This is way more intricate than it needs to be. Game coders have all these old ideas floating around like quad trees and aabb collision detection which has gott

This is way more intricate than it needs to be. Game coders have all these old ideas floating around like quad trees and aabb collision detection which has gotten a lot of improvements over the years (a lot of which is just conceptual improvements). I really like PBD as a good alternative to the formulation linked above: https://www.youtube.com/c/TenMinutePhysics https://www.youtube.com/c/TenMinutePhysics.