[Fixed] Physics bodies behave fits-and-starts on iOS 5.0.1 when using Build 645 to 688

Solar2D Daily Builds and Public Releases
#1

I play tested a device build on iOS 5.0.1 (iPhone4S 64GB, bought from Verizon, brand new), and to my surprise, physics bodies behave fits-and-starts.

I installed the same exact game build on all other device I have, and it plays fine without such oddity. Here are the list of device I tested (and had no fits-and-starts issue):

iOS 3.1.3 (iPod touch)
4.2.1 (iPod touch)
4.2.1 (iPad)
4.3.3 (iPad).

What I mean by “fits and starts” is that the physics bodies that move around the screen suddenly stop for a second and then, as if they never froze like that, continue on moving again. It’s as if physics engine briefly stops/pauses every few seconds. Very strange.

This problem appears both on Daily Build 648 and 688. Since my game used to work on all device I tested on (including iPhone4S) without any problem, I downloaded the oldest daily build I could fetch (just in time before it disappeared on me!), and I verified that this problem does NOT exist on Daily Build 644.

It would be great if this bug gets fixed before the new stable build is released…

Naomi

EDIT: I downloaded the Daily Build 645, and it shows the same fits-and-starts issue. So it appears that Daily Build 644 was the very last build that can generate a device build without this issue.
[import]uid: 67217 topic_id: 17951 reply_id: 317951[/import]

#2

Hey Naomi,

Thanks for posting this - and thank you very much for taking the time to try and track down where the problem first appeared.

Would you mind filing a bug report with the same info you’ve put here? (And if you have it, some code showing the issue would be super!)

Peach :slight_smile: [import]uid: 52491 topic_id: 17951 reply_id: 68532[/import]

#3

Hi Peach, I just filed the bug report. Case #9763.

Thanks,
Naomi [import]uid: 67217 topic_id: 17951 reply_id: 68646[/import]

#4

Thanks very much Naomi - will pass this on.

Peach :slight_smile: [import]uid: 52491 topic_id: 17951 reply_id: 68694[/import]

#5

Namoi,

I looked up your bug report and can you supply some sample code showing the problem? Do you see this happening with any of the Corona Physics sample code?

Have you tried this on a non-iPhone4S running iOS5?

I looked at the release notes for build 645 and noticed a fix for a crash when debug/hybrid drawing mode is on and joints are present. Does your app use joints?

Thanks for isolating this bug down to the build number. That really helps.

Thanks,
Tom [import]uid: 7559 topic_id: 17951 reply_id: 68763[/import]

#6

Hi Tom,

I’ve emailed you a stripped down basic physics project (by replying to the email I received). The test project also manifests the same oddity.

FYI, Joints are not used in the test project (so I can’t tell you if joints are affected by this bug.)

When I build the test project using Daily Build 644, I see no problem, but when I build it with 645, 648 or 688, I see the oddity only with iPhone4S with iOS5.0.1 – other devices I listed above manifest none of the oddity observed on iPhone4S.

I don’t have non-iPhone4S device with iOS5 installed – so I don’t know how it may behave on such device.

I hope this helps.

Naomi [import]uid: 67217 topic_id: 17951 reply_id: 68809[/import]

#7

Hi Tom, another issue with daily build beyond 644 is identified. It relates to camera freeze:

http://developer.anscamobile.com/forum/2011/11/22/camera-bug-freezes-camera-preview-screen-ios-501

Naomi

Edit: The camera issue appears to be fixed – physics issue is still being sorted. [import]uid: 67217 topic_id: 17951 reply_id: 69243[/import]

#8

Here’s an update regarding this issue. Eric got back to me (a few times! BIG THANKS) and clearly this is associated with the Open AL bug brought on by iOS 5. The work-around implemented to deal with the Open AL bug triggered this fits-and-starts issue.

I have not been able to verify if the latest work-around has completely eliminated the performance issue (i.e., fits-and-starts issue). Just in case anyone is interested, in my case, my human ears do not hear any sounds being broken when they play. I can only see the physics body behavior being wrong, and only on iOS 5.0.1 device – so I did not associate the problem with audio…

Anyhow, I filed a bug with Apple Bug ID# 10520420 after Eric encouraged me to do so on this post.

Naomi

Edit: Please see the release note for Daily Build 698 regarding the fix implemented for this bug. I lost access to the iPhone4S with iOS 5.0.1 – my husband returned it around Thanksgiving and got another phone (Galaxy S2 for only 1 cent with 2 year contract, kinda crazy deal)… oh well… meanwhile, I’m pretty confident that iOS 5.1 will not manifest this problem based on the test result posted by ingemar here and here. Thanks Eric for the fix, and thanks ingemar for sharing your test result. I totally appreciate it.

[import]uid: 67217 topic_id: 17951 reply_id: 71128[/import]

#9

I tested this again on iOS 5.0.1 device and I confirm this issue is completely gone. I’m using daily build 706. Way to go, Eric!

I’d like to add that Apple just got back to me about this bug, and they noted that what I reported is a known issue, and it is being investigated. The original bug was filed with bug ID#10071081.

Naomi

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