kepler.gl/src/layers/s2-geometry-layer/s2-utils.js

kepler.gl is a webgl based application to visualize large scale location data in the browser

// Copyright (c) 2020 Uber Technologies, Inc.
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// of this software and associated documentation files (the "Software"), to deal
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import Long from 'long';
import {S2} from 's2-geometry';

const MAXIMUM_TOKEN_LENGTH = 16;

/**
 * Retrieve S2 geometry center
 * @param s2Token string | number
 * @return {*[]}
 */
export function getS2Center(s2Token) {
  const paddedToken = s2Token.toString().padEnd(MAXIMUM_TOKEN_LENGTH, '0');
  const s2Id = Long.fromString(paddedToken, MAXIMUM_TOKEN_LENGTH);
  const {lat, lng} = S2.idToLatLng(s2Id.toString());
  return [lng, lat];
}