Allow Vsync to be enabled/disabled at runtime

[totebo]

It looks like Vsync can’t be enabled/disabled at runtime:

Animate with Vsync

I’m back! Power saving mode on iOS has become a bother, and I can’t seem to find any way to make it run faster than 30fps. It seems it’s hardware locked to 30fps, so this code in fact has no effect: msg.post("@system:", "set_update_frequency", { frequency = 60 } ) msg.post("@system:", "set_vsync", { swap_interval = 0 } ) In my desperation I even tried to set frequency to 120, which made no difference.

Allowing Vsync to be disabled/enabled at runtime would allow having a smooth game (with Vsync enabled) for most players, and dropping it when on iOS power saving mode and other edge cases.