Does anyone have a somewhat working Android example?

[bit-garden]

I understand that Android support is 'broken', but I think we need to have a list somewhere that shows exactly how it's broken. I've been attempting to get a working example for a while now, but I'm running into errors on fresh clones of the Bevy repo like missing shared libraries, vk swapchain errors and so on.

Currently I see screenshots of people getting something visual at least but I cannot find a repo or guide that show how to get Bevy into a basic workable state on Android.

Currently I'm hung up on the ndk libraries returning null pointers when attempting to get the current activity and can't tell if it's my issue or an issue affecting everyone.

I feel like I'm missing something since these screenshots exist there's an example folder that is being updated.

[alice-i-cecile]

This broke at the 0.6 release of Bevy, due to the rendering rework. There's been ongoing work to try and fix this (see #4139), but it requires dedicated attention by Android experts (if you have it, reviews would be 💯).

[bit-garden]

I cloned the 0.5.0 release and it looks like it's suffering from the same issue. It looks like it's panicking because it cannot get the running android context.

This unfortunately lands in an area I know nothing about and am having trouble even seeing how this works in the first place.

[mockersf]

there are three issues with Bevy on Android that I know of, let's make individual threads for each 🙂

[mockersf]

Mismatched ndk-glue between Bevy and winit: #4774

This only happens on main
Symptom will probably be something like no activity found

[bit-garden]

Letting Winit pull from github directly instead of version 0.26.0 will fix the mismatch enough to let this work. I had another issue that is being kept open as a reminder to push the update asap when it's ready.

(I just figured this out today)

[alice-i-cecile]

Fix in #4916

[mockersf]

Issue getting the window on Bevy start #3639 #4139

This happens since 0.6
Bevy is trying to get the window handle as soon as it starts, but it should wait for the Resume event on Android
Symptom is a black screen and a message in the log about failure to get the window

[bit-garden]

This is sort of remedied by putting a loop that waits for the window to not be null before starting the Bevy app. Some people have resolved this by adding in a timed delay instead.

[mockersf]

The PR linked used to work for me but I tried them again 2 weeks ago and it didn't work anymore. I didn't spend a lot of time investigating why... If one of them was in a workable state it should be doable to fix it enough following Cart review

[bit-garden]

I swear I tried this fork already and it didn't work. Now it seems to be working.

[bit-garden]

This line hinted how to get the rendering to work with Bevy 0.8.0-dev.

Block this line for target_os android.

    #[cfg(not(target_os = "android"))]
    handle_create_window_events(&mut app.world, &event_loop, &mut create_window_reader.0);

Add this before Bevy app run to wait for window to initialize.

  #[cfg(target_os = "android")]
  {
    use bevy::ndk_glue;
    println!("Waiting for NativeScreen");
    loop {
      match ndk_glue::native_window().as_ref() {
        Some(_) => {
          println!("NativeScreen Found:{:?}", ndk_glue::native_window());
          break;
        }
        None => (),
      }
    }
  }

So far this works while having only render and bevy-winit features enabled. I'm not sure of the rest of the features yet.

This brings the application to a non panicking state that has a visual output.

[mockersf]

Linking issue on compilation #4616

I can't talk much about this one as I never reproduced it but it seems to happen to many people
I'm guessing it's a local setup issue / path issue / version mismatched on the install ndk

[bit-garden]

I think this is depending on the NDK version. I have seen other posts noting that specific ones don't seem to include it by default, but you can use a build.rs file to force it to be linked. It doesn't seem to work for everyone though.

[bit-garden]

Android: Panic, VK_ERROR_NATIVE_WINDOW_IN_USE_KHR with minimal example. #4538

This one is my current issue, but I don't know enough about Vulkan to start with, so I'm currently crash coursing myself on this.

Edit:
Freshly cloning 0.8 and applying my fix at least stops the black screen issue on start up.

There are some inherent issues with this fix that should be addressed in the Android lifetime issues(like not being able to resume the application, or proper fixes for when to get window/activity pointers), but this technically gives a working, non crashing application with some input and visual output.

So currently I have a somewhat working Android example :D Thanks!

[bit-garden]

This resolves this. It looks like there is a note about creating a window early for WASM and that it breaks Android, but the line isn't guarded already?