Using Unity as a library in native iOS/Android apps

Is Unity as a library able to render in just a part of the screen yet? Or is it still full screen?

 

Can It render android ui elements over the top of the unity full screen?

 

Yes, thats possible

 

I've been scanning the forum and can't find any reference to a use case where I want Unity to feed back data to the main application. We have an external device controlled by the main Android application and want to read data from the Unity "library" instance to update the external device. In short, we want to broadcast/callback/send data from the Unity library back to the Android app without closing or exiting the Unity library, is this possible?

 

Yes. If I remember correctly you can send message back and forth.

 

Is there any guide on how to use this with Flutter? I am aware of the Flutter for Unity plugin already on github which has over 113 issues and we can't get it working. It would be very nice to be able to use this with Unity as a library

 

I have UnitySendMessage working fine form sending data from a Java class/function to Unity C# script, the problem is performance, I need to move a byte[] from Java to Unity, is there a way to pass a pointer to the memory address in Java to C# and update the array or texture2D in Unity?