examples: Remove unneeded error handlings

examples/audio/main.go

@@ -84,10 +84,7 @@ func (p *Player) updateSE() error {
 	if keyState[ebiten.KeyP] != 1 {
 		return nil
 	}
-	sePlayer, err := audio.NewPlayerFromBytes(audioContext, seBytes)
-	if err != nil {
-		return err
-	}
+	sePlayer, _ := audio.NewPlayerFromBytes(audioContext, seBytes)
 	sePlayer.Play()
 	return nil
 }
@@ -126,7 +123,8 @@ func (p *Player) updatePlayPause() error {
 	if p.audioPlayer.IsPlaying() {
 		return p.audioPlayer.Pause()
 	}
-	return p.audioPlayer.Play()
+	p.audioPlayer.Play()
+	return nil
 }
 
 func (p *Player) updateBar() {
@@ -287,10 +285,7 @@ func main() {
 		}
 		close(musicCh)
 		// TODO: Is this goroutine-safe?
-		if err := p.Play(); err != nil {
-			log.Fatal(err)
-			return
-		}
+		p.Play()
 	}()
 	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Audio (Ebiten Demo)"); err != nil {
 		log.Fatal(err)

examples/pcm/main.go

@@ -97,7 +97,7 @@ func toBytes(l, r []int16) []byte {
 	return b
 }
 
-func addNote() (rune, error) {
+func addNote() rune {
 	size := sampleRate / ebiten.FPS
 	notes := []float64{freqC, freqD, freqE, freqF, freqG, freqA * 2, freqB * 2}
 
@@ -126,25 +126,16 @@ func addNote() (rune, error) {
 	square(l, vol, freq, 0.25)
 	square(r, vol, freq, 0.25)
 	b := toBytes(l, r)
-	p, err := audio.NewPlayerFromBytes(audioContext, b)
-	if err != nil {
-		return 0, err
-	}
-	if err := p.Play(); err != nil {
-		return 0, err
-	}
-	return rune(note), nil
+	p, _ := audio.NewPlayerFromBytes(audioContext, b)
+	p.Play()
+	return rune(note)
 }
 
 var currentNote rune
 
 func update(screen *ebiten.Image) error {
 	if frames%30 == 0 {
-		n, err := addNote()
-		if err != nil {
-			return err
-		}
-		currentNote = n
+		currentNote = addNote()
 	}
 	frames++
 	if err := audioContext.Update(); err != nil {

examples/piano/main.go

@@ -81,17 +81,15 @@ func toBytes(l, r []int16) []byte {
 	return b
 }
 
-func addNote(freq float64, vol float64) error {
+func addNote(freq float64, vol float64) {
 	// TODO: Call Close method of *audio.Player.
 	// However, this works without Close because Close is automatically called when GC
 	// collects a *audio.Player object.
 	f := int(freq)
 	if n, ok := noteCache[f]; ok {
 		p, _ := audio.NewPlayerFromBytes(audioContext, n)
-		if err := p.Play(); err != nil {
-			return err
-		}
-		return nil
+		p.Play()
+		return
 	}
 	length := len(pcm) * baseFreq / f
 	l := make([]int16, length)
@@ -108,10 +106,8 @@ func addNote(freq float64, vol float64) error {
 	n := toBytes(l, r)
 	noteCache[f] = n
 	p, _ := audio.NewPlayerFromBytes(audioContext, n)
-	if err := p.Play(); err != nil {
-		return err
-	}
-	return nil
+	p.Play()
+	return
 }
 
 var keys = []ebiten.Key{
@@ -197,9 +193,7 @@ func update(screen *ebiten.Image) error {
 		if keyStates[key] != 1 {
 			continue
 		}
-		if err := addNote(220*math.Exp2(float64(i-1)/12.0), 1.0); err != nil {
-			return err
-		}
+		addNote(220*math.Exp2(float64(i-1)/12.0), 1.0)
 	}
 	if ebiten.IsRunningSlowly() {
 		return nil

examples/sinewave/main.go

@@ -95,9 +95,7 @@ func update(screen *ebiten.Image) error {
 		if err != nil {
 			return err
 		}
-		if err := player.Play(); err != nil {
-			return err
-		}
+		player.Play()
 	}
 	if ebiten.IsRunningSlowly() {
 		return nil