I am so out of math that it hurts, but for some of you this should be a piece of cake. I want to move an object around another along its ages or circumference on a simple circular path. At the moment my game algorithm knows how to move and position a sprite just at the edge of an obstacle and now it waits for the next point to move depending on various conditions.

So the mathematical problem here is how to get (aX, aY) and (bX, bY) positions, when I know the Centre (cX, cY), the object position (oX, oY) and the distance required to move (d)