cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   robodude666
   Member

   Hey guys,

   What is the primary difference between each of the different Director Types? I know there are 4 of them:

   CCTimerDirector - Uses an NSTimer
   CCDisplayLinkDirector - Uses CADisplayLink
   CCFastDirector - Uses NSInvocation
   CCThreadedFastDirector - Uses NSThread

   What is the best use for each one of them? From playing around I discovered:

   CCTimerDirector works best with UIView elements like UIScrollView with a small modification to CCDirector.m, though it's a little slow.

   CCDisplayLinkDirector uses CADisplayLink which is recommended by Apple for OS 3.1+ devices as it's the fastest, though it freezes with UIScrollView elements.

   The CCFastDirector works with UIScrollView elements except it breaks the momentum scroll,

   And lastly the CCThreadedFastDirector is in between the timer director and display link in terms of performance, with native support for UIScrollView elements.

   Which is best for what, and which should be avoided altogether? I'm only testing on a Simulator now, so I can't exactly see if the results translate to a device.

   -robodude666

   Posted 1 year ago #
2. 

   araker
   Moderator

   A very short answer would be use NSThread for devices < 3.1 and CADisplayLink for everything else. Never use NSTimer, since it has a bad resolution, eg no guarantee when the timer will fire.

   You want a game loop to be as stable as possible and synced to the refresh rate of the screen. That way drawing is synched and your game looks as smooth as possible. CADisplayLink does just that, when using the other methods you're just trying to emulate what CADisplayLink does out of the box, so those will never perform as good.

   For further reading, a forum topic about CADisplayLink (link).

   Regarding your problems with UIScrollView, it should work fine in combination with displaylink. In fact in WWDC session 401 (Game Design and Development for iPhoneOS) they showed a game where UIKit was layered on top of OpenGL and I believe they also used a UIScrollView.

   Posted 1 year ago #
3. 

   robodude666
   Member

   Figured so.

   I've watched a couple dozen or so WWDC2010 videos, and was specifically inspired by Quest.

   The reason I bring up the UIScrollView is that I'm attempting to create a little mini-map-like thing similar to Quest. I got the UIScrollView to show up fine, but when I use the CADisplayLink as my director type any scrolling causes Cocos2D to freeze in the background. I'm not entirely sure why. All searches point to using the TimerDirector with the line of code uncommented to make it snappy with UIView elements. Can't seem to find anything related to DisplayLink + UIScrollView playing nice together.

   I really wish they released the code for Quest, or at least parts of it.

   -robodude666

   Posted 1 year ago #
4. 

   araker
   Moderator

   It could be that the director is blocking the main thread so much that it prevents system messages from coming through on time. In this topic there are several suggestions how to deal with that.

   Posted 1 year ago #
5. 

   robodude666
   Member

   Interesting.. This didn't work the first time I tried it, but now the NSRunLoopCommonModes edit works with the CADisplayLink also.

   In CCDisplayLinkDirector's startAnimation method I commented out:

   [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

   and replaced it with:

   [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

   Now Cocos2D doesn't freeze in the background while the UIScrollView is being moved around :).

   riq, if you're reading this, is Cocos2D set to NSDefaultRunLoopMode as a feature or a bug? I'm assuming using the NSRunLoopCommonModes has a small performance hit as it lets all loops run.

   -robodude666

   Posted 1 year ago #
6. 

   riq
   Key Master

   is Cocos2D set to NSDefaultRunLoopMode as a feature or a bug? I'm assuming using the NSRunLoopCommonModes has a small performance hit as it lets all loops run..

   I would say it is a feature, but if NSRunLoopCommonModes is useful, could open a ticket ? thanks.

   Posted 1 year ago #
7. 

   rsanchezsaez
   Member

   I tried this solution, as I'm trying to use CCDisplayLinkDirector together with an overlaid UIScrollView, but using

   [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

   in CCDisplayLinkDirector partially breaks UIScrollView behaviour (very fast burst scrolling doesn't get any inertia).

   robodude666: Are you experiencing this issue?

   Posted 9 months ago #
8. 

   rsanchezsaez
   Member

   I found the ultimate solution in this question:
   - http://stackoverflow.com/questions/5944050/cadisplaylink-opengl-rendering-breaks-uiscrollview-behaviour

   Posted 9 months ago #
9. 

   cacao
   Member

   @rsanchezsaez where do you apply this solution? CCDirector.m?

   Posted 9 months ago #
10. 

    Normal Force
    Member

    I would be interested, as well, in knowing where the GCD was applied to obtain this ultimate solution.

    Posted 6 months ago #

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