S2 Geometry
Computational geometry and spatial indexing on the sphere
...The library provides a robust mathematical framework for spherical geometry, allowing developers to work with polygons, points, and regions on the Earth’s surface using consistent and precise algorithms. Unlike traditional 2D geometry libraries, S2 ensures accuracy over large scales by modeling the globe directly, avoiding distortions caused by map projections. The project includes core C++ support, optional Python bindings, and integrations with Bazel and CMake for flexible builds. It relies on Abseil, OpenSSL, and googletest, and is tested across major platforms.