Thanks J.P, but actually I know the gameoflife example almost by heart already and this won't fit the bill: I need a real "single pass ping pong" rendering here if I want to achieve good performances.
Cheers, Manu. 2011/9/28 J.P. Delport <jpdelp...@csir.co.za> > Hi, > > I can't help you with your specific drawable question, but what would you > like to achieve? In the osggameoflife example there is an example of > ping-pong using multiple cameras and switches. You can also swap output > textures if they are exactly the same using a callback. See here for > inspiration: > http://code.google.com/p/**flitr/source/browse/trunk/** > examples/keep_history_pass/**keep_history_pass.cpp<http://code.google.com/p/flitr/source/browse/trunk/examples/keep_history_pass/keep_history_pass.cpp> > > cheers > jp > > > On 28/09/2011 10:45, Emmanuel Roche wrote: > >> Hi everyone, >> >> I'm trying to setup an pure OpenGL FBO with render to texture target in >> an OSG drawable. But I just can't figure out how to do that "properly" >> (eg. how to "isolate those pure openGL calls from the rest of the OSG >> scene). >> >> in my drawa implementation I just have: >> >> virtual void drawImplementation(osg::**RenderInfo& info) const >> { >> OSG_NOTICE << "Drawing PingPongDrawable..."; >> >> osg::State* state = info.getState(); >> const unsigned int contextID = state->getContextID(); >> >> if(!_initialized && !init(contextID,*state)) { >> OSG_WARN << "Failed FBO setup!"; >> return; >> } >> >> state->checkGLErrors("end of PingPongDrawable drawing."); >> } >> >> So i'm really just calling an "init" function once to jus try to >> _create_ an FBO... I didn't even start using it..., the code of the init >> function is as follow: >> >> bool init(unsigned int contextID, osg::State& state) const { >> >> const FBOExtensions* fbo_ext = >> FBOExtensions::instance(**contextID,true); >> const osg::Texture2DArray::**Extensions* t2darray_ext = >> osg::Texture2DArray::**getExtensions(contextID,true); >> >> // Push attribs to avoid collisions with existing OSG scene ? >> glPushAttrib(GL_VIEWPORT_BIT | GL_COLOR_BUFFER_BIT | GL_TEXTURE_BIT >> | GL_ENABLE_BIT); >> >> state.checkGLErrors("Before PPD init."); >> >> // Prepare the target texture for the FBO: >> state.setActiveTextureUnit(1); >> state.checkGLErrors("**Activating texture slot 1"); >> >> int FFT_SIZE=256; >> >> GLuint fftaTex = 0; >> glGenTextures(1, &fftaTex); >> glBindTexture(GL_TEXTURE_2D_**ARRAY_EXT, fftaTex); >> glTexParameteri(GL_TEXTURE_2D_**ARRAY_EXT, GL_TEXTURE_MIN_FILTER, >> GL_LINEAR_MIPMAP_LINEAR); >> glTexParameteri(GL_TEXTURE_2D_**ARRAY_EXT, GL_TEXTURE_MAG_FILTER, >> GL_LINEAR); >> glTexParameteri(GL_TEXTURE_2D_**ARRAY_EXT, GL_TEXTURE_WRAP_S, >> GL_REPEAT); >> glTexParameteri(GL_TEXTURE_2D_**ARRAY_EXT, GL_TEXTURE_WRAP_T, >> GL_REPEAT); >> glTexParameterf(GL_TEXTURE_2D_**ARRAY_EXT, >> GL_TEXTURE_MAX_ANISOTROPY_EXT, 16); >> t2darray_ext->glTexImage3D(GL_**TEXTURE_2D_ARRAY_EXT, 0, >> GL_RGBA16F_ARB, FFT_SIZE, FFT_SIZE, 5, 0, GL_RGBA, GL_FLOAT, NULL); >> fbo_ext->glGenerateMipmap(GL_**TEXTURE_2D_ARRAY_EXT); >> state.checkGLErrors("preparing target texture"); >> >> >> // Initialize the FBO >> fbo_ext->glGenFramebuffers(1, &_fftFbo); >> state.checkGLErrors("**Generating FBO"); >> >> >> fbo_ext->glBindFramebuffer(GL_**FRAMEBUFFER_EXT, _fftFbo); >> state.checkGLErrors("Bind Framebuffer in init."); >> #ifdef ATTACH_TEXTURE >> fbo_ext->glFramebufferTexture(**GL_FRAMEBUFFER_EXT, >> GL_COLOR_ATTACHMENT0_EXT, fftaTex, 0); >> state.checkGLErrors("**FramebufferTexture setup"); >> #endif >> GLuint fboId = state.getGraphicsContext() ? >> state.getGraphicsContext()->**getDefaultFboId() : 0; >> fbo_ext->glBindFramebuffer(GL_**FRAMEBUFFER_EXT, fboId); >> >> >> if(fbo_ext->**glCheckFramebufferStatus(GL_**FRAMEBUFFER_EXT) != >> GL_FRAMEBUFFER_COMPLETE_EXT) { >> OSG_WARN << "Error while setting up Pingpong FBO."; >> } >> >> state.checkGLErrors("end of Framebuffer settings"); >> >> glBindTexture( GL_TEXTURE_2D_ARRAY_EXT, 0 ); >> >> glPopAttrib(); >> >> _initialized = true; >> return true; >> } >> >> Adding such a drawable in my scene, i don't have any problem as long as >> ATTACH_TEXTURE is *undefined*. But when I define this, I still don't >> have any error reported by the drawable itself (all the checkGLErrors I >> inserted). But then getcontinous list of >> >> " Warning: detected OpenGL error 'invalid operation' at after >> RenderBin::draw(..)" messages :-( >> >> => Any idea what I'm doing wrong here ? How can I "enforce" the >> isolation between those openGL calls and what's left from the OSG scene >> ? after all, since this init function is called only once, there should >> not be any continous warning report if it didn't have a side effect >> outside of this drawable encapsulation... >> >> >> Thanks for you help !! I really feel desperated now... :'( >> >> Manu. >> >> >> >> >> >> ______________________________**_________________ >> osg-users mailing list >> osg-users@lists.**openscenegraph.org <osg-users@lists.openscenegraph.org> >> http://lists.openscenegraph.**org/listinfo.cgi/osg-users-** >> openscenegraph.org<http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org> >> > > -- > This message is subject to the CSIR's copyright terms and conditions, > e-mail legal notice, and implemented Open Document Format (ODF) standard. > The full disclaimer details can be found at http://www.csir.co.za/** > disclaimer.html <http://www.csir.co.za/disclaimer.html>. > > This message has been scanned for viruses and dangerous content by > MailScanner, and is believed to be clean. > > ______________________________**_________________ > osg-users mailing list > osg-users@lists.**openscenegraph.org <osg-users@lists.openscenegraph.org> > http://lists.openscenegraph.**org/listinfo.cgi/osg-users-** > openscenegraph.org<http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org> >
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