Indirectly related: I did an audio space animated thing using the canvas bouncing ball, and then I wanted to add arbitrary obstacle with lines at are at 90 or

Indirectly related: I did an audio space animated thing using the canvas bouncing ball, and then I wanted to add arbitrary obstacle with lines at are at 90 or 180 degrees. The math gets a magnitude more complicated immediately. Changing the angle of the ball doesn’t do that, but taking the walls off of the coordinate system does. You go from simply adding a positive or negative signed number to some other situation where you have to calculate the vectors of all the bodies involved. I’ve always suspected there’s some elegant solution that I’m missing.