wluma
A tool for wlroots-based compositors that automatically adjusts screen brightness based on the screen contents and amount of ambient light around you.
Idea
The app will automatically brighten the screen when you are looking at a dark window (such as a fullscreen terminal) and darken the screen when you are looking at a bright window (such as web browser). The algorithm takes into consideration the amount of ambient light around you, so the same window can be brighter during the day than during the night.
With permission of Lumen's author (the project that inspired me to create this app), I'm reusing a demo GIF:
Usage
Simply launch wluma and continue adjusting your screen brightness as you usually do - the app will learn your preferences.
Performance
The app has minimal impact on system resources and battery life even though it is able to monitor screen contents several times a second. This is achieved by using export-dmabuf Wayland protocol to get access to the screen contents and doing computations entirely on GPU using Vulkan API.
Installation
On Arch Linux you can use wluma package.
Alternatively, build using make build and install via sudo make install.
Run
To run the app, simply launch wluma or use the provided systemd user service.
Strategies other than ambient light sensor
By default wluma uses ambient light sensor device to decide the best brightness value. If your laptop doesn't have this sensor, or if you simply want to use other strategies to distinguish day from night, you can use environment variable WLUMA_AMBIENT_LIGHT_SENSOR_BASE_PATH to point wluma to a different strategy.
See wluma-als-emulator project for more details of how this can be used.
Caveats
- Current drivers do not support importing images with custom DRM modifiers, this work is being done in mesa. Until then, the only workaround is to use
WLR_DRM_NO_MODIFIERS=1from wlroots.
Relevant projects
- wluma-als-emulator: emulate ambient light sensor using a webcam or time of the day
- lumen: project that inspired me to create this app