Re: drawables and refresh rates

["Andrew E. Makeev" <andrew solvo ru>]

Rob Benton wrote:

> Jan Hudec wrote:
>
> > On Wed, Dec 01, 2004 at 11:14:58 -0600, Rob Benton wrote:
> >
> > > I have a Gdk::Drawable where I'm drawing 2 arcs.  A blue circle and 
> > > a red arc drawn on top of the blue circle.  I've got 2 Gtk::HScale 
> > > widgets using a DISCONTINUOUS_UPDATE that modify the angle and width 
> > > of the red arc.  On update the the blue circle is redrawn and then 
> > > the red is redrawn on top of it using the values from the scale 
> > > widgets.  This causes some flickering on the drawing area.  Is there 
> > > a better way to do this?
> >
> >
> >
> > Computer graphics 101. Double buffering.
> >
> > ------------------------------------------------------------------------------- 
> >
> >                          Jan 'Bulb' Hudec <bulb ucw cz>
>
>
>
> Well I'm a mediocre pencil & paper artist but I'm a total noob at 
> computer graphics.  Do you guys know of any resources I could use to 
> get started?

Before to answer you, we need to know how do you "draw" your circles? 
The common way is to use expose_event to redraw only those parts of the 
drawing area that actually were changed. In this case I never seen any 
flickering in my applications even on Celeron 300Mhz.

Regards,
-andrew