private static Move DetermineMove(Board board, UCIChessMove uciMove)
{
string from = uciMove.From;
string to = uciMove.To;
var fromPos = Position.Parse(from);
var toPos = Position.Parse(to);
var fromPiece = board[fromPos];
int fileDiff = Math.Abs((int)fromPiece.Position.File - (int)toPos.File);
if (fromPiece.Type == PieceType.King && (fileDiff == 3 || fileDiff == 4))
{
King king = (King)fromPiece;
Rook rook;
if (fileDiff == 4)
{
rook = (Rook)board[File.A, fromPiece.Position.Rank];
}
else
{
rook = (Rook)board[File.H, fromPiece.Position.Rank];
}
return(MoveBuilder.CreateCastleMove(king, rook));
}
if (uciMove.PromotionChar != null)
{
string promotionChar = uciMove.PromotionChar.ToUpper();
var promotionType = (from p in (PieceType[])Enum.GetValues(typeof(PieceType))
where p.ToNotationLetter().ToUpper() == promotionChar.ToUpper()
select p).First();
var promotionMoves = MoveBuilder.CreatePromotionMoves((Pawn)fromPiece, toPos, board[toPos] != null);
return((from m in promotionMoves
where m.Promotion.NewPieceType.Type == promotionType
select m).First());
}
// Check for en passant
var existingPieceRank = fromPiece.Position.Rank;
var isCorrectRank = fromPiece.Color == PieceColor.Black ? existingPieceRank == Rank._4 : existingPieceRank == Rank._5;
try
{
int vertDir = fromPiece.Color == PieceColor.White ? -1 : 1;
var existingPieceTo = board[toPos];
var capturedPiecePos = toPos.MoveVert(vertDir);
var capturedPiece = board[capturedPiecePos];
if (capturedPiece.Color == fromPiece.Color.Opposite() &&
capturedPiece.MoveHistory.Count == 1)
{
// This is an en passant
return(MoveBuilder.CreateEnPassantMove((Pawn)fromPiece, toPos, capturedPiecePos));
}
}
catch { }
// Only other option is that this is a normal move.
return(MoveBuilder.CreateNormalMove(fromPiece, toPos, board[toPos] != null));
}
public override List <Move> FindMoves(Board board)
{
var advancingMoves = GetAdvancingMoves(board);
var capturingMoves = GetCapturingMoves(board);
var advancingAndCapturingMoves = GetAdvancingMoves(board)
.Concat(GetCapturingMoves(board))
.ToList();
// We need to go through and swap out capturing moves for
// promotion moves if the pawn gets to the last rank
var movesWithPromotions = new List <Move>();
foreach (var m in advancingAndCapturingMoves)
{
var newPos = m.NormalPieceMove.NewPosition;
if (newPos.Rank == Rank._8 || newPos.Rank == Rank._1)
{
// Promotion move!
movesWithPromotions.AddRange(MoveBuilder.CreatePromotionMoves(this, newPos, true));
}
else
{
movesWithPromotions.Add(m);
}
}
return(movesWithPromotions.Concat(GetEnPassantMoves(board)).ToList());
}