Question: How does the background-command need to be run only once?

[TornaxO7]

Hello! This is just a question. May I ask how feh just needs to be executed once to set the wallpaper? Like, why doesn't feh has to run in the background to redraw the wallpaper after, for example, a window has been displayed over the background?

[TornaxO7]

If I'm following the code correctly:

1. feh_wm_set_bg_centered
2. gib_imlib_render_image_part_on_drawable_at_size
3. glib_imlib.c

And understanding it correctly, then Imlib2 takes care of rerendering the wallpaper if needed, right?