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
>
>
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