Quick-pausing is one tic ahead
Quick-pausing (the pause
command or "Pause/Run Retry" control) shows the current tic, not the previous tic. When fpscap
is not set to 35, since gameplay is always interpolated from the previous tic to the current tic (making the "current tic" into a new "previous tic" when it finishes), this means that quick-pausing effectively jumps one tic ahead. and un-quick-pausing jumps one tic back in time.
This is most easily noticeable by setting timescale
to 0.1 or 0.05, using bind X "pause;wait;pause"
, running, quick-pausing, and pressing X to un- and re-quick-pause. The camera and all objects will jolt one tic back in time when un-pausing, then interpolate towards the next tic, then jolt one tic ahead in time when re-quick-pausing.
Note that the normal-pause menu does not jump one tic ahead; it shows the previous tic, not the current tic, which feels smoother when pausing/unpausing with interpolation.
(Also note that the normal-pause menu shows the "previous tic" even with fpscap
set to 35, unlike quick-pausing. This long-time(?) discrepancy is only noticeable now thanks to frame interpolation.)