4z3/illum

== illum ==

Illum is a backlight manager for linux. It changes the screen backlight level
based on keypresses (brightness up and brightness down).

=== Instal (via distro) ===

Arch Linux:

https://aur.archlinux.org/packages/illum-git/

pacaur -S illum-git
systemctl enable illum.service
systemctl start illum.service

Gentoo:

https://github.com/jmesmon/overlay
https://github.com/jmesmon/overlay/blob/master/sys-apps/illum/illum-9999.ebuild

layman -a jmesmon
ACCEPT_KEYWORDS="**" emerge illum-git
rc-update add illum default
/etc/init.d/illum start

=== build ===

git submodule update --init
./build

OR

git submodule update --init
./configure
ninja

Note that ninja does not recognize env vars like CC and CFLAGS, but
./configure does. ./build is just a convenience wrapper to configure and
then call ninja.

=== Use ===

Run ./illum-d.

Currently, it attaches to all event sources that supply backlight up and
backlight down keys (assuming they exist under /dev/input/* )

=== Notes ===

• The user running illum-d needs the appropriate permisions to read from the
  input device (on Arch a member of group 'input' works) and to write to the
  backlight control

=== Dependencies ===

• libev :: an event loop
• libevdev :: wrapper for linux's input event system
• ccan (as a submodule) :: misc utility code

To build:

• sh
• ninja
• pkg-config (to find libevdev)
• a C compiler (gcc is tested)

=== License ===

GNU Affero General Public License version 3 (AGPL-3) as published by GNU: https://www.gnu.org/licenses/agpl-3.0.en.html

==== TODO ====

• support a "sticky" levels when switching between 0 and 1 (raw values) to
  better support backlights that can turn completely off.
• better brightness curve (right now is based on squaring, exponential might
  be more acurrate).
• automatically select "best" backlight driver rather than just "first"
• play nice with old-bios that also want to adjust the screen on keypresses
• figure out the right way to enumerate input devices (rather than readdir of
  /dev/input)
• Hotplug new input devices
• support using key combinations to adjust at different rates/different ways.
• add a client control program/library to allow syncronized control from different sources.
• dimming based on "activity"
  • detects activity
  • obeys inhibits (time limited and lifetime limited)
  • [optionally] displays the current backlight status via an overlay
    • showing other status (caps lock, num lock) may also be useful on come
      machines
  • dim bl durring inactivity

Inspiration:

• brightd: dims on inactivity