In my 2d pixel old-school platformer, I'm looking for methods for bouncing particles off of background tiles. Particles aren't affected by gravity and collisions are "reflective". By that I mean a particle hitting the side of a square tile at 45 degrees should bounce off at 45 degrees as well.
We can assume that tiles will always be perfectly square. No slopes or anything.
What are efficient methods and algorithms to do this? I'd be implementing this on a Sega Genesis.