Function S2CellId.toFaceIJOrientation
Return the (face, i, j) coordinates for the leaf cell corresponding to this cell id. Since cells are represented by the Hilbert curve position at the center of the cell, the returned (i,j) for non-leaf cells will be a leaf cell adjacent to the cell center. If "orientation" is non-nullptr, also return the Hilbert curve orientation for the current cell.
int toFaceIJOrientation
(
out int pi,
out int pj
) const;