Save the quiz settings to the config folder

The quiz card's settings are saved to quiz_settings.cfg in OS.get_config_dir()
on every change and loaded at start. Debug builds use their own file, and
MUSICPLAYER_CONFIG_DIR moves the file elsewhere so tests never touch it.

Count plays in statistics and Prefer less played soundtracks are not saved and
move from the quiz card to the Settings popup.

data/settings.gd

@@ -17,6 +17,17 @@ const SERVERS: Array[String] = [
 const DEBUG_SERVER: String = "http://localhost:8080"
 ## The winning score debug builds start with, so a game is quick to win while testing.
 const DEBUG_WINNING_SCORE: int = 5
+## The quiz settings that are saved to [method quiz_settings_path] and loaded at start.
+## Count plays in statistics and Prefer less played soundtracks are left out on purpose.
+const QUIZ_SETTINGS: Array[StringName] = [
+	&"auto_repeat_song", &"stop_after_current", &"hide_next_track", &"hide_beginning",
+	&"hide_for_seconds", &"hide_length", &"hide_ticks", &"winning_score",
+	&"inspiration_list_speed",
+]
+## When this environment variable is set, the settings file is kept in that folder instead
+## of the user's config folder. The tests set it so they never touch the real file.
+const CONFIG_DIR_ENV: String = "MUSICPLAYER_CONFIG_DIR"
+const QUIZ_SETTINGS_SECTION: String = "quiz"
 
 var default_path: String = "https://music.sanplex.xyz"
 ## Password for getting an API token from the server. Any password works when the
@@ -49,13 +60,52 @@ var version: String = ProjectSettings.get_setting("application/config/version",
 
 
 # Autoloads are ready before any scene, so debug builds use the local server and the
-# low winning score from the very first request
+# low winning score from the very first request. The saved quiz settings come after, so
+# the debug winning score is only used until another one is saved.
 func _ready() -> void:
 	if OS.has_feature("debug"):
 		is_debug = true
 		default_path = DEBUG_SERVER
 		selected_server = SERVERS.find(DEBUG_SERVER)
 		winning_score = DEBUG_WINNING_SCORE
+	load_quiz_settings()
+
+
+## Where the quiz settings are saved: a MusicPlayer folder in the user's config folder,
+## e.g. [code]~/.config[/code] on Linux and [code]%APPDATA%[/code] on Windows. Debug
+## builds use a file of their own, so testing never changes the real settings.
+func quiz_settings_path() -> String:
+	var config_dir: String = OS.get_environment(CONFIG_DIR_ENV)
+	if config_dir.is_empty():
+		config_dir = OS.get_config_dir().path_join("MusicPlayer")
+	var file_name: String = "quiz_settings_debug.cfg" if is_debug else "quiz_settings.cfg"
+	return config_dir.path_join(file_name)
+
+
+## Loads the saved quiz settings. Settings missing from the file, or saved with the
+## wrong type, keep their current value.
+func load_quiz_settings() -> void:
+	var file: ConfigFile = ConfigFile.new()
+	if file.load(quiz_settings_path()) != OK:
+		return
+	for setting: StringName in QUIZ_SETTINGS:
+		var current: Variant = get(setting)
+		var saved: Variant = file.get_value(QUIZ_SETTINGS_SECTION, setting, current)
+		if typeof(saved) == typeof(current):
+			set(setting, saved)
+
+
+## Saves the quiz settings, so they are the same the next time the game starts.
+func save_quiz_settings() -> void:
+	var path: String = quiz_settings_path()
+	DirAccess.make_dir_recursive_absolute(path.get_base_dir())
+	var file: ConfigFile = ConfigFile.new()
+	for setting: StringName in QUIZ_SETTINGS:
+		file.set_value(QUIZ_SETTINGS_SECTION, setting, get(setting))
+	var error: Error = file.save(path)
+	if error != OK:
+		GameLog.warning("Could not save the quiz settings to %s: %s"
+				% [path, error_string(error)])
 
 
 func delete_children(node: Node) -> void:

main/MainWindow.tscn

@@ -98,9 +98,9 @@ unique_name_in_owner = true
 visible = false
 layout_mode = 1
 offset_left = 700.0
-offset_top = 454.0
+offset_top = 419.0
 offset_right = 700.0
-offset_bottom = 454.0
+offset_bottom = 419.0
 
 [node name="SoundtrackStatsPopup" parent="." unique_id=1213999001 instance=ExtResource("soundtrack_stats_popup_scene")]
 visible = false

popups/SettingsPopup.tscn

@@ -16,7 +16,7 @@ panel = NodePath("SettingsPanel")
 unique_name_in_owner = true
 layout_mode = 0
 offset_right = 520.0
-offset_bottom = 172.0
+offset_bottom = 242.0
 theme_type_variation = &"PopupBackground"
 
 [node name="VBoxContainer" type="VBoxContainer" parent="SettingsPanel" unique_id=1796635163]
@@ -25,7 +25,7 @@ layout_mode = 0
 offset_left = 20.0
 offset_top = 12.0
 offset_right = 500.0
-offset_bottom = 160.0
+offset_bottom = 230.0
 
 [node name="Label" type="Label" parent="SettingsPanel/VBoxContainer" unique_id=1111531402]
 layout_mode = 2
@@ -85,6 +85,20 @@ focus_mode = 0
 action_mode = 0
 text = "+1"
 
+[node name="LowPlayedCheckButton" type="CheckButton" parent="SettingsPanel/VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+focus_mode = 0
+action_mode = 0
+text = "Prefer less played soundtracks"
+
+[node name="AddToDatabaseCheckButton" type="CheckButton" parent="SettingsPanel/VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+focus_mode = 0
+action_mode = 0
+text = "Count plays in statistics"
+
 [node name="LocalButton" type="CheckButton" parent="SettingsPanel/VBoxContainer" unique_id=905844805]
 unique_name_in_owner = true
 visible = false

popups/settings_popup.gd

@@ -1,7 +1,8 @@
 class_name SettingsPopup
 extends BasePopup
-## The application settings: which MusicServer to use, fullscreen and how many songs to
-## download ahead. Opened from the Settings button in the top bar.
+## The application settings: which MusicServer to use, fullscreen, how many songs to
+## download ahead, whether to prefer less played soundtracks and whether plays count in
+## the statistics. Opened from the Settings button in the top bar.
 ##
 ## The quiz settings, such as the winning score, are in [QuizSettingsCard].
 
@@ -14,6 +15,8 @@ signal server_changed
 @onready var cache_label: Label = %CacheLabel
 @onready var lower_cache_button: Button = %LowerCacheButton
 @onready var increase_cache_button: Button = %IncreaseCacheButton
+@onready var low_played_button: CheckButton = %LowPlayedCheckButton
+@onready var add_to_database_button: CheckButton = %AddToDatabaseCheckButton
 @onready var local_button: CheckButton = %LocalButton
 
 
@@ -29,6 +32,9 @@ func _ready() -> void:
 	lower_cache_button.pressed.connect(lower_cache)
 	increase_cache_button.pressed.connect(increase_cache)
 	select_server_button.item_selected.connect(select_server)
+	low_played_button.toggled.connect(
+			func(on: bool) -> void: Settings.use_low_played_mode = on)
+	add_to_database_button.toggled.connect(func(on: bool) -> void: Settings.add_to_stats = on)
 	visibility_changed.connect(_on_visibility_changed)
 	# Alt+Enter switches fullscreen from the main window, which resizes the window
 	get_window().size_changed.connect(_update_fullscreen_button)
@@ -75,9 +81,12 @@ func _use_server(new_server: int) -> void:
 	server_changed.emit()
 
 
+# Winning a game turns statistics off, so the toggles are refreshed every time this opens
 func _on_visibility_changed() -> void:
 	if visible:
 		_update_fullscreen_button()
+		low_played_button.set_pressed_no_signal(Settings.use_low_played_mode)
+		add_to_database_button.set_pressed_no_signal(Settings.add_to_stats)
 
 
 func _update_fullscreen_button() -> void:

quiz/QuizSettingsCard.tscn

@@ -104,20 +104,6 @@ focus_mode = 0
 action_mode = 0
 text = "Hide ticks in the playbar"
 
-[node name="LowPlayedCheckButton" type="CheckButton" parent="CardPanel/VBox"]
-unique_name_in_owner = true
-layout_mode = 2
-focus_mode = 0
-action_mode = 0
-text = "Prefer less played soundtracks"
-
-[node name="AddToDatabaseCheckButton" type="CheckButton" parent="CardPanel/VBox"]
-unique_name_in_owner = true
-layout_mode = 2
-focus_mode = 0
-action_mode = 0
-text = "Count plays in statistics"
-
 [node name="WinningScoreRow" type="HBoxContainer" parent="CardPanel/VBox"]
 layout_mode = 2
 

quiz/quiz_settings_card.gd

@@ -1,8 +1,10 @@
 class_name QuizSettingsCard
 extends BasePopup
 ## The quiz settings, in a small card that opens above the Quiz settings button by the
-## music player: how songs are played and hidden, statistics, the winning score and the
-## inspiration list. It does not dim the quiz, so it can be changed during a song.
+## music player: how songs are played and hidden, the winning score and the inspiration
+## list. It does not dim the quiz, so it can be changed during a song.
+##
+## Every change is saved at once with [method Settings.save_quiz_settings].
 ##
 ## The card's bottom edge is where the card is placed, just above the player bar, and
 ## it grows upward to fit its rows.
@@ -26,8 +28,6 @@ const PADDING: Vector2 = Vector2(16, 12)
 @onready var increase_hide_for_seconds_button: Button = %IncreaseHideForSecondsButton
 @onready var hide_length_button: CheckButton = %HideLengthCheckButton
 @onready var hide_ticks_button: CheckButton = %HideTicksCheckButton
-@onready var low_played_button: CheckButton = %LowPlayedCheckButton
-@onready var add_to_database_button: CheckButton = %AddToDatabaseCheckButton
 @onready var score_label: Label = %ScoreLabel
 @onready var lower_winning_score_button: Button = %LowerButton
 @onready var increase_winning_score_button: Button = %IncreaseButton
@@ -37,17 +37,12 @@ const PADDING: Vector2 = Vector2(16, 12)
 
 
 func _ready() -> void:
-	auto_repeat_button.toggled.connect(func(on: bool) -> void: Settings.auto_repeat_song = on)
-	stop_after_current_button.toggled.connect(
-			func(on: bool) -> void: Settings.stop_after_current = on)
-	hide_next_track_button.toggled.connect(
-			func(on: bool) -> void: Settings.hide_next_track = on)
+	auto_repeat_button.toggled.connect(_save_toggle.bind(&"auto_repeat_song"))
+	stop_after_current_button.toggled.connect(_save_toggle.bind(&"stop_after_current"))
+	hide_next_track_button.toggled.connect(_save_toggle.bind(&"hide_next_track"))
 	hide_beginning_button.toggled.connect(_on_hide_beginning_toggled)
-	hide_length_button.toggled.connect(func(on: bool) -> void: Settings.hide_length = on)
-	hide_ticks_button.toggled.connect(func(on: bool) -> void: Settings.hide_ticks = on)
-	low_played_button.toggled.connect(
-			func(on: bool) -> void: Settings.use_low_played_mode = on)
-	add_to_database_button.toggled.connect(func(on: bool) -> void: Settings.add_to_stats = on)
+	hide_length_button.toggled.connect(_save_toggle.bind(&"hide_length"))
+	hide_ticks_button.toggled.connect(_save_toggle.bind(&"hide_ticks"))
 	lower_winning_score_button.pressed.connect(lower_winning_score)
 	increase_winning_score_button.pressed.connect(increase_winning_score)
 	lower_inspiration_speed_button.pressed.connect(lower_inspiration_speed)
@@ -58,8 +53,8 @@ func _ready() -> void:
 	show_settings()
 
 
-## Shows the current settings. Some change outside this card, e.g. winning turns
-## statistics off, so this runs every time the card opens.
+## Shows the current settings. This runs every time the card opens, in case a setting
+## was changed somewhere else.
 func show_settings() -> void:
 	auto_repeat_button.set_pressed_no_signal(Settings.auto_repeat_song)
 	stop_after_current_button.set_pressed_no_signal(Settings.stop_after_current)
@@ -67,8 +62,6 @@ func show_settings() -> void:
 	hide_beginning_button.set_pressed_no_signal(Settings.hide_beginning)
 	hide_length_button.set_pressed_no_signal(Settings.hide_length)
 	hide_ticks_button.set_pressed_no_signal(Settings.hide_ticks)
-	low_played_button.set_pressed_no_signal(Settings.use_low_played_mode)
-	add_to_database_button.set_pressed_no_signal(Settings.add_to_stats)
 	hide_for_seconds_row.visible = Settings.hide_beginning
 	hide_for_seconds_label.text = "%d" % Settings.hide_for_seconds
 	score_label.text = str(Settings.winning_score)
@@ -88,30 +81,41 @@ func increase_winning_score() -> void:
 func set_winning_score(new_score: int) -> void:
 	Settings.winning_score = maxi(new_score, 1)
 	score_label.text = str(Settings.winning_score)
+	Settings.save_quiz_settings()
 
 
 func lower_inspiration_speed() -> void:
 	Settings.inspiration_list_speed = maxi(Settings.inspiration_list_speed - 1, 1)
 	inspiration_speed_label.text = str(Settings.inspiration_list_speed)
+	Settings.save_quiz_settings()
 
 
 func increase_inspiration_speed() -> void:
 	Settings.inspiration_list_speed += 1
 	inspiration_speed_label.text = str(Settings.inspiration_list_speed)
+	Settings.save_quiz_settings()
 
 
 func lower_hide_for_seconds() -> void:
 	Settings.hide_for_seconds = maxf(Settings.hide_for_seconds - 1.0, 0.0)
 	hide_for_seconds_label.text = "%d" % Settings.hide_for_seconds
+	Settings.save_quiz_settings()
 
 
 func increase_hide_for_seconds() -> void:
 	Settings.hide_for_seconds = minf(Settings.hide_for_seconds + 1.0, MAX_HIDE_SECONDS)
 	hide_for_seconds_label.text = "%d" % Settings.hide_for_seconds
+	Settings.save_quiz_settings()
+
+
+# Sets the on/off quiz setting named [param setting] and saves the quiz settings
+func _save_toggle(on: bool, setting: StringName) -> void:
+	Settings.set(setting, on)
+	Settings.save_quiz_settings()
 
 
 func _on_hide_beginning_toggled(on: bool) -> void:
-	Settings.hide_beginning = on
+	_save_toggle(on, &"hide_beginning")
 	hide_for_seconds_row.visible = on
 	_fit_to_rows()
 

run_tests.sh

@@ -32,6 +32,11 @@ find_godot() {
 
 godot_bin="$(find_godot)"
 
+# Keeps the tests away from the real quiz settings file, see Settings.CONFIG_DIR_ENV
+MUSICPLAYER_CONFIG_DIR="$(mktemp -d)"
+export MUSICPLAYER_CONFIG_DIR
+trap 'rm -rf "$MUSICPLAYER_CONFIG_DIR"' EXIT
+
 paths=("$@")
 if [[ ${#paths[@]} -eq 0 ]]; then
     paths=(res://tests/unit res://tests/integration)

tests/integration/test_quiz_settings_card.gd

@@ -69,8 +69,6 @@ func test_each_toggle_changes_its_setting() -> void:
 		"hide_beginning_button": "hide_beginning",
 		"hide_length_button": "hide_length",
 		"hide_ticks_button": "hide_ticks",
-		"low_played_button": "use_low_played_mode",
-		"add_to_database_button": "add_to_stats",
 	}
 	await _open()
 	for button_name: String in toggles:
@@ -89,12 +87,12 @@ func test_each_toggle_changes_its_setting() -> void:
 func test_card_shows_settings_changed_elsewhere() -> void:
 	await _open()
 	_card.close()
-	Settings.add_to_stats = false
+	Settings.hide_next_track = false
 	Settings.auto_repeat_song = false
 
 	await _open()
 
-	assert_bool(_card.add_to_database_button.button_pressed).is_false()
+	assert_bool(_card.hide_next_track_button.button_pressed).is_false()
 	assert_bool(_card.auto_repeat_button.button_pressed).is_false()
 
 
@@ -158,3 +156,24 @@ func test_card_grows_upward_for_the_seconds_row() -> void:
 	assert_float(open_row.size.y).is_greater(closed_row.size.y)
 	# Every row stays inside the card
 	assert_bool(open_row.encloses(_card.rows.get_global_rect())).is_true()
+
+
+func test_statistics_settings_are_in_the_settings_popup_instead() -> void:
+	await _open()
+
+	assert_object(_card.find_child("LowPlayedCheckButton")).is_null()
+	assert_object(_card.find_child("AddToDatabaseCheckButton")).is_null()
+
+
+func test_changes_are_saved_at_once() -> void:
+	Settings.hide_next_track = true
+	Settings.winning_score = 20
+	await _open()
+
+	await _click_at(_card.hide_next_track_button.get_global_rect().get_center())
+	_card.lower_winning_score_button.pressed.emit()
+
+	var saved: ConfigFile = ConfigFile.new()
+	assert_int(saved.load(Settings.quiz_settings_path())).is_equal(OK)
+	assert_bool(saved.get_value("quiz", "hide_next_track")).is_false()
+	assert_int(saved.get_value("quiz", "winning_score")).is_equal(19)

tests/integration/test_settings_popup.gd

@@ -0,0 +1,55 @@
+extends MainWindowTestSuite
+## The statistics settings in the application Settings popup.
+
+var _popup: SettingsPopup
+
+
+func before_test() -> void:
+	super()
+	_popup = _window.get_node("SettingsPopup")
+
+
+func test_less_played_toggle_changes_the_setting() -> void:
+	Settings.use_low_played_mode = false
+	_popup.open()
+	await _runner.simulate_frames(1)
+	assert_bool(_popup.low_played_button.button_pressed).is_false()
+
+	await _click_at(_popup.low_played_button.get_global_rect().get_center())
+
+	assert_bool(Settings.use_low_played_mode).is_true()
+
+
+func test_statistics_toggle_changes_the_setting() -> void:
+	Settings.add_to_stats = true
+	_popup.open()
+	await _runner.simulate_frames(1)
+	assert_bool(_popup.add_to_database_button.button_pressed).is_true()
+
+	await _click_at(_popup.add_to_database_button.get_global_rect().get_center())
+
+	assert_bool(Settings.add_to_stats).is_false()
+
+
+func test_statistics_settings_are_not_saved_with_the_quiz_settings() -> void:
+	Settings.add_to_stats = false
+	Settings.use_low_played_mode = true
+
+	Settings.save_quiz_settings()
+
+	var saved: ConfigFile = ConfigFile.new()
+	assert_int(saved.load(Settings.quiz_settings_path())).is_equal(OK)
+	assert_bool(saved.has_section_key("quiz", "add_to_stats")).is_false()
+	assert_bool(saved.has_section_key("quiz", "use_low_played_mode")).is_false()
+
+
+func test_popup_fits_its_rows_and_is_centred() -> void:
+	_popup.open()
+	await _runner.simulate_frames(1)
+
+	var panel: Rect2 = _popup.settings_panel.get_global_rect()
+	var rows: Control = _popup.settings_panel.get_node("VBoxContainer")
+	assert_bool(panel.encloses(rows.get_global_rect())).is_true()
+	# The rows' own height fits, so the last toggle is not squeezed or cut off
+	assert_float(rows.get_combined_minimum_size().y).is_less_equal(rows.size.y)
+	assert_vector(panel.get_center()).is_equal(Vector2(960, 540))

tests/integration/test_settings_popup.gd.uid

@@ -0,0 +1 @@
+uid://cp3f85h44jh3x

tests/integration/test_stats_after_win.gd

@@ -12,7 +12,7 @@ func before_test() -> void:
 
 
 func _stats_checkbox() -> CheckButton:
-	return _quiz.get_node("QuizSettingsCard").get_node("%AddToDatabaseCheckButton")
+	return _window.get_node("SettingsPopup").get_node("%AddToDatabaseCheckButton")
 
 
 func test_winning_turns_statistics_off() -> void:
@@ -41,7 +41,7 @@ func test_statistics_turned_off_by_hand_stay_off_after_reset() -> void:
 func test_settings_checkbox_shows_statistics_off_after_win() -> void:
 	await _give_point_with_keybind(1)
 
-	_press("QuizSettingsButton")
+	(_window.get_node("SettingsPopup") as SettingsPopup).open()
 
 	assert_bool(_stats_checkbox().button_pressed).is_false()
 

tests/unit/test_quiz_settings_file.gd

@@ -0,0 +1,97 @@
+extends GdUnitTestSuite
+## Saving the quiz settings to a file in the config folder and loading them back.
+
+const SAVED_VALUES: Dictionary = {
+	&"auto_repeat_song": false, &"stop_after_current": false, &"hide_next_track": false,
+	&"hide_beginning": true, &"hide_for_seconds": 7.0, &"hide_length": true,
+	&"hide_ticks": true, &"winning_score": 13, &"inspiration_list_speed": 4,
+}
+
+var _snapshot: AutoloadSnapshot
+var _config_dir_before: String
+var _config_dir: String
+
+
+func before_test() -> void:
+	_snapshot = AutoloadSnapshot.take([Settings])
+	_config_dir_before = OS.get_environment(Settings.CONFIG_DIR_ENV)
+	_config_dir = create_temp_dir("quiz_settings_file")
+	OS.set_environment(Settings.CONFIG_DIR_ENV, _config_dir)
+	DirAccess.remove_absolute(Settings.quiz_settings_path())
+
+
+func after_test() -> void:
+	OS.set_environment(Settings.CONFIG_DIR_ENV, _config_dir_before)
+	_snapshot.restore()
+
+
+func _set_settings(values: Dictionary) -> void:
+	for setting: StringName in values:
+		Settings.set(setting, values[setting])
+
+
+func test_saved_settings_load_back() -> void:
+	_set_settings(SAVED_VALUES)
+	Settings.save_quiz_settings()
+	_snapshot.restore()
+
+	Settings.load_quiz_settings()
+
+	for setting: StringName in SAVED_VALUES:
+		assert_that(Settings.get(setting)).override_failure_message(setting) \
+				.is_equal(SAVED_VALUES[setting])
+
+
+func test_every_quiz_setting_is_saved() -> void:
+	assert_array(Settings.QUIZ_SETTINGS).contains_exactly_in_any_order(SAVED_VALUES.keys())
+
+
+func test_missing_file_keeps_the_current_settings() -> void:
+	Settings.winning_score = 9
+
+	Settings.load_quiz_settings()
+
+	assert_int(Settings.winning_score).is_equal(9)
+
+
+func test_value_of_the_wrong_type_is_ignored() -> void:
+	var file: ConfigFile = ConfigFile.new()
+	file.set_value("quiz", "winning_score", "lots")
+	file.set_value("quiz", "hide_ticks", true)
+	DirAccess.make_dir_recursive_absolute(Settings.quiz_settings_path().get_base_dir())
+	file.save(Settings.quiz_settings_path())
+	Settings.winning_score = 9
+	Settings.hide_ticks = false
+
+	Settings.load_quiz_settings()
+
+	assert_int(Settings.winning_score).is_equal(9)
+	assert_bool(Settings.hide_ticks).is_true()
+
+
+func test_statistics_settings_are_not_saved() -> void:
+	Settings.save_quiz_settings()
+
+	var file: ConfigFile = ConfigFile.new()
+	file.load(Settings.quiz_settings_path())
+	assert_bool(file.has_section_key("quiz", "add_to_stats")).is_false()
+	assert_bool(file.has_section_key("quiz", "use_low_played_mode")).is_false()
+
+
+func test_file_is_in_the_folder_from_the_environment() -> void:
+	assert_str(Settings.quiz_settings_path().get_base_dir()).is_equal(_config_dir)
+
+
+func test_file_is_in_the_config_folder_without_the_environment() -> void:
+	OS.unset_environment(Settings.CONFIG_DIR_ENV)
+
+	assert_str(Settings.quiz_settings_path().get_base_dir()) \
+			.is_equal(OS.get_config_dir().path_join("MusicPlayer"))
+
+
+func test_debug_builds_use_a_file_of_their_own() -> void:
+	Settings.is_debug = true
+	var debug_path: String = Settings.quiz_settings_path()
+	Settings.is_debug = false
+
+	assert_str(debug_path).is_not_equal(Settings.quiz_settings_path())

tests/unit/test_quiz_settings_file.gd.uid

@@ -0,0 +1 @@
+uid://5qjw3px3wve6

tools/take_screenshots.gd

@@ -2,7 +2,10 @@ extends SceneTree
 ## Takes a screenshot of the main window in every UiTour state, against a fake server.
 ##
 ## Usage:
-##   godot --path . -s tools/take_screenshots.gd -- <output dir>
+##   MUSICPLAYER_CONFIG_DIR=$(mktemp -d) godot --path . -s tools/take_screenshots.gd -- <dir>
+##
+## Setting [code]MUSICPLAYER_CONFIG_DIR[/code] keeps your saved quiz settings out of the
+## pictures.
 ##
 ## Writes [code]<state>.png[/code] for each state and [code]layout.json[/code] with where
 ## every node is in each state. With [code]--headless[/code] only the layout is written.