cocos2d for iPhone

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

1. 

   calin
   Member

   This is a high severity message I get when running OpenGL ES Analyzer on a cocos 2.0 project with default settings (3d projection, depth test enabled). Details on the log:

   Category:

   Depth Test Enabled Without Depth Buffer

   Summary:

   Depth testing enabled without an attached depth buffer

   Recommendation:

   OpenGL ES Analyzer detected rendering with GL_DEPTH_TEST enabled into a framebuffer without an attached depth buffer. To get useful results from depth testing, attach a depth buffer to your FBO.

   Responsible Command:
   

   glDrawElements(GL_TRIANGLES, 18, GL_UNSIGNED_SHORT, NULL)
   glDrawArrays(GL_TRIANGLE_STRIP, 0, 4)

   What does it mean exactly? Can it affect performance? Thanks

   UPDATE:

   If setting depthFormat:GL_DEPTH_COMPONENT16_OES instead of depthFormat:0 in AppDelegate removes that message from the analyzer, since it successfully creates the depth buffer.
   Not sure though why is that set to 0 if depth test is enabled? Probably just a template error..?

   Posted 5 months ago #
2. 

   riq
   Key Master

   Use it with 0 if you don't want a depth buffer.

   If you use a depth buffer of 16 or 24bits, cocos2d will perform a bit slower.

   As far as I know, there is no performance penalty on enabling the depth buffer, but setting a 0-bit depth buffer.

   Posted 5 months ago #
3. 

   calin
   Member

   Thanks @riq - as always a very quick answer :)

   But just to clear that message from the opengl es analyzer, probably setting [director setDepthTest:NO] would be better if you don't need it ?!

   EDIT: thanks @araker - yeah :)

   Posted 5 months ago #
4. 

   araker
   Moderator

   It's safe indeed to turn off the depth test if you don't have a depth buffer.

   [[CCDirector sharedDirector] setDepthTest:NO];

   That's something that needs to change in the code as well. Turn the depth test on only if the EAGLView is initialized with a depth buffer. Not that the current situation will affect performance, the depth test can't do a thing without a depth buffer.

   I would only turn on the depth buffer if you need 3D effects. Otherwise it's a waste of memory.

   --edit, I see you already figured it out--

   Posted 5 months ago #
5. 

   CJ
   Moderator

   It's probably not a performance issue but one of correctness. This should be filed as a bug to correct the behavior when there is no depth buffer the depth testing should be disabled.

   Posted 5 months ago #

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