Framebuffer Write Test

[j]

It would be nice if OpenGL had functionality to set a fence and then check if anything has been drawn since the fence has been set.

This would be useful for occlusion culling, especially during multipass rendering.

I don't know how easy this would be to implement in hardware, though.

j

[cunniff]

You might look at the GL_HP_occlusion_test extension (just do a search
on www.opengl.org). (http://www.opengl.org).) It's been implemented on both HP Visualize as well as
3D Labs products (and maybe others). HP is working on a new, improved
version which we will release eventually, which allows for multiple pending
visibility test results.

[j]

That's almost exactly what I'm looking for. Too bad it isn't used in any consumer class video cards.

j