I have two 3D angles, represented by [a1,a2] [a1,a2] where the a2 is < 180. My coordinates are represented as [X,Y,Z], where X,Y,Z are 64 bit ints (longs in my lang). My direction angles are represented as (Angle1, Angle2) where Angle1 is 360 degrees along the X/Y plane, and Angle2 is 180 degrees along the Z axis.
In this case, I know for a fact that both angles were calculated from a single starting point, so there should be a single angle between them. However, the math eludes me. I sure would appreciate some help.
I've read the stuff on calculating the angle between two vectors, which is great, but for me would involve multiplying two longs together, which is 1. not practical, and 2. shouldn't be necessary.
My goal is to determine whether obj1 is moving generally towards obj2. One of the angles is the direction of movement of obj1, and the other is the direction from obj1 to obj2. Can I get there from here?