unity-input

Unity Input System Rules

Note: All private fields in the examples use camelCase names with a leading underscore, following common Microsoft C# naming conventions for fields.[web:17]

REQUIRED: New Input System

⚠️ Legacy Input System is FORBIDDEN for new projects

Package installation

Package Manager → Input System → Install

In Project Settings → Player → Active Input Handling:

• Select "Input System Package (New)"

Input Actions Asset

Creating Input Actions

// ✅ DO: Create an Input Actions Asset
// Assets → Create → Input Actions

Input Actions structure

PlayerInputActions
├── Gameplay
│   ├── Move (Value, Vector2)
│   ├── Look (Value, Vector2)
│   ├── Jump (Button)
│   ├── Fire (Button)
│   └── Interact (Button)
├── UI
│   ├── Navigate (Value, Vector2)
│   ├── Submit (Button)
│   └── Cancel (Button)
└── Menu
    ├── Pause (Button)
    └── OpenInventory (Button)

PlayerInput Component Approach

Automatic wiring via PlayerInput

using UnityEngine;
using UnityEngine.InputSystem;

/// <summary>
/// Handles player input via the PlayerInput component.
/// </summary>
public class PlayerInputHandler : MonoBehaviour
{
    [Header("References")]
    [SerializeField] private PlayerInput _playerInput;

    private Vector2 _moveInput;
    private Vector2 _lookInput;
    private bool _jumpPressed;

    private void Awake()
    {
        if (_playerInput == null)
        {
            _playerInput = GetComponent<PlayerInput>();
            if (_playerInput == null)
            {
                Debug.LogError("PlayerInput component is missing on PlayerInputHandler.");
                enabled = false;
            }
        }
    }

    // ✅ DO: Use message methods (automatically called by PlayerInput)
    // NOTE: Prefer InputAction.CallbackContext over InputValue
    public void OnMove(InputAction.CallbackContext context)
    {
        _moveInput = context.ReadValue<Vector2>();
    }

    public void OnLook(InputAction.CallbackContext context)
    {
        _lookInput = context.ReadValue<Vector2>();
    }

    public void OnJump(InputAction.CallbackContext context)
    {
        _jumpPressed = context.ReadValueAsButton();

        if (_jumpPressed)
        {
            PerformJump();
        }
    }

    public void OnFire(InputAction.CallbackContext context)
    {
        if (context.performed)
        {
            PerformFire();
        }
    }

    private void Update()
    {
        // Use cached values for continuous input
        ProcessMovement(_moveInput);
        ProcessLook(_lookInput);

        // Example: reset one-frame jump flag if it is meant to be transient
        _jumpPressed = false;
    }

    private void ProcessMovement(Vector2 input)
    {
        // Movement logic
    }

    private void ProcessLook(Vector2 input)
    {
        // Look logic
    }

    private void PerformJump()
    {
        // Jump logic
    }

    private void PerformFire()
    {
        // Fire logic
    }
}