code: private float pointToAngle(float x, float y, float centerX, float centerY) {
          double diffX = x - centerX;
          double diffY = y - centerY;
          // Pass -diffX to get clockwise degrees order.
          double radian = Math.atan2(-diffX, diffY);
  
          float angle = ((float) Math.toDegrees(radian) + 360) % 360;
          // Add 90 because atan2 returns 0 degrees at 6 o'clock.
          angle += 90f;
          return angle;
      }
docs: Calculates angle of touched point.