public functions?

Small problem: If I have a function (int name(int x)) that I wish to use in all my cpp files, in the same project, where should I declar it???

It is considered back practice, so I suggest you redesign your program a bit. But here is how…

you can use ‘extern’.

For each source file that needs to call the function, put this at the top:

extern int name(int x);

For the one source that defines the function:

int name( int x ) {
  // stuff


uh huh. and isn’t this off-topic?

(OpenGL != C++ != language semantics)