[PyOpenGL-Users] off-screen rendering and/or shutting down GLUT

[Maciej K. <ma...@dg...>]

Hello all,

I'm trying to do some off-screen rendering in my app. Alas, from what I
understand, GLUT does not (yet) support off-screen rendering.  GLX and WGL do,
IIRC, but these APIs are not exposed by pyopengl.  Is there some way I can
achieve off-screen rendering using just GL/GLU calls in pyopengl?

For now I've settled for rendering on-screen with GLUT, but would like to shut
down the GLUT/OpenGL system when I've done the render (need to return control
to my app).  Currently I grab the image with glReadPixels in the GLUT display
function, and immediately do glutDestroyWindow(), but this does not exit
glutMainLoop() as I was hoping, but instead shuts down the whole app, which
does not fit my needs.

So how can I read the OpenGL framebuffer with pyopengl and return control to
my main app?  My app is mostly just a computational package, not a graphical
app, one that uses OpenGL purely for terrain rasterization, and some other
things, hence I do not want to structure the whole app around glutMainLoop()
or equivalent...  the routines I'm writing have to be drop-in replacements for
the standard versions already in the application...

-- 
Maciej Kalisiak <ma...@dg...>
http://www.dgp.toronto.edu/~mac/