Hi,
I'm having an issue with texture buffer objects in OpenGL. It seems as though calling glBufferData on a texture buffer object (GL_TEXTURE_BUFFER) object that already has memory allocated with it will not reallocate any new memory. Any shader that attempts to read from the texture buffer object will get invalid data (just 0's actually) for any data that wasn't within the initial allocation size (pre-allocating enough data obviously masks/fixes the problem). It is my understanding that glBufferData should reallocate memory if called on an object which has already allocated memory.
The last driver that this was working on was Catalyst 12.8. I've tested this with an Radeon 6850 and a Radeon 7950 - both cards exhibit the same behavior.
I've tested the problem on the following drivers (and on both Windows 7 and Windows 8):
12.8: works
12.9 beta: broken
12.11 beta 4: broken
Cheers