hayai/vendor/github.com/hajimehoshi/oto/driver_js.go
2024-12-21 17:26:50 +01:00

386 lines
9.8 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 oto
import (
"encoding/base64"
"errors"
"fmt"
"sync"
"syscall/js"
)
type driver struct {
sampleRate int
channelNum int
bitDepthInBytes int
nextPos float64
tmp []byte
bufferSize int
context js.Value
ready bool
callbacks map[string]js.Func
// For Audio Worklet
workletNode js.Value
workletNodePost js.Value
messageArray js.Value
transferArray js.Value
bufs [][]js.Value
cond *sync.Cond
}
type warn struct {
msg string
}
func (w *warn) Error() string {
return w.msg
}
const audioBufferSamples = 3200
func tryAudioWorklet(context js.Value, channelNum int) (js.Value, error) {
if !js.Global().Get("AudioWorkletNode").Truthy() {
return js.Undefined(), nil
}
worklet := context.Get("audioWorklet")
if !worklet.Truthy() {
return js.Undefined(), &warn{
msg: "AudioWorklet is not available due to the insecure context. See https://developer.mozilla.org/en-US/docs/Web/API/AudioWorklet",
}
}
script := `
class EbitenAudioWorkletProcessor extends AudioWorkletProcessor {
constructor() {
super();
this.buffers_ = [[], []];
this.offsets_ = [0, 0];
this.offsetsInArray_ = [0, 0];
this.consumed_ = [];
this.port.onmessage = (e) => {
const bufs = e.data;
for (let ch = 0; ch < bufs.length; ch++) {
const buf = bufs[ch];
this.buffers_[ch].push(new Float32Array(buf.buffer, buf.byteOffset, buf.byteLength / 4));
}
};
}
bufferTotalLength(ch) {
const sum = this.buffers_[ch].reduce((total, buf) => total + buf.length, 0);
return sum - this.offsetsInArray_[ch];
}
consume(ch, i) {
while (this.buffers_[ch][0].length <= i - this.offsets_[ch]) {
this.offsets_[ch] += this.buffers_[ch][0].length;
this.offsetsInArray_[ch] = 0;
const buf = this.buffers_[ch].shift();
this.appendConsumedBuffer(ch, buf);
}
this.offsetsInArray_[ch]++;
return this.buffers_[ch][0][i - this.offsets_[ch]];
}
appendConsumedBuffer(ch, buf) {
let idx = this.consumed_.length - 1;
if (idx < 0 || this.consumed_[idx][ch]) {
this.consumed_.push([]);
idx++;
}
this.consumed_[idx][ch] = new Uint8Array(buf.buffer, buf.byteOffset, buf.byteLength);
}
process(inputs, outputs, parameters) {
const out = outputs[0];
if (this.bufferTotalLength(0) < out[0].length) {
for (let ch = 0; ch < out.length; ch++) {
for (let i = 0; i < out[ch].length; i++) {
out[ch][i] = 0;
}
}
return true;
}
for (let ch = 0; ch < out.length; ch++) {
const offset = this.offsets_[ch] + this.offsetsInArray_[ch];
for (let i = 0; i < out[ch].length; i++) {
out[ch][i] = this.consume(ch, i + offset);
}
}
for (let bufs of this.consumed_) {
this.port.postMessage(bufs, bufs.map(buf => buf.buffer));
}
this.consumed_ = [];
return true;
}
}
registerProcessor('ebiten-audio-worklet-processor', EbitenAudioWorkletProcessor);`
scriptURL := "data:application/javascript;base64," + base64.StdEncoding.EncodeToString([]byte(script))
ch := make(chan error)
worklet.Call("addModule", scriptURL).Call("then", js.FuncOf(func(js.Value, []js.Value) interface{} {
close(ch)
return nil
})).Call("catch", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
err := args[0]
ch <- fmt.Errorf("oto: error at addModule: %s: %s", err.Get("name").String(), err.Get("message").String())
close(ch)
return nil
}))
if err := <-ch; err != nil {
return js.Undefined(), err
}
options := js.Global().Get("Object").New()
arr := js.Global().Get("Array").New()
arr.Call("push", channelNum)
options.Set("outputChannelCount", arr)
node := js.Global().Get("AudioWorkletNode").New(context, "ebiten-audio-worklet-processor", options)
node.Call("connect", context.Get("destination"))
return node, nil
}
func newDriver(sampleRate, channelNum, bitDepthInBytes, bufferSize int) (tryWriteCloser, error) {
if js.Global().Get("go2cpp").Truthy() {
return newDriverGo2Cpp(sampleRate, channelNum, bitDepthInBytes, bufferSize)
}
class := js.Global().Get("AudioContext")
if !class.Truthy() {
class = js.Global().Get("webkitAudioContext")
}
if !class.Truthy() {
return nil, errors.New("oto: audio couldn't be initialized")
}
options := js.Global().Get("Object").New()
options.Set("sampleRate", sampleRate)
context := class.New(options)
node, err := tryAudioWorklet(context, channelNum)
if err != nil {
w, ok := err.(*warn)
if !ok {
return nil, err
}
js.Global().Get("console").Call("warn", w.Error())
}
bs := bufferSize
if !node.Truthy() {
bs = max(bufferSize, audioBufferSamples*channelNum*bitDepthInBytes)
} else {
bs = max(bufferSize, 4096)
}
p := &driver{
sampleRate: sampleRate,
channelNum: channelNum,
bitDepthInBytes: bitDepthInBytes,
context: context,
workletNode: node,
bufferSize: bs,
}
if node.Truthy() {
port := node.Get("port")
p.workletNodePost = port.Get("postMessage").Call("bind", port)
p.messageArray = js.Global().Get("Array").New(2)
p.transferArray = js.Global().Get("Array").New(2)
p.cond = sync.NewCond(&sync.Mutex{})
s := p.bufferSize / p.channelNum / p.bitDepthInBytes * 4
p.bufs = [][]js.Value{
{
js.Global().Get("Uint8Array").New(s),
js.Global().Get("Uint8Array").New(s),
},
{
js.Global().Get("Uint8Array").New(s),
js.Global().Get("Uint8Array").New(s),
},
}
node.Get("port").Set("onmessage", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
p.cond.L.Lock()
defer p.cond.L.Unlock()
bufs := args[0].Get("data")
var arr []js.Value
for i := 0; i < bufs.Length(); i++ {
arr = append(arr, bufs.Index(i))
}
notify := len(p.bufs) == 0
p.bufs = append(p.bufs, arr)
if notify {
p.cond.Signal()
}
return nil
}))
}
setCallback := func(event string) js.Func {
var f js.Func
f = js.FuncOf(func(this js.Value, arguments []js.Value) interface{} {
if !p.ready {
p.context.Call("resume")
p.ready = true
}
js.Global().Get("document").Call("removeEventListener", event, f)
return nil
})
js.Global().Get("document").Call("addEventListener", event, f)
p.callbacks[event] = f
return f
}
// Browsers require user interaction to start the audio.
// https://developers.google.com/web/updates/2017/09/autoplay-policy-changes#webaudio
p.callbacks = map[string]js.Func{}
setCallback("touchend")
setCallback("keyup")
setCallback("mouseup")
return p, nil
}
func toLR(data []byte) ([]float32, []float32) {
const max = 1 << 15
l := make([]float32, len(data)/4)
r := make([]float32, len(data)/4)
for i := 0; i < len(data)/4; i++ {
l[i] = float32(int16(data[4*i])|int16(data[4*i+1])<<8) / max
r[i] = float32(int16(data[4*i+2])|int16(data[4*i+3])<<8) / max
}
return l, r
}
func (p *driver) TryWrite(data []byte) (int, error) {
if !p.ready {
return 0, nil
}
if p.workletNode.Truthy() {
p.cond.L.Lock()
defer p.cond.L.Unlock()
n := min(len(data), max(0, p.bufferSize-len(p.tmp)))
p.tmp = append(p.tmp, data[:n]...)
if len(p.tmp) < p.bufferSize {
return n, nil
}
for len(p.bufs) == 0 {
p.cond.Wait()
}
l, r := toLR(p.tmp[:p.bufferSize])
tl := p.bufs[0][0]
tr := p.bufs[0][1]
copyFloat32sToJS(tl, l)
copyFloat32sToJS(tr, r)
p.tmp = p.tmp[p.bufferSize:]
bufs := p.messageArray
bufs.SetIndex(0, tl)
bufs.SetIndex(1, tr)
transfers := p.transferArray
transfers.SetIndex(0, tl.Get("buffer"))
transfers.SetIndex(1, tr.Get("buffer"))
p.workletNodePost.Invoke(bufs, transfers)
p.bufs = p.bufs[1:]
return n, nil
}
n := min(len(data), max(0, p.bufferSize-len(p.tmp)))
p.tmp = append(p.tmp, data[:n]...)
c := p.context.Get("currentTime").Float()
if p.nextPos < c {
p.nextPos = c
}
// It's too early to enqueue a buffer.
// Highly likely, there are two playing buffers now.
if c+float64(p.bufferSize/p.bitDepthInBytes/p.channelNum)/float64(p.sampleRate) < p.nextPos {
return n, nil
}
le := audioBufferSamples * p.bitDepthInBytes * p.channelNum
if len(p.tmp) < le {
return n, nil
}
buf := p.context.Call("createBuffer", p.channelNum, audioBufferSamples, p.sampleRate)
l, r := toLR(p.tmp[:le])
tl, freel := float32SliceToTypedArray(l)
tr, freer := float32SliceToTypedArray(r)
if buf.Get("copyToChannel").Truthy() {
buf.Call("copyToChannel", tl, 0, 0)
buf.Call("copyToChannel", tr, 1, 0)
} else {
// copyToChannel is not defined on Safari 11
buf.Call("getChannelData", 0).Call("set", tl)
buf.Call("getChannelData", 1).Call("set", tr)
}
freel()
freer()
s := p.context.Call("createBufferSource")
s.Set("buffer", buf)
s.Call("connect", p.context.Get("destination"))
s.Call("start", p.nextPos)
p.nextPos += buf.Get("duration").Float()
p.tmp = p.tmp[le:]
return n, nil
}
func (p *driver) Close() error {
for event, f := range p.callbacks {
// https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/removeEventListener
// "Calling removeEventListener() with arguments that do not identify any currently registered EventListener on the EventTarget has no effect."
js.Global().Get("document").Call("removeEventListener", event, f)
f.Release()
}
p.callbacks = nil
return nil
}
func (d *driver) tryWriteCanReturnWithoutWaiting() bool {
return true
}