Re: Scrolling commands and skipping redisplay, was: Re: emacs rendering comparisson between emacs23 and emacs26.3

[Dmitry Gutov]

On 12.04.2020 08:03, Stefan Monnier wrote:
> > > Normally, input_was_pending should be the same during scroll than during
> > > the subsequent redisplay, so there should not be any loss of precision, no.
> > No, the same loss of precision as associated with f-b-i-s. Since font-lock
> > won't occur while scrolling, whatever different-sized fonts, etc, that could
> > be applied, won't be. So the scrolling positions will be imprecise.
> It is precise in the sense that it will skip exactly the amount
> corresponding to what is displayed.  Because jit-lock is skipped, what
> is displayed is different, but the scrolling itself is "precise".

Hmm, good point.

Overall, this approach might be better than nothing (better than 
stalling display, I think), especially if font-lock right after a file 
has been visited can be fixed.

As default behavior, though, users or mid-power systems might prefer if 
we throttle keyboard input in such conditions instead.