[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-devel
Subject:    Re: Howto reduce X11 memory usage with several QCanvas /
From:       Lubos Lunak <l.lunak () suse ! cz>
Date:       2004-06-28 13:13:05
Message-ID: 200406281513.05868.l.lunak () suse ! cz
[Download RAW message or body]

On Monday 28 of June 2004 14:04, Achim Spangler wrote:
> Am Sonntag 27 Juni 2004 15:23 schrieb Lubos Lunak:
> > Dne čt 24. června 2004 21:48 Achim Spangler napsal(a):
> > > So I have the following questions:
> > > 1) What can cause this high memory usage of X11 ( the umbrello
> > > footprint would be acceptable )?
> >
> >  QPixmap's are stored in the XServer. Every pixmap takes roughly
> > width*height*depth/8 bytes of memory in the XServer.
>
> Is there a possibility to tell X11 / Qt that all items on a Canvas should
> be only displayed with a lower color depth than the X11 desktop has in
> general - i.e. my screen/ X11 desktop has 24Bit. Thus even simple diagrams
> which contain mostly QCanvasRectangle ( plain color - no shapes or other
> effects ) instances can cause a lot of memory usage.
>
> I think that there is no way to tell the X11 server / Qt to use some method
> of compression for hided QCanvas instances - or is there a possibility to
> do this or comparable?
 
 X11 pixmaps can have lower depths, QPixmap seems to support only monochrome 
and full depth. But that'd be probably just too much trouble. If it's really 
QCanvas causing this high usage, then QCanvas should get optimized. I suggest 
you ask on qt-bugs@ or some Qt forum.

-- 
Lubos Lunak
KDE developer
---------------------------------------------------------------------
SuSE CR, s.r.o.  e-mail: l.lunak@suse.cz , l.lunak@kde.org
Drahobejlova 27  tel: +420 2 9654 2373
190 00 Praha 9   fax: +420 2 9654 2374
Czech Republic   http://www.suse.cz/
 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<
[prev in list] [next in list] [prev in thread] [next in thread]