I'm trying to simulate the behavior of universal split screen, which is for Windows only on Linux (Fedora, preferably Gnome/XOrg)
I found a lot about xrandr, Xephyr and xinerama, but while all tutorials I found sound a lot like what I need, I didn't manage to "just" run two instances of an application (Terraria in my case) in one window, side by side.
The closest I found was
Xephyr -br -ac -noreset -screen 1920x600 :1 &
Xephyr -br -ac -noreset -screen 1920x600 :2 &
DISPLAY=:1 <command> &
DISPLAY=:2 <command> &
.. which is at least hard to use because you have two separate windows with their decorations.
Is there a way (without installing a tiling window manager, which would be my next approach) to "run applications in one window which contains the output of different virtual displays in a static pre-defined manner"?
Or put less technical: is there a way to run applications which do not support 'side-by-side' operation in a side-by-side manner anyway on Linux? Like with Nucleus, universal split screen or tModLoader - Split Screen (which somehow does not work for me)