Quote Originally Posted by pitfiend View Post
EDIT: another thing to have in mind. bullets and asteroids don't dodge each other, they follow straight paths. so, if from one frame to the next, the bullet position cross the path of an asteroid, it's a hit too even if they didn't hit due to small sized asteroid.
If so, then linear algebra can be used to detect if two trajectories crosses (line v line), or if the bullet trajectory collides with the asteroid (line v circle, line v ellipse or line v rectangle).