OpenGL via realvnc or xrdp etc

[timrowledge]

I've spent far too long flailing around trying to make sense of what I find with assorted searching, so I'm just going to ask for guidance and be done with it -

What is the current state of using openGL (or openGLES, not massively picky right now) on a Pi displaying via either the default realVNC or xrdp (which historically has given me much less hassle, but whatever) ?

I'd like to be able to use openGL to draw my graphics. I pretty much never have a Pi directly attached to a monitor. What do I need to do please?

[ghans]

The RealVNC server has an experimental direct capture option in its settings. Enable it.

ghans

[timrowledge]

Grans, yes, I spotted that - but there is a fairly big logic problem in that my software has to run on pretty much every machine you could imagine (yes, we have actually run on OS/2, BM mainframe and so as well as the Usual Suspects) and so I need to avoid too much in the way of system specific tricks. I dare say RealVNC have ambitions to become a major player in the unix/X market but it may take a while before it is the standard.

I *have* seen mentions of something call GLX, which appears to be openGL for X. So far I'm not understanding enough to be able to follow much further and one of those ouch-my-back-aaaargh problems is not helping me to concentrate right now...