Unity C# input code demos for Studio 1, Fall 2020 at NYU Game Center

AxisInput.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class AxisInput : MonoBehaviour
{
    void Update()
    {
        // Input Axis is a virtual joystick... unlike GetKey, it returns -1.0 - +1.0
        // e.g. holding your joystick to the left: -1.0f
        // holding you joystick to the right: +1.0f
        // not touching joystick at all: 0f

        // WASD controller?
        // float horizontal = Input.GetAxis("Horizontal"); // A+D capital H!!!
        // float vertical = Input.GetAxis("Vertical"); // W+S

        // mouse controller?
        float horizontal = Input.GetAxis("Mouse X") * 0.5f; // MOUSE_X
        float vertical = Input.GetAxis("Mouse Y") * 10f; // vertical mouse speed, 0 when not moving

        transform.Translate( 
            horizontal * Time.deltaTime * 5f,
            vertical * Time.deltaTime * 5f,
            0f 
        );
    }
}

CursorInput.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CursorInput : MonoBehaviour
{
    void Update()
    {
        // 1. get mouse cursor position
        Vector3 mouseCursor = Input.mousePosition; // in pixel screen-space

        // 2. convert mouse cursor position into WORLD SPACE / game space
        Vector3 worldPosition = Camera.main.ScreenToWorldPoint( mouseCursor );
        worldPosition.z = 0f;

        // 3. move triangle to my world position
        transform.position = worldPosition;

        // bonus: hide the mouse cursor?
        // IMPORTANT: hide / lock cursor only when the user clicks, to ensure this window has focus
        if ( Input.GetMouseButtonDown(0)) { // did user left-click? 1 = right click, 2=middle click
            // clicking = give focus to this application window
            Cursor.visible = false; // hide cursor?
            // Cursor.lockState = CursorLockMode.Locked; // good for mouse look?
        }
    }
}

KeyInput.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class KeyInput : MonoBehaviour
{
    float timeHeldDown = 0f; // timer that tracks how long we held down the button?

    void Update()
    {   
        // KEY PRESS INPUTS

        // GetKeyDown happens on the first frame when you start pressing down a key
        if ( Input.GetKeyDown(KeyCode.Space) ) {
            transform.Rotate( 0f, 0f, 5f );
        }
        
        // GetKeyUp happens on the first frame when you RELEASE a key
        if ( Input.GetKeyUp(KeyCode.Space) ) {
            transform.Rotate( 0f, 0f, -5f );
        }

        // KEY HOLDING DOWN

        // GetKey happens EVERY FRAME as long as you're holding down the key
        if ( Input.GetKey(KeyCode.Space ) ) {
            transform.localScale += Vector3.one * Time.deltaTime; // grow bigger
        }

        // TIMED PRESS? COMBINES ALL THREE
        // if we're holding down G on keyboard, then we turn red gradually / charge up?
        if ( Input.GetKey(KeyCode.G) ) {
            if ( timeHeldDown < 2f ) {
                timeHeldDown += Time.deltaTime; // deltaTime = duration of frame in seconds
                // e.g. if game is running at 60 FPS, dT = 1/60... 10 FPS? dT = 1/10
                Debug.Log( timeHeldDown );
            }
            // hacky way of turning red, don't do this
            GetComponent<SpriteRenderer>().color = Color.Lerp( 
                GetComponent<SpriteRenderer>().color, 
                Color.red, 
                Time.deltaTime * 2f
            );
        }

        // when you release G, you reset
        if ( Input.GetKeyUp(KeyCode.G ) ) {
            timeHeldDown = 0f; // reset
            GetComponent<SpriteRenderer>().color = Color.white;
            // expel energy, etc. do game code here
        }

    }
}