Audio

jEngine uses kira for native audio and the Web Audio API in the editor and web builds.

Preload every clip

A clip plays only if the scene lists it in its top-level "audio_refs" array. clip_id is the path under assets/:

{ "audio_refs": ["sounds/jump.ogg", "music/theme.ogg"], "entities": [] }

Sound Effects

-- Play a one-shot sound
local h = Audio.play_sound("sounds/jump.ogg")

-- With volume and pitch
local h2 = Audio.play_sound("sounds/coin.ogg", 0.5, 1.2)

-- Stop a specific sound
Audio.stop_sound(h)

-- Adjust volume of playing sound
Audio.set_sound_volume(h2, 0.3)

Background Music

-- Play music (loops by default)
Audio.play_music("music/theme.ogg", 0.8, true)

-- Control playback
Audio.pause_music()
Audio.resume_music()
Audio.stop_music()

-- Adjust volume
Audio.set_music_volume(0.5)

Master Volume

Audio.set_master_volume(0.8)  -- affects all audio

Timing to the music

Audio.get_music_position() is the music’s own playhead in seconds. It is coarse - the device reports in buffer steps, a frame late - so run a clock on dt and ease it toward each reading, rather than adding up dt alone.

Mixer buses and effects

Sounds play on buses that nest under master; each has a volume, mute and solo, a low-pass filter and a reverb:

Audio.create_bus("sfx", "master", 1.0)
Audio.set_bus_volume("sfx", 0.7)
Audio.set_bus_effect("master", "lowpass", 400)  -- muffle everything (0 turns it off)
Audio.set_bus_effect("sfx", "reverb", 0.6)      -- how much reverb is mixed in, 0..1
Audio.set_bus_effect("sfx", "room", 0.9)        -- a closet (0) to a cathedral (1)

An audio_zone applies those effects while the listener is inside a box, fading in over fade units:

"audio_zone": { "size": [420, 260], "bus": "sfx", "reverb": 0.75, "room": 0.95, "fade": 90 }

Spatial sound

A sound can be heard from where it is: set spatial on an audio_source (with min_distance and max_distance), or play a one-shot at a point with Audio.play_sound_at(clip_id, x, y, volume, pitch). The listener is the entity with an audio_listener, or the camera.

AudioSource Component

Attach audio directly to entities via the audio_source component:

{
  "audio_source": {
    "clip_id": "sounds/ambient.ogg",
    "volume": 1.0,
    "pitch": 1.0,
    "looping": true,
    "auto_play": true
  }
}

Supported Formats

• .ogg (Vorbis) — recommended for music
• .wav — recommended for short SFX
• .mp3 — supported but larger files