I'll let this picture to tell what exactly I need:
So I need the angle between the north line and AB line. As most of you already know there're no opcode for the invert function of tangens in Vice City.
I've only found this one:
It doesn't calculate arctg but arccos instead.
Why do I need this directional angle:
I want to force any moving helicopter to look directly at players car all the time no matter which coordinates it has. I've tried a simple method:
Well this do trick but only aproximately - I need a precise direction.
I'm starting to think that heli speed or maybe a mass has something to do with this problem.
Any suggestions? Thanks