mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 04:57:26 +01:00
108 lines
2.9 KiB
Go
108 lines
2.9 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 (
|
|
"errors"
|
|
"io"
|
|
|
|
"github.com/gopherjs/gopherjs/js"
|
|
"github.com/hajimehoshi/ebiten"
|
|
)
|
|
|
|
type player struct {
|
|
src io.Reader
|
|
sampleRate int
|
|
positionInSamples int64
|
|
context *js.Object
|
|
bufferSource *js.Object
|
|
}
|
|
|
|
func newPlayer(src io.Reader, sampleRate int) (*player, error) {
|
|
class := js.Global.Get("AudioContext")
|
|
if class == js.Undefined {
|
|
class = js.Global.Get("webkitAudioContext")
|
|
}
|
|
if class == js.Undefined {
|
|
return nil, errors.New("audio: audio couldn't be initialized")
|
|
}
|
|
p := &player{
|
|
src: src,
|
|
sampleRate: sampleRate,
|
|
bufferSource: nil,
|
|
context: class.New(),
|
|
}
|
|
p.positionInSamples = int64(p.context.Get("currentTime").Float() * float64(p.sampleRate))
|
|
return p, nil
|
|
}
|
|
|
|
func toLR(data []byte) ([]int16, []int16) {
|
|
l := make([]int16, len(data)/4)
|
|
r := make([]int16, len(data)/4)
|
|
for i := 0; i < len(data)/4; i++ {
|
|
l[i] = int16(data[4*i]) | int16(data[4*i+1])<<8
|
|
r[i] = int16(data[4*i+2]) | int16(data[4*i+3])<<8
|
|
}
|
|
return l, r
|
|
}
|
|
|
|
func max64(a, b int64) int64 {
|
|
if a > b {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
|
|
func (p *player) proceed() error {
|
|
bufferSize := p.sampleRate * bytesPerSample * channelNum / ebiten.FPS
|
|
c := int64(p.context.Get("currentTime").Float() * float64(p.sampleRate))
|
|
if p.positionInSamples < c {
|
|
p.positionInSamples = c
|
|
}
|
|
b := make([]byte, bufferSize)
|
|
n, err := p.src.Read(b)
|
|
if 0 < n {
|
|
buf := p.context.Call("createBuffer", channelNum, n/bytesPerSample/channelNum, p.sampleRate)
|
|
l := buf.Call("getChannelData", 0)
|
|
r := buf.Call("getChannelData", 1)
|
|
il, ir := toLR(b[:n])
|
|
const max = 1 << 15
|
|
for i := 0; i < len(il); i++ {
|
|
l.SetIndex(i, float64(il[i])/max)
|
|
r.SetIndex(i, float64(ir[i])/max)
|
|
}
|
|
p.bufferSource = p.context.Call("createBufferSource")
|
|
p.bufferSource.Set("buffer", buf)
|
|
p.bufferSource.Call("connect", p.context.Get("destination"))
|
|
p.bufferSource.Call("start", float64(p.positionInSamples)/float64(p.sampleRate))
|
|
// Call 'stop' or we'll get noisy sound especially on Chrome.
|
|
p.bufferSource.Call("stop", float64(p.positionInSamples+int64(len(il)))/float64(p.sampleRate))
|
|
p.positionInSamples += int64(len(il))
|
|
}
|
|
return err
|
|
}
|
|
|
|
func (p *player) close() error {
|
|
if p.bufferSource == nil {
|
|
return nil
|
|
}
|
|
p.bufferSource.Call("stop")
|
|
p.bufferSource.Call("disconnect")
|
|
p.bufferSource = nil
|
|
return nil
|
|
}
|