Godot 4 Beta 1 - Click to Move with NavigationAgent2D

movement_controller.gd

extends Node2D
class_name MovementController

var player : CharacterBody2D = null

func _ready():
	var parent = self.get_parent()
	if parent:
		if parent.get_class() == "CharacterBody2D": player = parent

func _unhandled_input(event):
	if event is InputEventMouseButton:
		var mouse_event = event as InputEventMouseButton
		
		if mouse_event.is_pressed() and mouse_event.button_index == MOUSE_BUTTON_LEFT:
			var target_location = get_global_mouse_position()
			player.set_target_position(target_location)

player.gd

extends CharacterBody2D
class_name Player

signal path_changed(path : PackedVector2Array)

@export_range(1, 5, 1) var walk_speed : float = 3
@export_range(1, 5, 1) var acceleration : float = 3

var _agent : NavigationAgent2D = null
var _velocity := Vector2.ZERO
var _path : PackedVector2Array = []
var _is_finished := false

func _ready():
	for child in self.get_children():
		if child.get_class() == "NavigationAgent2D": 
			_agent = child
			break
		
	if _agent == null:
		_agent = NavigationAgent2D.new()
		_agent.name = "NavigationAgent2d"
		self.add_child(_agent)
		
	if _agent != null:
		_agent.set_target_position(self.position)
		_agent.path_changed.connect(_on_path_changed)
		_agent.velocity_computed.connect(_on_velocity_computed)
		_agent.radius = 35.0
		_agent.path_desired_distance = 50.0
		_agent.target_desired_distance = 100.0
		_agent.path_max_distance = 10.0
		_agent.max_speed = (walk_speed * 100) * (acceleration * 0.5)
		_agent.avoidance_enabled = true

# Start move when this method called.
func set_target_location(mouse_target: Vector2) -> void:
	_agent.set_target_position(mouse_target)
	self.set_active(true)

func _physics_process(delta):
	if not visible: return
	_is_finished = true

	var target_global_position = _agent.get_next_path_position()
	var direction := Vector2(lerp(self.global_transform.origin, target_global_position, 0.5)).direction_to(target_global_position)
	if _path.size() > 1:
		if  _agent.distance_to_target() > _agent.radius:
			var desired_velocity := direction * _agent.max_speed
			var steering = (desired_velocity - _velocity) * delta * 4.0
			_velocity += steering
			
			_agent.set_velocity(_velocity)
			_is_finished = false
		
	if _is_finished:
		self.path_changed.emit([])
		self.set_active(false)

func _on_velocity_computed(safe_velocity):
	velocity = safe_velocity
	move_and_slide()
	
func set_active(enable : bool):
	if enable == null or enable:
		set_physics_process(true)
	else:
		_agent.set_target_position(self.global_transform.origin)
		set_physics_process(false)

func _on_path_changed():
	_path = _agent.get_current_navigation_path()
	self.path_changed.emit(_path)