godot-demo-projects/loading/threads/thread.gd

extends Control


var thread: Thread


func _on_load_pressed():
	if is_instance_valid(thread) and thread.is_started():
		# If a thread is already running, let it finish before we start another.
		thread.wait_to_finish()
	thread = Thread.new()
	print("START THREAD!")
	# Our method needs an argument, so we pass it using bind().
	thread.start(_bg_load.bind("res://mona.png"))


func _bg_load(path: String):
	print("THREAD FUNC!")
	var tex = load(path)
	# call_deferred() tells the main thread to call a method during idle time.
	# Our method operates on nodes currently in the tree, so it isn't safe to
	# call directly from another thread.
	_bg_load_done.call_deferred()
	return tex


func _bg_load_done():
	# Wait for the thread to complete, and get the returned value.
	var tex = thread.wait_to_finish()
	print("THREAD FINISHED!")
	$TextureRect.texture = tex
	# We're done with the thread now, so we can free it.
	thread = null # Threads are reference counted, so this is how we free them.


func _exit_tree():
	# You should always wait for a thread to finish before letting it get freed!
	# It might not clean up correctly if you don't.
	if is_instance_valid(thread) and thread.is_started():
		thread.wait_to_finish()
		thread = null