XWayland Receive An EGL-Based GLX Provider, Helping Various Games On Linux

A notable improvement was merged into the "xserver" Git tree for the eventual X.Org Server 1.21 release that will improve the support for various Linux games relying on XWayland for running under a Wayland compositor.

Adam Jackson of Red Hat landed an EGL-backed GLX provider for the xorg-server's XWayland code. Adam explained in the commit:

Without this we're using driswrast to set up GLX visuals. This is unfortunate because llvmpipe does not expose multisample configs, so various apps that expect them will fail. With this we just query the capabilities of the EGL that's backing glamor, and reflect that to the GLX clients. This also paves the way for xserver to stop being a DRI driver loader, which is nice.

This allows multi-sample anti-aliasing (MSAA) visuals to be exposed under XWayland and addresses various games/applications that expect the ability for multi-sample configurations. Among the known games that this merged patch fixes are Hearts of Iron IV, Stellaris, and Europa Universalis IV that up to now ran into problems when trying to run under XWayland.

Unfortunately, there is no release schedule yet for X.Org Server 1.21 so it could end up being a while before seeing this GLX provider in a released X.Org Server version. In fact, unless the xorg-server 1.21 effort starts getting organized soon, it's probably unlikely we'd see that version make it into the autumn Linux distribution updates like Ubuntu 19.10 and Fedora 31.