screen filters system?

autoloads/display.gd

@@ -18,9 +18,13 @@ enum ScaleMode {
 		if is_node_ready():
 			_update_scale()
 
+## Directory to scan screen filters from.
+@export_dir var filters_dir: String = "res://"
+
 @export_group("Internal References")
 @export var _viewport: SubViewport
 @export var _viewport_container: SubViewportContainer
+@export var _native_filters_layer: CanvasLayer
 
 
 ## The native resolution of the game.
@@ -29,11 +33,37 @@ var size: Vector2i = Vector2i(
 	ProjectSettings.get_setting("display/window/size/viewport_height"),
 )
 
+## Whether each filter is enabled or disabled.
+var filters_enabled: Dictionary[StringName, bool] = {}
+
+
+var _filter_instances: Dictionary[StringName, ColorRect] = {}
+
 
 func _enter_tree() -> void:
 	get_tree().scene_changed.connect(_on_scene_changed)
 	get_tree().root.size_changed.connect(_update_scale)
 	
+	# populate screen filters
+	for file in ResourceLoader.list_directory(filters_dir):
+		var material = load(filters_dir.path_join(file)) as Material
+		if material:
+			var id = StringName(file.get_basename())
+			
+			if _filter_instances.has(id):
+				push_error("Screen filter %s exists in two different resource files. Only one will exist" % id)
+				_filter_instances[id].queue_free()
+				_filter_instances.erase(id)
+			
+			var instance = ColorRect.new()
+			instance.material = material
+			if material.get_meta(&"filter_native_resolution", false):
+				_native_filters_layer.add_child(instance)
+			else:
+				_viewport_container.add_child(instance)
+			_filter_instances[id] = instance
+			filters_enabled[id] = true
+	
 	_update_scale.call_deferred()
 	
 	var current_scene = get_tree().current_scene
@@ -69,3 +99,8 @@ func _update_scale() -> void:
 		ScaleMode.STRETCH:
 			# just use the ratio as-is
 			_viewport_container.scale = size_ratio
+	
+	# update screen filters state
+	for filter in filters_enabled:
+		_filter_instances[filter].visible = filters_enabled[filter]
+		_filter_instances[filter].custom_minimum_size = Vector2(size)