I think I found the issue for doing collision here https://stackoverflow.com/questions/630 ... 20#6312520

In your function LineAngle, replace math.atan with math.atan2 and replace the division sign with a comma. Specifically, note the differences between the parameters for math.atan and math.atan2 in the Lua 5.1 documentation . Also note that math.atan2 was deprecated in 5.3 (emphasis mine): The follow...

SO, I made the following simple circle pong toy. I am having issues with getting the correct angle . I'm getting negative values for the top-half of the circle ?! how can I just get 0 -> 360 ?!
https://github.com/Sweetkubuni/circle_pong