audio-patterns

Audio Patterns

Audio Bus Architecture (Godot)

# AudioBusLayout setup - configure programmatically or in AudioBusLayout editor
# Bus hierarchy: Master -> Music, SFX, Voice, Ambient
# Each sub-bus routes to Master, apply effects on sub-buses

class_name AudioManager extends Node
# Bus names must match AudioBusLayout asset
const BUS_MASTER  := &"Master"
const BUS_MUSIC   := &"Music"
const BUS_SFX     := &"SFX"
const BUS_VOICE   := &"Voice"
const BUS_AMBIENT := &"Ambient"

func set_music_volume(db: float) -> void:
    var bus_idx := AudioServer.get_bus_index(BUS_MUSIC)
    AudioServer.set_bus_volume_db(bus_idx, db)

func duck_music(duck_db: float = -12.0, duration: float = 0.3) -> void:
    # Duck music when important SFX or voice plays
    var bus_idx := AudioServer.get_bus_index(BUS_MUSIC)
    var tween := create_tween()
    tween.tween_method(
        func(v: float): AudioServer.set_bus_volume_db(bus_idx, v),
        AudioServer.get_bus_volume_db(bus_idx),
        duck_db,
        duration
    )

func unduck_music(duration: float = 0.5) -> void:
    var bus_idx := AudioServer.get_bus_index(BUS_MUSIC)
    var tween := create_tween()
    tween.tween_method(
        func(v: float): AudioServer.set_bus_volume_db(bus_idx, v),
        AudioServer.get_bus_volume_db(bus_idx),
        0.0,
        duration
    )

Audio Pool Implementation

# Fixed-size audio pool prevents per-sound node allocation
class_name AudioPool extends Node
const POOL_SIZE := 16

var _players: Array[AudioStreamPlayer] = []
var _priorities: Array[float] = []

func _ready() -> void:
    for i in POOL_SIZE:
        var player := AudioStreamPlayer.new()
        player.bus = &"SFX"
        add_child(player)
        player.finished.connect(_on_player_finished.bind(i))
        _players.append(player)
        _priorities.append(0.0)

func play(stream: AudioStream, volume_db: float = 0.0, priority: float = 1.0) -> AudioStreamPlayer:
    # Find free player
    for i in POOL_SIZE:
        if not _players[i].playing:
            return _start_player(i, stream, volume_db, priority)

    # Pool exhausted: steal lowest priority
    var lowest_idx := 0
    for i in POOL_SIZE:
        if _priorities[i] < _priorities[lowest_idx]:
            lowest_idx = i
    return _start_player(lowest_idx, stream, volume_db, priority)

func _start_player(idx: int, stream: AudioStream, volume_db: float, priority: float) -> AudioStreamPlayer:
    _players[idx].stream = stream
    _players[idx].volume_db = volume_db
    _players[idx].play()
    _priorities[idx] = priority
    return _players[idx]

func _on_player_finished(idx: int) -> void:
    _priorities[idx] = 0.0

# 3D variant - takes world position for spatialized pool
class AudioPool3D extends Node:
    # Same pattern but uses AudioStreamPlayer3D with position assignment
    pass