[osg-users] Barenaked FBO-based-Viewer without window

Chris 'Xenon' Hanson xenon at alphapixel.com
Sat Apr 9 08:44:07 PDT 2011

On 4/9/2011 8:53 AM, pmartz at skew-matrix.com wrote:
> I'm fairly certain there's a way to create a window that's not visible, supported by all
> three major windowing APIs. I know that's not quite what your looking for, but it's an option.

  I've done this approach in the past in other apps, and I always found weirdness lurking
in the non-visible windows. Especially as MSWin and Linux windows managers evolve, there
was a tendency for them to 'find' my non-visible windows and list them in ALT+TAB or other
task/window displays.

> I do agree with J-S, I think you need to have a context current to something. Since the
> calling app appears to already have a context current to a visible window, it seems like
> the best solution would be for your code to bind the FBO, render to texture, then unbind
> and return to the calling app -- all while the callng app's context is current to its
> visible window.

  This would be smart, but I'm loathe to encourage any cross-contamination between the
existing context already bound to a visible window. Again, not for any specific reason,
just a "here there be dragons" kind of gut instinct.

  Thanks everyone for the input. The PBuffer approach I've already gotten to work seems
good enough, and safe, so I'll proceed with that. And I'm much more enlightened than a few
days ago.

>    -Paul

Chris 'Xenon' Hanson, omo sanza lettere. Xenon at AlphaPixel.com http://www.alphapixel.com/
  Digital Imaging. OpenGL. Scene Graphs. GIS. GPS. Training. Consulting. Contracting.
    "There is no Truth. There is only Perception. To Perceive is to Exist." - Xen

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