Sway: Changing screen brightness for OLED displays

[mherzberg]

Is there any way to change the screen brightness for OLED displays? Using /sys/class/backlight does not work with OLEDs, since they do not have any backlight. Under X, I was using xrandr --output eDP1 --brightness , which does not work anymore. It seems it must now be handled by the Wayland compositor.

[mpsq]

https://github.com/swaywm/sway/wiki/i3-Migration-Guide

Use light or brightnessctl.

EDIT: https://github.com/udifuchs/icc-brightness looks promising too.

[mherzberg]

Thank you for your answer. Since tools like light and brightnessctl all rely on /sys/class/backlight, they do unfortunately not work.

icc-brightness looks interesting, but I was unfortunately not able to get it to work on my machine. I was hoping to find a more lightweight and sway-native solution, but it seems there are currently no plans for that. Thanks again.

[cafehaine]

since it's OLED you could rely on changing the gamma ramps to achieve the same effect as lowering the 'backlight'. For this you could use one of the redshift forks supporting wayland

[emersion]

FWIW the wlroots gamma example supports setting brightness:

https://github.com/swaywm/wlroots/blob/master/examples/gamma-control.c#L144