Re: expose event compression

[Owen Taylor <otaylor redhat com>]

On Mon, 2003-10-13 at 15:40, John Cupitt wrote:
> Hi all, 
> 
> I'm porting an app to gtk2 and I've come across some performance problems caused (I think) by gtk's new expose event compression system.
> 
> One of the app's widgets is an image display window, and one of the tools is a panner. Pure left/right and up/down pans are fast and smooth, but diagonal drags are very choppy. I think this is because gtk is sending me the bounding box of all exposes since the last repaint, and for a diagonal drag, the bounding box of a thin strip down the right and a thin strip across the bottom is the entire window. 
> 
> Has anyone come across this before, and is there an easy solution?
> 
> (in case it matters, it's a drawing area inside viewport inside a scrolled window, and it's being panned by setting new values for the adjustments and calling value_changed on the h and v adjustments separately)

You get the exact region in the expose event along with the bounding
box.

Regards,
						Owen