About SDL2 + GameCenter on iOS

I’ve read a few posts about the argument and as far as I see the correct
way to do this is to give Cocoa the control of the main loop,
using SDL_iPhoneSetAnimationCallback to update my game logic (that is then
restricted to work every 16 or every 32msec).

I’ve seen a pair of examples of this logic, but my question if there is a
way to make the cocoa loop running keeping the control of the main loop.

Something like one can do with GTK:

while (gtk_events_pending())

I’ve googled a bit for this but there is too much info about cocoa and
loops to find what I want :frowning: about GameCenter + SDL.

The reason for this is that I have a multiplatform app and I’d like to
insert game center support in the iOS version without changing the main
loop logic…–