audio: Remove the error returning value from NewContext

Updates #1380

audio/audio.go

@@ -84,10 +84,8 @@ var (
 // Other values might not work.
 // For example, 22050 causes error on Safari when decoding MP3.
 //
-// Error returned by NewContext is always nil as of 1.5.0-alpha.
-//
 // NewContext panics when an audio context is already created.
-func NewContext(sampleRate int) (*Context, error) {
+func NewContext(sampleRate int) *Context {
 	theContextLock.Lock()
 	defer theContextLock.Unlock()
 	if theContext != nil {
@@ -127,7 +125,7 @@ func NewContext(sampleRate int) (*Context, error) {
 		return err
 	})
 
-	return c, nil
+	return c
 }
 
 // CurrentContext returns the current context or nil if there is no context.

audio/audio_test.go

@@ -25,11 +25,7 @@ import (
 var context *Context
 
 func setup() {
-	var err error
+	context = NewContext(44100)
-	context, err = NewContext(44100)
-	if err != nil {
-		panic(err)
-	}
 }
 
 func teardown() {

audio/vorbis/vorbis_test.go

@@ -23,15 +23,7 @@ import (
 	. "github.com/hajimehoshi/ebiten/v2/audio/vorbis"
 )
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(44100)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(44100)
-	if err != nil {
-		panic(err)
-	}
-}
 
 func TestMono(t *testing.T) {
 	bs := test_mono_ogg

examples/audio/main.go

@@ -267,10 +267,7 @@ type Game struct {
 }
 
 func NewGame() (*Game, error) {
-	audioContext, err := audio.NewContext(sampleRate)
+	audioContext := audio.NewContext(sampleRate)
-	if err != nil {
-		return nil, err
-	}
 
 	m, err := NewPlayer(audioContext, typeOgg)
 	if err != nil {

examples/audioinfiniteloop/main.go

@@ -37,15 +37,7 @@ const (
 	loopLengthInSecond  = 4
 )
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(sampleRate)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
 
 type Game struct {
 	player *audio.Player

examples/audiopanning/main.go

@@ -41,15 +41,7 @@ const (
 
 var img *ebiten.Image
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(sampleRate)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
 
 type Game struct {
 	player    *audio.Player

examples/flappy/main.go

@@ -116,14 +116,12 @@ func init() {
 }
 
 var (
-	audioContext *audio.Context
+	audioContext = audio.NewContext(44100)
 	jumpPlayer   *audio.Player
 	hitPlayer    *audio.Player
 )
 
 func init() {
-	audioContext, _ = audio.NewContext(44100)
-
 	jumpD, err := vorbis.Decode(audioContext, audio.BytesReadSeekCloser(raudio.Jump_ogg))
 	if err != nil {
 		log.Fatal(err)

examples/pcm/main.go

@@ -32,15 +32,7 @@ const (
 	sampleRate   = 44100
 )
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(sampleRate)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
 
 const (
 	freqA  = 440.0

examples/piano/main.go

@@ -64,15 +64,7 @@ const (
 	baseFreq     = 220
 )
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(sampleRate)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
 
 // pianoAt returns an i-th sample of piano with the given frequency.
 func pianoAt(i int, freq float64) float64 {

examples/sinewave/main.go

@@ -33,15 +33,7 @@ const (
 	frequency    = 440
 )
 
-var audioContext *audio.Context
+var audioContext = audio.NewContext(sampleRate)
-
-func init() {
-	var err error
-	audioContext, err = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
 
 // stream is an infinite stream of 440 Hz sine wave.
 type stream struct {

examples/wav/main.go

@@ -42,10 +42,7 @@ var g Game
 func init() {
 	var err error
 	// Initialize audio context.
-	g.audioContext, err = audio.NewContext(sampleRate)
+	g.audioContext = audio.NewContext(sampleRate)
-	if err != nil {
-		log.Fatal(err)
-	}
 
 	// In this example, embedded resource "Jab_wav" is used.
 	//