Math-like problem with circles and coords
In a map in my game, I've got a X and Y location, so do other players. I'm trying to draw this on a little radar.
In the first pic (click the link below) you can see the red dot (you) and the blue dot is the other player and the arrow is where you're looking at (ingame). The other player is left in front of you as you can see.
In the second pic you look to the left, on your screen you will see the other player right infront of you, but on the radar nothing has changed.
In the third pic you can see what should've happened. All dots need to 'move' on that imaginary circle, just the ammount of degrees you have turned around - just in the opposite direction so if you look to the left, the dots will need to move to the right (on that imaginary circle)...hard to explain - At least thats my interpretation of how it should be done.
Link to explanatory image ->http://img495.imageshack.us/img495/254/radar4wc.png
I'm guessing I need to 'draw' a circle with a radius of half the distance between the two players, and move the dot a negative ammount of degrees on that circle, depending on the ammount of degrees I look around. So if I look 90 degrees to the left, all the dots on the radar will need to move -90 degrees 'on' that circle (which will be the hardest part to do...).
Any ideas how this last bit can be done?
Thanks in advance.
Ps - Sorry for the hard explanation...