/// <summary>
/// Determine whether the given move is valid for this chess piece on the given chess board.
/// </summary>
/// <param name="chessBoard">The chess board on which the chess piece is being moved.</param>
/// <param name="from">The board position from which the chess piece is being moved.</param>
/// <param name="to">The board position to which the chess piece is being moved.</param>
/// <returns></returns>
internal virtual MoveResult ValidateMove(
ChessBoard chessBoard,
BoardPosition from,
BoardPosition to,
out ExceptionReasonDetail exceptionReasonDetail)
{
exceptionReasonDetail = ExceptionReasonDetail.None;
return MoveResult.Illegal;
}
internal override MoveResult ValidateMove(
ChessBoard chessBoard,
BoardPosition from,
BoardPosition to,
out ExceptionReasonDetail exceptionReasonDetail)
{
exceptionReasonDetail = ExceptionReasonDetail.None;
MoveResult result = MoveResult.Illegal;
int fileDiff = Math.Abs(from.InternalFile - to.InternalFile);
int forward = (this.Colour == Colour.White) ? to.InternalRank - from.InternalRank : from.InternalRank - to.InternalRank;
Square toSquare = chessBoard.GetSquare(to);
if (forward == 1) {
if (fileDiff == 0) {
if (toSquare.ChessPiece != null) {
result = MoveResult.Collision;
}
else {
result = MoveResult.Valid;
}
}
if (fileDiff == 1) {
if (toSquare.ChessPiece != null && toSquare.ChessPiece.Colour != this.Colour) {
result = MoveResult.Valid;
}
else {
exceptionReasonDetail = ExceptionReasonDetail.PawnCannotMoveDiagonallyUnlessCapturing;
}
}
}
if (forward == 2 && fileDiff == 0) {
bool onHomeRank = (this.Colour == Colour.White && from.Rank == 2) || (this.Colour == Colour.Black && from.Rank == 7);
if (onHomeRank && chessBoard.Round == 1) {
int inbetweenFile = from.InternalFile;
int inbetweenRank = (this.Colour == Colour.White) ? from.InternalRank + 1 : from.InternalRank - 1;
Square inbetweenSquare = chessBoard.GetSquare(new BoardPosition(inbetweenFile, inbetweenRank));
if (inbetweenSquare.ChessPiece != null) {
result = MoveResult.Collision;
}
else {
if (toSquare.ChessPiece == null) {
result = MoveResult.Valid;
}
}
}
else {
exceptionReasonDetail = ExceptionReasonDetail.PawnCannotMoveTwoSpacesAtThisTime;
}
}
return result;
}
internal override MoveResult ValidateMove(
ChessBoard chessBoard,
BoardPosition from,
BoardPosition to,
out ExceptionReasonDetail exceptionReasonDetail)
{
exceptionReasonDetail = ExceptionReasonDetail.None;
MoveResult result = MoveResult.Illegal;
int fileDiff = Math.Abs(from.InternalFile - to.InternalFile);
int rankDiff = Math.Abs(from.InternalRank - to.InternalRank);
if ((fileDiff == 2 && rankDiff == 1) || (fileDiff == 1 && rankDiff == 2)) {
Square toSquare = chessBoard.GetSquare(to);
if (toSquare.ChessPiece == null || toSquare.ChessPiece.Colour != this.Colour) {
result = MoveResult.Valid;
}
}
return result;
}
public ChessBoardException(ExceptionReason exceptionReason, ExceptionReasonDetail exceptionReasonDetail, Exception innerException)
: base(MessageFromExceptionReason(exceptionReason), innerException)
{
this.ExceptionReason = exceptionReason;
this.ExceptionReasonDetail = exceptionReasonDetail;
}
public ChessBoardException(ExceptionReason exceptionReason, ExceptionReasonDetail exceptionReasonDetail)
: this(exceptionReason, exceptionReasonDetail, null)
{
}
