Question

I am writing an application which contains some graphs drawn in OpenGL ES. each of these graphs are in a table cell, when I press some of those graphs, it is being opened in full screen mode.
Everything worked perfectly since I upgraded to iOS4.2. Now the problem is in simulator, I can’t see the drawn graph in cells, but in full screen mode I do see the chart. There are no changes no the device, it is only on the simulator and only in a case.
The behavior is the same for other Mac’s here.

Does anyone have a clue?

Answer 1

As explained in this answer to this similar question, there has been a change in the way that 4.2 handles renderbuffers in Core Animation layers. From the OpenGL ES Programming Guide:

In iOS 4.2 and later, the performance
of Core Animation rotations of
renderbuffers have been significantly
improved, and are now the preferred
way to rotate content between
landscape and portrait mode. For best
performance, ensure the renderbuffer’s
height and width are each a multiple
of 32 pixels.

It appears that if your renderbuffer isn’t an even multiple of 32 pixels, it doesn’t display in the Simulator. This is a bug in the Simulator, but you should probably make your renderbuffer a multiple of 32 in either dimension in any case to improve performance.