Circle gesture recognition using touch inputs?

Hello guys,
I have been stuck for a few days on this problem and i would really appreciate any help.

So i’m making a mobile game, and in the game i’m having some quick action events, these events require the user to draw circles really fast (clock wise and counter clock wise).

Currently i was able to achieve the following:

  • I’m able to specify an upper and lower radius for a circle, and if the input is outside those boundaries it registers as a false. (This helps me to know that the user is actually drawing a circle by comparing their input to the lower and upper values).
  • I’m able to calculate the angle between 2 2DVectors (The first touched location, and the current touch location). “The problem with this one is that when ever i change the screen size the angles change drastically and i cannot determine a way to use it”
  • I’m able to draw a circle using a while loop in UI, but i don’t know how it could help in the gesture recognition

Any Help is MUCH appreciated.

Thanks.