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View Full Version : Possible to do dependent reads with combiners?



charliejay
11-11-2005, 12:03 PM
The red book, version 2.0, bottom of page 655, seems to imply that it's possible to do dependent texture reads with texture combiners. The paragraph is a bit ambiguous, though.

As far as I was aware, this isn't possible; am I wrong?

CJ

Obli
11-13-2005, 09:44 AM
I believe you're right.
As far as I can remember the only way to do dependant lookups is to use NV_texture_shader[2,3] (and they are somewhat limited anyway) or jump directly into fragment programming.

charliejay
11-14-2005, 12:43 AM
Nice one, much obliged... ;)

CJ

shelll
11-14-2005, 09:59 AM
nv_texture_shader is nearly the same as d3d's pixel shader 1.1

dorbie
11-14-2005, 11:43 PM
Nothing in vanilla combiners uses dependent reads. ARB combiner & crossbar specifications don't actually say anything about setting texture cooridnates of another unit.

charliejay
11-15-2005, 04:33 AM
Many thanks folks, that'll be a "no", then :)

CJ