GPU: Correct geometry shader culling

[unknownbrackets]

There still seem to be other problems, though. When I run the dump in #11578 (comment), it shows the problem as noted - not sure if there's some issue with clip distance, as I think that was clipping.

Are we guaranteed gl_ClipDistance in the geometry shader? Wouldn't it run on the vertex shader anyway?

The interesting thing, though, is when I step using the GE debugger through using "Step Draw", then it draws properly. The issue only shows when running the whole frame.

Still, this is at least an incremental improvement. Many of the cull frame dumps look right with this.

-[Unknown]

[hrydgard]

Maybe we can keep some parts in the vertex shader that make sense there actually, there's no need to be fully either/or...

Those issues do sound like more uninitialized values though, weird..