I'm a programmer who is studying physics in college, and a couple years back I had a similar experience with simulation code as you did. I didn't have any issues with the math—the program I was working on didn't have anything more conceptually advanced than multivariable calculus—but I did struggle significantly to understand the physics behind the simulation.
It didn't help that most programs use, for example, the variable 'rho' for density instead of just writing out 'density'.
On the other hand, reading game physics libraries (written by programmers, not physicists) can be just as bad. There are physics hacks all over ("it's not stable, so let's throw in an arbitrary constant") and there's code repetition where the programmer doesn't understand that two concepts are closely related.
It didn't help that most programs use, for example, the variable 'rho' for density instead of just writing out 'density'.
On the other hand, reading game physics libraries (written by programmers, not physicists) can be just as bad. There are physics hacks all over ("it's not stable, so let's throw in an arbitrary constant") and there's code repetition where the programmer doesn't understand that two concepts are closely related.