@SuppressWarnings("DiscouragedApi")
    private static Drawable getDTRatingMarkerSection(final Resources res, final String packageName, final String ratingLetter, final float rating, final float scaling) {
        // ensure that rating is an integer between 0 and 50 in steps of 5
        final int r = Math.max(0, Math.min(Math.round(rating * 2) * 5, 50));
        return new ScalableDrawable(ResourcesCompat.getDrawable(res, res.getIdentifier("marker_rating_" + ratingLetter + "_" + r, "drawable", packageName), null), scaling);
    }
Create a LayerDrawable showing the caches difficulty and terrain rating. If the connector doesn't support D/T show a "-" instead, if the info is missing (not loaded) a "?"
@param res           Resources bundle
@param difficulty    Difficulty rating
@param terrain       Terrain rating
@return              LayerDrawable composed of round background and foreground showing the ratings
main/src/main/java/cgeo/geocaching/utils/MapMarkerUtils.java