Add setting for Godots low processor usage mode (#1056)

* Add setting for Godots low processor usage mode

* Update name and description of low processor usage mode setting in preferences

* Fix a tiny mistake

src/Autoload/Global.gd

@@ -475,6 +475,10 @@ var fps_limit := 0:
 ## Found in Preferences. Affects the per_pixel_transparency project setting.
 ## If [code]true[/code], it allows for the window to be transparent.
 ## This affects performance, so keep it [code]false[/code] if you don't need it.
+var update_continuously := false:
+	set(value):
+		update_continuously = value
+		OS.low_processor_usage_mode = !value
 var window_transparency := false:
 	set(value):
 		if value == window_transparency:

src/Preferences/PreferencesDialog.gd

@@ -175,6 +175,12 @@ var preferences: Array[Preference] = [
 		"button_pressed",
 		true
 	),
+	Preference.new(
+		"update_continuously",
+		"Performance/PerformanceContainer/UpdateContinuously",
+		"button_pressed",
+		false
+	),
 	Preference.new(
 		"window_transparency",
 		"Performance/PerformanceContainer/WindowTransparency",

src/Preferences/PreferencesDialog.tscn

@@ -1058,6 +1058,19 @@ mouse_default_cursor_shape = 2
 button_pressed = true
 text = "On"
 
+[node name="UpdateContinuouslyLabel" type="Label" parent="HSplitContainer/VBoxContainer/ScrollContainer/RightSide/Performance/PerformanceContainer"]
+layout_mode = 2
+tooltip_text = "If this is toggled on, the application will redraw the screen continuously, even while it's not used. Turning this off helps lower CPU and GPU usage when idle."
+mouse_filter = 0
+text = "Update Continuously"
+
+[node name="UpdateContinuously" type="CheckBox" parent="HSplitContainer/VBoxContainer/ScrollContainer/RightSide/Performance/PerformanceContainer"]
+layout_mode = 2
+tooltip_text = "If this is toggled on, the application will redraw the screen continuously, even while it's not used. Turning this off helps lower CPU and GPU usage when idle."
+mouse_default_cursor_shape = 2
+button_pressed = true
+text = "On"
+
 [node name="WindowTransparencyLabel" type="Label" parent="HSplitContainer/VBoxContainer/ScrollContainer/RightSide/Performance/PerformanceContainer"]
 layout_mode = 2
 tooltip_text = "If enabled, the application window can become transparent. This affects performance, so keep it off if you don't need it."