Audio

Audio playback uses the Rodio library through the AudioProvider trait.

Providers

AudioSource Component

Attach AudioSource to an entity for audio playback.

Channels

Audio is routed through named channels with independent volume control:

Volume Control

Three levels of volume control, applied multiplicatively:

1. Master volume — global scaling for all audio
2. Channel volume — per-channel scaling (Music, SFX, etc.)
3. Instance volume — per-source scaling on individual playback instances

Spatial Audio

When spatial is enabled on an AudioSource:

• Set listener position with set_listener_position([x, y, z]) (or 2D helper variants)
• Source position is read from the entity’s transform
• Two attenuation models: InverseDistance and LinearDistance
• max_distance controls the cutoff range

Engine-level controls include explicit listener/source placement:

• goud_audio_set_listener_position_3d()
• goud_audio_set_source_position_3d()
• 2D convenience variants: goud_audio_set_listener_position() and goud_audio_set_source_position()

Crossfade And Mixing

Batch 2.5 added timed and immediate blend controls:

• goud_audio_crossfade(from, to, mix) for immediate two-player blend
• goud_audio_crossfade_to(from, asset, duration, channel) for timed transition to new content
• goud_audio_mix_with(primary, asset, secondary_volume, secondary_channel) for layered playback
• goud_audio_update_crossfades(delta_sec) to advance active timed transitions
• goud_audio_active_crossfade_count() to inspect active transitions

FFI

Audio FFI functions are in goud_engine/src/ffi/audio/. Key functions:

• goud_audio_play() / goud_audio_stop()
• goud_audio_pause() / goud_audio_resume()
• goud_audio_set_global_volume() / goud_audio_set_channel_volume()
• goud_audio_set_listener_position_3d() / goud_audio_set_source_position_3d()
• goud_audio_crossfade() / goud_audio_crossfade_to() / goud_audio_mix_with()
• goud_audio_update_crossfades() / goud_audio_active_crossfade_count()