[vtkusers] OpenGL question

[Praveen Bhaniramka]

Hi Jianlong,

Depending on the OpenGL hardware that you are running on, you should be
able to use pbuffers for what you are trying to do. See -
http://www.mesa3d.org/brianp/sig97/offscrn.htm

You can also find other useful links by searching for "OpenGL pbuffers" on
google.

Assuming that you are using double buffering, which is most likely the
case, the rendered data will be displayed only when glXSwapBuffers is
called by the application. So alternatively, you can store the current
contents of the frame buffer, do your writes and reads and then restore
the contents of the frame buffer with the stored image. Depending on what
you are trying to do, this approach might also work.

hth,
Praveen

On Wed, 4 Jun 2003, Jianlong Zhou wrote:

> Hi, all,
>
> I want to know whether it is possible in OpenGL to disable rendering when reading and
> writing something in the framebuffer?
> I want to write and read(!) something in the framebuffer but meanwhile the
> framebuffer shouldn't be drawn.
>
> There are two functions related to this:
> glDrawBuffer - specifies a buffer to render to
> glReadBuffer - specifies the buffer where pixels are read from
>
> But I couldn't find the function for disabling rendering the framebuffer to the
> monitor! Or isn't it possible to disable it and the current read buffer is
> displayed?
>
> Best regards,
>
> Jianlong
>
>
> _______________________________________________
> This is the private VTK discussion list.
> Please keep messages on-topic. Check the FAQ at: <http://public.kitware.com/cgi-bin/vtkfaq>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/vtkusers
>

-- 
-----------------------------------------------------------------
Praveen Bhaniramka               Member of Technical Staff (MTS)
praveenb at sgi.com                 Advanced Graphics Division
(650)933-1785                    Silicon Graphics, Inc.
-----------------------------------------------------------------