Option available for geographic

[mali151298]

There are two type of geometry available.

1. Cartesian
2. Geographic

Geos all algorithm like buffer, union act as a Cartesian geometry, Any options available to convert cartesion to geographic geometry type likes(boost::geometry) into geos library?

[pramsey]

Nope. See https://github.com/google/s2geometry

[mali151298]

Thanks for your reply.

[jorisvandenbossche]

And if you would be interested in a GEOS-like C API on top of s2geometry, https://github.com/paleolimbot/s2geography/ might be interesting (it's extracted from the R s2 bindings, to be more generally usable outside of R)

[roya0045]

Nope. See https://github.com/google/s2geometry

I'm looking into this to scope things out and I was curious to know if https://github.com/libgeos/geos/blob/main/src/operation/buffer/OffsetSegmentGenerator.cpp could be modified to pass on a flag that would modify how the points are generated.

For instance using https://geographiclib.sourceforge.io/Python/doc/code.html#geographiclib.geodesic.Geodesic.Direct would require a conversion in lat long, which seems to be out of scope and would add more dependencies, but would provide the needed result. It might be easier to make a separate buffer generator from scratch than trying to fit that option in geos.

[pramsey]

The simplest way to coerce the existing code into doing correct geographics it to push everything into Gnomonic before calculating new vertices. This will work fine for constrained areas but naturally fall apart for larger areas. You can try that yourself just by conditioning your inputs and see if you like the result.