Decode a Polyline String in Xamarin.Android

polyline.cs

private IEnumerable<LatLng> DecodePolylineString(string encodedPath)
{
    var len = encodedPath.Length;
    var index = 0;
    var lat = 0;
    var lng = 0;

    while (index < len)
    {
        var result = 1;
        var shift = 0;
        int b;
        do
        {
            b = encodedPath[index++] - 63 - 1;
            result += b << shift;
            shift += 5;
        } while (b >= 0x1f);
        lat += (result & 1) != 0 ? ~(result >> 1) : (result >> 1);

        result = 1;
        shift = 0;
        do
        {
            b = encodedPath[index++] - 63 - 1;
            result += b << shift;
            shift += 5;
        } while (b >= 0x1f);
        lng += (result & 1) != 0 ? ~(result >> 1) : (result >> 1);

        yield return new LatLng(lat * 1e-5, lng * 1e-5);
    }
}