Re: setMarkerLocation = 44% CPU?

FROM : Alastair Houghton
DATE : Mon Jan 07 19:25:20 2008

On 7 Jan 2008, at 18:01, Lorenzo wrote:

> Hi,
> I run my animation at 60 FPS speed.
> During the playback I move a timeMarker along its NSRulerView with
>
>    [hRulerView setNeedsDisplayInRect:[playbackMarker 
> imageRectInRuler]];
>    [playbackMarker setMarkerLocation:playbackTime];
>    [hRulerView setNeedsDisplayInRect:[playbackMarker 
> imageRectInRuler]];
>
> Well, I have checked the CPU % with "top" on the Terminal and during 
> the
> playback my app gets 44% of the CPU. If I comment the 3 lines of 
> code here
> above, the CPU % goes down dramatically to 3.6%. Even if I comment 
> the line
> setMarkerLocation only it goes to 3.6%.
> I have verified with "Quartz Debug" that the "yellow" region of the
> NSRulerView I refresh is just the one under the timeMarker. I am 
> sure I am
> making something wrong, because that 44% value is really to much, so 
> please
> where should I look at to catch my bug?


Use Shark (or Instruments or Sampler) to find the code that is 
actually eating CPU time.  Make the bit of code that's taking the most 
time more efficient.  Re-run your measurements.  Repeat until bored.

Kind regards,

Alastair.

--
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