On Wednesday 27 July 2005 04:54 pm, Ian Romanick wrote: > Patrick McFarland wrote: > > Even if we violate precision/range stuff, being able to accelerate > > simplistic shaders would be quite useful. Its better than not having a > > software implementation of the shader pipeline. > > The problem is that most shaders that use ARB_fp or NV_fp aren't > simplistic enough. It would be a *lot* of work to benefit 1% of > real-world shaders.
I think ATI really screwed R200 owners then. The shader pipeline ultimately is useless. > > Also, what stops you from splitting up a shader, and running the peices > > back to back over multiple passes? Can't you emulate longer shaders doing > > that? > > So, I looked into this really deeply in the past for other things. The > problem is it gets *very* hard to deal with framebuffer blend modes. If > you have an arbitrary triangle list, triangles in the list may overlap. > If you have a framebuffer blend mode other than dst=src, you can't > multipass it (generally) without breaking up the triangle list and > sending one triangle at a time. It would not surprise me at all if the > performance there was close to that of a good software implementation. So, how many games use blend modes other than dst=src? Also, even if it isn't faster than a good software implementation, its still less work done by the CPU. I own a pretty outdated P3 550, and I'd rather have any sort of boost I can get. > This, BTW, is what ATI's "fbuffer" in all about. I'm trying to find more information about this "fbuffer", but Google isn't being too friendly. -- Patrick "Diablo-D3" McFarland || [EMAIL PROTECTED] "Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." -- Kristian Wilson, Nintendo, Inc, 1989
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