Re: Emacs and Gnome Canvas

[Eli Zaretskii]

> Date: Thu, 15 Jul 2010 17:16:31 +0200
> From: Jan Djärv <address@hidden>
> CC: address@hidden, address@hidden
> 
> 2010-07-15 16:35, Eli Zaretskii skrev:
> >> Date: Thu, 15 Jul 2010 16:24:27 +0200
> >> From: Jan Djärv<address@hidden>
> >> Cc: address@hidden, address@hidden
> >>
> >> No, they need to be done anyway sometime, it is no waste.  If the text 
> >> isn't
> >> displayed, the attributes are nvertheless set up correctly for the time 
> >> when
> >> the text is to be displayed later (by scrolling for example).
> >
> > By which time those attributes could have recomputed many times, for
> > just one display!
> >
> 
> That may be so.  But there is nothing actually displayed, you just do a 
> update 
> of the attributes.

This "just" is the hottest bottleneck of the current display engine.
That's why we try so hard to avoid it.

> I'm sure one could hook in to the scroll bars and just update the
> visible portion if that is needed.

I don't think updating the scroll bar is an important CPU user in
today's redisplay.

> >> If done right, I don't think it would be slower.  But someone has to do the
> >> code before we know.
> >
> > Well, naturally, if "done right"s definition is "to be no slower" ;-)
> >
> 
> Isn't that always implied by "right"?

Of course.