ebiten/internal/audio/audio_js.go
2015-01-26 10:14:03 +09:00

70 lines
1.9 KiB
Go

// 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 nodes = []js.Object{}
var context js.Object
const bufferSize = 1024
func audioProcess(channel int) func(e js.Object) {
return func(e js.Object) {
defer func() {
currentPosition += bufferSize
}()
l := e.Get("outputBuffer").Call("getChannelData", 0)
r := e.Get("outputBuffer").Call("getChannelData", 1)
inputL, inputR := loadChannelBuffer(channel, bufferSize)
const max = 1 << 15
for i := 0; i < bufferSize; i++ {
// TODO: Use copyFromChannel?
if len(inputL) <= i {
l.SetIndex(i, 0)
r.SetIndex(i, 0)
continue
}
l.SetIndex(i, float64(inputL[i])/max)
r.SetIndex(i, float64(inputR[i])/max)
}
}
}
func initialize() {
context = js.Global.Get("AudioContext").New()
// TODO: ScriptProcessorNode will be replaced with Audio WebWorker.
// https://developer.mozilla.org/ja/docs/Web/API/ScriptProcessorNode
for i := 0; i < MaxChannel; i++ {
node := context.Call("createScriptProcessor", bufferSize, 0, 2)
node.Call("addEventListener", "audioprocess", audioProcess(i))
nodes = append(nodes, node)
}
audioEnabled = true
}
func start() {
// TODO: For iOS, node should be connected with a buffer node.
for _, node := range nodes {
node.Call("connect", context.Get("destination"))
}
}