VTM: Rotate map according to riding

[Adi Barda]

Hi Everyone,

I'm in the process of integrating VTM/MapsForge in my Android application (AdvRider WD).

I have a requirement of rotating the map to the direction of the riding (I have previous and current GPS locations)

What is the best way to do that in VTM? Is there an automatic way for doing so?

Thanks,

Adi

[Emux]

Can check the viewport various setters, e.g.:

mapView.map().viewport().setRotation(degree);

--
Emux

[Adi Barda]

Thanks, I'm a little confused between setting the MapPosition bearing and rotating the map.

For google maps the below formula for calculating the bearing according to 2 Lat/Lng works for me:

private double getBearing(double lat1, double lng1, double lat2, double lng2) {
   double dLon = (lng2 - lng1);
   double y = Math.sin(dLon) * Math.cos(lat2);
   double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1)
         * Math.cos(lat2) * Math.cos(dLon);
   double brng = Math.toDegrees((Math.atan2(y, x)));

   return brng;
}

However, when I set this bearing number to the MapPosition's setBearing() just before using it with:  animator().animateTo

It doesn't work as expected. There is a difference between Google maps and VTM when using the bearing.

I always want the map to point (rotate) to the direction which I'm heading

[Adi Barda]

OK, I think I solved the problem by multiplying by -1. Maybe VTM bearing is probably works the opposite from Google maps