I'm currently porting / learning C++ code of a lightweight physics engine over to a C code variant engine. The lightweight physics engine is qu3e, written by Randy Gaul.
While porting the code over, I spot a few things that I'm confused about. Given that there are no comments that explain what these variables are for, and doesn't say what their meanings are, I am asking for help to explain the meaning and intentions for these variables.
I know Feature Pairs in a physics engine refers to "The closest pair of features (edge or vertex)". So I am confused about what
inR, inI, outR, and outI
stands for. What do these 4 variables have to do with Feature Pairs?
In this context, I know this struct is referred to as the Axis-Aligned Bounding Box struct, or AABB. Even with that in mind, I still have no idea what the
variable represents in the AABBes. Is there something important about the letter "e", as in, it could be some mathematical constant? Or is it energy?