Ebiten example - audio
// +build example
package main
import (
"fmt"
"image/color"
"io/ioutil"
"log"
"time"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/audio"
"github.com/hajimehoshi/ebiten/audio/vorbis"
"github.com/hajimehoshi/ebiten/audio/wav"
"github.com/hajimehoshi/ebiten/ebitenutil"
)
const (
screenWidth = 320
screenHeight = 240
)
var (
playerBarImage *ebiten.Image
playerCurrentImage *ebiten.Image
)
func init() {
var err error
playerBarImage, err = ebiten.NewImage(300, 4, ebiten.FilterNearest)
if err != nil {
log.Fatal(err)
}
if err := playerBarImage.Fill(&color.RGBA{0x80, 0x80, 0x80, 0xff}); err != nil {
log.Fatal(err)
}
playerCurrentImage, err = ebiten.NewImage(4, 10, ebiten.FilterNearest)
if err != nil {
log.Fatal(err)
}
if err := playerCurrentImage.Fill(&color.RGBA{0xff, 0xff, 0xff, 0xff}); err != nil {
log.Fatal(err)
}
}
type Player struct {
audioPlayer *audio.Player
total time.Duration
seekedCh chan error
}
var (
audioContext *audio.Context
musicPlayer *Player
seBytes []byte
musicCh = make(chan *Player)
seCh = make(chan []byte)
mouseButtonState = map[ebiten.MouseButton]int{}
keyState = map[ebiten.Key]int{}
volume128 = 128
)
func playerBarRect() (x, y, w, h int) {
w, h = playerBarImage.Size()
x = (screenWidth - w) / 2
y = screenHeight - h - 16
return
}
func (p *Player) updateSE() error {
if seBytes == nil {
return nil
}
if !ebiten.IsKeyPressed(ebiten.KeyP) {
keyState[ebiten.KeyP] = 0
return nil
}
keyState[ebiten.KeyP]++
if keyState[ebiten.KeyP] != 1 {
return nil
}
sePlayer, err := audio.NewPlayerFromBytes(audioContext, seBytes)
if err != nil {
return err
}
return sePlayer.Play()
}
func (p *Player) updateVolume() {
if p.audioPlayer == nil {
return
}
if ebiten.IsKeyPressed(ebiten.KeyZ) {
volume128--
}
if ebiten.IsKeyPressed(ebiten.KeyX) {
volume128++
}
if volume128 < 0 {
volume128 = 0
}
if 128 < volume128 {
volume128 = 128
}
p.audioPlayer.SetVolume(float64(volume128) / 128)
}
func (p *Player) updatePlayPause() error {
if p.audioPlayer == nil {
return nil
}
if !ebiten.IsKeyPressed(ebiten.KeyS) {
keyState[ebiten.KeyS] = 0
return nil
}
keyState[ebiten.KeyS]++
if keyState[ebiten.KeyS] != 1 {
return nil
}
if p.audioPlayer.IsPlaying() {
return p.audioPlayer.Pause()
}
return p.audioPlayer.Play()
}
func (p *Player) updateBar() {
if p.audioPlayer == nil {
return
}
if p.seekedCh != nil {
return
}
if !ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
mouseButtonState[ebiten.MouseButtonLeft] = 0
return
}
mouseButtonState[ebiten.MouseButtonLeft]++
if mouseButtonState[ebiten.MouseButtonLeft] != 1 {
return
}
x, y := ebiten.CursorPosition()
bx, by, bw, bh := playerBarRect()
const padding = 4
if y < by-padding || by+bh+padding <= y {
return
}
if x < bx || bx+bw <= x {
return
}
pos := time.Duration(x-bx) * p.total / time.Duration(bw)
p.seekedCh = make(chan error, 1)
go func() {
// This can't be done parallely! !?!?
p.seekedCh <- p.audioPlayer.Seek(pos)
}()
}
func (p *Player) close() error {
return p.audioPlayer.Close()
}
func update(screen *ebiten.Image) error {
if musicPlayer == nil {
select {
case musicPlayer = <-musicCh:
default:
}
}
if seBytes == nil {
select {
case seBytes = <-seCh:
default:
}
}
if musicPlayer != nil {
musicPlayer.updateBar()
if err := musicPlayer.updatePlayPause(); err != nil {
return err
}
if err := musicPlayer.updateSE(); err != nil {
return err
}
musicPlayer.updateVolume()
}
if ebiten.IsRunningSlowly() {
return nil
}
op := &ebiten.DrawImageOptions{}
x, y, w, h := playerBarRect()
op.GeoM.Translate(float64(x), float64(y))
screen.DrawImage(playerBarImage, op)
currentTimeStr := "00:00"
if musicPlayer != nil {
c := musicPlayer.audioPlayer.Current()
// Current Time
m := (c / time.Minute) % 100
s := (c / time.Second) % 60
currentTimeStr = fmt.Sprintf("%02d:%02d", m, s)
// Bar
cw, ch := playerCurrentImage.Size()
cx := int(time.Duration(w)*c/musicPlayer.total) + x - cw/2
cy := y - (ch-h)/2
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(float64(cx), float64(cy))
screen.DrawImage(playerCurrentImage, op)
}
msg := fmt.Sprintf(`FPS: %0.2f
Press S to toggle Play/Pause
Press P to play SE
Press Z or X to change volume of the music
%s`, ebiten.CurrentFPS(), currentTimeStr)
if musicPlayer == nil {
msg += "\nNow Loading..."
} else if musicPlayer.seekedCh != nil {
select {
case err := <-musicPlayer.seekedCh:
if err != nil {
return err
}
close(musicPlayer.seekedCh)
musicPlayer.seekedCh = nil
default:
msg += "\nSeeking..."
}
}
ebitenutil.DebugPrint(screen, msg)
if err := audioContext.Update(); err != nil {
return err
}
return nil
}
func main() {
wavF, err := ebitenutil.OpenFile("_resources/audio/jab.wav")
if err != nil {
log.Fatal(err)
}
oggF, err := ebitenutil.OpenFile("_resources/audio/game.ogg")
if err != nil {
log.Fatal(err)
}
// This sample rate doesn't match with wav/ogg's sample rate,
// but decoders adjust them.
const sampleRate = 48000
const bytesPerSample = 4 // TODO: This should be defined in audio package
audioContext, err = audio.NewContext(sampleRate)
if err != nil {
log.Fatal(err)
}
go func() {
s, err := wav.Decode(audioContext, wavF)
if err != nil {
log.Fatal(err)
return
}
b, err := ioutil.ReadAll(s)
if err != nil {
log.Fatal(err)
return
}
seCh <- b
close(seCh)
}()
go func() {
s, err := vorbis.Decode(audioContext, oggF)
if err != nil {
log.Fatal(err)
return
}
p, err := audio.NewPlayer(audioContext, s)
if err != nil {
log.Fatal(err)
return
}
musicCh <- &Player{
audioPlayer: p,
total: time.Second * time.Duration(s.Size()) / bytesPerSample / sampleRate,
}
close(musicCh)
// TODO: Is this goroutine-safe?
if err := p.Play(); err != nil {
log.Fatal(err)
return
}
}()
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Audio (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
if musicPlayer != nil {
if err := musicPlayer.close(); err != nil {
log.Fatal(err)
}
}
}