[FaceKicker]

As someone who's never done any game development at all, can you give me some sense of the work that would be involved to port a Windows-only OpenGL game to Mac or Linux? What pieces of it would need to be redone or significantly overhauled?

I would have expected it would be quite minimal compared to the work involved in developing the game itself, but I guess I must be wrong if there are "many" Windows-only OpenGL games.

[kabdib]

Sound. Networking. Decent async file I/O. Threading libraries. Dynamic loading of components. Anti-cheat techniques (or any other security stuff you might need). Device input. Choosing and supporting a platform (and the follow-on customer support issues). Diagnosis of customer problems (because they _will_ have them).

[eropple]

Sound: OpenAL abstracts this decently. If you're not using it or an equivalent, you're doing it wrong.

Networking: Most folks building a bespoke networking layer seem to go with ENET, which is cross-platform.

Async file I/O: yup.

Threading libraries: something wrong with Boost Thread? (Boost gets coroutines, too, in 1.53, which I'm pretty excited about.)

Honestly, the biggest problem I see in writing a cross-platform game is device input. Trying to build a joystick/gamepad-based game for Linux and OS X are pretty painful. Fortunately I've lucked onto GLFW as a windowing toolkit, which handles the HID Manager boilerplate and other badness for them.

[munchbunny]

The main difficulty in porting has less to do with OpenGL itself and more to do with the number of platform-specific issues you encounter when you're trying to port code that is highly optimized for specific platforms.

[FaceKicker]

Interesting, can you give any examples of these issues?