Problem with iPhone 4S + iOS5 + CCLayerColor

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Problem with iPhone 4S + iOS5 + CCLayerColor

(9 posts) (5 voices)

Started 7 months ago by scatterpic
Latest reply from zaaroth

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scatterpic
Member

Hi,

I've been writing a game for about 6 months now using Cocos2D v1.0.1 and Xcode 4.
I recently got to test my almost-finished game on an iPhone 4S with iOS5, and I'm seeing some strange behavior with CCLayerColor.

I'm using CCLayerColor to bring up a transparent overlay, displaying some text. The text is implemented with CCLabelTTF instances added as children of the CCLayerColor. The whole things scrolls in and out from the bottom of the screen as needed, using a CCMoveTo action.

This all works fine on iPad, and all simulators (including iPhone iOS5). However, when running on a 4S, the text is only displayed intermittently when the layer is scrolling in or out. It is not displayed at all when the layer is stationary.

Even stranger: in an attempt to debug this myself, I separated out the text onto a new layer - so now we have a CCLayerColor simply acting as a background, and a new CCLayer-derived class to host the text. Both layers are added as children of the scene, with the text layer given a higher Z value.

Same problem! The CCLayerColor, which is underneath the text layer, is somehow obscuring the text. If I remove the CCLaterColor, the text displays perfectly.

Anyone else seen this problem, or is able to try and re-create on a 4S? Any idea if I'm doing anything bad, or what I should try next?

Thanks in advance,

David
http://www.scatterpic.com

Posted 7 months ago #
CJ
Moderator

Any chance you are using a 3D projection with a depth buffer?

Posted 7 months ago #
scatterpic
Member

No, certainly not that I'm aware of! Just creating plain old 2D scenes and layers.

David

Posted 7 months ago #
araker
Moderator

Cocos uses a 3d projection by default, normally it wouldn't affect rendering in this way. To test whether it's the projection or not, add this line in your appDelegate, after the OpenGL view is created.

[[CCDirector sharedDirector] setProjection:CCDirectorProjection3D];

Posted 7 months ago #
slembcke
Administrator

Check how your director is set up. It certainly does sound like you have depth buffering enabled somehow.

Posted 7 months ago #
scatterpic
Member

Thanks all,

Using this line as araker suggested makes no difference:

[[CCDirector sharedDirector] setProjection:CCDirectorProjection3D];

... but changing it to the following does resolve the problem:

[[CCDirector sharedDirector] setProjection:CCDirectorProjection2D];

HOWEVER, my 3D scene transitions have now stopped working. Does this shed any light on the problem?

Best,
David

Posted 7 months ago #
CJ
Moderator

Yep. This is the same issue as discussed here and now we know the 4s and iPad2 have something in common :)

http://www.cocos2d-iphone.org/forum/topic/14495

A workaround is to just use a 2D projection and no depth buffer and then you could just enable 3d/depth buffer before 3d transitions and disable it after.

Posted 7 months ago #
scatterpic
Member

Thanks all - I now have a work-around (still not perfect, as flickering is still present during the scene transitions with the depth buffer is on).
What is the best way to track the progress of this issue, so I know when it has been resolved?

Thanks again for the support,

David

Posted 7 months ago #
zaaroth
Member

If I am remembering correctly, according to the thread, it wont be fixed. That was reported as expected behavior when @riq contacted imagination. The solutions proposed by Imagination would result in big changes on cocos2d rendering engine, so my guess is that it wont be done.

See Gordon's post here: http://www.imgtec.com/forum/forum_posts.asp?TID=1256&PID=4255

Posted 7 months ago #

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