drawables and refresh rates

[Rob Benton <rob benton conwaycorp net>]

Hey guys it's been about 8 hours since my last e-mail so it's time to 
post again :)

Other than the gtkmm docs, are there any books or sites which have more 
info on using graphics in Gtk?

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?