What constitutes drawing a weapon on somebody?
Grasping the wepon in your hand & clearing the holster.
I think what you are asking is what *Justifies* drawing on someone.
That would change depending on what state you happen to be in. Here in MI we now can use deadly force if a reasonable man would feel threatened with all the usual stuff........
Banging on my window at a traffic light??? I don't think so but when it broke..... Look out. Shooting someone is still the LAST resort but if I thought I needed to... I wouldn't be worried about if someone else thought it was legal.