Does it help to start intensive core animation blocks in another thread?

Question

I have an scroll view with some sophisticated animations happening during scrolling. Although after 2 weeks of finetuning the performance is acceptable now, the scrolling is not 100% smooth when the animations happen.

I know that core animation does animations in a background thread. But I wonder if it would help to split those animation blocks (10 of them at pretty much the same time) into threads.

There are a few methods that look interesting:

– performSelector:onThread:withObject:waitUntilDone: – performSelectorInBackground:withObject:

or is that nonsense to do?

Answer 1

No, it won't help. As you correctly stated yourself, Core Animation already runs in a seperate thread. Core Animation is smart enough to handle animation blocks as efficiently as possible. I wouldn't advise interfering with it.

The Core Animation Programming Guide says:

An abstract animation interface that allows animations to run on a separate thread, independent of your application's run loop. Once an animation is configured and starts, Core Animation assumes full responsibility for running it at frame rate.

Answer 2

Are you sure the choppy behavior is really from CA? Do you have anything else going on?

If you have any background network access, consider moving that into a separate thread - the time taken to service those calls takes away from time the UI spends updating the screen as you scroll.