Investigate WebXR with WebKit

[msub2]

WebKit has had WebXR in the source tree for some time now thanks to work from Igalia, and it looks like their OpenXR backend is using XR_MNDX_egl_enable for doing EGL-backed sessions, which is only available in Monado and SteamVR Linux. A long time ago I tried getting WebXR working on WebKit in Windows, not knowing about this detail, but I never actually tried to get it working on Linux. Might be worth looking into.

[msub2]

The primary upstream target for this would probably be GNOME Web/Epiphany

[mrxz]

Initially I did try to get WPE Webkit with the OpenXR backend working, but ran into some issue. Don't remember the specifics, but it was to the effect that compiling/launching with the flags needed for WebXR caused rendering/stability issues with any WebGL context. At the time it felt that Gecko and Chromium were more fruitful to pursue.

Also, XR_MNDX_egl_enable is only supported by the Monado runtime, not by SteamVR as far as I know.

[wurcyc]

hello, it seems the patch has not been compatible with the newest chromium version
would u please help update?

[mrxz]

hello, it seems the patch has not been compatible with the newest chromium version would u please help update?

@wurcyc This issue is for WebKit, not the Chromium patch. Either way, the patch hasn't been updated in a long time, so it's not surprising that it no longer cleanly applies. There is a newer version of the patch for Chromium 130 made by rcelyte, who also did the majority of the work on the original patch. Which you can find here: https://github.com/rcelyte/webxr-linux/tree/chromium.

[rcelyte]

@wurcyc @mrxz Small disclaimer about that - Chromium added some new overlay logic which my patch only has stubs for, so permission prompts and whatnot will likely be invisible while still interactable.