examples: Use RunGame

Updates #1111

examples/infinitescroll/main.go

@@ -54,10 +54,6 @@ func init() {
 	bgImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
 }
 
-var (
-	theViewport = &viewport{}
-)
-
 type viewport struct {
 	x16 int
 	y16 int
@@ -78,14 +74,17 @@ func (p *viewport) Position() (int, int) {
 	return p.x16, p.y16
 }
 
-func update(screen *ebiten.Image) error {
+type Game struct {
-	theViewport.Move()
+	viewport viewport
+}
 
-	if ebiten.IsDrawingSkipped() {
+func (g *Game) Update(screen *ebiten.Image) error {
-		return nil
+	g.viewport.Move()
-	}
+	return nil
+}
 
-	x16, y16 := theViewport.Position()
+func (g *Game) Draw(screen *ebiten.Image) {
+	x16, y16 := g.viewport.Position()
 	offsetX, offsetY := float64(-x16)/16, float64(-y16)/16
 
 	// Draw bgImage on the screen repeatedly.
@@ -101,11 +100,16 @@ func update(screen *ebiten.Image) error {
 	}
 
 	ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f", ebiten.CurrentTPS()))
-	return nil
+}
+
+func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
+	return screenWidth, screenHeight
 }
 
 func main() {
-	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Infinite Scroll (Ebiten Demo)"); err != nil {
+	ebiten.SetWindowSize(screenWidth*2, screenHeight*2)
+	ebiten.SetWindowTitle("Infinite Scroll (Ebiten Demo)")
+	if err := ebiten.RunGame(&Game{}); err != nil {
 		log.Fatal(err)
 	}
 }

examples/keyboard/main.go

@@ -45,18 +45,21 @@ func init() {
 	keyboardImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
 }
 
-func update(screen *ebiten.Image) error {
+type Game struct {
-	var pressed []ebiten.Key
+	pressed []ebiten.Key
+}
+
+func (g *Game) Update(screen *ebiten.Image) error {
+	g.pressed = nil
 	for k := ebiten.Key(0); k <= ebiten.KeyMax; k++ {
 		if ebiten.IsKeyPressed(k) {
-			pressed = append(pressed, k)
+			g.pressed = append(g.pressed, k)
 		}
 	}
+	return nil
+}
 
-	if ebiten.IsDrawingSkipped() {
+func (g *Game) Draw(screen *ebiten.Image) {
-		return nil
-	}
-
 	const (
 		offsetX = 24
 		offsetY = 40
@@ -70,7 +73,7 @@ func update(screen *ebiten.Image) error {
 
 	// Draw the highlighted keys.
 	op = &ebiten.DrawImageOptions{}
-	for _, p := range pressed {
+	for _, p := range g.pressed {
 		op.GeoM.Reset()
 		r, ok := keyboard.KeyRect(p)
 		if !ok {
@@ -82,16 +85,20 @@ func update(screen *ebiten.Image) error {
 	}
 
 	keyStrs := []string{}
-	for _, p := range pressed {
+	for _, p := range g.pressed {
 		keyStrs = append(keyStrs, p.String())
 	}
 	ebitenutil.DebugPrint(screen, strings.Join(keyStrs, ", "))
+}
 
-	return nil
+func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
+	return screenWidth, screenHeight
 }
 
 func main() {
-	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Keyboard (Ebiten Demo)"); err != nil {
+	ebiten.SetWindowSize(screenWidth*2, screenHeight*2)
+	ebiten.SetWindowTitle("Keyboard (Ebiten Demo)")
+	if err := ebiten.RunGame(&Game{}); err != nil {
 		log.Fatal(err)
 	}
 }

examples/life/main.go

@@ -33,6 +33,10 @@ import (
 	"github.com/hajimehoshi/ebiten"
 )
 
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
 // World represents the game state.
 type World struct {
 	area   []bool
@@ -51,11 +55,6 @@ func NewWorld(width, height int, maxInitLiveCells int) *World {
 	return w
 }
 
-func init() {
-	rand.Seed(time.Now().UnixNano())
-	world = NewWorld(screenWidth, screenHeight, int((screenWidth*screenHeight)/10))
-}
-
 // init inits world with a random state.
 func (w *World) init(maxLiveCells int) {
 	for i := 0; i < maxLiveCells; i++ {
@@ -156,25 +155,36 @@ const (
 	screenHeight = 240
 )
 
-var (
+type Game struct {
 	world  *World
-	pixels = make([]byte, screenWidth*screenHeight*4)
+	pixels []byte
-)
+}
 
-func update(screen *ebiten.Image) error {
+func (g *Game) Update(screen *ebiten.Image) error {
-	world.Update()
+	g.world.Update()
-
-	if ebiten.IsDrawingSkipped() {
-		return nil
-	}
-
-	world.Draw(pixels)
-	screen.ReplacePixels(pixels)
 	return nil
 }
 
+func (g *Game) Draw(screen *ebiten.Image) {
+	if g.pixels == nil {
+		g.pixels = make([]byte, screenWidth*screenHeight*4)
+	}
+	g.world.Draw(g.pixels)
+	screen.ReplacePixels(g.pixels)
+}
+
+func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
+	return screenWidth, screenHeight
+}
+
 func main() {
-	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Game of Life (Ebiten Demo)"); err != nil {
+	g := &Game{
+		world: NewWorld(screenWidth, screenHeight, int((screenWidth*screenHeight)/10)),
+	}
+
+	ebiten.SetWindowSize(screenWidth*2, screenHeight*2)
+	ebiten.SetWindowTitle("Game of Life (Ebiten Demo)")
+	if err := ebiten.RunGame(g); err != nil {
 		log.Fatal(err)
 	}
 }