[vbox-dev] OpenGL 3.2 support

[Klaus Espenlaub]

Hi Rūdolfs,

On 15.01.2017 15:46, Rūdolfs Bundulis wrote:
> Hi,
>
> I am trying to run a 3D visualization demo built on Unreal Engine on a
> Ubuntu VM. The demo does not run failing with an error that tells OpenGL
> 3.2 is not supported. I have guest additions installed and 3d
> acceleraction enabled (glxinfo shows the correct "2.1 Chromium 1.9"). I
> was under the impression that the guest additions fully forward
> everything to the host GPU and thus since the underlying Quadro 4200 has
> OpenGL 4.x it should work but apparently it is not that simple.

The point is that Chromium is only handling OpenGL 2.x (and IIRC a tiny 
subset of 3.x, far from allowing it to report this version).

Chromium is currently used as the transport of 3D information from the 
guest to the host (think of it as a marshalling/IPC solution).

> Can anyone briefly explain is this a dead end, or I am missing something
> trivial or there is coding that needs to be done to enable support for
> OpenGL 3.x? If the latter is true, can anyone give a brief notion how
> big/small is the stuff that needs to be done? We have some resources in
> the university that we could use to try and come up with something and
> then (if it looks good enough) contribute it back to VirtualBox.

 From my knowledge (I'm far from having deep knowledge about the 3D code 
in VirtualBox) it's a serious amount of work which would need to be done.

Since we're already planning to completely throw out Chromium (since 
it's effectively dead for a long time) and redoing all our 3D support 
based on Gallium (part of the Mesa project) which should give us OpenGL 
4.x coverage I don't see a good reason for teaching the really old dog 
some new tricks...

Switching to Gallium/Mesa based code would also make it far easier to 
improve the Direct3D coverage for Windows VMs, where with the old style 
3D we would first need to improve Wine's D3D code, usually pushing 
Chromium beyond its comfort zone, needing more work.

Regards,
Klaus

> Best Regards,
> Rudolfs Bundulis