public static Move ValidatePawnMove(Move move, BoardSetup board)
{
var file = move.TargetSquare.File;
var rank = move.TargetSquare.Rank;
Color color = board.IsWhiteMove ? Color.White : Color.Black;
int direction = color == Color.White ? 1 : -1;
int pawnLine = color == Color.White ? 2 : 7;
var targetPiece = board[move.TargetSquare];
var ppc = move.PromotedPiece == null || (move.PromotedPiece != PieceType.King &&
move.PromotedPiece != PieceType.Pawn);
var isCorrectPawnArea = color == Color.White && rank >= 2 && rank <= 8 ||
color == Color.Black && rank >= 1 && rank <= 7;
var result = move.Clone();
if (move.Type == MoveType.Simple)
{
if (targetPiece == null && ppc && isCorrectPawnArea == false)
{
throw new InvalidOperationException();
}
if (board[file, rank - direction]?.PieceType == PieceType.Pawn && board[file, rank - direction]?.Color == color)
{
result.OriginFile = file;
result.OriginRank = rank - direction;
result.OriginSquare = new Square(result.OriginFile.Value, result.OriginRank.Value);
return(result);
}
else if (board[file, rank - direction] == null && board[file, rank - 2 * direction]?.PieceType == PieceType.Pawn &&
board[file, rank - 2 * direction]?.Color == color && rank - 2 * direction == pawnLine)
{
result.OriginFile = file;
result.OriginRank = rank - 2 * direction;
result.OriginSquare = new Square(result.OriginFile.Value, result.OriginRank.Value);
return(result);
}
}
else if (move.Type == MoveType.Capture)
{
if (ppc && targetPiece != null && color != targetPiece.Color && isCorrectPawnArea && move.OriginFile.HasValue == false)
{
throw new InvalidOperationException();
}
if (board[move.OriginFile.Value, rank - direction]?.Color == color &&
board[move.OriginFile.Value, rank - direction]?.PieceType == PieceType.Pawn)
{
result.OriginRank = rank - direction;
result.OriginSquare = new Square(result.OriginFile.Value, result.OriginRank.Value);
return(result);
}
}
else if (move.Type == MoveType.CaptureEnPassant)
{
throw new NotImplementedException();
}
throw new InvalidOperationException("No piece can make this move");
}
public static Move ValidateKnightMove(Move move, BoardSetup board)
{
var rank = move.TargetSquare.Rank - 1;
var ifile = (int)move.TargetSquare.File - 1;
Color color = board.IsWhiteMove ? Color.White : Color.Black;
var targetPieceNotKing = board[move.TargetSquare]?.PieceType != PieceType.King &&
board[move.TargetSquare]?.Color != color;
Func <int, int, bool> pieceCondition = (f, r) => Math.Abs(Math.Abs(ifile - f) - Math.Abs(rank - r)) == 1 &&
Math.Max(Math.Abs(ifile - f), Math.Abs(rank - r)) == 2;
Square original = null;
for (int f = 0; f < 8; f++)
{
for (int r = 0; r < 8; r++)
{
if (board[f, r]?.PieceType == PieceType.Knight && board[f, r]?.Color == color &&
pieceCondition(f, r) && targetPieceNotKing &&
(move.OriginRank == null || move.OriginRank == (r + 1)) &&
(move.OriginFile == null || move.OriginFile == (File)(f + 1)))
{
if (original == null)
{
original = new Square((File)(f + 1), r + 1);
}
else
{
throw new InvalidOperationException("More than one piece can make a given move");
}
}
}
}
if (original != null)
{
var result = move.Clone();
result.OriginSquare = original;
result.OriginFile = original.File;
result.OriginRank = original.Rank;
return(result);
}
throw new InvalidOperationException("No piece can make this move");
}
static Move ValidatePieceMove(Move move, BoardSetup board,
PieceType piece, PieceType pieceType)
{
var rank = move.TargetSquare.Rank - 1;
var ifile = (int)move.TargetSquare.File - 1;
Color color = board.IsWhiteMove ? Color.White : Color.Black;
var targetPieceNotKing = board[move.TargetSquare]?.PieceType != PieceType.King &&
board[move.TargetSquare]?.Color != color;
Func <int, int, bool> pieceCondition;
if (pieceType == PieceType.Bishop)
{
pieceCondition = (f, r) => Math.Abs(ifile - f) == Math.Abs(rank - r);
}
else if (pieceType == PieceType.Rook)
{
pieceCondition = (f, r) => (ifile == f || rank == r);
}
else if (pieceType == PieceType.King)
{
pieceCondition = (f, r) => Math.Abs(ifile - f) <= 1 && Math.Abs(rank - r) <= 1;
}
else
{
throw new InvalidOperationException("Invalid piece was passed to func");
}
Square original = null;
for (int f = 0; f < 8; f++)
{
for (int r = 0; r < 8; r++)
{
if (board[f, r]?.PieceType == piece &&
board[f, r]?.Color == color &&
pieceCondition(f, r) &&
targetPieceNotKing &&
(move.OriginRank == null || move.OriginRank == (r + 1)) &&
(move.OriginFile == null || move.OriginFile == (File)(f + 1)))
{
int pathLenght = Math.Abs(ifile - f);
int df = Math.Sign(ifile - f);
int dr = Math.Sign(rank - r);
bool freePath = true;
for (int i = 1; i < pathLenght; i++)
{
if (board[f + df * i, r + dr * i] != null)
{
freePath = false;
break;
}
}
if (freePath == true)
{
if (original == null)
{
original = new Square((File)(f + 1), r + 1);
}
else
{
throw new InvalidOperationException("More than one piece can make a given move");
}
}
}
}
}
if (original != null)
{
var result = move.Clone();
result.OriginSquare = original;
result.OriginFile = original.File;
result.OriginRank = original.Rank;
return(result);
}
return(null);
}