//checks in all 4 directions to see if piece at (xFrom, yFrom) can move in that direction
//if so, creates a board in that state and adds it to the list
public static List <Board> GetMovesForPiece(Board state, int xFrom, int yFrom)
{
var movesFound = new List <Board>();
if (MoveIsPossible(state, xFrom, yFrom, xFrom + 1, yFrom + 1))
{
sbyte[,] layout = state.CloneBoardState();
if (yFrom + 1 == 7)//back row reached, make piece into a king
{
layout[xFrom + 1, yFrom + 1] = Board.BlackKing;
}
else
{
layout[xFrom + 1, yFrom + 1] = layout[xFrom, yFrom];
}
layout[xFrom, yFrom] = Board.Empty;
movesFound.Add(new Board(layout));
}
if (MoveIsPossible(state, xFrom, yFrom, xFrom - 1, yFrom + 1))
{
sbyte[,] layout = state.CloneBoardState();
if (yFrom + 1 == 7)//back row reached, make piece into a king
{
layout[xFrom - 1, yFrom + 1] = Board.BlackKing;
}
else
{
layout[xFrom - 1, yFrom + 1] = layout[xFrom, yFrom];
}
layout[xFrom, yFrom] = Board.Empty;
movesFound.Add(new Board(layout));
}
if (MoveIsPossible(state, xFrom, yFrom, xFrom - 1, yFrom - 1))
{
sbyte[,] layout = state.CloneBoardState();
layout[xFrom - 1, yFrom - 1] = layout[xFrom, yFrom];
layout[xFrom, yFrom] = Board.Empty;
movesFound.Add(new Board(layout));
}
if (MoveIsPossible(state, xFrom, yFrom, xFrom + 1, yFrom - 1))
{
sbyte[,] layout = state.CloneBoardState();
layout[xFrom + 1, yFrom - 1] = layout[xFrom, yFrom];
layout[xFrom, yFrom] = Board.Empty;
movesFound.Add(new Board(layout));
}
return(movesFound);
}
//Moves piece at (xFrom, yFrom) to (xTo, yTo) and returns a board representing the new state
public static Board ExecuteMove(Board state, int xFrom, int yFrom, int xTo, int yTo)
{
if (xTo < 0 || xTo >= 8 || yTo < 0 || yTo >= 8 || xFrom < 0 || xFrom >= 8 || yTo < 0 || yTo >= 8)
{
throw new InvalidOperationException("ExecuteMove method called with out-of-bounds coordinates");
}
sbyte[,] layout = state.CloneBoardState();
layout[xTo, yTo] = layout[xFrom, yFrom]; //Move piece to new space
layout[xFrom, yFrom] = Board.Empty; //Origin space is empty
if (Math.Abs(xFrom - xTo) == 2 || Math.Abs(yFrom - yTo) == 2) //piece was captured, make this space empty too
{
layout[(xFrom + xTo) / 2, (yFrom + yTo) / 2] = Board.Empty;
}
Board result = new Board(layout);
return(result);
}
