examples/audio: Refactoring

This commit is contained in:
Hajime Hoshi 2018-01-22 02:15:04 +09:00
parent 3ee42c0c1e
commit 20e12a7ea9

View File

@ -47,6 +47,11 @@ var (
playerCurrentColor = color.RGBA{0xff, 0xff, 0xff, 0xff}
)
// Input manages the current input state to detect keys 'just pressed'.
//
// Note: 'just pressed' is a very common idiom.
// There is a plan to create a new package for input utility.
// See https://github.com/hajimehoshi/ebiten/issues/415.
type Input struct {
mouseButtonStates map[ebiten.MouseButton]int
keyStates map[ebiten.Key]int
@ -67,7 +72,7 @@ func (i *Input) update() {
}
}
func (i *Input) isKeyTriggered(key ebiten.Key) bool {
func (i *Input) isKeyJustPressed(key ebiten.Key) bool {
return i.keyStates[key] == 1
}
@ -75,25 +80,22 @@ func (i *Input) isKeyPressed(key ebiten.Key) bool {
return i.keyStates[key] > 0
}
func (i *Input) isMouseButtonTriggered(mouseButton ebiten.MouseButton) bool {
func (i *Input) isMouseButtonJustPressed(mouseButton ebiten.MouseButton) bool {
return i.mouseButtonStates[mouseButton] == 1
}
// Player represents the current audio state.
type Player struct {
input *Input
audioContext *audio.Context
audioPlayer *audio.Player
current time.Duration
total time.Duration
seBytes []uint8
seCh chan []uint8
seBytes []byte
seCh chan []byte
volume128 int
}
var (
musicPlayer *Player
)
func playerBarRect() (x, y, w, h int) {
w, h = 300, 4
x = (screenWidth - w) / 2
@ -128,7 +130,7 @@ func NewPlayer(audioContext *audio.Context) (*Player, error) {
audioPlayer: p,
total: time.Second * time.Duration(s.Length()) / bytesPerSample / sampleRate,
volume128: 128,
seCh: make(chan []uint8),
seCh: make(chan []byte),
}
if player.total == 0 {
player.total = 1
@ -158,32 +160,36 @@ func (p *Player) update() error {
p.seCh = nil
default:
}
if p.audioPlayer.IsPlaying() {
p.current = p.audioPlayer.Current()
}
p.updateBar()
p.updatePlayPause()
p.updateSE()
p.updateVolume()
if p.input.isKeyTriggered(ebiten.KeyB) {
p.seekBarIfNeeded()
p.switchPlayStateIfNeeded()
p.playSEIfNeeded()
p.updateVolumeIfNeeded()
if p.input.isKeyJustPressed(ebiten.KeyB) {
b := ebiten.IsRunnableInBackground()
ebiten.SetRunnableInBackground(!b)
}
return nil
}
func (p *Player) updateSE() {
func (p *Player) playSEIfNeeded() {
if p.seBytes == nil {
// Bytes for the SE is not loaded yet.
return
}
if !p.input.isKeyTriggered(ebiten.KeyP) {
if !p.input.isKeyJustPressed(ebiten.KeyP) {
return
}
sePlayer, _ := audio.NewPlayerFromBytes(p.audioContext, p.seBytes)
sePlayer.Play()
}
func (p *Player) updateVolume() {
func (p *Player) updateVolumeIfNeeded() {
if p.input.isKeyPressed(ebiten.KeyZ) {
p.volume128--
}
@ -199,8 +205,8 @@ func (p *Player) updateVolume() {
p.audioPlayer.SetVolume(float64(p.volume128) / 128)
}
func (p *Player) updatePlayPause() {
if !p.input.isKeyTriggered(ebiten.KeyS) {
func (p *Player) switchPlayStateIfNeeded() {
if !p.input.isKeyJustPressed(ebiten.KeyS) {
return
}
if p.audioPlayer.IsPlaying() {
@ -210,11 +216,12 @@ func (p *Player) updatePlayPause() {
p.audioPlayer.Play()
}
func (p *Player) updateBar() {
if !p.input.isMouseButtonTriggered(ebiten.MouseButtonLeft) {
func (p *Player) seekBarIfNeeded() {
if !p.input.isMouseButtonJustPressed(ebiten.MouseButtonLeft) {
return
}
// Start seeking.
// Calculate the next seeking position from the current cursor position.
x, y := ebiten.CursorPosition()
bx, by, bw, bh := playerBarRect()
const padding = 4
@ -234,40 +241,45 @@ func (p *Player) close() error {
}
func (p *Player) draw(screen *ebiten.Image) {
// Bar
// Draw the bar.
x, y, w, h := playerBarRect()
ebitenutil.DrawRect(screen, float64(x), float64(y), float64(w), float64(h), playerBarColor)
currentTimeStr := "00:00"
// Current Time
// Draw the cursor on the bar.
c := p.current
m := (c / time.Minute) % 100
s := (c / time.Second) % 60
currentTimeStr = fmt.Sprintf("%02d:%02d", m, s)
// Cursor
cw, ch := 4, 10
cx := int(time.Duration(w)*c/p.total) + x - cw/2
cy := y - (ch-h)/2
ebitenutil.DrawRect(screen, float64(cx), float64(cy), float64(cw), float64(ch), playerCurrentColor)
// Compose the curren time text.
m := (c / time.Minute) % 100
s := (c / time.Second) % 60
currentTimeStr := fmt.Sprintf("%02d:%02d", m, s)
// Draw the debug message.
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
Press B to switch the run-in-background state
%s`, ebiten.CurrentFPS(), currentTimeStr)
Current Time: %s`, ebiten.CurrentFPS(), currentTimeStr)
ebitenutil.DebugPrint(screen, msg)
}
var (
musicPlayer *Player
)
func update(screen *ebiten.Image) error {
if err := musicPlayer.update(); err != nil {
return err
}
if ebiten.IsRunningSlowly() {
return nil
}
musicPlayer.draw(screen)
return nil
}
@ -285,9 +297,7 @@ func main() {
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)
}
}
}