# channels.ludic - a volume per kind of sound, under the master: what the player does, the
# animals, the ambience (its loop is the runtime's music channel) and the interface
export const AUD_CH_EFFECTS: int = 0
export const AUD_CH_WILDLIFE: int = 1
export const AUD_CH_AMBIENT: int = 2
export const AUD_CH_UI: int = 3
export const AUD_CH_N: int = 4

export function aud_channel(audio_st: AudioState, ch: int) -> float {
  if ch < 0 or ch >= AUD_CH_N { return 1.0 }
  return audio_st.ch_gain[ch]
}

export function aud_channel_set(audio_st: mut AudioState, ch: int, v: float) -> void {
  if ch < 0 or ch >= AUD_CH_N { return }
  let g = Math.clamp(v, 0.0, 1.0)
  audio_st.ch_gain[ch] = g
  if ch == AUD_CH_AMBIENT { Audio.music_volume(fixed(g)) }
}

# a sound in the world on a channel: its gain from where it is, scaled by the channel's
export function aud_emit_on(audio_st: mut AudioState, ch: int, h: int, gain: float, pitch: float, pan: float) -> void {
  aud_emit(audio_st, h, gain * aud_channel(audio_st, ch), pitch, pan)
}