Day 162: A buggy integration, and an unexpected surprise

Today I finally managed to integrate the physics, even though most of it is buggy and there are random crashes that will be a pain to track down.
In the gif you can see that sphere collisions are correctly resolved, as well as the half plane collisions (the invisible floor). However box-sphere collisions are slightly buggy, while box-box collisions are completely broken.

However the balance of this day is absolutely positive, because thanks to a bug in the physics engine I found a bug that was literally killing the performance of the rendering engine (which I actually thought were pretty good): each GameObject was duplicated in the copy constructor!
I tested immediately the old scenes, and the results are outstanding: the scene with 1000 dynamic lights from 17 fps skyrocketed to 40, and the directional lights scene went from ~40 to a perfect 60 fps.