private void ensureBmSizes() {
        if (bmHeight >= 0) {
            return;
        }
        ensureBmSizes(bitmapProvider == null ? null : bitmapProvider.getRotatedBitmapDimensions(getRotation()));
    }
if the marker should rotate together with the map (flat mode) or should be displayed as billboard popup. Default is billboard.
main/src/main/java/cgeo/geocaching/models/geoitem/GeoIcon.java