Unity Development Cookbook, 2nd Edition

Chapter 3. Input

Letting the player exert control over your game is, well, kind of important! It’s a core tenet of interactive games. In this chapter, we’ll look at some of the most common input requirements game developers have. Thankfully, Unity has a variety of input methods available, ranging from keyboard and mouse input to gamepad input to more sophisticated systems allowing for mouse pointer control. We’ll touch on each of them here.

Note

You’ll use both the legacy Input class, as well as Unity’s new input system in this chapter. They both have their place in a modern Unity project.

3.1 Getting Simple Keyboard Input

Problem

You want to know when the user is pressing keys on a keyboard, with as few steps as possible.

Solution

Use the legacy Input class’s GetKeyDown, GetKeyUp, and GetKey methods to find out what keys are being pressed:

if (Input.GetKeyDown(KeyCode.A))
{
    Debug.Log("The A key was pressed!");
}

if (Input.GetKey(KeyCode.A))
{
    Debug.Log("The A key is being held down!");
}

if (Input.GetKeyUp(KeyCode.A))
{
    Debug.Log("The A key was released!");
}

if (Input.anyKeyDown) {
    Debug.Log("A key was pressed!");
}

Discussion

Each of these methods responds at different times:

• GetKeyDown returns true when the key started being pressed on this frame.

• GetKeyUp returns true when the key was released on this frame.

• GetKey returns true if the key is currently being held down.

You can also use the anyKeyDown property to find out if any key at all is being pressed, which ...