Originally posted by esc: Then I looked in the ARP_fp spec, and found a comment about “ARB_precision_hint_fastest”.
But that doesn’t exist, at least I can’t find it.
What do you mean with “doesn’t exist” / “can’t find it”?
Add this on top of your shader, and it should do the trick:
Originally posted by Humus: Add this on top of your shader, and it should do the trick:
OPTION ARB_precision_hint_fastest;
Of course, stupid me, thanks!
However, I’m still confused about Kilgards post (link above) about Geforce FX’s varying precision:
Originally posted by Mark Kilgard:
The per-fragment fragment program operations (ARB_fragment_program) are performed with s23e8, s10e5, or s1.10 numerics depending on the instruction & register formats.
Is there anyway of finding nVidias specs for this? Or does it change per driver or hardware chip?
I just thought that knowing this more closely would help optimizing, or should we (app. programmers) leave it all to the drivers people?
You don’t get access to these different precision modes with ARB_fp. Unfortunately, the precision hint doesn’t seem to make much difference either. The only way to exploit the multiple precisions fully is to use NV_fp.
Currently, precision hint is not used (as Tom said). Expect future drivers to use precision hint more, though it is still a hint and subject to interpretation between drivers/chips/vendors etc.