Godot 4 and GDScript - Part 3 (the lifecycle)

Description

00:36:
- A game is composed of scenes
- scenes are created using a tree of nodes that define logic in our game and everything that should happen
00:57: _ underscore methods like: _ready()
- These are virtual functions, provided by the library.
- By default they do nothing.
- they are designed to be overridden by you and the engine will call them at the appropriate time.
_init()02:14:
- Called when the node is initialized.
- called with MyNodeType.new()
_enter_tree()02:55:
- Called when the node is added to the scene tree
- We are guaranteed that the node has been added to the tree, but it may not be ready for use yet.
03:23 _ready()
- called when all child nodes have been initialized and are ready
- 04:17:
  - _enter_tree() is called on each node from trunk to leaf
  - _ready() is called from leaf to trunk
    - This is the opposite order from _enter_tree()
04:52: _exit_tree():
- called when a node exits the tree, for example:
  - after remove_child()
  - after change_scene_to_file("res://scene.tscn")
  - after queue_free()
- 06:34 how to ensure that a thread is terminated correctly:

func _exit_tree():
	if thread.is_alive():
		thread.wait_to_finish()

05:20: _process(delta):
- called once every frame:
- delta is the elapsed time since the last frame
05:51: _physics_process(delta):
- called a fixed number of times per second. Usually 60 times per second
06:59 _input(_event):
- this will be invoked for each input received.
- It’s usually better to use _unhandled_input(event)
08:06_notification(what):
- Use this to respond to miscellaneous, less common notifications
- Here is how to pause the game when the player clicks outside the window:

func _notification(what):
	if what == MainLoop.NOTIFICATION_APPLICATION_FOCUS_OUT:
		pause_game()