made visual updates

main.gd

@@ -1,19 +1,44 @@
 class_name Main
-extends SubViewportContainer
+extends Node
+
+@export var scene: Node
+@export var movies: Node
 
 var loaded: bool = false
+var main_menu_scene_path: String = "res://Scenes/Menus/MainMenu/main_menu.tscn"
+var multiplayer_lobby_scene_path: String = "res://Scenes/Menus/multiplayer_lobby.tscn"
+var singleplayer_lobby_scene_path: String = "res://Scenes/Menus/singleplayer_lobby.tscn"
 
 func _ready() -> void:
-	ResourceLoader.load_threaded_request("res://Scenes/Menus/MainMenu/main_menu.tscn")
+	Game.switch_to_main_menu.connect(load_main_menu)
+	Game.switch_to_single_player.connect(load_singleplayer)
+	Game.switch_to_multi_player.connect(load_multiplayer)
 
 
-func _process(delta: float) -> void:
-	if !loaded:
-		var progress: Array = []
-		ResourceLoader.load_threaded_get_status("res://Scenes/Menus/MainMenu/main_menu.tscn", progress)
-		$SubViewport/ProgressBar.value = progress[0] * 100.0
+func load_main_menu() -> void:
+	load_scene(main_menu_scene_path)
+
+
+func load_singleplayer() -> void:
+	load_scene(singleplayer_lobby_scene_path)
+
+
+func load_multiplayer() -> void:
+	load_scene(multiplayer_lobby_scene_path)
+
+
+func load_scene(scene_path: String) -> void:
+	ResourceLoader.load_threaded_request(scene_path)
+	for node: Node in scene.get_children():
+		node.queue_free()
+	var progress: Array = [0.0]
+	while progress[0] < 1.0:
+		await get_tree().process_frame
+		ResourceLoader.load_threaded_get_status(scene_path, progress)
 		if progress[0] >= 1.0:
-			$SubViewport/ProgressBar.queue_free()
-			var main_menu: PackedScene = ResourceLoader.load_threaded_get("res://Scenes/Menus/MainMenu/main_menu.tscn")
-			$SubViewport/Node.add_child(main_menu.instantiate())
-			loaded = true
+			var new_scene: PackedScene = ResourceLoader.load_threaded_get(scene_path)
+			if movies:
+				movies.queue_free()
+				movies = null
+				$CanvasLayer.visible = true
+			scene.add_child(new_scene.instantiate())