I'm using this method to detect collision between two AABBs. The algorithm is simple, fast and works great. It uses the relative velocity between the two objects to calculate TOI. This works fine with Euler, but now i'm trying to switch to RK4, which makes it hard for me to determine the TOI since i can't just divide the distance between the two AABBs by their relative velocity. Since RK4 is so popular, how do people deal with this issue? How to calculate a TOI for a swept AABB with RK4?