How can I check which Version of OpenGL is supported on a linux system with optirun?

Question

I have had a lot of problems / confusion setting up my laptop to work for OpenGL programming / the running of OpenGL programs.

My laptop has one of these very clever (too clever for me) designs where the Intel CPU has a graphics processor on chip, and there is also a dedicated graphics card. Specifically, the CPU is a 3630QM, with "HD Graphics 4000" (a very exciting name, I am sure), and the "proper" Graphics Processor is a Nvidia GTX 670MX.

Theoretically, according to Wikipedia, the HD Graphics Chip (Intel), under Linux, supports OpenGL 3.1, if the correct drivers are installed. (They probably aren't.)

According to NVIDIA, the 670MX can support OpenGL 4.1, so ideally I would like to develop and execute on this GPU.

Do I have drivers installed to enable me to execute OpenGL 4.1 code on the NVIDIA GPU? Answer: Probably no, currently I use this "optirun" thing to execute OpenGL programs on the dedicated GPU. See this link to see the process I followed to setup my computer.

My question is, I know how to run a compiled program on the 670MX; that would be 'optirun ./programname', but how can I find out what OpenGL version the installed graphics drivers on my system will support? Running 'glxinfo | grep -i opengl' in a terminal tells me that the Intel Chip supports OpenGl version 3.0. See the below information:

ed@kubuntu1304-P151EMx:~$ glxinfo | grep -i opengl
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile 
OpenGL version string: 3.0 Mesa 9.1.3
OpenGL shading language version string: 1.30
OpenGL extensions:

How do I do the same or similar thing to find out what support is available under 'optirun', and what version of OpenGL is supported?

Update

Someone suggested I use glGetString() to find this information: I am now completely confused! Without optirun, the supported OpenGL version is '3.0 MESA 9.1.3', so version 3, which is what I expected. However, under optirun, the supported OpenGL version is '4.3.0 NVIDIA 313.30', so version 4.3?! How can it be Version 4.3 if the hardware specification from NVIDIA states only Version 4.1 is supported?

Answer 1

You can just run glxinfo under optirun:

optirun glxinfo | grep -i opengl

Both cards have different features, so its normal to get different OpenGL versions.