I have managed to make the example from http://cvit.iiit.ac.in/
work on my Mac (OSX 10.6, Snow Leopard).
I’ve got a very simple example that just renders 2 points, which works, i.e., I do get the points from the geometry shader in the transform feedback buffer (TFB).
However, basically the same example that renders 2 triangles instead of the points does not work.
You can find the two sample source codes here:
http://zach.in.tu-clausthal.de/tmp/main_points.cpp
http://zach.in.tu-clausthal.de/tmp/main_triangles.cpp
They are both self-contained.
As you can see in the source code, I render two points, have the geometry shader just pass the data through, and capture the geometry shader’s output in the TFB. Then, I render the contents of the TFB again.
This works fine.
However, the same procedure, but with triangles instead of points, does not work.
Can you spot anything I did wrong?
Thanks a lot in advance for any kind of insights, pointers, or suggestions!
Best regards,
Gabriel.
PS:
Yes, it has to be GLSL 1.20