Game Development Patterns and Best Practices

Introduction to State Machines

We often write code to react to things happening within the game environment based on the expectations of us, as well as our players. For instance, if we are creating a 2D side-scrolling platformer game, when the player presses one of the arrow keys, we're expecting the player's character to move and, whenever we press the spacebar, we expect the sprite to jump into the air. Or perhaps in a 3D game, when our player sees a panel with a large button, they expect to be able to press it.

Tons of things in our ordinary lives act this way as well, reactive to certain stimuli. For instance, when you use your television remote, you expect certain things to happen, or even when swiping or tapping on your mobile phone. ...