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Ataru

CG optimization

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I've been looking at my debugger output for shader performance using CG and I found some distressing stuff. To confirm, I ran some of NVIDIA's cg examples and I'm getting the same calls. Something like this: glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB,GL_PROGRAM_BINDING_ARB,0x....) glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,8) glProgramLoacalParamter4dvARB(GL_FRAGMENT_PROGRAM_ARB,0,....) glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,8) glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB,GL_PROGRAM_BINDING_ARB,0x....) glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,8) glProgramLoacalParamter4dvARB(GL_FRAGMENT_PROGRAM_ARB,1,....) glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,8) and so on... and this process repeats for every single local parameter. I thought the idea was to have glProgramLocalParam() glProgramLocalParam() glProgramLocalParam() . . . and then one call to glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,8) or whatever the fragment program. Anyone know why CG has to call glGetProgramivARB every single time? I doubt the driver is ignoring all the glBindProgram calls. Is Cg really this inefficient, or are there ways to prevent this? Any info is appreciated.

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Quote:
I ran some of NVIDIA's cg examples

examples are usually writen (i hope) for (*)clarity first, performance shouldnt be part of the equation

(*)though many aint even written with that

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I understand that, but it seems to me like this is a Cg thing in general. I mean these calls are not being made by the examples, they're being made by Cg. I can't believe it's that inefficient.

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