add ai, photo_mode and radio

core/audio/audio_manager.gd

@@ -0,0 +1,31 @@
+extends Node
+
+const MIN_VOLUME: float = 0.0
+const MAX_VOLUME: float = 1.0
+
+func _ready() -> void:
+	load_save_data()
+
+func load_save_data() -> void:
+	for bus_name in GameState.save_data.audio_bus_volumes:
+		_apply_audio_bus_volume(bus_name, GameState.save_data.audio_bus_volumes[bus_name])
+
+func set_audio_bus_volume(bus_name: StringName, linear_value: float) -> void:
+	var normalized_bus_name := str(bus_name)
+	var clamped_value := clampf(linear_value, MIN_VOLUME, MAX_VOLUME)
+
+	GameState.save_data.audio_bus_volumes[normalized_bus_name] = clamped_value
+	_apply_audio_bus_volume(normalized_bus_name, clamped_value)
+	GameState.save_game()
+
+func get_audio_bus_volume(bus_name: StringName, default_value: float = 1.0) -> float:
+	return float(GameState.save_data.audio_bus_volumes.get(str(bus_name), default_value))
+
+func _apply_audio_bus_volume(bus_name: String, linear_value: float) -> void:
+	var bus_index := AudioServer.get_bus_index(bus_name)
+	if bus_index == -1:
+		return
+
+	var clamped_value := clampf(linear_value, MIN_VOLUME, MAX_VOLUME)
+	AudioServer.set_bus_volume_db(bus_index, linear_to_db(clamped_value))
+	AudioServer.set_bus_mute(bus_index, is_zero_approx(clamped_value))