Firefox 94 comes with EGL on X11

(In)Famous WebGL Aquarium demo. EGL brings you more fish 🙂

Firefox 94 is coming out next week and brings awesome news. OpenGL EGL backend its enabled by default on Intel/AMD and recent Mesa for users on X11.

This project has been driven by Robert Mader (most of the EGL work), Andrew Osmond (glxtest fixes and config), Jamie Nicol (EGL/Android and partial damage), Greg V (partial damage support) and Jan Ikenmeyer (Darkspirit) (help with issues, testing).

Historically Linux comes with GLX (OpenGL X11 extension) but that era is finally ending and we’re moving forward to EGL which promises all the goodness you can expect from modern graphics subsystem…or you can create a texture over graphics memory at least 🙂

I’ll keep aside all EGL / GLX difference and focus to changes from user perspective. GLX is old, well debugged and tied closely to X11 which means seamless experience and wide support by gfx drivers (like proprietary NVIDIA ones). It’s used by most X11 applications and ‘just works’.

EGL is ‘new’ from Linux desktop perspective and used mainly by Wayland, Android and various small devices. It’s not fully supported by all desktop drivers and has glitches (broken rendering of transparent windows for instance). But as Wayland is gaining momentum also EGL is getting more attention and fixes on Linux desktop.

And why we actually want EGL? Because it gives us a cool toy – EGLImages (and EGLFence). EGLImage is an object which is created over a piece of GPU memory (which can be DMA-Buf), shared with different process, used as a frame buffer (target of GL rendering) or a texture (source of GL rendering).

EGLImage allows to use GPU memory in a very creative way. VA-API decoded video frames or WebGL scenes can be mapped as EGLImages, moved from decode process to rendering process and used as a texture. EGLFence allows to lock EGLImages across process so we don’t re-paint WebGL scene while it’s used in a different process or recycle VA-API video frames too early.

And what you can expect from EGL in Firefox? Faster WebGL rendering (used on Google Maps for instance), more effective rendering due to to partial damage support and potential VA-API video decoding (that’s blocked by Bug 1698778 on both Wayland and X11). It also unifies rendering path for Wayland and X11, which means X11 will gain features done for Wayland (suspended rendering for invisible windows, better VSync support and more).

NVIDIA is also working on EGL & DMA-Buf support in their proprietary drivers so there’s a hope for owners of such FOSS unfriendly hardware.

So give Firefox 94 a try. If anything goes wrong, please file a bug. You can also disable EGL and switch back to GLX. Go to about:config page and flip gfx.x11-egl.force-disabled preference and restart browser.