Android activity lifecycle

blaind commented 3 years ago

Currently the android (Oculus Quest 2) lifecycle has problems. Especially after the initial startup, if user navigates back to the application. Seems like that Oculus may also initialize apps before actually displaying them to user?

Some pointers for investigation:

main() at https://github.com/blaind/xrbevy/blob/df535495d100697857cfcbe4a58f135b488082b1/examples/xr_apk_scene.rs#L6 can be called multiple times, each from different thread. See https://www.khronos.org/registry/OpenXR/specs/1.0/html/xrspec.html#XR_OCULUS_android_session_state_enable
event loop handling happens at https://github.com/blaind/bevy_openxr/blob/e48bd27130cfb3b735edf2d6ce6355bb5c2490f0/crates/bevy_openxr_core/src/lib.rs#L124. The process::exit(0) at line 135 should be eventually removed
Session states explanied at https://www.khronos.org/registry/OpenXR/specs/1.0/html/xrspec.html#session-states

For running the example, in case of problems current "quick fix" is to just run make run_xr_apk a few times until Oculus kills all remaining instances and launches a new one.

blaind commented 3 years ago

Might need to use separate (activity-based instead of XR events) lifecycle for android. See:

https://developer.oculus.com/downloads/package/oculus-openxr-mobile-sdk/

https://github.com/KhronosGroup/OpenXR-SDK-Source/blob/42b694c4daf3530bf5d66803ef73e189a80c2ef6/src/tests/hello_xr/main.cpp#L156

Ping also @agrande (related to #7)

blaind commented 3 years ago

There was a problem with older version of cargo-apk of silently ignoring the singletask androidmanifest config option.

Fixed in https://github.com/blaind/xrbevy/commit/e99355ab80d50b8fb1fbb5b2f6e7f1e8b6824389. Newest cargo-apk from crates can be used now (cargo install cargo-apk)

Also some changes to lifecycle in https://github.com/blaind/bevy_openxr/commit/0cbefb25876e89bb6b4cf242de0f07bcc72052b9

blaind / xrbevy

Android activity lifecycle #3