Frontend and backend communication

[Steven Schveighoffer]

On Wed, 27 Jul 2011 13:41:37 -0400, Dainius (GreatEmerald)  
<pastas4 at gmail.com> wrote:

> I have one program design problem and I wonder if anyone here could
> give any suggestions about it. The situation is like this: I am
> splitting a game into a frontend (a library) and a backend (an
> executable). The backend is going to handle all the game mechanics,
> while the frontend is going to handle I/O. But there are certain
> problems. For example, now I have a function Shuffle() that calls
> PlaySound(SHUFFLE). Shuffle() is a backend function, while PlaySound()
> is a frontend one, so obviously it won't work that way after the
> split. It would be ideal if there was a way to create hooks - say an
> empty PlaySound() function that the frontend could receive calls to.
> But I can't see a way to do that. Another way to do that that was
> suggested to me was to use an event loop - set a global variable, then
> have the frontend monitor it for changes and then respond as
> necessary, but that just isn't a very clean way to do it.

Actually, an event loop is a good way to do it.  If your front end is a  
GUI, it's already likely running an event loop.  All you need to do is  
stick an event in the event queue.

I'd examine how to create custom events for your front end's probably  
already existing event loop.

-Steve