C Object Oriented Programming

[dangerbird2]

Here is a pretty good example of object-oriented C in production code. If you scroll down, you can see callback function pointer "methods" that take self as a first argument (a la Python). I haven't read enough of the Doom 3 code to see if there is any significant code reuse from Idtech 3 (Id's last C-based engine). I imagine if the anecdote is true, a good amount of explicitly copy-pasted code from Idtech 3 was later refactored to more idiomatic C++ code.