I knew if I got my thoughts out in writing it would dawn on me. The player should be (a,b) because that is the reliable position. Only when (x,y) is xxx meters from (a,b) should the action take place.
I need an equation to see if the target is A, which is outside the circle, or B which is inside the circle, and C which is the max distance.
i wonder if i can use teh Heading to determine the segment, and whether or not that is overkill.