ccTouchesMoved Strange Behavior on iPhone4/iOS4

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ccTouchesMoved Strange Behavior on iPhone4/iOS4

(23 posts) (9 voices)

Started 1 year ago by ddeaco
Latest reply from bluelobster

Tags:

ddeaco
Member
I've just been working on a bit of code that moves a CCQuadParticleSystem around the screen with the ccTouchesMoved.
```
- (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
	for( UITouch *touch in touches ) {
		CGPoint location = [touch locationInView: [touch view]];
		location = [[CCDirector sharedDirector] convertToGL: location];
		touchPos = location;
		[emitter setPosition:location];
	}
}
```
Using the latest 0.99.4Rc, on my 3G running os3.1, everthing runs fine at 60fps, but on my iPhone4 running 4.0 there is a random problem where the emitter position doesn't update every frame, so lags behind.

It also seems a little random briefly it seems to work but quickly starts lagging behind.

I doesn't seem to be loosing the touch as a brake point added to ccTouchesEnded doesn't get activated until i actually release from the screen.

Not sure whats going on.

Dave
Posted 1 year ago #
ddeaco
Member

I have been doing some more testing, and still haven't made much progress. Ive removed everything apart from a sprite that is getting its position set in the ccTouchesMoved method.

Same code, both phones run at 60fps, 3G on iOS 3.1 runs perfect and the iPhone4 running iOS 4.0 the sprite starts to lag behind the touch almost immediately.

Any thoughts? :(

Posted 1 year ago #
ddeaco
Member

Here is a video demoing the problem,

http://www.daviddeacon.co.uk/iphone4Bug.MOV

Dave

Posted 1 year ago #
CJ
Moderator

Wow that looks really bad. Wish I could help, but I don't have an iPhone4.

Posted 1 year ago #
ddeaco
Member

Ive made a test project to try and get to the bottom of this here is the link :

http://www.daviddeacon.co.uk/bugTestProject.zip

It has been made from the cocos2D 0.99.4 chipmunk template, all I have changed is add an extra spinning sprite to demonstrate the screen is updating correctly and I also left the default one physics body added in the init method.

Slide your finger around the screen a white dot should follow it all nice and smooth. The bug normally appears right away, with the first initial movement being smooth and then becoming jerky right away. If the bug doesn't appear try restarting the app, I'm pretty confidant it will show up on an iPhone4 running iOS4.

If someone could test this on any device running iOS 4.0 to work out if its an SDK or device issue.

Thanks for the Help,

Dave

Posted 1 year ago #
cybergreg
Member

I ran your test project, all devices running iOS 4:
On my 3G iPhone & 2nd gen iPod Touch there is NO slow down at all
On my iPhone 4 and my 3rd Gen iPod Touch - nasty slow down after a few seconds

Seems to be related around multitasking since the 3rd gen iPod is not a retina display.

Posted 1 year ago #
ddeaco
Member

Great its not just me then,

Ive submitted the bug.

http://code.google.com/p/cocos2d-iphone/issues/detail?id=907&colspec=ID%20Type%20Status%20Priority%20Milestone%20Component%20Owner%20Summary&start=100

Thanks cybergreg

Posted 1 year ago #
noThree
Member

It seems that I am having the same problem as you. I tried your test app on a 3GS running IOS4 and there is a lag.

Have you tried the simulator? It seems that the problem only happens on the device and not the simulator as my app and your test app appear to function correctly.

Posted 1 year ago #
edge17
Member

I ran into what I believe to be the same issue with an existing app I have. The issue seemed to go away when I rebooted the phone and there wasn't any multitasking apps running in the background

Posted 1 year ago #
sabshire
Member

I've seen the same thing on my 3GS w/ iOS4 using the 0.99 rc2. Haven't upgraded to rc3 to see if it is fixed yet. I have also noticed this same behavior with the accelerometer too... silky smooth for a bit, then it starts lagging, and it gets progressively worse. Sometimes task switching and coming back and it's fine, but just for a short bit. Has anyone comfirmed if this is fixed in rc3?

Posted 1 year ago #
edge17
Member

@sabshire: According to the bug report it's a defect and not a bug in cocos2d: http://code.google.com/p/cocos2d-iphone/issues/detail?id=907

Posted 1 year ago #
sabshire
Member

defect in what? the developer's code? iOS4? what? I'd like to know what a good resolution to this is because having the touches lag like that really affects game play for me.

Posted 1 year ago #
sabshire
Member

Ok re-read what they wrote.. seems it is believed to be an ios4 bug which really sucks if is the case.

Posted 1 year ago #
edge17
Member

sorry, meant to say - defect in iOS4 and not a bug in cocos2d

Posted 1 year ago #
SDKTutor
Member

Hmm.... strange. I'm almost positive this has something to do with iOS4 and Open GLES.... have you tried making a UIKit version of the test and see if it is responsive. I have experienced problems with playing an Open GLES app and then closing it and opening up another one and the old gameplay showed up with streaks in the screen and problems like that...... try making a UIKit version to see if the touches are laggy.

Posted 1 year ago #
sabshire
Member

Tested older version of app that never exhibited this lagginess.

And on ios4 on iPhone 3GS it has the lag issue. Task switching and it goes away for a bit but comes back.

So it does seem to be ios4 and the multitasking.

I'll try an older model iPod with ios4 later to see if it does it or not

Posted 1 year ago #
noThree
Member

I was making excellent progress with my game but this is a massive setback and will basically ruin my game if it cannot be fixed. Does anyone have any ideas as to why it is happening?

Posted 1 year ago #
edge17
Member

@ddeaco: just wondering, but have you tried compiling with the new xcode w/ the new version of the compiler? (llvm or llvm+clang)

Posted 1 year ago #
sabshire
Member

I've tried a lot of things.... Sometimes I think that it has been fixed by some change I've made, but it always seems to come back. It's like I am just prolonging the inevitable. The upside is my code is a lot more efficient, but the touch lag still shows up. In certains cases it happens a lot sooner... sometimes it takes a while before it shows up, but it is still there. I've still not been able to test iOS4 on my ipod yet, but iOS4 on 3gs definitely has this issue. Same code on 3.1.3 no lag whatsoever, so it's something to do with iOS4, and like @SDKTutor mentioned, I think it has something to do with OpenGLES.

Posted 1 year ago #
sabshire
Member

Well, I added a log event to the CCTouchDispatcher, and I can confirm that the touchesMoved is not firing when it gets laggy. So definitely getting lost somehow.

Posted 1 year ago #
sabshire
Member

Well, I believe I have fixed this for me by switching over to using CCSpriteFramCache and CCSpriteSheet ( i know it has a diff class name now, but don't recall it off the top of my head), so it is something to do with openGL, and using the batching features makes a big difference it seems.

Posted 1 year ago #
Acceleroto
Member

I just noticed the same problem in bringing some old code (Cocos2d 0.7.3-based) up to iOS4 & Cocos2d 0.99.5. After pulling my hair out all afternoon, I reduced my accelerometer sampling down to 30Hz (like was recommended in the Cocos bug report linked to above) and everything seems to be working well on my iOS4.2.1 devices.

Did Apple fix this bug, then let it sneak back in?

Posted 1 year ago #
bluelobster
Member

I am seeing this without even without cocos2d so definitely seems to be an apple issue. I am also running the accelerometer at 60Hz so will try this evening at 30 to see if there is any improvement. Talk about a show stopping issue =(

Posted 1 year ago #

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