OpenGL in live cards?

问题:

I've been playing with the glass GDK and glass 'native' (Java) development in general. I've got a open GL app that works well enough on Glass (using standard android conventions) and I'm looking to port it to the GDK to take advantage of voice triggers and what not.

While I can certainly use it easily enough as an Immersion (I think anyway) what I'd like to do is use it as a Live Card. I'm just not sure how possible or practical this is. The documentation seems to imply that with a high frequency rendering card this should be possible but before I dive in I was hoping someone with more experience could weigh in.

(Forgive me if this is obvious -- I'm new to Android having spent the last few years in IOS/obj-c land)

回答1:

XE16 supports OpenGL in live cards. Use the class GlRenderer: https://developers.google.com/glass/develop/gdk/reference/com/google/android/glass/timeline/GlRenderer

回答2:

I would look at your app and determine if you want to have more user input or not and whether you want it to live in a specific part of your Timeline or just have it be launched when the user wants it.

Specifically, since Live Cards live in the Timeline, they will not be able to capture the swipe backward or swipe forwards gestures since those navigate the Timeline. See the "When to use Live Cards" section of: https://developers.google.com/glass/develop/gdk/ui/index

If you use an Immersion, however you will be able to use those swipe backwards and forwards gestures as well as these others: https://developers.google.com/glass/develop/gdk/input/touch This will give you complete control over the UI and touchpad, with the exception that swipe down should exit your Immersion.

The downside is that once the user exits your Immersion, they will need to start it again likely with a Voice Trigger, whereas a Live Card can live on in part of your Timeline.

You should be able to do your rendering in both a Surface, which a LiveCard can use or in whatever View you choose to put in your Activity which is what an Immersion is. GLSurfaceView for example may be what you need and that internally uses a Surface: http://developer.android.com/guide/topics/graphics/opengl.html Note that you'll want to avoid RemoteViews but I think you already figured that out.