Quote:Original post by Anonymous Poster
Thanks Yann L,
why I am using texture shaders is because I'm working on hardware
accelerated volume rendering and I would like widest support possible. So
I guess NV_texture_shader is supported from GForce2 till now, so majority of
NVIDIA cards support it whereas GLSL, cg and other stuff aren't supported
on older cards.
Basic texture shaders were supported on GeForce3 on upwards, but they were
extremely slow on that card. The more 'powerful' ones from GeForce4 on, but not really fast either. But as I mentioned, those extensions are
really outdated, and for all practical purposes, they're dead. They won't ever be updated anymore, nor maintained. It's very well possible that future GPUs and driver revisions will entirely drop support for them, or introduce bugs that will break your code.
And as you noted, they're only supported by Nvidia, and won't work on ATI.
Quote:Original post by Anonymous Poster
So I need basicly tex.shaders to interactivly change transfer
functions in volume rendering and in the same time require support of minimum number of extensions as possible . . I'm limited with time but maby I even add
lighning effects to VR, such ass diffuse, specular, etc. So I'm not really sure how to do it - texture_shaders+register_combiners?
The best possible solution is to go with time, and use a modern form of shader programming through GLSL or Cg. Cg might be an even better option for you, since it
can compile to old texture_shader and register_combiner profiles. Although this support might also be dropped in a not too distant future.
Seriously, texture shaders and register combiners are a dead end road. Save yourself the hassle, and use GLSL or fragment programs instead. They will be faster, they're vendor independent, and they're allow for much quicker development. But note that the ASM variant (ie. fragment programs) are not updated anymore, although they will still stick around for some time to come (support won't be removed from future drivers). But GLSL is definitely the way of the future.