Move move in Moves)
{
mask <<= 1;
if (move.Direction == skipDirection)
{
continue;
}
else
{
skipDirection = MoveDirections.Move_0;
}
if (continueIfCastle(board, StartPiece, move))
{
continue;
}
Piece EndPiece = board.GetPiece(move.MovePosition);
Piece CapturePiece = board.GetPiece(move.CapturePosition);
if (continueIfEnPassant(board, move, CapturePiece))
{
continue;
}
if (endPiecesMatchMoveFlags(StartPiece, move, EndPiece, CapturePiece))
{
// check if move is legal
Gamestate testBoard = new Gamestate(board);
if (testBoard.GetPiece(move.CapturePosition) != null)
{
testBoard.RemovePiece(move.CapturePosition);
}
Piece piece = testBoard.GetPiece(StartPosition);
testBoard.RemovePiece(StartPosition);
testBoard.PutPiece(piece, move.MovePosition);
testBoard.turnColor = (testBoard.turnColor == PieceColor.White) ? PieceColor.Black : PieceColor.White;
ControlledPositions controlledMoves = new ControlledPositions(testBoard);
if (controlledMoves.Check == null)
{
if (castleSquaresInCheck(move, piece, controlledMoves))
{
continue;
}
EndPositionBitMask |= ((UInt64)1 << (byte)move.MovePosition);
MoveBitMask |= mask;
MoveCount++;
}
}
if (EndPiece != null || CapturePiece != null)
{
skipDirection = move.Direction;
}
}
MoveBitMask >>= 1;
}
private int calculateScore(uint depth, ref UInt64 candidateCount, Optimize optimize)
{
if (depth > 0)
{
gamestate.flipTurnColor();
gamestate.setEnPassantPosition(gamestate.turnColor, null);
IEnumerable <Move> allMoves = getAllMoves();
int bestScore = (optimize == Optimize.Highest) ? int.MinValue : int.MaxValue;
Move bestMove = null;
foreach (Move move in allMoves)
{
Gamestate testState = new Gamestate(gamestate);
GameControl testControl = new GameControl(testState);
testControl.makeMove(move);
Piece piece = gamestate.GetPiece(move.StartPosition);
//for (int d = 0; d <= 5 - depth; d++) Console.Write(" ");
//Console.WriteLine(" considering move " + gamestate.turnColor + " " + piece.Type +" from " + move.StartPosition + " to " + move.MovePosition);
int score = testControl.calculateScore(depth - 1, ref candidateCount, (optimize == Optimize.Highest) ? Optimize.Lowest : Optimize.Highest);
//for (int d = 0; d <= 5 - depth; d++) Console.Write(" ");
//Console.WriteLine(" -> score " + score);
if (optimize == Optimize.Highest && score > bestScore || optimize == Optimize.Lowest && score < bestScore)
{
bestScore = score;
bestMove = move;
}
}
//Piece bestPiece = gamestate.GetPiece(bestMove.StartPosition);
//for (int d = 0; d <= 5 - depth; d++) Console.Write(" ");
//Console.WriteLine(" selected move " + gamestate.turnColor + " " + bestPiece.Type + " from " + bestMove.StartPosition + " to " + bestMove.MovePosition + " with score " + bestScore);
return(bestScore);
}
else
{
ControlledPositions cp = new ControlledPositions(gamestate);
int score = 0;
for (Square pos = Square.A1; pos <= Square.H8; pos++)
{
Piece piece = gamestate.GetPiece(pos);
if (piece != null && piece.Color == gamestate.turnColor)
{
score += 3 * (int)piece.Value;
}
if ((cp.ControlledPositionsBitMask & ((UInt64)1 << (byte)pos)) != 0)
{
score += 8;
if (piece != null && (piece.Type != PieceType.King || piece.Color != gamestate.turnColor))
{
score += (int)piece.Value;
}
}
}
cp = new ControlledPositions(gamestate, (gamestate.turnColor == PieceColor.White) ? PieceColor.Black : PieceColor.White);
for (Square pos = Square.A1; pos <= Square.H8; pos++)
{
Piece piece = gamestate.GetPiece(pos);
if (piece != null && piece.Color != gamestate.turnColor)
{
score -= 3 * (int)piece.Value;
}
if ((cp.ControlledPositionsBitMask & ((UInt64)1 << (byte)pos)) != 0)
{
score -= 8;
if (piece != null && (piece.Type != PieceType.King || piece.Color != gamestate.turnColor))
{
score -= (int)piece.Value;
}
}
}
candidateCount++;
return(score);
}
}