Honestly, there is a lot that can go wrong when writing OpenGL code. So my
question is, do you have an `OpenGl debug context
<https://lva.cg.tuwien.ac.at/cgue/wiki/doku.php?id=students:debugcontext>`_? If
not, you need it. Then additionally to that, I can recommend you to use an
OpenGl debugger. For example the `nvidia tools
<https://developer.nvidia.com/gameworksdownload#?tx=$gameworks,developer_tools$target,desktop$graphics_api,opengl_4.3,opengl_4.4,opengl_4.5$activity,debug>`_,
or `apitrace <http://apitrace.github.io/>`_.
