public Tile[][]changeX(Tile[][] piece, int offset)
        {
                for (int i = 0; piece != null && i < piece.length; i++)
                        for (int j = 0; j < piece[i].length; j++)
                        {
                                if (piece[i][j] != null)
                                        piece[i][j].setX(piece[i][j].getX() + offset);
                        }
                return piece;
        }