Comment 7 for bug 1382291

There are some additional functions that those bitmaps relative operations should follow up.

<quote>
Hi-DPI for developers

GTK+ makes hi-dpi work transparently in most places, but sometimes it may be necessary to do some extra work for best results. Here are some APIs to learn about the scale factor:

gdk_screen_get_monitor_scale_factor
gdk_window_get_scale_factor
gtk_widget_get_scale_factor

Similarly, Clutter tries to automatically handle the scaling factor on each drawing surface, but it provides explicit API to retrieve and set the scaling factor:

ClutterSettings:window-scaling-factor
clutter_canvas_set_scale_factor
clutter_canvas_get_scale_factor
</quote>

Excerpt from https://wiki.gnome.org/HowDoI/HiDpi.