extends Node
## Small synthesized arcade effects; no external audio assets required.
var voices: Array[AudioStreamPlayer] = []
var sounds: Dictionary = {}
var voice_index := 0
func _ready() -> void:
	for i in range(6):
		var voice := AudioStreamPlayer.new()
		voice.volume_db = -17.0
		add_child(voice)
		voices.append(voice)
	sounds["fire"] = tone(1300.0, 220.0, 0.09)
	sounds["hit"] = tone(170.0, 40.0, 0.18)
	sounds["zap"] = tone(1700.0, 70.0, 0.55)
	sounds["death"] = tone(440.0, 35.0, 0.7)
	sounds["level"] = tone(220.0, 880.0, 0.4)
func tone(start: float, finish: float, duration: float) -> AudioStreamWAV:
	var samples := PackedByteArray()
	var count := int(22050 * duration)
	samples.resize(count * 2)
	var phase := 0.0
	for i in range(count):
		var t := float(i) / count
		phase += lerpf(start, finish, t) * TAU / 22050.0
		var envelope := minf(t * 50.0, 1.0) * pow(1.0 - t, 1.5)
		var value := int((sin(phase) + sin(phase * 2.0) * 0.25) * envelope * 18000)
		samples.encode_s16(i * 2, value)
	var stream := AudioStreamWAV.new()
	stream.format = AudioStreamWAV.FORMAT_16_BITS
	stream.mix_rate = 22050
	stream.data = samples
	return stream
func play(effect: String) -> void:
	if not sounds.has(effect) or voices.is_empty():
		return
	var voice := voices[voice_index]
	voice_index = (voice_index + 1) % voices.size()
	voice.stream = sounds[effect]
	voice.play()
func stop() -> void:
	for voice in voices:
		voice.stop()