Customize Compositor

A compositor is a UI component that applies visual effects to windows before they are rendered on-screen. Many desktop environments integrate a compositor directly into the window manager, making it difficult to switch out or disable. In Regolith, the compositor is defined as a pluggable “extension point” in the packaging system. This means that compositors can be switched out simply by installing the packages that contain them. The underlying packaging system will ensure there are no conflicts and that all the dependencies of a given compositor are also installed.

Finding available compositors

The following command will list all compositors configured to work with Regolith:

apt search regolith-compositor-

You should find at least the following:

• regolith-compositor-picom-glx [default]: Uses picom. Recommended for most users to resolve screen tearing and add visual effects. Modern and well-maintained fork of compton.
• regolith-compositor-none: No compositor. Best performance, no visual effects.
• regolith-compositor-compton-glx: An ancestor of picom which is no longer maintained.
• regolith-compositor-xcompmgr: An early compositor that may offer more consistent performance if more complex compositors are problematic.

Installing a compositor

Run the following package install command to swap out the compositor. In this case we’ll install picom:

sudo apt install regolith-compositor-picom-glx

To run without a compositor, install regolith-compositor-none the same way.

Log out and then log back in and the new compositor should be loaded. You can verify by checking the process list for picom:

pgrep -a picom

Overriding Regolith default compositor configuration

Picom

To provide your own Picom compositor config, copy the default or create your own and save it as ~/.config/regolith3/picom/config. It is loaded instead of the default config /etc/regolith/picom/config the next time i3 starts, so regolith-look refresh (which restarts i3) applies it without logging out:

mkdir -p ~/.config/regolith3/picom
cp /etc/regolith/picom/config ~/.config/regolith3/picom/config

Some looks ship their own Picom config and select it with the Xresource regolith.compositor.picom.config. A file in ~/.config/regolith3/picom/config takes precedence over it.

If the screen stops updating in the X11 session (new windows do not appear and workspace switches do not show), for example in a virtual machine without 3D acceleration, Picom’s glx backend may not work with software rendering. Set backend = "xrender"; in your config, or use regolith-compositor-none.

Compton

regolith-compositor-compton-glx reads ~/.config/regolith3/compton/config instead of its default config /etc/regolith/compton/config.