touchBegin always followed by touchEnd/Cancel?

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touchBegin always followed by touchEnd/Cancel?

(14 posts) (7 voices)

Started 2 years ago by LongJohnnyE
Latest reply from leftright

Tags:

touch handling

LongJohnnyE
Member

My game has had this bug for months, persisting through three complete re-writes of the touch handling code. I just spent a while updating StickWars to use cocos v0.8, and I was very, very happy to erase all of my painfully written touch handling code to use the much more elegant touchdispatcher w/ targeted touches.

The bug may stem from the fact that my game is not getting a touchEnd/Cancel call for every touch? This bug tends to happen somewhat rarely, I'd say one in a hundred touches. The result of sometimes not receiving the touch ended call is a figure being dragged is left floating in the air, and the only way to to fix it is to error check using a timer or when a new touch even happens.

Perhaps it is an error in my game logic, but I'd like to know if anybody else ever experiences this. I know I've seen the exact bug in at least one other game, and I talked to the dev who didn't understand why it was happening either.

Posted 2 years ago #
Thomvis
Member

I have never experienced a missing touchEnd/Cancel. I have been using the new v0.8 touch logic for a some weeks now and everything seems to work as it should. btw: I'm using the default (non-fast) Director

Posted 2 years ago #
LongJohnnyE
Member

Sorry, I should have added I don't suspect a problem in touchdirector here, as the problem existed before touchdirector.

I'm just surprised to see the bug still exist after I replaced my touch handling code with the touch handler, leading me to believe it could be 1) something that i missed about the way UITouch events are handled or 2) some subtle flaw in my specific game logic.

I'm currently working on some more tests for this, but I was just wondering in the meantime if anyone else experienced this.

Posted 2 years ago #
brcimo
Member

I have this happening, too. I'm using 0.8.0 and about 1 in every 10 it seems to happen. Are there any fixes any one has found lately?

Posted 2 years ago #
LongJohnnyE
Member

I still haven't figured out why this happens sometimes.

Posted 2 years ago #
arian487
Member

I remember reading somewhere that you cannot make this assumption when coding.

Posted 2 years ago #
adunsmoor
Member

I'm able to reproduce this but not reliably. It seems like a bug. The question is whether it a bug in the iphone OS or cocos.

To reproduce this I took the example Hello World project template from svn r1301 and changed the HelloWorld layer so that touchesEnabled = YES. Then I simply added the ccTouches* methods with NSLog statements in each.

I clearly see that after clicking around randomly (and fairly quickly) I can get in to a state where I get a Begin or Moved without an End or Cancelled. The main problem is that it's not easily reproducible but I can usually get in to that state within a few minutes.

For what it's worth, clicking a few more times seemed to get me back in to a decent state with touches being processed again.

Posted 2 years ago #
LongJohnnyE
Member

@arian487 I'll admit I haven't read all the docs from Apple like I should have, but I checked over the touch stuff and never came across that (though I might have missed it!). Do you remember at all where you saw this?

I don't see why it is unsafe to assume that I will eventually receive an event that tells me a UITouch event that began has either ended or been cancelled.

@adunsmoor I agree with your findings. It doesn't happen often, and when it does it is usually due to many fast touches. Unfortunately for me, this happens relatively often in StickWars :(.

Posted 2 years ago #
arian487
Member

Sorry johnny. I wish I could remember I just remember reading an article somewhere that we can't assume a touch began will always be accompanied by a touch ended. I read that we should build the reactions completely independent of each other and not have touch ended do something DEPENDING on a touch began or something.

I don't even know if it was reliable I just really remember reading. I'm sorry man, I know it's not much info :(

Posted 2 years ago #
adunsmoor
Member

It seems we aren't the only ones noticing this problem.

http://discussions.apple.com/thread.jspa?messageID=9617480

I tried switching to fast director and then changing around some of the parameters used in CFRunLoopRunInMode. Unfortunately, none of the changes made any real difference. I was always able to get back to a point where an ended or cancelled were missed.

Posted 2 years ago #
leftright
Member

I also observing some sort of issue with handling multitouch with touchesMoved. I've made sure that my layers enableTouch is enabled and finally placed a few NSLog in TouchDispatcher and did not see any print out which points to a problem with the iPhone SDK.

Here's my way of reproducing it, start with one finger and then do a move. Make sure you're doing this with the iPhone securely on the desk. Once you stopped at a spot after the move, you should notice that there are no more touch events. Then place 2nd finger onto screen without moving first finger. You would expect to see touchesBegan called at the TouchDispatcher level, but I'm not seeing that at all.

Posted 2 years ago #
Steve Oldmeadow
Administrator

@leftright - are you sure you have multi touch enabled on the window e.g setMultipleTouchEnabled:YES

Posted 2 years ago #
leftright
Member

@steve I'm sure that multitouch was enabled because my game has 2 modes and I toggle between enabled and not. When this was happening, I tried doing 2 fingers tap and I did get 2 touches.

I'm not sure if it's a bug with my iPhone OS since I'm still using 3.0. I guess I will upgrade 3.1.2 and then try with a template project.

Posted 2 years ago #
leftright
Member

@steve, looks like my toggling of the multitouch enabled was the indeed the cause of the issue, my app delegate sets multitouch disabled and later I would enable it but it looks like just enable that for the Window is not enough, Director needs to be enabled too since it only does that at init.

Posted 2 years ago #

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