// This example demonstrates how to display text in the UI that involves action bindings.
// When the player switches control schemes or customizes controls (the latter is not set up
// in this example but if supported, would work with the existing code as is), text that
// is shown to the user may be affected.
//
// In the example, the player is able to move around the world and look at objects (simple
// cubes). When an object is in sight, the player can pick the object with a button. While
// having an object picked up, the player can then either throw the object or drop it back
// on the ground.
//
// Depending on the current context, we display hints in the UI that reflect the currently
// active bindings.
using UnityEngine.UI;
namespace UnityEngine.InputSystem.Samples.InGameHints
{
public class InGameHintsExample : MonoBehaviour
{
public Text helpText;
public float moveSpeed;
public float rotateSpeed;
public float throwForce;
public float pickupDistance;
public float holdDistance;
private Vector2 m_Rotation;
private enum State
{
Wandering,
ObjectInSights,
ObjectPickedUp
}
private PlayerInput m_PlayerInput;
private State m_CurrentState;
private Transform m_CurrentObject;
private MaterialPropertyBlock m_PropertyBlock;
// Cached help texts so that we don't generate garbage all the time. Could even cache them by control
// scheme to not create garbage during control scheme switching but we consider control scheme switches
// rare so not worth the extra cost in complexity and memory.
private string m_LookAtObjectHelpText;
private string m_ThrowObjectHelpText;
private const string kDefaultHelpTextFormat = "Move close to one of the cubes and look at it to pick up";
private const string kLookAtObjectHelpTextFormat = "Press {pickup} to pick object up";
private const string kThrowObjectHelpTextFormat = "Press {throw} to throw object; press {drop} to drop object";
public void Awake()
{
m_PlayerInput = GetComponent<PlayerInput>();
}
public void OnEnable()
{
ChangeState(State.Wandering);
}
// This is invoked by PlayerInput when the controls on the player change. If the player switches control
// schemes or keyboard layouts, we end up here and re-generate our hints.
public void OnControlsChanged()
{
UpdateUIHints(regenerate: true); // Force re-generation of our cached text strings to pick up new bindings.
}
private int m_UpdateCount;
public void Update()
{
var move = m_PlayerInput.actions["move"].ReadValue<Vector2>();
var look = m_PlayerInput.actions["look"].ReadValue<Vector2>();
Move(move);
Look(look);
switch (m_CurrentState)
{
case State.Wandering:
case State.ObjectInSights:
// While looking around for an object to pick up, we constantly raycast into the world.
if (Physics.Raycast(transform.position, transform.forward, out var hitInfo,
pickupDistance) && !hitInfo.collider.gameObject.isStatic)
{
if (m_CurrentState != State.ObjectInSights)
ChangeState(State.ObjectInSights);
m_CurrentObject = hitInfo.transform;
// Set a custom color override on the object by installing our property block.
if (m_PropertyBlock == null)
{
m_PropertyBlock = new MaterialPropertyBlock();
m_PropertyBlock.SetColor("_Color", new Color(0.75f, 0, 0));
}
m_CurrentObject.GetComponent<MeshRenderer>().SetPropertyBlock(m_PropertyBlock);
}
else if (m_CurrentState != State.Wandering)
{
// No longer have object in sight.
ChangeState(State.Wandering);
if (m_CurrentObject != null)
{
// Clear property block on renderer to get rid of our custom color override.
m_CurrentObject.GetComponent<Renderer>().SetPropertyBlock(null);
m_CurrentObject = null;
}
}
if (m_PlayerInput.actions["pickup"].triggered && m_CurrentObject != null)
{
PickUp();
ChangeState(State.ObjectPickedUp);
}
break;
case State.ObjectPickedUp:
// If the player hits the throw button, throw the currently carried object.
// For this example, let's call this good enough. In a real game, we'd want to avoid the raycast
if (m_PlayerInput.actions["throw"].triggered)
{
Throw();
ChangeState(State.Wandering);
}
else if (m_PlayerInput.actions["drop"].triggered)
{
Throw(drop: true);
ChangeState(State.Wandering);
}
break;
}
}
private void ChangeState(State newState)
{
switch (newState)
{
case State.Wandering:
break;
case State.ObjectInSights:
break;
case State.ObjectPickedUp:
break;
}
m_CurrentState = newState;
UpdateUIHints();
}
private void UpdateUIHints(bool regenerate = false)
{
if (regenerate)
{
m_ThrowObjectHelpText = default;
m_LookAtObjectHelpText = default;
}
switch (m_CurrentState)
{
case State.ObjectInSights:
if (m_LookAtObjectHelpText == null)
m_LookAtObjectHelpText = kLookAtObjectHelpTextFormat.Replace("{pickup}",
m_PlayerInput.actions["pickup"].GetBindingDisplayString());
helpText.text = m_LookAtObjectHelpText;
break;
case State.ObjectPickedUp:
if (m_ThrowObjectHelpText == null)
m_ThrowObjectHelpText = kThrowObjectHelpTextFormat
.Replace("{throw}", m_PlayerInput.actions["throw"].GetBindingDisplayString())
.Replace("{drop}", m_PlayerInput.actions["drop"].GetBindingDisplayString());
helpText.text = m_ThrowObjectHelpText;
break;
default:
helpText.text = kDefaultHelpTextFormat;
break;
}
}
// Throw or drop currently picked up object.
private void Throw(bool drop = false)
{
// Unmount it.
m_CurrentObject.parent = null;
// Turn physics back on.
var rigidBody = m_CurrentObject.GetComponent<Rigidbody>();
rigidBody.isKinematic = false;
// Apply force.
if (!drop)
rigidBody.AddForce(transform.forward * throwForce, ForceMode.Impulse);
m_CurrentObject = null;
}
private void PickUp()
{
// Mount to our transform.
m_CurrentObject.position = default;
m_CurrentObject.SetParent(transform, worldPositionStays: false);
m_CurrentObject.localPosition += new Vector3(0, 0, holdDistance);
// Remove color override.
m_CurrentObject.GetComponent<Renderer>().SetPropertyBlock(null);
// We don't want the object to be governed by physics while we hold it so turn it into a
// kinematics body.
m_CurrentObject.GetComponent<Rigidbody>().isKinematic = true;
}
private void Move(Vector2 direction)
{
if (direction.sqrMagnitude < 0.01)
return;
var scaledMoveSpeed = moveSpeed * Time.deltaTime;
// For simplicity's sake, we just keep movement in a single plane here. Rotate
// direction according to world Y rotation of player.
var move = Quaternion.Euler(0, transform.eulerAngles.y, 0) * new Vector3(direction.x, 0, direction.y);
transform.position += move * scaledMoveSpeed;
}
private void Look(Vector2 rotate)
{
if (rotate.sqrMagnitude < 0.01)
return;
var scaledRotateSpeed = rotateSpeed * Time.deltaTime;
m_Rotation.y += rotate.x * scaledRotateSpeed;
m_Rotation.x = Mathf.Clamp(m_Rotation.x - rotate.y * scaledRotateSpeed, -89, 89);
transform.localEulerAngles = m_Rotation;
}
}
}