yg.audio

Functions for audio playback.

Example

function init()
    -- Initialize the audio module with:
    --   5 sources
    --   Default number of channels
    --   Default sample rate
    yg.audio.init(5, 0, 0)
    -- Store a file to play it back
    yg.audio.storeFile("a//noise.ogg")
    -- Play the file looped endless and get the source id
    noiseSource = yg.audio.play("a//noise.ogg", true)
end

function tick()
    -- Manipulate the channel gains to simulate a moving object
    -- (assuming 2 channels)
    gains = {1.0, 0.3}
    yg.audio.setChannelGains(noiseSource, gains)
end

function yg.audio.init()

Enables the audio module.

yg.audio.init(numSources, numChannels, sampleRate) -> number (0 if successful)

Argument	Type	Info
numSources	number	Maximum number of audio sources to be mixed during playback [integer]
numChannels	number	Number of audio playback channels [integer]. set 0 for device default.
sampleRate	number	Sample rate. Set 0 for device default.

function yg.audio.shutdown()

Shuts down the audio module.

yg.audio.shutdown() -> void

function yg.audio.isInitialized()

Returns true if the audio module is initialized, false otherwise.

yg.audio.isInitialized() -> boolean

function yg.audio.storeFile()

Loads a sound file (.ogg) and stores it for being played back.

yg.audio.storeFile(filename) -> number (0 if successful)

Argument	Type	Info
filename	string	Name of the ogg file to load

function yg.audio.play()

Starts the playback of a previously stored audio file, if a free source slot is available. In this case, the index of the source is returned [0,numSources-1]. On error, a negative value is returned. The source index can be used to manipulate the playback once it has started (see yg.audio.stop(), yg.audio.pause(), etc.).

yg.audio.play(filename, loop) -> number (Audio source index, or < 0 on error)

Argument	Type	Info
filename	string	Name of the ogg file to play
loop	boolean	If true, playback loops endless. Plays once otherwise.

function yg.audio.stop()

Stops the playback of a source and clears the slot.

yg.audio.stop(sourceId) -> number (0 if successful)

Argument	Type	Info
sourceId	number	Index of the source, retrieved from yg.audio.play()

function yg.audio.pause()

Pauses the playback of a source.

yg.audio.pause(sourceId, pause) -> number (0 if successful)

Argument	Type	Info
sourceId	number	Index of the source, retrieved from yg.audio.play()
pause	boolean	If true, playback is paused. Options: true, false

function yg.audio.setChannelGains()

Sets the channel gains of a source: array of numbers, typically in [0,1] to reduce gain on individual channels. The audio signal of each channel gets multiplied by the appropriate gain value.

yg.audio.setChannelGains(sourceId, gains) -> number (0 if successful)

Argument	Type	Info
sourceId	number	Index of the source, retrieved from yg.audio.play()
gains	{number}	Gain values in [0,1] for each channel (array of number)