// Called when the number of buffered 'AudioData' objects increases by 1
func (audio *SDLAudio) bufferAdd() {
audio.mutex.Lock()
{
audio.bufSize++
// Unpause SDL audio if we have BUFSIZE_IDEAL 'AudioData' objects
if !audio.sdlAudioUnpaused && (audio.bufSize == BUFSIZE_IDEAL) {
sdl_audio.PauseAudio(false)
audio.sdlAudioUnpaused = true
}
}
audio.mutex.Unlock()
}
func NewAudio() *Audio {
as = sdl_audio.AudioSpec{
Freq: 44100,
Format: sdl_audio.AUDIO_S16SYS,
Channels: 1,
Out_Silence: 0,
Samples: uint16(SampleSize),
Out_Size: 0,
}
if sdl_audio.OpenAudio(&as, nil) < 0 {
log.Fatal(sdl.GetError())
}
sdl_audio.PauseAudio(false)
return &Audio{
samples: make([]int16, SampleSize),
}
}
func (a *Audio) Run() {
as := sdl_audio.AudioSpec{
Freq: 44100,
Format: sdl_audio.AUDIO_S16SYS,
Channels: 1,
Out_Silence: 0,
Samples: uint16(SampleSize),
Out_Size: 0,
}
if sdl_audio.OpenAudio(&as, nil) < 0 {
log.Fatal(sdl.GetError())
}
sdl_audio.PauseAudio(false)
for {
select {
case s := <-a.sample:
a.AppendSample(s)
}
}
}
func NewAudio(frequency int, sampleSize int) (audio *SDLAudio, err error) {
spec := sdl_audio.AudioSpec{
Freq: frequency,
Format: sdl_audio.AUDIO_S16SYS,
Channels: 1,
Out_Silence: 0,
Samples: uint16(sampleSize),
Out_Size: 0,
}
if sdl_audio.OpenAudio(&spec, nil) < 0 {
err = errors.New(sdl.GetError())
return
}
sdl_audio.PauseAudio(false)
audio = &SDLAudio{
samples: make([]int16, sampleSize),
input: make(chan int16),
}
return
}
func (a *Audio) Close() {
fmt.Println("Closing!")
sdl_audio.PauseAudio(true)
sdl_audio.CloseAudio()
}
// Forward 'AudioData' objects from 'audio.data' to 'audio.playback'
func forwarderLoop(evtLoop *spectrum.EventLoop, audio *SDLAudio) {
audioDataChannel := audio.data
playback_closed := false
shutdown.Add(1)
for {
select {
case <-evtLoop.Pause:
// Remove all enqueued AudioData objects
loop:
for {
select {
case <-audio.playback:
default:
break loop
}
}
audio.mutex.Lock()
{
if !audio.sdlAudioUnpaused {
// Unpause SDL Audio. This is needed in order to avoid
// a potential deadlock on 'sdl_audio.SendAudio_int16()'.
// (If audio is paused, 'sdl_audio.SendAudio_int16()' waits indefinitely.)
sdl_audio.PauseAudio(false)
audio.sdlAudioUnpaused = true
}
}
audio.mutex.Unlock()
close(audio.playback)
playback_closed = true
<-audio.playbackLoopFinished
sdl_audio.CloseAudio()
audio.mutex.Lock()
forwarderLoopFinished := audio.forwarderLoopFinished
audio.mutex.Unlock()
if forwarderLoopFinished != nil {
forwarderLoopFinished <- 0
}
evtLoop.Pause <- 0
case <-evtLoop.Terminate:
// Terminate this Go routine
if evtLoop.App().Verbose {
evtLoop.App().PrintfMsg("audio forwarder loop: exit")
}
evtLoop.Terminate <- 0
shutdown.Done()
return
case audioData := <-audioDataChannel:
if audioData != nil {
if !playback_closed {
audio.bufferAdd()
audio.playback <- audioData
}
} else {
// Prevent any future sends via the 'audio.data' channel
close(audio.data)
// Replace 'audioDataChannel' with nil,
// so that future executions of the 'select' statement ignore the "<-audioDataChannel" case
audioDataChannel = nil
// Go to the '<-evtLoop.Pause' case
done := evtLoop.Delete()
go func() { <-done }()
}
}
}
}
func (audio *SDLAudio) Close() {
sdl_audio.PauseAudio(true)
sdl_audio.CloseAudio()
}
func (audio *SDLAudio) TogglePaused() {
audio.paused = !audio.paused
sdl_audio.PauseAudio(audio.paused)
}