[CMake] Forcing finding FreeGLUT instead of the system GLUT on MacOS

[ardi]

Hi,

I built and installed FreeGLUT in a custom location in my home
directory (Note: it's a custom location, but I also have pkg-config
installed on my PATH, and I did set it up so that when I do
'pkg-config --list-all' it successfully detects FreeGLUT in the
location where I installed it).

Now I'm trying to build a project that has find_package(GLUT REQUIRED)
and, as I would expect, it detects the system GLUT that comes standard
with MacOS. But for this particular build, I want it to find FreeGLUT
instead of the system GLUT. How can I force finding FreeGLUT?

Thanks a lot in advance,

ardi