// Copyright 2014 Google Inc. All rights reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. /* Package s2 is a library for working with geometry in S² (spherical geometry). Its related packages, parallel to this one, are s1 (operates on S¹), r1 (operates on ℝ¹), r2 (operates on ℝ²) and r3 (operates on ℝ³). This package provides types and functions for the S2 cell hierarchy and coordinate systems. The S2 cell hierarchy is a hierarchical decomposition of the surface of a unit sphere (S²) into ``cells''; it is highly efficient, scales from continental size to under 1 cm² and preserves spatial locality (nearby cells have close IDs). More information including an in-depth introduction to S2 can be found on the S2 website https://s2geometry.io/ */ package s2