Bounding rectangle for the cell.
Uses S2's own rectangle bound, which accounts for geodesic edges bulging beyond the corners and for cells that contain a pole. Taking the extent of the four corners alone would understate both.
Optional
Bounding rectangle for the cell.
Uses S2's own rectangle bound, which accounts for geodesic edges bulging beyond the corners and for cells that contain a pole. Taking the extent of the four corners alone would understate both.