[Xfce4-commits] r27940 - xfdesktop/trunk/src

[Brian J. Tarricone]

On Thu, 25 Sep 2008 08:32:33 +0100 Olivier Fourdan wrote:

> 
> On Thu, Sep 25, 2008 at 7:27 AM, Brian Tarricone <kelnos at xfce.org>
> wrote:
> > Author: kelnos
> > Date: 2008-09-25 06:27:26 +0000 (Thu, 25 Sep 2008)
> > New Revision: 27940
> >
> > Modified:
> >   xfdesktop/trunk/src/xfce-desktop.c
> > Log:
> > double-buffer the desktop window again.
> >
> > i'm not entirely sure why we turned this off years and years ago.
> > it doesn't really impact performance (well, except for positively)
> > or memory usage, and fixes a bunch of flicker issues i never got
> > around to fixing.
> 
> The logic behind this was to work arround a major slowdown on some
> NVidia card when double buffering was set.
> 
> My understanding of the issue is that the driver was allocating a huge
> amount of memory for textures leaving a lot less for regular pixmaps.
> By turning on double buffering on the desktop window, we basically
> double the amount of pixmap used (one for the background picture
> itself and other one for the buffer) causing the pixmaps to be stored
> in main memory instead of video memory, causing the slowdown on
> redraw.
> 
> Today, with compositing, the amount of pixmap memory used has
> increased a lot so I guess the driver was modified to support larger
> amount of pixmaps. Still, we may still have the problem with lower end
> video cards, dunno.

Ah, I see.  Well, double buffering fixes a lot of flicker/repaint
issues with the icon view -- not sure if they're my fault and the
double buffering is just hiding bugs, but...  we'll see if people
complain, I guess.

	-b