Compton

Compton is a compositor for X, and a fork of xcompmgr-dana.

I was frustrated by the low amount of standalone lightweight compositors. Compton was forked from Dana Jansens' fork of xcompmgr and refactored. I fixed whatever bug I found, and added features I wanted. Things seem stable, but don't quote me on it. I will most likely be actively working on this until I get the features I want. This is also a learning experience for me. That is, I'm partially doing this out of a desire to learn Xlib.

Changes from xcompmgr:

• OpenGL backend (--backend glx), in addition to the old X Render backend.
• inactive window transparency / dimming
• titlebar/frame transparency (specified with -e)
• menu transparency (thanks to Dana)
• shadows are now enabled for argb windows, e.g. terminals with transparency
• removed serverside shadows (and simple compositing) to clean the code, the only option that remains is clientside shadows
• configuration files (see the man page for more details)
• colored shadows (--shadow-[red/green/blue])
• a new fade system
• VSync support (not always working)
• Blur of background of transparent windows, window color inversion (bad in performance)
• Some more options...

Fixes from the original xcompmgr:

• fixed a segfault when opening certain window types
• fixed a memory leak caused by not freeing up shadows (from the freedesktop repo)
• fixed the conflict with chromium and similar windows
• many more

Building

Dependencies:

B for build-time

R for runtime

• libx11 (B,R)
• libxcomposite (B,R)
• libxdamage (B,R)
• libxfixes (B,R)
• libXext (B,R)
• libxrender (B,R)
• libXrandr (B,R)
• pkg-config (B)
• make (B)
• xproto / x11proto (B)
• sh (R)
• xprop,xwininfo / x11-utils (R)
• libpcre (B,R) (Can be disabled with NO_REGEX_PCRE at compile time)
• libconfig (B,R) (Can be disabled with NO_LIBCONFIG at compile time)
• libdrm (B) (Can be disabled with NO_VSYNC_DRM at compile time)
• libGL (B,R) (Can be disabled with NO_VSYNC_OPENGL at compile time)
• libdbus (B,R) (Can be disabled with NO_DBUS at compile time)
• asciidoc (B)

How to build

To build, make sure you have the dependencies above:

# Make the main program
$ make
# Make the man pages
$ make docs
# Install
$ make install

(Compton does include a _CMakeLists.txt in the tree, but we haven't decided whether we should switch to CMake yet. The Makefile is fully usable right now.)

Known issues

• VSync does not work too well. It's widely reported that tearing still happens on the top of the screen. I do not know how to fix the issue.

• If --unredir-if-possible is enabled, when compton redirects/unredirects windows, the screen may flicker. Using --paint-on-overlay minimizes the problem from my observation, yet I do not know if there's a cure.

• compton may not track focus correctly in all situations. The focus tracking code is experimental. --use-ewmh-active-win might be helpful.

• Compton may give ugly shadow to windows with ARGB background if -z is enabled, because compton cannot determine their real shapes. One may have to disable shadows on those windows with window-type-specific settings in configuration file or --shadow-exclude.

• The performance of blurring is terrible, probably because of a problem in the X Render implementation. Its behavior is driver-dependent: With nvidia-drivers it works but there are strange 1px lines remaining when you operate on windows (not sure if it's a bug in compton or in the driver); with nouveau it's utterly broken.

Usage

Please refer to the Asciidoc man pages (man/compton.1.asciidoc & man/compton-trans.1.asciidoc) for more details and examples.

Note a sample configuration file compton.sample.conf is included in the repository.

Support

• Bug reports and feature requests should go to the "Issues" section above.

• Our (semi?) official IRC channel is #compton on FreeNode.

• Some information is available on the wiki, including (and presently, only includes) a FAQ.

License

Although compton has kind of taken on a life of its own, it was originally an xcompmgr fork. xcompmgr has gotten around. As far as I can tell, the lineage for this particular tree is something like:

• Keith Packard (original author)
• Matthew Hawn
• ...
• Dana Jansens
• chjj and richardgv

Not counting the tens of people who forked it in between.

Compton is distributed under MIT license, as far as I (richardgv) know. See LICENSE for more info.