Re: Why gtk applications redraw so slow?

[Gustavo Joćo Alves Marques Carneiro <ee96090 fe up pt>]

On Thu, 4 Nov 1999, Alexander Piskunov wrote:

> 
> 
> On Thu, 4 Nov 1999, Antonio Campos wrote:
> 
> > 
> > Why gtk applications redraw so slow compared to KDE applications or
> > others X-Window applications?
> > Is it inherent to the design of gtk?
> > 
> To many overhead, too many unneeded redraws - this is a reason. Hundreds
> of X calls to draw ordinary window.
> Drawing engine will be changed in future versions to pixmap backed. All
> drawing will go to memory buffer and only resulting pixmap will be
> displayed.

Yes, that is true. I've seen it myself when I was trying to change the
gtkruler sources to make a custom ruler. I found something odd: the
Gtk?Ruler (GtkHRuler or GtkVRuler) uses an memory pixmap to instead of
drawing directly to the window. But, every time it receives an expose
event, it completely redraws the memory pixmap and then blits it to
widget's x window. I simply cannot understand why it was done that way.


> Perhaps this technique is used in Motif, Qt, Win9x and other toolkits (at
> least it seems so:)
> 
> 
> 

-- 
Gustavo J.A.M. Carneiro
World::Portugal::FEUP::DEEC::LEEC::TEC
[reinolinux.fe.up.pt/~ee96090]