Cg shaders limited to ARB profiles on non-nvidia cards

[ninth]

On ATI and Intel onboard cards Cg report that "Cg program too complex for driver " if shader contain cycles with many iterations or non constant cycles. This is because Cg unroll cycles. It would be great if we could control options like "unroll" by instructions in the header of shader or in the confir.prc

[rdb (rdb)]

This would indeed be a nice feature to control, but cgc already does this by default. The error is caused by a different issue. You should try a recent build of Panda3D (1.8.1 won't work) and let me know what error messages it reports, particularly with "notify-level-gobj" set to "debug".

[ninth (rupanda3d)]

Panda3D-2013.05.06-22
Windows 7 x32
Intel HD Graphics 2000
In shader file I define:
//Cg
//Cg profile glsl

If you need, I can make log on another system with ATI graphic card.

[rdb (rdb)]

The correct line in the shader is "//Cg profile glslv glslf", the one you posted is a no-op.

Could you also give me the output with "notify-level-glgsg debug"? Thanks! Also, please make sure that basic-shaders-only is set to #f, of course.

[ninth (rupanda3d)]

New log with both gobj and glgsg debug. Also I changed profile definition to "//Cg profile glslv glslf"
basic-shaders-only is already #f

[rdb (rdb)]

Thank you, that is immensely helpful.
From what I gather, there are two problems:
* For your graphics card, the Cg runtime is always reporting that the 'latest' profile is arbvp1/arbfp1, which is nonsense. We could work around this easily, and this would already solve the problem by itself.
* But setting the profile in the shader is also supposed to make it work, and the fact that it doesn't suggests there's something wrong in the code that parses the shader file. I'll have to look into this, but I cannot do so currently as my Panda build is currently crashing.

Fixing these two things should be able to finally resolve the issues, though, so many thanks for helping out in tracking this bug down.

[rdb (rdb)]

I'm going to roll back my 'fix' due to completely broken shaders with the AMD Catalyst drivers.
The ARB profiles seem to be the only reliable ones on non-NVIDIA cards. Please limit your shader complexity or switch to GLSL entirely.

[rdb (rdb)]

I had another stab at this. I had to completely overhaul the way we compile Cg shaders, and needed some pretty obscene workarounds, but I think I fixed it. I can now use non-basic Cg shaders (via GLSL profiles) on both my AMD card on Linux and my Intel card on Windows.

There are some limitations with regards to the semantics that are used in the shader, though - in particular, using "NORMAL0" produces errors while "NORMAL" does not. Weird stuff.