audio: Add driver_mobile.go

audio/internal/driver/driver_mobile.go

@@ -0,0 +1,139 @@
+// Copyright 2016 Hajime Hoshi
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build android
+
+package driver
+
+import (
+	"fmt"
+	"runtime"
+
+	"golang.org/x/mobile/exp/audio/al"
+)
+
+const (
+	maxBufferNum = 8
+)
+
+type Player struct {
+	alSource   al.Source
+	alBuffers  []al.Buffer
+	sampleRate int
+	isClosed   bool
+	alFormat   uint32
+}
+
+func alFormat(channelNum, bytesPerSample int) uint32 {
+	switch {
+	case channelNum == 1 && bytesPerSample == 1:
+		return al.FormatMono8
+	case channelNum == 1 && bytesPerSample == 2:
+		return al.FormatMono16
+	case channelNum == 2 && bytesPerSample == 1:
+		return al.FormatStereo8
+	case channelNum == 2 && bytesPerSample == 2:
+		return al.FormatStereo16
+	}
+	panic(fmt.Sprintf("driver: invalid channel num (%d) or bytes per sample (%d)", channelNum, bytesPerSample))
+}
+
+func NewPlayer(sampleRate, channelNum, bytesPerSample int) (*Player, error) {
+	var p *Player
+	if err := al.OpenDevice(); err != nil {
+		return nil, fmt.Errorf("driver: OpenAL initialization failed: %v", err)
+	}
+	s := al.GenSources(1)
+	if e := al.Error(); e != 0 {
+		return nil, fmt.Errorf("driver: al.GenSources error: %d", e)
+	}
+	p = &Player{
+		alSource:   s[0],
+		alBuffers:  []al.Buffer{},
+		sampleRate: sampleRate,
+		alFormat:   alFormat(channelNum, bytesPerSample),
+	}
+	runtime.SetFinalizer(p, (*Player).Close)
+
+	bs := al.GenBuffers(maxBufferNum)
+	const bufferSize = 1024
+	emptyBytes := make([]byte, bufferSize)
+	for _, b := range bs {
+		// Note that the third argument of only the first buffer is used.
+		b.BufferData(p.alFormat, emptyBytes, int32(p.sampleRate))
+		p.alSource.QueueBuffers(b)
+	}
+	al.PlaySources(p.alSource)
+	return p, nil
+}
+
+func (p *Player) Proceed(data []byte) error {
+	if err := al.Error(); err != 0 {
+		return fmt.Errorf("driver: before proceed: %d", err)
+	}
+	processedNum := p.alSource.BuffersProcessed()
+	if 0 < processedNum {
+		bufs := make([]al.Buffer, processedNum)
+		p.alSource.UnqueueBuffers(bufs...)
+		if err := al.Error(); err != 0 {
+			return fmt.Errorf("driver: Unqueue in process: %d", err)
+		}
+		p.alBuffers = append(p.alBuffers, bufs...)
+	}
+
+	if len(p.alBuffers) == 0 {
+		// This can happen (#207)
+		return nil
+	}
+	buf := p.alBuffers[0]
+	p.alBuffers = p.alBuffers[1:]
+	buf.BufferData(p.alFormat, data, int32(p.sampleRate))
+	p.alSource.QueueBuffers(buf)
+	if err := al.Error(); err != 0 {
+		return fmt.Errorf("driver: Queue in process: %d", err)
+	}
+
+	if p.alSource.State() == al.Stopped || p.alSource.State() == al.Initial {
+		al.RewindSources(p.alSource)
+		al.PlaySources(p.alSource)
+		if err := al.Error(); err != 0 {
+			return fmt.Errorf("driver: PlaySource in process: %d", err)
+		}
+	}
+
+	return nil
+}
+
+func (p *Player) Close() error {
+	if err := al.Error(); err != 0 {
+		return fmt.Errorf("driver: error before closing: %d", err)
+	}
+	if p.isClosed {
+		return nil
+	}
+	var bs []al.Buffer
+	al.RewindSources(p.alSource)
+	al.StopSources(p.alSource)
+	if n := p.alSource.BuffersQueued(); 0 < n {
+		bs = make([]al.Buffer, n)
+		p.alSource.UnqueueBuffers(bs...)
+		p.alBuffers = append(p.alBuffers, bs...)
+	}
+	p.isClosed = true
+	if err := al.Error(); err != 0 {
+		return fmt.Errorf("driver: error after closing: %d", err)
+	}
+	runtime.SetFinalizer(p, nil)
+	return nil
+}

audio/internal/driver/driver_openal.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build !js,!windows
+// +build !js,!windows,!android
 
 package driver
 
@@ -87,7 +87,6 @@ func NewPlayer(sampleRate, channelNum, bytesPerSample int) (*Player, error) {
 	for _, b := range bs {
 		// Note that the third argument of only the first buffer is used.
 		b.SetData(p.alFormat, emptyBytes, int32(p.sampleRate))
-		//p.alSource.QueueBuffer(b)
 		p.alBuffers = append(p.alBuffers, b)
 	}
 	p.alSource.Play()