Re: NSView -drawRect optimization

FROM : Peter Ammon
DATE : Tue Feb 12 23:31:26 2008

On Feb 12, 2008, at 2:02 PM, Paul Bruneau wrote:

>
> My only concern with it is the frames per second draw speed of the 
> view (it's all done in -drawRect). I have done pretty good testing 
> to remove individual segments of code from the loop in order to see 
> what is taking the time:


Hi Paul,

It's not clear how you are measuring the fps, but a common cause of 
slow drawing is that your app triggers immediate rendering too often, 
which will be throttled by coalesced updates.  See http://
developer.apple.com/technotes/tn2005/tn2133.html for more information.

To determine if you are being bitten by this, launch Quartz Debug and 
turn on Disable Beam Synchronization under the Tools menu.  If your 
fps improves substantially, that's the culprit.

-Peter