Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!voder!pyramid!epimass!jbuck
From: jbuck@epimass.EPI.COM (Joe Buck)
Newsgroups: gnu.emacs
Subject: Re: smooth scrolling
Message-ID: <3493@epimass.EPI.COM>
Date: 3 Aug 89 20:10:56 GMT
References: <8908021543.AA00534@romano.cs.wisc.edu>
Reply-To: jbuck@epimass.EPI.COM (Joe Buck)
Distribution: gnu
Organization: Entropic Processing, Inc., Cupertino, CA
Lines: 16

In article <8908021543.AA00534@romano.cs.wisc.edu> dave@CS.WISC.EDU (Dave Cohrs) writes:
>Have you ever noticed that sometimes when you (scroll-up) or
>(scroll-down), emacs (18.54) insists on doing really ugly things to your
>display, like scrolling the entire display up/down (moving the banner
>line) and then scrolling it back again?

Emacs attempts to optimize things by sending the smallest number of
characters to the screen.  It thinks inserting and deleting lines is
preferable to repainting because fewer characters are required.
Unfortunately, this is not the appropriate metric for a bitmap
display.  One easy workaround is to modify your TERMCAP entry to say
that "al" and "dl" require padding.  (I used "2*" before the normal al
and dl entries).  The result is much more pleasant.  It's a much
cleaner solution than your elisp functions.
-- 
-- Joe Buck	jbuck@epimass.epi.com, uunet!epimass.epi.com!jbuck