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When I've used painting/drawing apps, I never notice a delay between pressing my finger and being able to see something drawn on the display. However with my app, the initial touches are received very slowly. The second and third and fourth gestures are received a 60 per second, but the first gesture is maybe 2-3 touch events per second. Furthermore if I let the app sit idle for a 10 seconds, the same delay happens again. It's as though iOS forgets that the app needs attention, or the device (iPad 3, iOS 5.1.1) goes into a kind of sleep where the display is on but touch response slows.

UPDATE: If I put the iPad 3 to sleep/lock by closing the display and leave it for 10 seconds, then open the display, the initial sluggish touches response happens every time.

UPDATE: This problem is not occurring on my iPad 1 running iOS 5.1.1. Even when I bring the iPad 1 back from sleep/unlock, there is no delay.

1 Answers1

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I haven't really worked with this kind of thing before, but I recall reading somewhere about using a UIBezierPath to create a drawing app. You could try to use that. According to this question, it's faster:

Why is UIBezierPath faster than Core Graphics path?

A tutorial is here: http://soulwithmobiletechnology.blogspot.com/2011/05/uibezierpath-tutorial-for-iphone-sdk-40.html

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gtmtg
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  • UIBezierPath does other things too, according to the [Apple documentation](http://developer.apple.com/library/ios/#documentation/2ddrawing/conceptual/drawingprintingios/BezierPaths/BezierPaths.html). – gtmtg Jun 07 '12 at 23:09
  • Weird... you'd think that newer hardware would be more responsive... Maybe the UIBezierPath will work on the new iPad as well... – gtmtg Jun 07 '12 at 23:40