public override bool IsLegalMove(Move move, ChessGame game)
{
ChessUtility.ThrowIfNull(move, "move");
ChessUtility.ThrowIfNull(game, "game");
BoardPosition origin = move.OriginalPosition;
BoardPosition destination = move.NewPosition;
BoardDistance posDelta = new BoardDistance(origin, destination);
if (posDelta.X != posDelta.Y)
{
return(false);
}
bool increasingRank = destination.Rank > origin.Rank;
bool increasingFile = (int)destination.File > (int)origin.File;
for (int f = (int)origin.File + (increasingFile ? 1 : -1), r = origin.Rank + (increasingRank ? 1 : -1);
increasingFile?f <(int)destination.File : f> (int) destination.File;
f += increasingFile ? 1 : -1, r += increasingRank ? 1 : -1)
{
if (game.GetPieceAt((ChessFile)f, r) != null)
{
return(false);
}
}
return(true);
}
public override bool IsLegalMove(Move move, ChessGame game)
{
ChessUtility.ThrowIfNull(move, "move");
ChessUtility.ThrowIfNull(game, "game");
BoardPosition origin = move.OriginalPosition;
BoardPosition destination = move.NewPosition;
BoardDistance posDelta = new BoardDistance(origin, destination);
if ((posDelta.X != 2 || posDelta.Y != 1) && (posDelta.X != 1 || posDelta.Y != 2))
{
return(false);
}
return(true);
}
public override bool IsLegalMove(Move move, ChessGame game)
{
ChessUtility.ThrowIfNull(move, "move");
BoardPosition origin = move.OriginalPosition;
BoardPosition destination = move.NewPosition;
BoardDistance distance = new BoardDistance(origin, destination);
if ((distance.X != 1 || distance.Y != 1) &&
(distance.X != 0 || distance.Y != 1) &&
(distance.X != 1 || distance.Y != 0) &&
(distance.X != 2 || distance.Y != 0))
{
return(false);
}
if (distance.X != 2)
{
return(true);
}
return(CanCastle(origin, destination, game));
}
public override bool IsLegalMove(Move move, ChessGame game)
{
ChessUtility.ThrowIfNull(move, "move");
ChessUtility.ThrowIfNull(game, "game");
BoardPosition origin = move.OriginalPosition;
BoardPosition destination = move.NewPosition;
ChessPiece promotion = null;
if (move.Promotion.HasValue && ValidPromotionPieces.Contains(move.Promotion.Value))
{
promotion = game.MapPgnCharToPiece(char.ToUpper(move.Promotion.Value), move.Player);
}
BoardDistance posDelta = new BoardDistance(origin, destination);
if ((posDelta.X != 0 || posDelta.Y != 1) && (posDelta.X != 1 || posDelta.Y != 1) &&
(posDelta.X != 0 || posDelta.Y != 2))
{
return(false);
}
if (Owner == ChessPlayer.White)
{
if (origin.Rank > destination.Rank)
{
return(false);
}
if (destination.Rank == 8)
{
if (promotion == null)
{
return(false);
}
if (promotion.Owner != ChessPlayer.White)
{
return(false);
}
if (!ValidPromotionPieces.Contains(promotion.GetFENLetter()))
{
return(false);
}
}
}
if (Owner == ChessPlayer.Black)
{
if (origin.Rank < destination.Rank)
{
return(false);
}
if (destination.Rank == 1)
{
if (promotion == null)
{
return(false);
}
if (promotion.Owner != ChessPlayer.Black)
{
return(false);
}
if (!ValidPromotionPieces.Contains(promotion.GetFENLetter()))
{
return(false);
}
}
}
bool checkEnPassant = false;
if (posDelta.Y == 2)
{
if ((origin.Rank != 2 && Owner == ChessPlayer.White) ||
(origin.Rank != 7 && Owner == ChessPlayer.Black))
{
return(false);
}
if (origin.Rank == 2 && game.GetPieceAt(origin.File, 3) != null)
{
return(false);
}
if (origin.Rank == 7 && game.GetPieceAt(origin.File, 6) != null)
{
return(false);
}
}
ChessPiece pieceAtDestination = game.GetPieceAt(destination);
if (posDelta.X == 0 && (posDelta.Y == 1 || posDelta.Y == 2))
{
if (pieceAtDestination != null)
{
return(false);
}
}
else
{
if (pieceAtDestination == null)
{
checkEnPassant = true;
}
else if (pieceAtDestination.Owner == Owner)
{
return(false);
}
}
if (checkEnPassant)
{
ReadOnlyCollection <DetailedMove> _moves = game.Moves;
if (_moves.Count == 0)
{
return(false);
}
if ((origin.Rank != 5 && Owner == ChessPlayer.White) ||
(origin.Rank != 4 && Owner == ChessPlayer.Black))
{
return(false);
}
Move latestMove = _moves[_moves.Count - 1];
if (latestMove.Player != ChessUtility.GetOpponentOf(Owner))
{
return(false);
}
if (!(game.GetPieceAt(latestMove.NewPosition) is Pawn))
{
return(false);
}
if (game.GetPieceAt(latestMove.NewPosition).Owner == Owner)
{
return(false);
}
if (Owner == ChessPlayer.White)
{
if (latestMove.OriginalPosition.Rank != 7 || latestMove.NewPosition.Rank != 5)
{
return(false);
}
}
else // (m.Player == Players.Black)
{
if (latestMove.OriginalPosition.Rank != 2 || latestMove.NewPosition.Rank != 4)
{
return(false);
}
}
if (destination.File != latestMove.NewPosition.File)
{
return(false);
}
}
return(true);
}
