cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   db82
   Member

   Hi

   When I use setColor on an AtlasSprite the colour changes fine.

   But if I then apply opacity to the sprite, the sprite reverts back to it's original color.

   This only happens on the iphone, I don't get this bug when running in the simulator.

   Can anyone help with this?

   I'm using cocos2d 0.8.2

   Thanks for any help!

   Posted 2 years ago #
2. 

   mobilebros
   Moderator

   Its a known bug on the iphone, appears you have to use libpng somehow... looks like it it will be the default soon enough:

   http://code.google.com/p/cocos2d-iphone/issues/detail?id=502&q=libpng&colspec=ID%20Type%20Status%20Priority%20Milestone%20Component%20Owner%20Summary

   Posted 2 years ago #
3. 

   riq
   Key Master

   this bug supersedes the libpng feature:
   http://code.google.com/p/cocos2d-iphone/issues/detail?id=697
   (see the lasts comments).

   I prefer to have 697 implemented than libpng. But until 697 is not done, libpng is the alternative to have opacity + color working correctly in the same sprite.

   @db82: If you are happy with the results of the simulator, you can do this:

   [sprite setBlendFunc: (ccBlendFunc) { GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA }];

   Also, v0.9-beta has the simulator vs device issue fixed. Now everything looks like in the device.

   Posted 2 years ago #
4. 

   db82
   Member

   Thanks for the replies.

   Riq, do I need to apply the 697 patches to get this line to work?

   [sprite setBlendFunc: (ccBlendFunc) { GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA }];

   When I try applying it to an AtlasSprite I get the following warning -

   Warning: AtlasSprite may not respond to setBlendFunc.
   Messages without matching method signature...

   Posted 2 years ago #
5. 

   riq
   Key Master

   @db82: AtlasSprite doesn't support the blending function. But the AtlasSpriteManager does.

   Posted 2 years ago #
6. 

   db82
   Member

   For anyone experiencing this problem, here is the fix:

   do this on the AtlasSpriteManager
   

   [myAtlasSpriteManager setBlendFunc: (ccBlendFunc) { GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA }];

   AND this on the AtlasSprite
   

   [myAtlasSprite setOpacityModifyRGB:NO];

   No patches needed :)

   Posted 2 years ago #
7. 

   CJ
   Moderator

   It seems to me that the logic in CCSprite for setOpacity and setColor are flawed when opacityModifyRGB is true. Granted the r,g,b values should change depending on the opacity in this case, but the manner in which they were being modified IMHO was incorrect.

   I modified CCSprite so that externally you are always dealing with non-multiplied color. And internally it conditionally handles the opacityModifyRGB case for set/get color and set opacity. By all means tell me if I'm missing something about all this, but it seems to do what I want now in simulator and device when I combine setOpacity and setColor calls.

   You may consider changing the following issues to fixed:
   http://code.google.com/p/cocos2d-iphone/issues/detail?id=668

   http://code.google.com/p/cocos2d-iphone/issues/detail?id=675

   Since I cannot upload a patch here, I have attached it to the first issue listed above #668

   Posted 1 year ago #

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