kea-geo/src/latToTile.js

Collection of geo related utility

// source: https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#ECMAScript_.28JavaScript.2FActionScript.2C_etc..29

module.exports = function (lat, zoom) {
  return (Math.floor((1 - Math.log(Math.tan(lat * Math.PI / 180) + 1 / Math.cos(lat * Math.PI / 180)) / Math.PI) / 2 * Math.pow(2, zoom)))
}