How "block" part of the screen always, even in fullscreen (maybe with tint2)

I need to “block” up, right, bottom and left of the screen with a black bar (or whatever, i need fill with black)

I though in tint2 but when i go to “fullscreen” the bar go below… (sadly)

Im using now kde, but i really dont care, maybe it is better for acomplish this openbox, or i3 (i try in gnome and also dont could make it work) maybe in those desktop there is something better.

Thanks.

Please see tint2 - ArchWiki

Or doc/tint2.md · master · o9000 / tint2 · GitLab

HI.
thanks. I saw those links and not could do what i want.
I try:

panel_layer = top
strut_policy = follow_size
autohide = 0

And that work if you “maximize” a window. But if you put the an app fullscreen the tint2 panel go belows (i just making my test with firefox).

Also from the documentation:

as you can see, the documentation talk about “maximized” not about fullscreen window.
Maybe there is other option, or other program that could make what i want? or with the window managers?