extends Node

# Autoload: drops Engine.max_fps while the window is unfocused, so an idle
# background window doesn't keep rendering at whatever uncapped rate the
# hardware can hit. Independent of — and complementary to — the per-menu
# refresh-rate cap in main_menu.gd/settings_menu.gd, which only covers menu
# screens; this covers every scene, including gameplay.

const BACKGROUND_FPS := 30

# 0 means "uncapped"; also what we restore to if focus is lost before any
# menu/gameplay scene has had a chance to set its own cap.
var _foreground_max_fps := 0


func _notification(what: int) -> void:
	match what:
		NOTIFICATION_APPLICATION_FOCUS_OUT:
			_foreground_max_fps = Engine.max_fps
			Engine.max_fps = BACKGROUND_FPS
		NOTIFICATION_APPLICATION_FOCUS_IN:
			Engine.max_fps = _foreground_max_fps