immersiverpg/godotasyncloader

A Godot plugin to load, instance, and add scenes asynchronously using a background thread.

godotasyncloader's Issues

Add error handler callback

Because AsyncLoader.load_scene_async_with_cb is async, there is a chance that the target, instance, and cb have been deleted before use. So we would have to do a bunch of checks for each callback. Rather than do that, have a callback that is called on any of these situations.

func _on_orange_loaded_cb(instance : Node, data : Dictionary) -> void:
	# Just return if target is invalid
	if not is_instance_valid(target):
		return

	# Just return if instance is invalid
	if not is_instance_valid(instance):
		return

	# Just return if the cb is invalid
	if cb != null and not cb.is_valid():
		return

func _on_error(instance : Node, data : Dictionary) -> void:
	# Just return if target is invalid
	if not is_instance_valid(target):
		return

	# Just return if instance is invalid
	if not is_instance_valid(instance):
		return

	# Just return if the cb is invalid
	if cb != null and not cb.is_valid():
		return

AsyncLoader.start(groups, 100, funcref(self,"_on_error" ))

Extract into addon and put on Godot Asset Library

Get it on here https://godotengine.org/asset-library/asset

Replace 3 singletons with 1

Instead of having SceneAdder, SceneLoader, and SceneSwitcher, just have AsyncLoader. This should also get rid of the cyclic import error that requires restart.

Then our API can be:

AsyncLoader.set_groups()
AsyncLoader.change_scene_async()
AsyncLoader.load_scene_async()
AsyncLoader.load_scene_async_with_cb()
AsyncLoader.load_scene_sync()

Trying to load non existent scene silently fails

https://github.com/ImmersiveRPG/AsyncLoaderExample/blob/2174a7d0c247c63b038cf253fee951d37f202cbe/project/src/Singletons/SceneLoader.gd#L90

Android or IOS?

Does this plugin work on android or ios?

Add a way to remove scenes from cache?

I was looking at SceneLoader.gd, specifically the _get_cached_scene function, and it looks like scenes never get removed from the _scenes cache. It looks like the cache just going to grow and grow while the game runs, using ever more memory. Some way to remove scenes from the cache will probably be needed for larger games.

Move thread setup out of AutoLoad _enter_tree

Having threads start inside AutoLoad can lead to crashes. This is because the main loop (and signal system) isn't loaded yet, and we have to poll for its existence like so:

func _enter_tree() -> void:
	_thread = Thread.new()
	var err = _thread.start(self, "_run_thread", 0, Thread.PRIORITY_LOW)
	assert(err == OK)

func _run_thread(_arg : int) -> void:
	# Wait for main loop to initialize
	var is_waiting_for_main_loop_to_load := true
	while is_waiting_for_main_loop_to_load:
		var loop = self.get_tree()
		if loop != null:
			is_waiting_for_main_loop_to_load = false

		if is_waiting_for_main_loop_to_load:
			print("Still waiting for main loop to initialize ...")
			OS.delay_msec(100)

	# Do actual thread stuff here ...

Also, setting up the plugin like this, is annoying and not obvious to users:

const GROUPS := [
	"terrain",
	"building",
]

func _ready() -> void:
	AsyncLoader._sleep_msec = 100
	AsyncLoader.set_groups(GROUPS)

So we can replace both of these with a start function that does setup and starts threads:

const GROUPS := [
	"terrain",
	"structure",
]
const SLEEP_MSEC := 100

func _ready() -> void:
	AsyncLoader.start(GROUPS, SLEEP_MSEC)

Add functions for sleeping off screen nodes out of tree

Make logging display times for each chunk

Make output like this:

!!!!!! scene load res://src/World/World.tscn
    $Plants/Cactus
    load 10 ms in THREAD
    instance 13 ms in THREAD
    add 0 ms in MAIN!!!!!!!!!!!!

    $Plants/Cactus2
    load 2 ms in THREAD
    instance 13 ms in THREAD
    add 0 ms in MAIN!!!!!!!!!!!!

Get some lag spikes while loading ?

Hi !
I searched for a plugin like yours because having my scene loading at start makes my game a bit long to load so I wanted to delay some loading while the player is in the menus.
I managed to get the plugin to work even if I'm in 2D, but for some reasons I still get little lag spikes when it loads.

I don't know exactly what could cause this,

Here is basically the code I'm using (I removed all "position" related args everywhere as I don't need them and it was not compatible with 2D)

Init :

const GROUPS := [
	"Foreground",
	"UI",
	"Background",
]
const SLEEP_MSEC := 100

func _init():
	SceneAdder._sleep_msec = 100
	SceneAdder.set_groups(GROUPS)

async calls :

func async_load(path,type,to_assign=null):
	yield(get_tree(),"idle_frame")
	var target
	
	match type:
		"canvas":
			target = canvas_layer
		"background":
			target = background
		"foreground":
			target = foreground
		"middle":
			target = middle
	
	
	if to_assign == null:
		SceneLoader.load_scene_async(target, path)
	else:
		SceneLoader.load_scene_async_with_cb(target, path, funcref(self, "handle_load_callback"), {"type":type,"to_assign":to_assign})

Callback :

func handle_load_callback(path : String, instance : Node, data : Dictionary) -> void:
	propagate_call("add_"+data.type,[instance])
	
	match data.to_assign:
		"fight_scene":
			fight_scene = instance
		"codex":
			codex = instance

AsyncLoadLagSpike.mp4

Replace SceneAdder 100ms sleeps with sleeps only as long as needed

Adding scenes is slow. At the current rate (100ms), we can only add 10 scenes per second. This makes it seem very slow when adding tons of small scenes.

The game scene is not deleted?

With this extension, I switched from the main menu to the game scene. Later, I switched from the game scene to the main menu. I deleted the game scene with the commands get_tree().get_root().call_deferred("remove_child", game_scene) and game_scene.queue_free(). However, when I return to the main menu scene, the game scene is loading again. What should I do?

Make SceneAdder groups customizable

We shouldn't need to hard code groups to add. Make it so they are setup in code:

const CATEGORIES := [
	"terrain",
	"building",
	"furniture",
	"plant",
	"item",
	"npc",
	"etc",
]

func _init() -> void:
	SceneAdder.set_categories(CATEGORIES)

Simplify using SceneLoader.load_scene_async_with_cb

Using SceneLoader.load_scene_async_with_cb is confusing.

Add way to list scenes cached by SceneLoader