ChessDotNet.Pieces.Knight.GetValidMoves C# (CSharp) Method

        public override ReadOnlyCollection<Move> GetValidMoves(Position from, bool returnIfAny, ChessGame game, Func<Move, bool> gameMoveValidator)
        {
            List<Move> validMoves = new List<Move>();
            Piece piece = game.GetPieceAt(from);
            int l0 = game.BoardHeight;
            int l1 = game.BoardWidth;
            int[][] directions = new int[][] { new int[] { 2, 1 }, new int[] { -2, -1 }, new int[] { 1, 2 }, new int[] { -1, -2 },
                        new int[] { 1, -2 }, new int[] { -1, 2 }, new int[] { 2, -1 }, new int[] { -2, 1 } };
            foreach (int[] dir in directions)
            {
                if ((int)from.File + dir[0] < 0 || (int)from.File + dir[0] >= l1
                    || from.Rank + dir[1] < 1 || from.Rank + dir[1] > l0)
                    continue;
                Move move = new Move(from, new Position(from.File + dir[0], from.Rank + dir[1]), piece.Owner);
                if (gameMoveValidator(move))
                {
                    validMoves.Add(move);
                    if (returnIfAny)
                        return new ReadOnlyCollection<Move>(validMoves);
                }
            }
            return new ReadOnlyCollection<Move>(validMoves);
        }
    }