private bool StepIsEmptyAndValid(TravelStep direction, Square currentSquare, Board board)
{
if (direction.TravelFromSquare(currentSquare).IsOnTheBoard())
{
return(board.GetPiece(direction.TravelFromSquare(currentSquare)) == null);
}
return(false);
}
private bool DiagonalStepLandsOnOpposingPieceAndIsValid(TravelStep direction, Square currentSquare, Board board)
{
if (direction.TravelFromSquare(currentSquare).IsOnTheBoard())
{
return(board.GetPiece(direction.TravelFromSquare(currentSquare)) != null &&
board.GetPiece(direction.TravelFromSquare(currentSquare)).Player != this.Player);
}
return(false);
}
public List <Square> GetPawnMoves(Square currentSquare, Board board)
{
int drow = 0;
List <Square> diagonals = new List <Square>();
if (this.Player == Player.White)
{
drow = -1;
}
else if (this.Player == Player.Black)
{
drow = 1;
}
var pawnMoves = new List <Square>();
TravelStep forwards = new TravelStep(0, drow);
TravelStep forwardsTwo = new TravelStep(0, drow + drow);
TravelStep forwardLeft = new TravelStep(-1, drow);
TravelStep forwardRight = new TravelStep(1, drow);
if (StepIsEmptyAndValid(forwards, currentSquare, board))
{
pawnMoves.Add(forwards.TravelFromSquare(currentSquare));
if (!this.HasThisPieceEverMoved && StepIsEmptyAndValid(forwardsTwo, currentSquare, board))
{
pawnMoves.Add(forwardsTwo.TravelFromSquare(currentSquare));
}
}
if (DiagonalStepLandsOnOpposingPieceAndIsValid(forwardLeft, currentSquare, board))
{
pawnMoves.Add(forwardLeft.TravelFromSquare(currentSquare));
}
if (DiagonalStepLandsOnOpposingPieceAndIsValid(forwardRight, currentSquare, board))
{
pawnMoves.Add(forwardRight.TravelFromSquare(currentSquare));
}
if (DiagonalStepIsValidEnPassantMove(forwardLeft, currentSquare, board, drow))
{
pawnMoves.Add(forwardLeft.TravelFromSquare(currentSquare));
}
if (DiagonalStepIsValidEnPassantMove(forwardRight, currentSquare, board, drow))
{
pawnMoves.Add(forwardRight.TravelFromSquare(currentSquare));
}
return(pawnMoves);
}
private List <Square> MovesInDirection(Square startingSquare, TravelStep direction, Board board)
{
List <Square> moves = new List <Square>();
bool encounter = false;
Square tempSquare = direction.TravelFromSquare(startingSquare);
for (var steps = 0; tempSquare.IsOnTheBoard() && !encounter; steps++)
{
moves.Add(tempSquare);
if (board.GetPiece(tempSquare) == null)
{
tempSquare = direction.TravelFromSquare(tempSquare);
}
else
{
encounter = true;
}
}
return(moves);
}
private bool DiagonalStepIsValidEnPassantMove(TravelStep direction, Square currentSquare, Board board, int drow)
{
if (direction.TravelFromSquare(currentSquare).IsOnTheBoard())
{
if (board.GetPiece(direction.TravelFromSquare(currentSquare)) == null)
{
TravelStep sideways = new TravelStep(direction.DeltaCol, 0);
if (board.GetPiece(sideways.TravelFromSquare(currentSquare))?.GetType() == typeof(Pawn) &&
board.GetPiece(sideways.TravelFromSquare(currentSquare))?.Player != this.Player)
{
TravelStep originOfOpposingPawn = new TravelStep(direction.DeltaCol, 2 * direction.DeltaRow);
if (board.PreviousMove.From == originOfOpposingPawn.TravelFromSquare(currentSquare) &&
board.PreviousMove.To == sideways.TravelFromSquare(currentSquare))
{
return(true);
}
}
}
}
return(false);
}