Volume mixer settings with persistence to disk

default_bus_layout.tres

@@ -1,6 +1,7 @@
 [gd_resource type="AudioBusLayout" format=3 uid="uid://cwxndi28bii8d"]
 
 [resource]
+bus/0/volume_db = 0.0
 bus/1/name = &"SFX"
 bus/1/solo = false
 bus/1/mute = false

project.godot

@@ -61,6 +61,7 @@ config/controls/camera/y_axis_acceleration=30.0
 config/controls/camera/invert_pitch=false
 config/accessibility/enable_screen_shake=true
 config/accessibility/enable_hit_lag=true
+audio/buses/override_bus_layout="user://audio_bus_layout.tres"
 
 [global_group]
 

src/game/game_settings.gd

@@ -2,6 +2,7 @@ class_name GameSettingsType extends Node
 ## Container for project settings, for quick runtime access.
 
 var settings_file: String
+var audio_bus_file: String
 
 var free_camera_speed: float
 var x_sensitivity: float
@@ -15,10 +16,13 @@ var enable_hit_lag: bool
 
 func _init() -> void:
 	ProjectSettings.settings_changed.connect(_read_settings)
+	_read_settings()
+	_load_audio_bus_override()
 
 
 func _read_settings() -> void:
 	settings_file = ProjectSettings.get_setting("application/config/project_settings_override")
+	audio_bus_file = ProjectSettings.get_setting("game/audio/buses/override_bus_layout")
 
 	free_camera_speed = ProjectSettings.get_setting("game/config/controls/camera/free_camera_speed")
 	x_sensitivity = ProjectSettings.get_setting("game/config/controls/camera/x_axis_sensitivity")
@@ -31,3 +35,18 @@ func _read_settings() -> void:
 		"game/config/accessibility/enable_screen_shake"
 	)
 	enable_hit_lag = ProjectSettings.get_setting("game/config/accessibility/enable_hit_lag")
+
+
+func _load_audio_bus_override() -> void:
+	# Load override audio bus file
+	if FileAccess.file_exists(audio_bus_file):
+		print_debug("Loading audio bus override from ", audio_bus_file)
+		var bus_layout: AudioBusLayout = load(audio_bus_file)
+		AudioServer.set_bus_layout(bus_layout)
+
+
+func write() -> void:
+	print_debug("Writing settings to ", settings_file)
+	ProjectSettings.save_custom(settings_file)
+	print_debug("Writing audio bus levels to ", audio_bus_file)
+	ResourceSaver.save(AudioServer.generate_bus_layout(), audio_bus_file)

src/ui/main_theme.tres

@@ -56,6 +56,12 @@ CancelButton/colors/font_outline_color = Color(0, 0, 0, 1)
 CancelButton/constants/outline_size = 6
 CancelButton/font_sizes/font_size = 24
 CancelButton/fonts/font = ExtResource("2_5ty6u")
+ChannelMixerIcon/base_type = &"Label"
+ChannelMixerIcon/colors/font_color = Color(1, 1, 0.870588, 1)
+ChannelMixerIcon/colors/font_outline_color = Color(0, 0, 0, 1)
+ChannelMixerIcon/constants/outline_size = 5
+ChannelMixerIcon/font_sizes/font_size = 24
+ChannelMixerIcon/fonts/font = ExtResource("2_8kux8")
 CheckerContainerEven/base_type = &"PanelContainer"
 CheckerContainerEven/styles/panel = SubResource("StyleBoxFlat_rq1no")
 CheckerContainerOdd/base_type = &"PanelContainer"
@@ -75,10 +81,13 @@ ClubSelectLabelDisabled/colors/font_outline_color = Color(0.2, 0.2, 0.2, 1)
 ClubSelectLabelDisabled/colors/font_shadow_color = Color(0.2, 0.2, 0.2, 1)
 ClubSelectLabelDisabled/font_sizes/font_size = 84
 ClubSelectLabelDisabled/fonts/font = ExtResource("1_3rv2b")
+HeaderLarge/constants/outline_size = 8
 HeaderLarge/font_sizes/font_size = 28
+HeaderMedium/constants/outline_size = 6
 HeaderMedium/font_sizes/font_size = 24
 HeaderSmall/font_sizes/font_size = 20
 HeaderXLarge/base_type = &"Label"
+HeaderXLarge/constants/outline_size = 10
 HeaderXLarge/font_sizes/font_size = 36
 InputBindButton/base_type = &"UIButton"
 InputBindButton/colors/font_color = Color(1, 1, 0.870588, 1)

src/ui/menus/settings_menu/settings_menu.gd

@@ -2,11 +2,14 @@ extends MarginContainer
 ## Menu allowing the user to adjust game configuration.
 
 const SETTINGS_GROUP := "Settings"
+const VOLUME_GROUP := "VolumeSliders"
 
+@onready var bus_mixer_list: HBoxContainer = %BusMixerList
 @onready var control_binding_list: VBoxContainer = %ControlBindingList
 
 
 func _ready() -> void:
+	populate_volume_mixers()
 	populate_control_bindings()
 
 
@@ -16,12 +19,23 @@ func _get_settings_elements() -> Array[Setting]:
 	return elements
 
 
+func _get_volume_sliders() -> Array[VolumeSlider]:
+	var elements: Array[VolumeSlider] = []
+	elements.assign(get_tree().get_nodes_in_group(VOLUME_GROUP))
+	return elements
+
+
 func populate_control_bindings() -> void:
 	for action: StringName in InputMap.get_actions():
 		if not action.begins_with("ui_"):
 			control_binding_list.add_child(ControlBinding.create(action))
 
 
+func populate_volume_mixers() -> void:
+	for idx: int in range(AudioServer.bus_count):
+		bus_mixer_list.add_child(VolumeSlider.create(idx))
+
+
 ## Close menu without applying settings.
 func cancel() -> void:
 	queue_free()
@@ -31,12 +45,13 @@ func cancel() -> void:
 func apply() -> void:
 	for setting: Setting in _get_settings_elements():
 		setting.apply()
+	for mixer: VolumeSlider in _get_volume_sliders():
+		mixer.apply()
 
 
 ## Write all applied settings to disk.
 func save_settings() -> void:
-	print_debug("Writing settings to ", Game.settings.settings_file)
-	ProjectSettings.save_custom(Game.settings.settings_file)
+	Game.settings.write()
 	BindingLoader.write()
 
 

src/ui/menus/settings_menu/settings_menu.tscn

@@ -14,7 +14,7 @@ script = ExtResource("1_lbcn7")
 
 [node name="TabContainer" type="TabContainer" parent="."]
 layout_mode = 2
-current_tab = 3
+current_tab = 2
 
 [node name="Game" type="MarginContainer" parent="TabContainer"]
 visible = false
@@ -196,7 +196,6 @@ theme_type_variation = &"SettingsListMargin"
 layout_mode = 2
 
 [node name="Audio" type="MarginContainer" parent="TabContainer"]
-visible = false
 layout_mode = 2
 theme_type_variation = &"SettingsPageContainer"
 metadata/_tab_index = 2
@@ -229,10 +228,13 @@ size_flags_horizontal = 3
 size_flags_vertical = 3
 theme_type_variation = &"SettingsListMargin"
 
-[node name="SettingsList" type="VBoxContainer" parent="TabContainer/Audio/VBoxContainer/ScrollContainer/MarginContainer"]
+[node name="BusMixerList" type="HBoxContainer" parent="TabContainer/Audio/VBoxContainer/ScrollContainer/MarginContainer"]
+unique_name_in_owner = true
 layout_mode = 2
+theme_override_constants/separation = 16
 
 [node name="Controls" type="MarginContainer" parent="TabContainer"]
+visible = false
 layout_mode = 2
 theme_type_variation = &"SettingsPageContainer"
 metadata/_tab_index = 3

src/ui/menus/settings_menu/volume_slider/volume_slider.gd

@@ -0,0 +1,70 @@
+class_name VolumeSlider extends VBoxContainer
+## Input element for adjusting the volume of a single bus.
+
+const SCENE := preload("res://src/ui/menus/settings_menu/volume_slider/volume_slider.tscn")
+const VOLUME_FACTOR := 50.0
+
+@export var bus_idx: int
+
+var value: float:
+	get:
+		return slider.value
+	set(v):
+		slider.set_value_no_signal(v)
+		spin_box.set_value_no_signal(v)
+		_set_bus_volume(v)
+
+var _applied_value: float
+
+@onready var bus_name: Label = %BusName
+@onready var slider: VSlider = %Slider
+@onready var spin_box: SpinBox = %SpinBox
+@onready var audio_demo: AudioStreamPlayer = %AudioDemo
+
+
+func _ready() -> void:
+	bus_name.text = AudioServer.get_bus_name(bus_idx)
+	audio_demo.bus = bus_name.text
+	_applied_value = _db_to_volume(AudioServer.get_bus_volume_db(bus_idx))
+	value = _applied_value
+
+
+func _exit_tree() -> void:
+	# Revert volume to the value from the last time `apply` was called
+	_set_bus_volume(_applied_value)
+
+
+func _db_to_volume(db: float) -> float:
+	return db_to_linear(db) * VOLUME_FACTOR
+
+
+func _volume_to_db(volume: float) -> float:
+	return linear_to_db(volume / VOLUME_FACTOR)
+
+
+func _on_component_value_changed(new_value: float) -> void:
+	value = new_value
+
+
+func _set_bus_volume(new_value: float) -> void:
+	AudioServer.set_bus_volume_db(bus_idx, _volume_to_db(new_value))
+
+
+func apply() -> void:
+	# Prevent value from being reverted during destructor.
+	_applied_value = value
+
+
+func _on_slider_drag_ended(value_changed: bool) -> void:
+	if value_changed:
+		audio_demo.play()
+
+
+func _on_spin_box_value_changed(_new_value: float) -> void:
+	audio_demo.play()
+
+
+static func create(_bus_idx: int) -> VolumeSlider:
+	var instance: VolumeSlider = SCENE.instantiate()
+	instance.bus_idx = _bus_idx
+	return instance

src/ui/menus/settings_menu/volume_slider/volume_slider.tscn

@@ -0,0 +1,51 @@
+[gd_scene load_steps=3 format=3 uid="uid://d2ya6ly01724l"]
+
+[ext_resource type="Script" path="res://src/ui/menus/settings_menu/volume_slider/volume_slider.gd" id="1_rfe0k"]
+[ext_resource type="AudioStream" uid="uid://cllhgumv1fkju" path="res://assets/sound/sfx/player/drive1.wav" id="2_822gu"]
+
+[node name="VolumeSlider" type="VBoxContainer" groups=["VolumeSliders"]]
+custom_minimum_size = Vector2(300, 0)
+script = ExtResource("1_rfe0k")
+
+[node name="NameContainer" type="HBoxContainer" parent="."]
+layout_mode = 2
+alignment = 1
+
+[node name="Icon" type="Label" parent="NameContainer"]
+layout_mode = 2
+theme_type_variation = &"ChannelMixerIcon"
+text = "🎧"
+
+[node name="BusName" type="Label" parent="NameContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_vertical = 8
+theme_type_variation = &"HeaderMedium"
+text = "Channel"
+
+[node name="Slider" type="VSlider" parent="."]
+unique_name_in_owner = true
+layout_mode = 2
+size_flags_horizontal = 1
+size_flags_vertical = 3
+step = 0.1
+
+[node name="DigitalDisplay" type="HBoxContainer" parent="."]
+layout_mode = 2
+size_flags_horizontal = 4
+
+[node name="SpinBox" type="SpinBox" parent="DigitalDisplay"]
+unique_name_in_owner = true
+layout_mode = 2
+step = 0.1
+alignment = 2
+suffix = "%"
+
+[node name="AudioDemo" type="AudioStreamPlayer" parent="."]
+unique_name_in_owner = true
+stream = ExtResource("2_822gu")
+
+[connection signal="drag_ended" from="Slider" to="." method="_on_slider_drag_ended"]
+[connection signal="value_changed" from="Slider" to="." method="_on_component_value_changed"]
+[connection signal="value_changed" from="DigitalDisplay/SpinBox" to="." method="_on_component_value_changed"]
+[connection signal="value_changed" from="DigitalDisplay/SpinBox" to="." method="_on_spin_box_value_changed"]