register combiners and ATI


as far as i know, nv register combiners are better than ARB combiners because you can do more operations in one rendering pass. Is there an ATI pendant for this, or are the only choices ARB combiners and fragment programs (or am I missing something in general)?


Rumors pretend that ATi cards will be able to emulate the register combiner functionality in a future driver release so that games that used register combiners can look good on ATi cards too.

Anyway, ATi cards do support ATI_fragment_shader in Radeon8500+. It’s a shader extension that replaces the texturing stage only (unlike register combiners that overrides texturing stage and color sum stage and fog stage) and offers 8 operations per pass, up to 2 passes, which roughly allows a 16-operation shader.

Originally posted by JanHH:
…as far as i know, nv register combiners are better than ARB combiners…

Wait, there’s no such ARB_r_c on the extension registry… what are you talking about?


Ah, that one…
No, it’s not equivalent to NV_r_c, much more limitating.

Oh well, thank you for pointing out that, now I know that people says ARB_combiners to mean a totally different thing.