The app

The M5App or application layer is a class responsible for interfacing with the operating system. Since we are trying to write clean, reusable code, it is important that we don't mix our game code with any operating system function calls. If we did this, our game would be difficult to port to another system. The M5App class is created in WinMain and responsible for creating and destroying every other system. Anytime our game needs to interact with the OS, including changing resolution, switching to full screen, or getting input from a device, we will use the M5App class. In our case, the operating system that we will be using will be Windows.