Re: [h-e-w] Slow scroll speed in emacs 21?

[Andrew Innes]

On Mon, 17 Sep 2001 16:32:46 -0700, "Deep Blue" <address@hidden> said:

> I know we're not supposed to have it, but I was trying pretest
> 21.0.105.1 on Win2k.  Unfortunately I can't tolerate using it because
> the the scroll speed is quite slow, especially when using the mouse
> wheel.  I'm using the obj-spd version of emacs.exe.
> 
> It's slow in most font-locked buffers, and easy to repro.  One easy
> repro is to do an "ls" through eshell a couple of times in a directory
> with ~200 files and then try to scroll up using the wheel.  There are
> only about 200 lines, and only a little syntax highlighting, but there's
> a definite lag in scrolling (on a PIII).
> 
> Is this a a known issue?

Yes, the Windows portion of the new redisplay engine in Emacs 21 is not
well optimized at the moment.  (Jason did extremely well to get as much
of it working as he did - I've been unable to offer any real help in the
effort - and he rightly concentrated on getting as much functionality
implemented as he had time to do.)

A few people have already expressed interest in helping out, and of
course more are welcome.  We've been telling people that it will be
simplest for them to wait until 21.1 is officially released, so they can
work from the release code.  However, if you have a copy of a recent
pretest, then you can work from that if you want to try and improve some
aspect of it (in this case, profile the redisplay code to identify hot
spots).  I don't expect the Windows portion to change before the
release.

AndrewI