audio: Introduce audio.Player

example/audio/main.go

@@ -122,7 +122,8 @@ func addNote() {
 	square(l, vol, freq, 0.25)
 	square(r, vol, freq, 0.25)
 	b := toBytes(l, r)
-	audio.Queue(&stream{bytes.NewReader(b)}, sampleRate)
+	p := audio.NewPlayer(&stream{bytes.NewReader(b)}, sampleRate)
+	p.Play()
 }
 
 func update(screen *ebiten.Image) error {

example/piano/main.go

@@ -81,7 +81,8 @@ func (s *stream) Close() error {
 func addNote(freq float64, vol float64) {
 	f := int(freq)
 	if n, ok := noteCache[f]; ok {
-		audio.Queue(&stream{bytes.NewReader(n)}, sampleRate)
+		p := audio.NewPlayer(&stream{bytes.NewReader(n)}, sampleRate)
+		p.Play()
 		return
 	}
 	length := len(pcm) * baseFreq / f
@@ -98,7 +99,8 @@ func addNote(freq float64, vol float64) {
 	}
 	n := toBytes(l, r)
 	noteCache[f] = n
-	audio.Queue(&stream{bytes.NewReader(n)}, sampleRate)
+	p := audio.NewPlayer(&stream{bytes.NewReader(n)}, sampleRate)
+	p.Play()
 }
 
 var keys = []ebiten.Key{

exp/audio/audio.go

@@ -25,7 +25,12 @@ type ReadSeekCloser interface {
 	io.Closer
 }
 
-// Queue queues the given data to the given channel.
+type Player struct {
+	src        ReadSeekCloser
+	sampleRate int
+}
+
+// NewPlayer creates a new player with the given data to the given channel.
 // The given data is queued to the end of the buffer.
 // This may not be played immediately when data already exists in the buffer.
 //
@@ -33,6 +38,13 @@ type ReadSeekCloser interface {
 // without a header (e.g. RIFF header).
 //
 // TODO: Pass sample rate and num of channels.
-func Queue(src ReadSeekCloser, sampleRate int) error {
+func NewPlayer(src ReadSeekCloser, sampleRate int) *Player {
-	return audio.Queue(src, sampleRate)
+	return &Player{
+		src:        src,
+		sampleRate: sampleRate,
+	}
+}
+
+func (p *Player) Play() error {
+	return audio.Play(p.src, p.sampleRate)
 }

internal/audio/audio.go

@@ -25,15 +25,10 @@ type ReadSeekCloser interface {
 	io.Closer
 }
 
-type chunk struct {
-	buffer     ReadSeekCloser
-	sampleRate int
-}
-
 func Init() {
 	initialize()
 }
 
-func Queue(src ReadSeekCloser, sampleRate int) error {
+func Play(src ReadSeekCloser, sampleRate int) error {
-	return playChunk(src, sampleRate)
+	return play(src, sampleRate)
 }

internal/audio/audio_js.go

@@ -68,7 +68,7 @@ func (a *audioProcessor) play() error {
 	return nil
 }
 
-func playChunk(src ReadSeekCloser, sampleRate int) error {
+func play(src ReadSeekCloser, sampleRate int) error {
 	a := &audioProcessor{
 		src:        src,
 		sampleRate: sampleRate,

internal/audio/audio_openal.go

@@ -24,7 +24,7 @@ import (
 
 var players = map[*audio.Player]struct{}{}
 
-func playChunk(src ReadSeekCloser, sampleRate int) error {
+func play(src ReadSeekCloser, sampleRate int) error {
 	// TODO: audio.NewPlayer interprets WAV header, which we don't want.
 	// Use OpenAL or native API instead.
 	p, err := audio.NewPlayer(src, audio.Stereo16, int64(sampleRate))