Optimization global

2026-06-11 11:12:46 +02:00
parent 90ce89f880
commit 30c1a9863f
8 changed files with 105 additions and 42 deletions
@@ -0,0 +1,66 @@
+extends Node
+## Scene changer that keeps peak memory low on low-end devices.
+##
+## [method SceneTree.change_scene_to_file] loads the new scene while the old
+## one is still fully resident, so transitions between heavy scenes (gardens,
+## minigames) momentarily need the memory of both — enough to OOM-crash old
+## tablets. This helper frees the current scene first, then streams the new
+## scene from disk on a background thread so the main thread keeps rendering
+## frames instead of freezing.
+##
+## Callers are expected to have covered the screen (OpeningCurtain closed)
+## before calling [method change_scene]; the curtain stays visible while the
+## tree has no current scene.
+
+## Scene shown if the requested scene fails to load, so the player is never
+## stuck on a black screen.
+const FALLBACK_SCENE_PATH: String = "res://sources/menus/main/main_menu.tscn"
+
+var _is_changing: bool = false
+
+
+func change_scene(scene_path: String) -> void:
+	if _is_changing:
+		Log.warn("SceneLoader: Change to %s requested while another change is in progress; ignoring" % scene_path)
+		return
+	if not ResourceLoader.exists(scene_path):
+		Log.error("SceneLoader: Scene does not exist: %s" % scene_path)
+		return
+	_is_changing = true
+	# Defer so the calling scene is never freed while one of its methods is
+	# still on the stack.
+	_change_scene_deferred.call_deferred(scene_path)
+
+
+func _change_scene_deferred(scene_path: String) -> void:
+	var tree: SceneTree = get_tree()
+	# Free the old scene before loading the new one: this roughly halves the
+	# memory peak of the transition.
+	if tree.current_scene:
+		tree.unload_current_scene()
+	var error: Error = ResourceLoader.load_threaded_request(scene_path)
+	if error != OK:
+		Log.error("SceneLoader: Could not start loading %s (error %s)" % [scene_path, error_string(error)])
+		_finish_with_fallback(tree, scene_path)
+		return
+	var status: ResourceLoader.ThreadLoadStatus = ResourceLoader.load_threaded_get_status(scene_path)
+	while status == ResourceLoader.THREAD_LOAD_IN_PROGRESS:
+		await tree.process_frame
+		status = ResourceLoader.load_threaded_get_status(scene_path)
+	if status != ResourceLoader.THREAD_LOAD_LOADED:
+		Log.error("SceneLoader: Failed to load %s (status %d)" % [scene_path, status])
+		_finish_with_fallback(tree, scene_path)
+		return
+	var packed_scene: PackedScene = ResourceLoader.load_threaded_get(scene_path) as PackedScene
+	if not packed_scene:
+		Log.error("SceneLoader: %s is not a PackedScene" % scene_path)
+		_finish_with_fallback(tree, scene_path)
+		return
+	_is_changing = false
+	tree.change_scene_to_packed(packed_scene)
+
+
+func _finish_with_fallback(tree: SceneTree, failed_scene_path: String) -> void:
+	_is_changing = false
+	if failed_scene_path != FALLBACK_SCENE_PATH:
+		tree.change_scene_to_file(FALLBACK_SCENE_PATH)