The project is available on Simon’s page in Codepen:
In the two videos below Simon explains what the bug was (he had forgotten a “break” statement). He insisted I include both videos, but actually only the second one is informative:
Simon still needs to add explosions to this game (make the enemies explode), so there will probably be a follow-up on this one.
Simon built a Polar to Cartesian converter (Simon’s own code). You can enter the radius in pixels and the angle in degrees, click “convert” and you get the coordinates in x and y and a circle appears n that spot.
You are welcome to play with Simon’s converter online in CodePen at: https://codepen.io/simontiger/pen/MmdodP
Simon is also planning to make a similar converter for Spherical to Cartesian (where you would enter radius, latitude and longitude and convert those into x,y,z).
Here Simon explains the formulas to convert between Polar and Cartesian coordinates: