[fpc-pascal] GLM library alternative?

[Marco van de Voort]

In our previous episode, Anthony Walter said:
> By the way, what's stopping you guys from using OpenGL ES 2.0? It works on
> most all Windows, Mac, and Linux systems, and it's the only 3D graphics API
> on Raspberry Pi and most smart phones/tablets.

IIRC I went for opengl 3.3-4 because one could find more about it and
because opengl ES afaik has no geometry shader support.

The GL stuff is only for Windows PC (and very maybe Linux PC) anyway.