If anyone is interested, I’ve written up a small tutorial on Frustum Culling with OpenGL. It provides code for extracting the current frustum planes and routines to test points, spheres, and cubes against the frustum.
I think it’s fairly easy to follow, and it even includes a demo (source and Windows EXE are included as well).
You can access it here .
Feedback would be appreciated, especially if you spot any mistakes.