Map calculations

1. From screen coordinates to geo coordinates (in base layer projection):

  MapPos worldPos = mapView.screenToWorld(screenX, screenY);

2. From geo coordinates (in base layer projection) to screen:

  MapPos screenPos = mapView.worldToScreen(mapX, mapY);

3. Calculate width of map view in meters, using Android Location package:

private float getMapViewWidth(MapView mapView){
        MapPos bottomLeft = mapView.screenToWorld(0, mapView.getHeight());
        MapPos bottomRight = mapView.screenToWorld(mapView.getWidth(), mapView.getHeight());
        
        float[] results = new float[3];
        
        Location.distanceBetween(this.proj.toWgs84(bottomLeft.x,bottomLeft.y).x,
                this.proj.toWgs84(bottomLeft.x,bottomLeft.y).y,
                this.proj.toWgs84(bottomRight.x,bottomRight.y).x,
                this.proj.toWgs84(bottomRight.x,bottomRight.y).y, results);
        
        return results[0];
}