Display settings on Hi/LoDPI devices?

[René J.V. Bertin]

On Monday November 20 2023 06:30:39 Kristian wrote:
>On the other side, it seems at least GNOME somehow manages to handle this
>automatically so there apparently seems some way to detect the current
>configuration and use the "right" settings when booting the system.

I honestly don't know how far X11's support for multi-dpi configs goes, and then of course to what extent KDE has been written with the idea that one could have such a set-up (and support for it). The main components that come to mind where this is crucial are the ones always spanning all screens, so KWin and a number of the Plasma shell components.
But really every application faces the question when you move a window from one screen to another (or actually let it span multiple screens). How are you going to handle that?

(How) does Gnome "somehow manage" to do something sensible in such situations? And if it does: are you certain it isn't using Wayland? I was surprised to find that gdm3 uses Wayland now, after upgrading one of my systems to Devuan Chimaera (I think that's Debian 11) and I have to assume that an actual Gnome desktop would use that too.

One way Gnome might do something sensible is to set the internal hires screen to a "normal" *pixel* resolution with an as close as possible integer scale factor. That would probably allow to treat both screens like they were normal-resolution ones, and let the hardware handle the scaling. This shouldn't be different from playing with the DPI setting, besides of course the lack of antialiasing at a screen-pixel level.

I'm guessing that Dell came with (or has) MSWin installed, how does that OS handle this situation?

R.