An X11 backlight manager.
Using Nix, you can access build-time dependencies via the Nix shell:
nix-shell
Otherwise, please refer to buildInputs in shell.nix to check whether you
have all the required dependencies installed through other means.
To install it you will need a nightly Rust toolchain, then you can install it with Cargo:
cargo install duxdux can be used like a replacement for xbacklight, the command syntax
changes slightly but the functionality is the same (get, set, inc, dec,
all with the usual fade settings).
To start the adaptive brightness daemon just run:
dux adaptive &
To stop it gracefully (making sure the settings are saved) just run:
dux stop
Adaptive brightness manages the backlight automatically for you based on the selected mode and profile.
To select a mode you can either pass a --mode <mode> when starting the
adaptive brightness, or call dux mode <mode> after it's been started.
There's support for multiple profiles, to select a profile just pass --profile <name> when starting the adaptive brightness, or call dux profile <name>;
profiles are useful for example to have different settings during the night and
during the day, or when you're inside or outside.
To configure the brightness levels for the various modes all you have to do is
change the backlight from dux itself like you would with xbacklight and the
change will be saved. If you don't want to do that you can call dux sync after
changing the backlight with something else.
The desktop mode uses the current active desktop (also known as workspace in
some window managers) to reload the previously set brightness.
The window mode uses the active window to to reload the previously set
brightness.
Tt uses both the window's instance and class name to determine the brightness, this allows for a common brightness setting for the class and a specific one for the named window.
The luminance mode uses the screen content's contrast to reload the brightness
value.
When the luminance is between two different settings it will interpolate the brightness value between the two based on the distance between them.
For example if you have 10 luminance set at 80 brightness and 50 luminance
set at 20 brightness and the current luminance value is 20 the brightness
will be closer to 80 than 20.
Performance wise it uses some X extensions to avoid doing heavy work, it uses the MIT-SHM extension to avoid connection pressure when fetching the screen contents and the DAMAGE extension to only fetch and recalculate the areas that have actually changed.