X11 Resolution – Can X11 Scale to Virtual Resolutions on HiDPI/Retina Screens?

resolutionx11xorg

I've recently had the chance to use a Macbook Pro with Retina Display, and its quite clear that the display is futuristic enough to actually warrant Apple's over-the-top marketing.

I've got sensitive eyes, and I don't like looking at very small text. Apple's virtual scaling for HiDPI resolutions scales the entire screen, not just text/UI buttons. This creates a higher level of detail on a canvas encompassing a smaller virtual resolution.

Most discussions that I've found say there's no similar solution when using Linux except to change gnome DPI settings.

After some cursory research, it seems that scaled resolutions are possible under X11 (see here). The –scale feature can be used for netbooks virtualizing a larger resolution, but could inverted values emulate a 1440×900 desktop on a 2880×1800 screen? If not, why?

Best Answer

Why don't you try yourself?

xrandr --output LVDS-1 --scale 0.5x0.5

seems to work acceptably - but remember that it is just scaling, for example any font rendering will be blurry rather than fine and crisp (no matter what algorithm is used for the scaling it acts on bitmaps) - for that the correct solution is setting DPI of the display device and font/icon sizes.

Related Solutions

HiDPI scaling for non-aware applications

The following could provide a temporary solution.

https://github.com/rubo77/set_resolution.py

List the applications you wish to scale and the resolution you wish to scale them to. There is a second or so lag when switching applications, but it's the best I've got until developers start accommodating HiDPi screens by default.

Is it possible to configure a ‘scaled’ desktop in xorg.conf similar to using xrandr’s scale-from option

I just finished setting up a ~150% zoom under Cinnamon, hope this will help you too because GNOME is similar to Cinnamon.

I started with xrandr commands from this HiDPI ArchWiki article:

xrandr --output HDMI1 --scale 1.2x1.2 # try 1.3 also
xrandr --output HDMI1 --panning 2304x1296 # this is for 1920x1080 at 1.2

Then i wanted to set it permanent, tried xorg.conf but it does not want to catch Monitor sections of config whatever i try. I asked on ArchLinux forums and got an advice to accept it and throw away xorg.conf. Anyway, i think my config is correct and you can try and use it with changing Monitor Identifier. Most interesting part is transformation matrix. Xorg has no option for scaling, but i figured out that xrandr --scale is a shorthand for --xrandr --transform which corresponds to TransformationMatrix.

Here is my xorg.conf:

Section "Monitor"
    Identifier "TEST" # try changing this!
    Option "Panning" "2304x1296"
    Option "TransformationMatrix" "1.2 0 0 0 1.2 0 0 0 1"
EndSection

Section "Device"
    Identifier  "Intel Graphics" # change these lines according to your graphics card
    Driver  "intel"
    Option  "AccelMethod"   "sna"
    Option  "TearFree"  "true"
    Option  "Monitor-HDMI1" "TEST" # try changing this!
EndSection

This does not work for me, so i continued digging. My system has lightdm which starts first, and it needs xrandr commands to look HiDPIish. Then it starts cinnamon-session which overrides display settings and i need to run xrandr again. Lightdm is configured by etc/lightdm/lightdm.conf and by default it runs something specified in session-wrapper option. You need to create a script with desired xrandr tweaks and place it somewhere to be launched by session-wrapper. By the way, options session-setup-script and display-setup-script didn't work for me.

Then, in Cinnamon (or GNOME in your case) the best thing i could do is to use autostart feature and add xrandr script with zero timeout.

Best Answer

Related Solutions

HiDPI scaling for non-aware applications

Is it possible to configure a ‘scaled’ desktop in xorg.conf similar to using xrandr’s scale-from option

Related Question