[Android editor] Improve support for XR projects

[m4gr3d]

Port the Android editor to Meta Quest (HorizonOS) devices:

• Add support for developing, running and debugging 2D, 3D and XR projects natively on Meta Quest devices
• Add support for building Godot binaries natively on Meta Quest devices
• Leverage Meta's APIs to turn the editor into an Hybrid App
  • Provide the ability to open multi windows (editor and play window) side by side
  • Provide the ability to transition between the editor (2D) window and a running immersive XR project
  • Provide the ability to invoke the editor window while an immersive XR project is running to enable hot reload and live debugging

Note: Requires Horizon OS v69 or higher

[dsnopek]

I just tested on the Meta Quest 3, both with a flatscreen app and an immersive XR app. Everything seems to be working great!

The code looks good to me too.

[BastiaanOlij]

Very cool, you weren't kidding, I was expecting much more invasive changes. This creates a really nice platform to expand upon.

[akien-mga]

nice

[akien-mga]

Not necessarily for this PR, but I think the back and forth on this shows that we need a dedicated option for enabling debug symbols in gradle, and not just infer it from dev or debug symbols.

It should be possible for users to make template_release and template_debug builds with debug symbols, to be stripped when uploading their builds, so they can symbolicate crashes.

[akien-mga]

Looks really clean and the refactor makes sense to properly support multiple flavors of the Android editor.

Can't test it for now as I believe my dusty Quest 1 doesn't have a recent enough OS version for this :D

[devloglogan]

LGTM, working great on my Quest 3!

[akien-mga]

Thanks to everyone involved! That's a pretty exciting change, I'm eager to see more of what it will enable :)

[Zeirus]

Please post screenshots or videos of the editor working in Quest 3 with some demos. We are very curious! P.S.: Is there any chance it could work in Quest 2?

[dsnopek]

We'll make some videos after not too long - this is just the beginning. :-)

It can "work" on the Quest 2, however, it's a little under-powered and doesn't provide as good an experience as Quest 3 and Quest Pro, so we decided not to support it, at least for now - perhaps we'll be able to optimize and improve the experience in the future.

However, if want to build it yourself and allow it to run on Quest 2, you just need to change this line in the AndroidManifest.xml: https://github.com/godotengine/godot/pull/96624/files#diff-336222dc899645e608d8d7355038c154f74316238dec6ab406bfe544441e9f0bR77