ffi for glutInit

[Aleix Conchillo Flaqué]

Hi,

I have started working on bindings for OpenGL and GLUT.

https://github.com/aconchillo/guile-gl

The work is very preliminar, which means I can't even show a window yet.

The scm files are semi-automatically generated by a python script that
uses pycparser. So that saved quite a lot of time.

Now, I'm stuck with glutInit. The signature of the function is like this:

glutInit(int *argc, char **argv);

See: http://www.opengl.org/resources/libraries/glut/spec3/node10.html

I don't really know how to do the char** part, so I need some help here.

For the user, the guile procedure will simply look like (glutInit) and
internally (command-line) would be ideally used to construct the
char**, etc.

All other functions in glut.scm should work (at least they evaluate
fine), except the ones related to fonts. So I would say that glutInit
is the last one to have a basic program that runs OpenGL.

Thanks in advance,

Aleix