proposal: x/mobile: start using OpenGL ES 3 instead of OpenGL ES 2 on Android

[hajimehoshi]

Now OpenGL ES 3 is not supported by gomobile-build as it was troublesome to detect whether a device supports GL ES 3 or not (https://github.com/golang/mobile/blob/7088062f872dd0678a87e8986c67992e9c8855a5/gl/work.h#L5-L10).

IMO, it is already safe to assume that most devices support GL ES 3, and we don't have to detect it. One reason is that ES 3 is supported by Android 5 (https://developer.android.com/guide/topics/graphics/opengl).

By this change, gomobile implementation will be slightly simpler.

What do you think?

/CC @hyangah @dmitshur @crawshaw

[dmitshur]

To clarify, is this proposal to replace OpenGL ES 2 on Android with OpenGL ES 3? That is, to drop 2 and add 3 in its place?

Given Android 5 was released in 2014 and is unsupported since 2016, I can't think of a good reason to object to the change. That said, given the state of x/mobile support and prioritization, I'm not sure who would have time to do the work and code reviews. If it can happen anyway, the change itself seems favorable to me.

[hajimehoshi]

To clarify, is this proposal to replace OpenGL ES 2 on Android with OpenGL ES 3? That is, to drop 2 and add 3 in its place?

I meant to drop 2 and add 3. So, if a device doesn't support ES 3, gomobile would not work there.

[ianlancetaylor]

CC @golang/mobile-admins @golang/android