GLUT mouse abilities

hi there

I need some help with glut & mouse control.

let say that my mouse is on the edge of the screen ( in glutFullScreen() ) and then I move the mouse toward the edge - which means that the mouse cursor doesn’t move a lot but the mouse actually does - how can I know how much the mouse moved ?

As I understand glutPassiveMotionFunc only returns the new cursor position, so there’s no use of using those values.

Thanks for your help

Record the mouse coord continously and form deltas between each new callback.