Code review comment for lp:~kdub/mir/post-if-optimizable

> Ah. Let me see if I've got how the nested case will work:
>
> The inner-Mir will always accept whatever renderable list you care to pass to
> post_renderables_if_optimizable() and send them down to the outer-Mir. The
> outer-Mir will then post_renderables_if_optimizable() and either go “yay!” or
> do a GL composition pass.
>
> And we optimise further the implementation of
> post_renderables_if_optimizable() running on the hardware will only bail if
> none of the renderables are optimisable.
>

Sounds right to me.

> So this makes it easier to bring up platforms in the short term, and will
> probably be a no-op in the long term?

I'm confused as what will 'be a no-op in the long term'. post_renderables_if_optimizable() will be the hardware optimized interface that compositors should try if they know they're doing something simple, and post_update() will be the interface that the compositors use to do anything they want with GL