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:

• inactive window transparency (specified with -i)
• 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

The above features give compton a feature set similar to the xfce compositor.

Compton has only been tested with openbox so far, but frame transparency should work with any window manager that properly sets _NET_FRAME_EXTENTS.

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)

Building

The same dependencies as xcompmgr.

Dependencies:

B for build-time

R for runtime

• libx11 (B,R)
• libxcomposite (B,R)
• libxdamage (B,R)
• libxfixes (B,R)
• libxrender (B,R)
• pkg-config (B)
• make (B)
• xproto / x11proto (B)
• bash (R)
• xprop,xwininfo / x11-utils (R)

To build, make sure you have the above dependencies:

$ make
$ make install

Usage

$ compton -cC -i 0.6 -e 0.6
$ compton -cC -i 0.6 -e 0.6 -fF
$ compton -cC -fF -I 0.065 -O 0.065 -D 6 -m 0.8 -i 0.6 -e 0.6

Options

compton [-d display] [-r radius] [-o opacity]
        [-l left-offset] [-t top-offset]
        [-i opacity] [-e opacity] [-cCfFSdG]

• -d display Specifies the display to manage.
• -r radius Specifies the blur radius for client-side shadows.
• -o opacity Specifies the opacity for client-side shadows.
• -l left-offset Specifies the left offset for client-side shadows.
• -t top-offset Specifies the top offset for client-side shadows.
• -I fade-in-step Specifies the opacity change between steps while fading in.
• -O fade-out-step Specifies the opacity change between steps while fading out.
• -D fade-delta Specifies the time (in milliseconds) between steps in a fade.
• -c Enable client-side shadows on windows.
• -f When -c is specified, enables a smooth fade effect for transient windows like menus, and for all windows on hide and restore events.
• -C When -c is specified, attempts to avoid painting shadows on panels and docks.
• -F When -f is specified, also enables the fade effect when windows change their opacity, as with transset(1).
• -i opacity Specifies inactive window transparency. (0.1 - 1.0)
• -e opacity Specifies window frame transparency. (0.1 - 1.0)
• -G Avoid painting shadows on DND windows.
• -b daemonize Attempt to daemonize process.
• -S Enables synchronous operation. Useful for debugging.

License

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
• Myself

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

See LICENSE for more info.