[Mesa-dev] [PATCH] draw: don't crash if GS doesn't emit anything

[Zack Rusin]

> > What is "IA"?
> 
> "Input Assembly", a D3D10 term that roughly matches pipe_vertex_elements /
> pipe_vertex_buffer state.
> 
> BTW, I think that Chris Forbes makes a good  point -- a GS might choose to
> not emit any vertices (e.g., that does fancy culling) -- so maybe this
> debugging message should be silent by default.

That's still a silly thing to do, because you're running a high cost operation on the slowest part of the pipeline. Ideally we'd connect to arb_debug_output for this stuff, but currently the most frequent cause of gs/ia not emitting any primitives is that something broke (e.g. one of our instructions is not fully compliant causing vs or gs errors in outputs) and the debug message is quite helpful in figuring that out. Of course I don't have a strong sentimental attachment to a debugging output but this particular one does make my job easier.

z