Add Experimental Audio API

_docs/public/example/blocks.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'blocks.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/hue.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'hue.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/keyboard.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'keyboard.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/mosaic.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'mosaic.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/paint.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'paint.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/perspective.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'perspective.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

_docs/public/example/rotate.content.html

@@ -31,7 +31,7 @@ window.addEventListener('load', function() {
   var s = document.createElement('script');
   var src = 'rotate.js';
   if (isProduction()) {
-    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/master/' + src;
+    src = 'http://hajimehoshi.github.io/ebiten.pagestorage/audio/' + src;
   }
   s.src = src;
   document.body.appendChild(s);

audio.go

@@ -0,0 +1,23 @@
+// Copyright 2015 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.
+
+package ebiten
+
+import (
+	"github.com/hajimehoshi/ebiten/internal/audio"
+)
+
+func AppendAudioBuffer(l []float32, r []float32) {
+	audio.Append(l, r)
+}

example/audio/main.go

@@ -0,0 +1,87 @@
+// Copyright 2015 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.
+
+package main
+
+import (
+	"fmt"
+	"github.com/hajimehoshi/ebiten"
+	"github.com/hajimehoshi/ebiten/ebitenutil"
+	"log"
+	"math/rand"
+)
+
+const (
+	screenWidth  = 320
+	screenHeight = 240
+)
+
+var frames = 0
+
+const (
+	hzA  = 440.0
+	hzAS = 466.2
+	hzB  = 493.9
+	hzC  = 523.3
+	hzCS = 554.4
+	hzD  = 587.3
+	hzDS = 622.3
+	hzE  = 659.3
+	hzF  = 698.5
+	hzFS = 740.0
+	hzG  = 784.0
+	hzGS = 830.6
+)
+
+// TODO: Need API to get sample rate?
+const sampleRate = 44100
+
+func square(out []float32, hz float64, sequence float64) {
+	length := int(sampleRate / hz)
+	if length == 0 {
+		panic("invalid hz")
+	}
+	for i := 0; i < len(out); i++ {
+		a := float32(1.0)
+		if i%length < int(float64(length)*sequence) {
+			a = 0
+		}
+		out[i] = a
+	}
+}
+
+func update(screen *ebiten.Image) error {
+	defer func() {
+		frames++
+	}()
+
+	const size = sampleRate / 60 // 3600 BPM
+	notes := []float64{hzA, hzB, hzC, hzD, hzE, hzF, hzG, hzA * 2}
+	if frames%30 == 0 {
+		l := make([]float32, size*30)
+		r := make([]float32, size*30)
+		note := notes[rand.Intn(len(notes))]
+		square(l, note, 0.5)
+		square(r, note, 0.5)
+		ebiten.AppendAudioBuffer(l, r)
+	}
+	ebitenutil.DebugPrint(screen, fmt.Sprintf("%0.2f", ebiten.CurrentFPS()))
+	return nil
+}
+
+func main() {
+	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Rotate (Ebiten Demo)"); err != nil {
+		log.Fatal(err)
+	}
+}

example/server/main.go

@@ -61,7 +61,7 @@ func createJSIfNeeded(name string) (string, error) {
 	if err != nil && !os.IsNotExist(err) {
 		return "", err
 	}
-	if (err != nil && os.IsNotExist(err)) || time.Now().Sub(stat.ModTime()) > 10*time.Second {
+	if (err != nil && os.IsNotExist(err)) || time.Now().Sub(stat.ModTime()) > 5*time.Second {
 		target := "github.com/hajimehoshi/ebiten/example/" + name
 		out, err := exec.Command("gopherjs", "build", "-o", out, target).CombinedOutput()
 		if err != nil {

internal/audio/audio.go

@@ -0,0 +1,29 @@
+// Copyright 2015 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 !js
+
+package audio
+
+func Init() {
+	// TODO: Implement
+}
+
+func Start() {
+	// TODO: Implement
+}
+
+func Append(l []float32, r []float32) {
+	// TODO: Implement
+}

internal/audio/audio_js.go

@@ -0,0 +1,78 @@
+// Copyright 2015 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 js
+
+package audio
+
+import (
+	"github.com/gopherjs/gopherjs/js"
+)
+
+// Keep this so as not to be destroyed by GC.
+var node js.Object
+var context js.Object
+
+const bufferSize = 1024
+
+var (
+	bufferL = make([]float32, 0)
+	bufferR = make([]float32, 0)
+)
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func Init() {
+	context = js.Global.Get("AudioContext").New()
+	// TODO: ScriptProcessorNode will be replaced Audio WebWorker.
+	// https://developer.mozilla.org/ja/docs/Web/API/ScriptProcessorNode
+	const bufLen = 1024
+	node = context.Call("createScriptProcessor", bufLen, 0, 2)
+	node.Call("addEventListener", "audioprocess", func(e js.Object) {
+		l := e.Get("outputBuffer").Call("getChannelData", 0)
+		r := e.Get("outputBuffer").Call("getChannelData", 1)
+		for i := 0; i < bufLen; i++ {
+			// TODO: Use copyFromChannel?
+			if len(bufferL) <= i {
+				l.SetIndex(i, 0)
+				r.SetIndex(i, 0)
+				continue
+			}
+			l.SetIndex(i, bufferL[i])
+			r.SetIndex(i, bufferR[i])
+		}
+		// TODO: Will the array heads be released properly on GopherJS?
+		usedLen := min(bufLen, len(bufferL))
+		bufferL = bufferL[usedLen:]
+		bufferR = bufferR[usedLen:]
+	})
+}
+
+func Start() {
+	// TODO: For iOS, node should be connected with a buffer node.
+	node.Call("connect", context.Get("destination"))
+}
+
+func Append(l []float32, r []float32) {
+	if len(l) != len(r) {
+		panic("len(l) must equal to len(r)")
+	}
+	bufferL = append(bufferL, l...)
+	bufferR = append(bufferR, r...)
+}

internal/ui/ui_glfw.go

@@ -19,6 +19,7 @@ package ui
 import (
 	"fmt"
 	glfw "github.com/go-gl/glfw3"
+	"github.com/hajimehoshi/ebiten/internal/audio"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"runtime"
 	"time"
@@ -81,6 +82,9 @@ func init() {
 			f()
 		}
 	}()
+
+	audio.Init()
+
 	current = u
 }
 
@@ -134,6 +138,8 @@ func Start(width, height, scale int, title string) (actualScale int, err error)
 	windowWidth, _ := window.GetFramebufferSize()
 	actualScale = windowWidth / width
 
+	audio.Start()
+
 	return actualScale, nil
 }
 

internal/ui/ui_js.go

@@ -19,6 +19,7 @@ package ui
 import (
 	"github.com/gopherjs/gopherjs/js"
 	"github.com/gopherjs/webgl"
+	"github.com/hajimehoshi/ebiten/internal/audio"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"strconv"
 )
@@ -26,6 +27,8 @@ import (
 var canvas js.Object
 var context *opengl.Context
 
+// TODO: This returns true even when the browser is not active.
+// The current behavior causes sound noise...
 func shown() bool {
 	return !js.Global.Get("document").Get("hidden").Bool()
 }
@@ -36,6 +39,8 @@ func Use(f func(*opengl.Context)) {
 
 func vsync() {
 	ch := make(chan struct{})
+	// TODO: In iOS8, this is called at every 1/30[sec] frame.
+	// Can we use DOMHighResTimeStamp?
 	js.Global.Get("window").Call("requestAnimationFrame", func() {
 		close(ch)
 	})
@@ -149,6 +154,8 @@ func init() {
 	canvas.Call("addEventListener", "contextmenu", func(e js.Object) bool {
 		return false
 	})
+
+	audio.Init()
 }
 
 func devicePixelRatio() int {
@@ -185,5 +192,7 @@ func Start(width, height, scale int, title string) (actualScale int, err error)
 	})
 	canvas.Call("focus")
 
+	audio.Start()
+
 	return actualScale, nil
 }