decode-google-map-polyline/index.js

A library to decode google map polyline using google official library.

function decodePolyline(polyline) {

  var _ = {};

  _.Ya = function(a, b, c) {
    null != b && (a = Math.max(a, b));
    null != c && (a = Math.min(a, c));
    return a
  };
  _.Za = function(a, b, c) { c -= b; return ((a - b) % c + c) % c + b };
  _.w = function(a) { return a ? a.length : 0 };

  _.E = function(a, b, c) {
    a -= 0;
    b -= 0;
    c || (a = _.Ya(a, -90, 90), 180 != b && (b = _.Za(b, -180, 180)));
    this.lat = function() { return a };
    this.lng = function() { return b }
  };

  function decodePath(a) {
    for (var b = _.w(a), c = Array(Math.floor(a.length / 2)), d = 0, e = 0, f = 0, g = 0; d < b; ++g) {
      var h = 1,
        l = 0,
        n;
      do n = a.charCodeAt(d++) - 63 - 1, h += n << l, l += 5; while (31 <= n);
      e += h & 1 ? ~(h >> 1) : h >> 1;
      h = 1;
      l = 0;
      do n = a.charCodeAt(d++) - 63 - 1, h += n << l, l += 5; while (31 <= n);
      f += h & 1 ? ~(h >> 1) : h >> 1;
      c[g] = new _.E(1E-5 * e, 1E-5 * f, !0)
    }
    c.length = g;
    return c
  }

  var result = decodePath(polyline).map(function(el) {
      return {lat:Number(el.lat().toFixed(5)),lng:Number(el.lng().toFixed(5))};
  });

  return result;

}

module.exports=decodePolyline;