Re: [Mesa3d-dev] Lighting code in 3.5

[Gareth H. <ga...@va...>]

Keith Whitwell wrote:
> 
> The early culling code turned out to be a dead end in the face of assembly,
> particularly 3dnow and I guess SSE, and cards that did fast culling at the end
> of the pipe.  There ended up being less and less reason for it until you look
> at the DRI drivers and they all turn it off.  I've removed it in 3.5.

Excellent.  I'd still like to do some performance analysis of culling in
render_vb_triangles and friends as we've discussed, but I'm glad to see
this gone.

> The IsMatSpecular test I'm not so adamant about.  It can come back if anyone
> feels strongly, but I felt it might be easier to get a clean assembly
> implementation of lighting without it.

Thinking about it, I don't really care either way.  It certainly reduces
the combinatoral explosion of my per-light assembly code, but it's not
that big a deal.  Non-specular lighting will be slower of course.

I'll forward my code for you and Brian to check out, and you'll be able
to see how I would handle specular vs. non-specular lights.  I'll
reserve my judgement for later on this one.

> Anyway, there's another change to that file rattling through the pipes.
> Here's my latest code which cleans a few things up, and importantly removes
> the requirement that VB->Flags exists (for DrawArrays this was a pain).

Nice work -- I really like the changes you've made here.  It fits in
quite nicely with what I've been working on, so there are no problems
there.  As I said, I'll forward a snapshot (based on the 3.4 code) on
Monday or thereabouts for you to check out.

-- Gareth