[osg-users] [ShaderComposition] Redondant call to useProgram

[Julien Valentin]

Hi Robert,


robertosfield wrote:
> Which version of the OSG are you using?  
> 

I'm talking about master git (haven't check out the branch)

robertosfield wrote:
> Is the standard osgshadercomposition example generating this issue or is it modified version?
> 

Yes, no mod required in the osgshadercomposition example

robertosfield wrote:
> How are you detecting up the redundant calls issue?
> 

I added a test a long time ago in Program.cpp Program::apply( osg::State& state ) 

Code:
     if( pcp != state.getLastAppliedProgramObject())
        {
            // for shader debugging: to minimize performance impact,
            // optionally validate based on notify level.
            // TODO: enable this using notify level, or perhaps its own getenv()?
            if( osg::isNotifyEnabled(osg::INFO) )
                pcp->validateProgram();

            pcp->useProgram();
            state.setLastAppliedProgramObject(pcp);
        }else{
            OSG_WARN<<"WARNING: redondant useProgram pcp == state.getLastAppliedProgramObject()"<<std::endl;
        }


Ihaven't check but perhaps I could have false positive in case state.LastProgram not updated (perhaps it's the case but i doubt of it)...

I'll try to find a more elegant way to avoid these redondant calls but as the author, you may have a better understanding of the impl.

Cheers

robertosfield wrote:
> Hi Julien,
> 
> I can't provide an answers without digging deeply in the code, this
> week I'm really busy with clients so can't look in to.  Next week I'll
> be getting back to the shader_pipeline branch and better able to look
> into it.
> 
> Which version of the OSG are you using?  Is the standard
> osgshadercomposition example generating this issue or is it modified
> version?  How are you detecting up the redundant calls issue?
> 
> Robert.
> 
> On 4 November 2017 at 18:03, Julien Valentin <> wrote:
> 
> > Hi Robert,
> > 
> > Using the new shader composition (ex osgshadercompostion), I was surprised to detect a lot of redondant call to gluseprogram...
> > I debugged a few and don't understand well State::push/popDefine and its policy to invalidate defineMap (defineMap.changed = true; seams to be called at each push/pop)
> > (It's difficult to interact since it' s in the header)
> > 
> > The problem seams here since it always tags as changed definemap (and so lead to some useless passage in State.cpp line 672
> > 
> > 
> > Code:
> > if ((_lastAppliedProgramObject!=0) && (previousLastAppliedProgramObject==_lastAppliedProgramObject) && _defineMap.changed)
> > {
> > // OSG_NOTICE<<"State::apply(StateSet*) Program already applied ("<<(previousLastAppliedProgramObject==_lastAppliedProgramObject)<<") and _defineMap.changed= "<<_defineMap.changed<<std::endl;
> > _lastAppliedProgramObject->getProgram()->apply(*this);
> > }
> > 
> > 
> > 
> > Hoping this helps you to diagnose the problem :/
> > 
> > Thank you!
> > 
> > Cheers,
> > Julien
> > 
> > ------------------
> > Read this topic online here:
> > http://forum.openscenegraph.org/viewtopic.php?p=72306#72306
> > 
> > 
> > 
> > 
> > 
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> > 
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Code:




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