Draw circle in Nutiteq SDK

Circle.java

    {
      // create layer and add a circle to it
      GeometryLayer locationLayer = new GeometryLayer(mapView.getLayers().getBaseProjection());
      mapView.getComponents().layers.addLayer(locationLayer);

      circle(-122.416667f, 37.766667f, 100, locationLayer);
    }

    // helper to draw a circle to given layer
    private void circle(float lat, float lon, float circleRadius, GeometryLayer layer){
        
       // number of circle line points
       int NR_OF_CIRCLE_VERTS = 18;
       
       List<MapPos> circleVerts = new ArrayList<MapPos>(NR_OF_CIRCLE_VERTS);

       MapPos circlePos = layer.getProjection().fromWgs84(lat, lon);
       
       // width of map to scale circle
       float projectionScale = (float) layer.getProjection().getBounds().getWidth();
       
       // convert radius from meters to map units
       float circleScale = circleRadius / 7500000f * projectionScale;

       for (float tsj = 0; tsj <= 360; tsj += 360 / NR_OF_CIRCLE_VERTS) {
           MapPos mapPos = new MapPos(circleScale * Math.cos(tsj * Const.DEG_TO_RAD) + circlePos.x, circleScale * Math.sin(tsj * Const.DEG_TO_RAD) + circlePos.y);
           circleVerts.add(mapPos);
       }
       
       LineStyle style = LineStyle.builder().setWidth(0.1f).setColor(Color.argb(192, 255, 255, 0)).build();
       Line circle = new Line(circleVerts, null, style, null);
       layer.add(circle);
    }

Hi Jaak,
Thanks for the code sample it works nicely.
I think there is a problem concerning the circle radius conversion though.
The comment says it should be in meters so for a circle with a radius of 2km (it's for an antenna's signal) I put 2000 as the circleRadius parameter.
The circle is drawn, but is way too big. I checked on google maps and it's around 8km.
Any ideas on what might be the issue ?

I could put 500 instead of 2000, It would draw the correct circle but it's not very clean :)

This function works on given latitudes only, there is "magic number" 7500000f in the calculations. Please use better one, which is independent from latitude: https://gist.github.com/jaakla/bd26bb02109f17e8135c