Lower level mapping for animation.

["John C Atkeson" <John C Atkeson noaa gov>]

  I'm interested in animating in a window using gtk.  Of course for speed I 
need a minimum of drawing overhead...    
  
  Since I can't do direct-video, what's the closest I can get?  I'd like to 
be able to draw my image onto a 2d array, then put the array straight into 
its window, and update repeatedly.  
  (Of course I'd have to poll the X server first for its color depth etc., 
but hopefully a one-time deal at the start of the program.)
  
  Can I write directly to a pixmap as if it were an array, then send the 
pixmap to the window?  (Probably not...)
  
  So then can I write directly to an XPM-data structure, then copy that to 
the pixmap, etc?  And re-use the same pixmap?
  
  Thanks,
  John