Easiest Method to Find Point on Circle
Following is the code to detect whether point is in circle or not :
Parameter contains Center Point, radius and test point. halflinewidth is same as threshold value. So that it will check the point for Circle with some width provided in halflinewidth.
It finds distance from center and if that distance somehow in between radius and halflinewidth radius. 🙂 quite easy. Let me know if you need more detail into that.