public Square(ChessGameState game, Square previous)
{
Game = game;
if (previous.Piece != null)
{
Piece = new SinglePiece(previous.Piece);
}
LastUpdate = previous.LastUpdate;
}
public ChessGameState GetNextMove(int x1, int y1, int x2, int y2)
{
ChessGameState toReturn = null;
if (squareInBoard(x1, y1) &&
squareInBoard(x2, y2))
{
toReturn = this[x1, y1].PossibleMoves.FirstOrDefault(
(elem) => elem.MovedTo.X == x2 && elem.MovedTo.Y == y2);
}
return(toReturn);
}
private ChessGameState(ChessGameState previous)
{
for (int i = 0; i < 8; i++)
{
for (int j = 0; j < 8; j++)
{
board[i, j] = new Square(this, previous.board[i, j]);
}
}
WhiteChecked = new Lazy <bool>(() => CheckForCheck(Color.White));
BlackChecked = new Lazy <bool>(() => CheckForCheck(Color.Black));
}
private ChessGameState generateStateForNextMove(Pair movedTo)
{
ChessGameState newGameState = new ChessGameState(this);
if (Tour == Color.White)
{
newGameState.Tour = Color.Black;
}
else
{
newGameState.Tour = Color.White;
}
newGameState.TourNumber = TourNumber + 1;
newGameState.MovedTo = movedTo;
return(newGameState);
}
/// <summary>
/// Compute all possible moves for exact square.
/// </summary>
private void ComputePossibleMoves(int column, int row)
{
Action <int, int> moveDiagonaly = (int x, int y) =>
{
int c = column + x;
int r = row + y;
while (squareInBoard(c, r) &&
this[c, r].Piece == null)
{
ChessGameState newState = generateStateForNextMove(new Pair(c, r));
newState[c, r].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
c += x;
r += y;
}
if (squareInBoard(c, r) &&
this[c, r].Piece != null &&
this[c, r].Piece.Color != Tour)
{
ChessGameState newState = generateStateForNextMove(new Pair(c, r));
newState[c, r].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
}
};
Action <int, int> moveJump = (int x, int y) =>
{
int c = column + x;
int r = row + y;
if (squareInBoard(c, r) &&
((this[c, r].Piece != null &&
this[c, r].Piece.Color != Tour) ||
this[c, r].Piece == null))
{
ChessGameState newState = generateStateForNextMove(new Pair(c, r));
newState[c, r].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
}
};
switch (this[column, row].Piece.Piece)
{
case PieceType.Pawn:
{
int direction = 0;
if (Tour == Color.White)
{
direction = 1;
}
else
{
direction = -1;
}
Action <PieceType> pawnPromote = (PieceType toPiece) =>
{
if (!squareInBoard(column, row + direction))
{
ChessGameState newState = generateStateForNextMove(new Pair(column, row));
newState[column, row].Piece.Piece = toPiece;
newState[column, row].LastUpdate = newState.TourNumber;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
}
};
Func <int, bool> pawnHasEnemyOnDiagonal = (int side) =>
{
return
(squareInBoard(column + side, row + direction) &&
this[column + side, row + direction].Piece != null &&
this[column + side, row + direction].Piece.Color != Tour);
};
Action <int> pawnBeat = (int side) =>
{
if (pawnHasEnemyOnDiagonal(side))
{
ChessGameState newState = generateStateForNextMove(new Pair(column + side, row + direction));
newState[column + side, row + direction].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
}
};
Action pawnMove = () =>
{
if (pawnHasEnemyOnDiagonal(1) ||
pawnHasEnemyOnDiagonal(-1))
{
return;
}
if (squareInBoard(column, row + direction) &&
this[column, row + direction].Piece == null)
{
ChessGameState newState = generateStateForNextMove(new Pair(column, row + direction));
newState[column, row + direction].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
// Double move
if (this[column, row].LastUpdate == 0 &&
squareInBoard(column, row + 2 * direction) &&
this[column, row + 2 * direction].Piece == null)
{
ChessGameState newState2 = generateStateForNextMove(new Pair(column, row + 2 * direction));
newState2[column, row + 2 * direction].Piece = newState2[column, row].Piece;
newState2[column, row].Piece = null;
if (!newState2.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState2);
}
}
}
};
Action <int> pawnPassat = (int side) =>
{
if (squareInBoard(column + side, row) &&
this[column + side, row].Piece != null &&
this[column + side, row].Piece.Piece == PieceType.Pawn &&
this[column + side, row].Piece.Color != Tour &&
this[column + side, row].LastUpdate == TourNumber &&
squareInBoard(column + side, row + 2 * direction) &&
this[column + side, row + 2 * direction].Piece == null &&
this[column + side, row + 2 * direction].LastUpdate == TourNumber)
{
ChessGameState newState = generateStateForNextMove(new Pair(column + side, row + direction));
newState[column + side, row + direction].Piece = newState[column, row].Piece;
newState[column, row].Piece = null;
newState[column + side, row].Piece = null;
if (!newState.IsChecked(Tour))
{
this[column, row].PossibleMoves.Add(newState);
}
}
};
pawnPromote(PieceType.Queen);
pawnPromote(PieceType.Rook);
pawnPromote(PieceType.Knight);
pawnPromote(PieceType.Bishop);
pawnBeat(-1);
pawnBeat(1);
pawnMove();
pawnPassat(-1);
pawnPassat(1);
break;
}
case PieceType.Rook:
{
moveDiagonaly(1, 0);
moveDiagonaly(-1, 0);
moveDiagonaly(0, 1);
moveDiagonaly(0, -1);
break;
}
case PieceType.Bishop:
{
moveDiagonaly(1, 1);
moveDiagonaly(-1, 1);
moveDiagonaly(1, -1);
moveDiagonaly(-1, -1);
break;
}
case PieceType.Queen:
{
moveDiagonaly(1, 0);
moveDiagonaly(-1, 0);
moveDiagonaly(0, 1);
moveDiagonaly(0, -1);
moveDiagonaly(1, 1);
moveDiagonaly(-1, 1);
moveDiagonaly(1, -1);
moveDiagonaly(-1, -1);
break;
}
case PieceType.Knight:
{
moveJump(1, 2);
moveJump(2, 1);
moveJump(2, -1);
moveJump(1, -2);
moveJump(-1, -2);
moveJump(-2, -1);
moveJump(-2, 1);
moveJump(-1, 2);
break;
}
case PieceType.King:
{
Action castlingLeft = () =>
{
if (this[column, row].LastUpdate == 0 &&
this[0, row].Piece != null &&
this[0, row].LastUpdate == 0 &&
this[1, row].Piece == null &&
this[2, row].Piece == null &&
this[3, row].Piece == null)
{
ChessGameState newState = generateStateForNextMove(new Pair(2, row));
newState[2, row].Piece = newState[4, row].Piece;
newState[4, row].Piece = null;
ChessGameState newCrossState = generateStateForNextMove(new Pair(3, row));
newState[3, row].Piece = newState[4, row].Piece;
newState[3, row].Piece = null;
if (!this.IsChecked(Tour) &&
!newState.IsChecked(Tour) &&
!newCrossState.IsChecked(Tour))
{
newState[3, row].Piece = newState[0, row].Piece;
newState[0, row].Piece = null;
this[column, row].PossibleMoves.Add(newState);
}
}
};
Action castlingRight = () =>
{
if (this[column, row].LastUpdate == 0 &&
this[7, row].Piece != null &&
this[7, row].LastUpdate == 0 &&
this[5, row].Piece == null &&
this[6, row].Piece == null)
{
ChessGameState newState = generateStateForNextMove(new Pair(6, row));
newState[6, row].Piece = newState[4, row].Piece;
newState[4, row].Piece = null;
ChessGameState newCrossState = generateStateForNextMove(new Pair(5, row));
newState[5, row].Piece = newState[4, row].Piece;
newState[4, row].Piece = null;
if (!this.IsChecked(Tour) &&
!newState.IsChecked(Tour) &&
!newCrossState.IsChecked(Tour))
{
newState[5, row].Piece = newState[7, row].Piece;
newState[7, row].Piece = null;
this[column, row].PossibleMoves.Add(newState);
}
}
};
moveJump(1, 1);
moveJump(1, 0);
moveJump(1, -1);
moveJump(0, -1);
moveJump(-1, -1);
moveJump(-1, 0);
moveJump(-1, 1);
moveJump(0, 1);
castlingLeft();
castlingRight();
break;
}
}
}
public Square(ChessGameState game)
{
Game = game;
LastUpdate = 0;
}