[arch-general] xrandr with XPS 13" (3840x2160) HiDPI and 30" (2560x1600) LowDPI

[Tyler]

> I guess --right-of/--left-of don't take the scale into account.
> Try to position your monitors absolutely with --pos, probably 0x0 for 
> DP1 and 5120x0 for eDP1.

xrandr --dpi 220 --output eDP1 --pos 5120x0 --auto \
       --output DP1 --pos 0x0 --auto --scale 2x2

https://i.imgur.com/pwcGct2.jpg success!

now I guess the only thing to do is to find a solution for Qt5. Windows
on my LowDPI screen don't change scale according to what screen they are
on eg everything is really small, on the laptop screen the scaling is
what it should be.

GTK3 works fine though.

i think that is why he didn't use auto

https://blog.summercat.com/configuring-mixed-dpi-monitors-with-xrandr.html

says:

> Second, switching back and forth between dual monitors to one monitor lead to interesting behaviour. For example, I kept losing the scale setting on the lower DPI monitor.

that's not exactly what is happening to me - because GTK2/3 works fine.

Maybe there are some more Qt vars I can play with besides

export QT_AUTO_SCREEN_SCALE_FACTOR=0
#export QT_SCALE_FACTOR=2
export QT_SCREEN_SCALE_FACTORS=2
export QT_QPA_PLATFORMTHEME=qt5ct

-- 
Tyler