Input Actions and Axes

Player input is the thing that distinguishes video games from other entertainment media: the fact that they're interactive. For a video game to be interactive, it must take into account the player's input. Many games do this by allowing the player to control a virtual character that acts upon the virtual world it's in, depending on the keys and buttons that the player presses, which is exactly what we'll be doing in this chapter.

Most game development tools nowadays allow you to abstract keypresses into Actions and Axes, which allow you to associate a name (for example, Jump) with several different player inputs (pressing a button, flicking a thumbstick, and so on). The difference between Actions and Axes is that Actions are used for binary inputs (inputs that can either be pressed or released, like the keys on the keyboard), while Axes are used for inputs that are scalar or continuous (that is, that can have a range of values, like...