İsmail,Thanks for your answer, probably you are right because it is a qt application. maybe i could not set the context id.
i think "state.getContextID()" does not match with the current context... i will check for it now.. if you know something about it please help me :) thanks again... :) On Tue, May 5, 2009 at 3:10 PM, Ismail Pazarbasi <[email protected]>wrote: > Ufuk, > > bool isVertexBufferObjectSupported() const { return > > _isVertexBufferObjectSupportResolved?_isVertexBufferObjectSupported:computeVertexBufferObjectSupported(); > } > > If you have seen the code that checks whether extension is supported: > bool State::computeVertexBufferObjectSupported() const > { > _isVertexBufferObjectSupportResolved = true; > _isVertexBufferObjectSupported = > osg::isGLExtensionSupported(_contextID,"GL_ARB_vertex_buffer_object"); > return _isVertexBufferObjectSupported; > } > > there are two things that may go wrong, as far as I can see: > 1. Context ID is not selected or not owned by current thread (see last > OpenGL error) > 2. Extension isn't supported > > To evaluate latter case, that is, that you certainly have the > extension, you can write a simple test case or download OpenGL > Extension Viewer application ( http://www.realtech-vr.com/glview/ ). > > To evaluate first case, well.. I don't know any better way but in my > application, I have a screenshot operation. It's a GraphicsOperation > that is added to the context. OpenGL graphics context will be selected > and owned by that graphics thread when operation is running. Anywhere > outside that thread (depending on threading model) may fail. To see > what went wrong, check last OpenGL error after that call (which, too, > may return an error if it isn't called from legal places). > > HTH > Ismail > > On Tue, May 5, 2009 at 1:30 PM, Ufuk <[email protected]> wrote: > > Thanks Robert, > > i know that you cant know the problem without seeing the code :) i just > want > > to know that when isVertexBufferObjectSupported() function returns true > or > > false? to use this support should i enable something? > > anyway now i will try to make a simpler example, then maybe i could show > you > > the codes.. > > thanks again... > > > > On Tue, May 5, 2009 at 11:48 AM, Robert Osfield < > [email protected]> > > wrote: > >> > >> Hi Ufuk, > >> > >> I really can't guess what might be wrong because I know absolutely > >> nothing about your application, I simply don't have magically powers > >> to divine this stuff. > >> > >> What I do know is that the vertex buffer objects support does usually > >> work, others do not report problems with it, so there likely something > >> quite specific about your setup that is introducing this problem. Try > >> using standard examples based on osgViewer as a sanity test then work > >> back to an test problem that more closely resembles how you use the > >> OSG. > >> > >> Robert. > >> > >> On Tue, May 5, 2009 at 8:57 AM, Ufuk <[email protected]> wrote: > >> > Hi, > >> > Actually i dont think it is about hardware or driver because i did a > >> > project > >> > similar to this with this hardware and it is still working on my > >> > computer. > >> > it returns true on "isVertexBufferObjectSupported()" but this project > >> > was > >> > made in like osg ~1.6. The function on Geometry was "virtual void > >> > drawImplementation(State& state) const;" on osg1.6 but now it is > >> > "virtual > >> > void drawImplementation(RenderInfo& renderInfo) const;" on 2.8 > >> > > >> > so do you think there could be other reasons? > >> > > >> > > >> > > >> > On Mon, May 4, 2009 at 5:52 PM, Robert Osfield > >> > <[email protected]> > >> > wrote: > >> >> > >> >> Hi Ufuk, > >> >> > >> >> The OSG checks for support of extensions such as vertex buffer > >> >> objects, and will osg::State is one class that does this, so if you > >> >> are isVertexBufferObjectSupported() is returning false.... then.... > >> >> wait for it.... there is very good chance that your OpenGL > >> >> driver/hardware doesn't support vertex buffer objects. > >> >> > >> >> Robert. > >> >> > >> >> On Mon, May 4, 2009 at 3:45 PM, Ufuk <[email protected]> wrote: > >> >> > Hi, > >> >> > i am trying to make a terrain editor. > >> >> > here i wanted to implement my own drawImplementation of geometry > but > >> >> > i > >> >> > could > >> >> > not get manage. > >> >> > i always get state.isVertexBufferObjectSupported() as false... when > i > >> >> > ignore > >> >> > this false, i got another problems.. > >> >> > i think my problem is this isVertexBufferObjectSupported(). > >> >> > i want to know that what makes it true or false. what should i do > to > >> >> > get > >> >> > it > >> >> > as true??? > >> >> > -- > >> >> > Ufuk > >> >> > > >> >> > _______________________________________________ > >> >> > osg-users mailing list > >> >> > [email protected] > >> >> > > >> >> > > >> >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >> >> > > >> >> > > >> >> _______________________________________________ > >> >> osg-users mailing list > >> >> [email protected] > >> >> > >> >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >> > > >> > > >> > > >> > -- > >> > Ufuk > >> > > >> > _______________________________________________ > >> > osg-users mailing list > >> > [email protected] > >> > > >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >> > > >> > > >> _______________________________________________ > >> osg-users mailing list > >> [email protected] > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > > > > > -- > > Ufuk > > > > _______________________________________________ > > osg-users mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > > > <div><br></div> > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > -- Ufuk
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