@jorgenphi/staticmaps/dist/helper/geo.js

A Node.js library for creating map images with markers, polylines, polygons and text.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;
var _default = {
  /**
   * Transform longitude to tile number
   */
  lonToX: function lonToX(lon, zoom) {
    return (lon + 180) / 360 * Math.pow(2, zoom);
  },

  /**
   *  Transform latitude to tile number
   */
  latToY: function latToY(lat, zoom) {
    return (1 - Math.log(Math.tan(lat * Math.PI / 180) + 1 / Math.cos(lat * Math.PI / 180)) / Math.PI) / 2 * Math.pow(2, zoom);
  },
  yToLat: function yToLat(y, zoom) {
    return Math.atan(Math.sinh(Math.PI * (1 - 2 * y / Math.pow(2, zoom)))) / Math.PI * 180;
  },
  xToLon: function xToLon(x, zoom) {
    return x / Math.pow(2, zoom) * 360 - 180;
  },
  meterToPixel: function meterToPixel(meter, zoom, lat) {
    var latitudeRadians = lat * (Math.PI / 180);
    var meterProPixel = 156543.03392 * Math.cos(latitudeRadians) / Math.pow(2, zoom);
    return meter / meterProPixel;
  },
  tileXYToQuadKey: function tileXYToQuadKey(x, y, z) {
    var quadKey = [];

    for (var i = z; i > 0; i--) {
      var digit = '0';
      var mask = 1 << i - 1;
      if ((x & mask) !== 0) digit++;

      if ((y & mask) !== 0) {
        digit++;
        digit++;
      }

      quadKey.push(digit);
    }

    return quadKey.join('');
  }
};
exports["default"] = _default;