Controlling the game with a GameState class

As the code for this game is spread over many classes to keep each class manageable, it raises the problem of what happens when one of these classes needs to know what is going on inside another of the classes. At least when we crammed everything into the main game engine class all the required variables were in scope!

Tip

My estimate is that if we continued with our usual pattern (where we cram everything into the game engine) for this project, then the GameEngine class would have around 600 lines of code! By the end of this project, doing things a little differently, it will have barely 100 lines of code. Each code file/class will be much simpler. We will, however, need to spend more time understanding how all the different classes interact with each other—and we will. Now we will move on to the GameState class.

There are many ways of dealing with this common issue and the solution(s) you use will be dependent upon the...