Standard and reliable mouse-reporting with GLUT

Question

I'm trying to use GLUT (freeglut) in my OpenGL application, and I need to register some callbacks for mouse wheel events. I managed to dig out a fairly undocumented function:

api documentation

But the man page and the API entry for this function both state the same thing:

Note: Due to lack of information about the mouse, it is impossible to implement this correctly on X at this time. Use of this function limits the portability of your application. (This feature does work on X, just not reliably.) You are encouraged to use the standard, reliable mouse-button reporting, rather than wheel events.

Fair enough, but how do I use this standard, reliable mouse-reporting? And how do I know which is the standard? Do I just use glutMouseFunc() and use button values like 4 and 5 for the scroll up and down values respectively, say if 1, 2 and 3 are the left, middle and right buttons? Is this the reliable method?

Bonus question: it seems the `xev' tool is reporting different values for my buttons. My mouse buttons are numbered from 1 to 5 with xev, but glut is reporting buttons from 0 to 4, i.e. an off-by-one. Is this common?

Answer 1

I thought I might revisit my own question since it has been a long time since I asked it without any replies.

Reading yet more thoroughly at aforementioned documentation, from what I understand it seems that my guess was indeed true.

My guess:

Do I just use glutMouseFunc() and use button values like 4 and 5 for the scroll up and down values respectively [...]?

I haven't tested it yet, but from the following quote from the documentation, I gather that this is indeed what they meant.

If you do not register a wheel callback, wheel events will be reported as mouse buttons.