Random PNG borders with transparent AtlasSprites

cocos2d for iPhone » Programming » cocos2d support (graphics engine)

Random PNG borders with transparent AtlasSprites

(7 posts) (3 voices)

Started 2 years ago by jrtb
Latest reply from jrtb

Tags:

jrtb
Member

Hi all :)

I've got a problem I'm hoping you can help with. I'm using Cocos2d
0.8.2 and rendering 10 AtlasSprites with a common AtlasSpriteManager.
As you can see from this screenshot (taken from an iPhone), 9
of the butterflies render with correct transparency.

The 10th renders with a border. Sometimes the number with a border is greater. It's
unpredictable.

I've read through the FAQ on this and have applied all the suggestions in it at:
http://www.cocos2d-iphone.org/wiki/doku.php/faq#my_png_doesn_t_look_like_in_photoshop
But without any success. I can make all of them have borders by using:
[sprite setBlendFunc: (ccBlendFunc) { GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA }];
The core issue that I wanted to get your input on is why it would
render 9 of them correctly and the 10th with a border, all other
things being equal.

Is there a known issue that would cause this and that I can correct?

Thanks! :)

James

Posted 2 years ago #
abitofcode
Moderator

Does the 10th one have a border if you add an 11th?

Posted 2 years ago #
jrtb
Member

It's completely random. If I add 10, there will be one or two with a border. If I add 4, sometimes 1 of them will. 20, there'll be 3-4.

Posted 2 years ago #
abitofcode
Moderator

You can get artifacts around an image if your using the pvrtc format and you've not left enough space between the images. Does the border occur on every frame of the sprite in question?

You could try defining the CGRectMake area within the current bounds and see whether it shows anything new i.e pvrtc textures can have (I believe) a 4 pixel bleed so try changing to;

CGRectMake(currentxval + 4, currentyval +4, currentwidth - 8, currentheight - 8)

It won't fix the issue but it may help narrow it down.

Posted 2 years ago #
jrtb
Member

Thanks abitofcode, I'm playing with it to see if I can get rid of the problem. I'll report back if I'm able to figure it out.. Thanks! :)

Posted 2 years ago #
renderplace
Member

@jrtb, I did have some similar issue when upgrading from cocos2d v0.7.3 --> v0.8.2

In my case the problem completely gone when applying these two fixes:

http://code.google.com/p/cocos2d-iphone/source/diff?spec=svn1656&r=1656&format=side&path=/trunk/cocos2d/CCTexture2D.m

http://code.google.com/p/cocos2d-iphone/source/diff?spec=svn1651&r=1651&format=side&path=/trunk/cocos2d/CCTexture2D.m

Found via http://code.google.com/p/cocos2d-iphone/issues/detail?id=697

-AntonG

Posted 2 years ago #
jrtb
Member

Fantastic AntonG, I'll try that next! :)

Posted 2 years ago #

RSS feed for this topic

Reply

You must log in to post.