@cmuratori hang on a minute here... with freesync/gsync, we don't know the exact timestamp of the currently rendered frame, that is, when it's gonna be presented... so how do we figure out the delta? keep the last frame's delta and hope it's close enough?
Accurately predicted frame rates are the only high-quality way to present animation. Freesync/gSync are fine, but your game should measure it's expected frame rate and set them to be a constant framerate at that interval, so you always know the correct timestep.