S2Polygon_Contains: Test of Containment in S2Polygon
In spatstat/s2: Google's S2 Library for Geometry on the Sphere

Test whether the given object(s) on the sphere are contained in a polygon. At the moment only point containment can be tested.

1	S2Polygon_Contains(poly, x, approx = TRUE)

`poly`	Named list containing an entry called 'loops' containing a list of polygon loops represented by three-column matrices.
`x`	Object(s) to test for containment in 'poly'. At the moment only points are handled and they must be specified as a three-column matrix.
`approx`	Logical to use approximate testing of point in polygon (allows points very slightly outside the polygon). Useful for allowing points directly on the border.