3 ms·

Nice to know, thanks. You say X, does that mean not Wayland/X-Wayland?

vetinari 7y ago
Wayland does that out of the box; unfortunately most people do not run Wayland, either because they prefer WM/DE that is X11 only (xfce, etc), or just because. On X11, scaling of entire framebuffer (i.e. scaling macOS style) is a standard xrandr functionality, but it was never exposed to UI. It has some drawbacks that macOS never had to solve (how it behaves over remote x11/vnc/etc, or memory requirements for framebuffer, for example), that make it unsuitable as a general solution. It is basically one of the hacks complained in this threads.
- alias_neo 7y ago
  I'm not sure what "Wayland does that out of the box" means; I ran 18.04 with Wayland since launch, it never gave me different scaling per monitor (not in the Gnome UI anyway). Are you saying it would have worked had I used xrandr?
  - vetinari 7y ago
    xrandr is X11 only; it is X11 extension, after all. Are you sure you were running Wayland? In Fedora under Wayland, you could pick a monitor and choose scaling for it in the setting applet.
    - alias_neo 7y ago
      I'm sure so far as when I login I select "Ubuntu on Wayland" and when I search through the output of top for "wayland" it's there. I'm not sure how else I prove I'm running Wayland. The machine I'm sending this from now is still running 18.04 on "Wayland" and I cannot set the DPI independently for each monitor, if I select my external monitor and set 200% and click "Done", I get 200% on all displays.
      - vetinari 7y ago
        You don't have to prove anything (but informatively, the way to detect wayland session is to check for XDG_SESSION_TYPE env variable). Also, just for curiosity, what GPU are you using? It is quite possible that 18.04 has some bugs. I don't have 18.04 machine with hidpi monitor at hand, so I can't have a look myself, so I chalk it up that there is something weird happening.
        alias_neo 7y ago
        Thanks for the tip. The XPS 15 that I've tested this most on has a 1050. I'm using the proprietary Nvidia driver. My XPS 13 is using Intel from an 8th gen i7.
Nursie 7y ago
Pretty sure xrandr is just for X. Am on debian with Xfce, so not using wayland at present. AFAICT Wayland is the default option for Gnome sessions on debian, but I fell out with gnome around the 2->3 transition and have never looked back. My xrandr line is not that easy to read but effectively, after I've set xfce hidpi support to double the size of screen elements, I increase the view window of the smaller screen by a factor of 1.8, and of the larger screen by a factor of 1.2, and put them next to each other - xrandr --output HDMI-0 --mode 1920x1200 --pos 0x100 --scale 1.8x1.8 --output DP-2 --mode 3840x2160 --primary --scale 1.2x1.2 --pos 3456x-180 If Wayland can do that without so much messing around, great :)

Wayland does that out of the box; unfortunately most people do not run Wayland, either because they prefer WM/DE that is X11 only (xfce, etc), or just because. On X11, scaling of entire framebuffer (i.e. scaling macOS style) is a standard xrandr functionality, but it was never exposed to UI. It has some drawbacks that macOS never had to solve (how it behaves over remote x11/vnc/etc, or memory requirements for framebuffer, for example), that make it unsuitable as a general solution. It is basically one of the hacks complained in this threads.

alias_neo 7y ago
I'm not sure what "Wayland does that out of the box" means; I ran 18.04 with Wayland since launch, it never gave me different scaling per monitor (not in the Gnome UI anyway). Are you saying it would have worked had I used xrandr?
- vetinari 7y ago
  xrandr is X11 only; it is X11 extension, after all. Are you sure you were running Wayland? In Fedora under Wayland, you could pick a monitor and choose scaling for it in the setting applet.
  - alias_neo 7y ago
    I'm sure so far as when I login I select "Ubuntu on Wayland" and when I search through the output of top for "wayland" it's there. I'm not sure how else I prove I'm running Wayland. The machine I'm sending this from now is still running 18.04 on "Wayland" and I cannot set the DPI independently for each monitor, if I select my external monitor and set 200% and click "Done", I get 200% on all displays.
    - vetinari 7y ago
      You don't have to prove anything (but informatively, the way to detect wayland session is to check for XDG_SESSION_TYPE env variable). Also, just for curiosity, what GPU are you using? It is quite possible that 18.04 has some bugs. I don't have 18.04 machine with hidpi monitor at hand, so I can't have a look myself, so I chalk it up that there is something weird happening.
      - alias_neo 7y ago
        Thanks for the tip. The XPS 15 that I've tested this most on has a 1050. I'm using the proprietary Nvidia driver. My XPS 13 is using Intel from an 8th gen i7.

Nursie 7y ago

Pretty sure xrandr is just for X. Am on debian with Xfce, so not using wayland at present. AFAICT Wayland is the default option for Gnome sessions on debian, but I fell out with gnome around the 2->3 transition and have never looked back. My xrandr line is not that easy to read but effectively, after I've set xfce hidpi support to double the size of screen elements, I increase the view window of the smaller screen by a factor of 1.8, and of the larger screen by a factor of 1.2, and put them next to each other - xrandr --output HDMI-0 --mode 1920x1200 --pos 0x100 --scale 1.8x1.8 --output DP-2 --mode 3840x2160 --primary --scale 1.2x1.2 --pos 3456x-180 If Wayland can do that without so much messing around, great :)