Simplify Run and Remove Game

example/blocks/blocks/game.go

@@ -70,7 +70,7 @@ func (game *Game) isInitialized() bool {
 	return true
 }
 
-func (game *Game) Update() error {
+func (game *Game) Update(g ebiten.GraphicsContext) error {
 	game.once.Do(func() {
 		game.textures = NewTextures()
 		for name, path := range texturePaths {
@@ -88,13 +88,6 @@ func (game *Game) Update() error {
 		SceneManager: game.sceneManager,
 		Input:        game.input,
 	})
-	return nil
-}
-
-func (game *Game) Draw(g ebiten.GraphicsContext) error {
-	if !game.isInitialized() {
-		return nil
-	}
 	game.sceneManager.Draw(g, game.textures)
 	return nil
 }

example/blocks/main.go

@@ -44,7 +44,7 @@ func main() {
 	}
 
 	game := blocks.NewGame()
-	if err := ebiten.Run(game, blocks.ScreenWidth, blocks.ScreenHeight, 2, "Blocks (Ebiten Demo)", 60); err != nil {
+	if err := ebiten.Run(game.Update, blocks.ScreenWidth, blocks.ScreenHeight, 2, "Blocks (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}
 }

example/image/main.go

@@ -33,7 +33,7 @@ type Game struct {
 	gophersTexture ebiten.TextureID
 }
 
-func (g *Game) Update() error {
+func (g *Game) Update(gr ebiten.GraphicsContext) error {
 	if g.gophersTexture.IsNil() {
 		file, err := os.Open("images/gophers.jpg")
 		if err != nil {
@@ -50,10 +50,6 @@ func (g *Game) Update() error {
 		}
 		g.gophersTexture = id
 	}
-	return nil
-}
-
-func (g *Game) Draw(gr ebiten.GraphicsContext) error {
 	if g.gophersTexture.IsNil() {
 		return nil
 	}
@@ -62,7 +58,8 @@ func (g *Game) Draw(gr ebiten.GraphicsContext) error {
 }
 
 func main() {
-	if err := ebiten.Run(new(Game), screenWidth, screenHeight, 2, "Image (Ebiten Demo)", 60); err != nil {
+	g := new(Game)
+	if err := ebiten.Run(g.Update, screenWidth, screenHeight, 2, "Image (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}
 }

example/paint/main.go

@@ -23,7 +23,6 @@ import (
 	"image/color"
 	"log"
 	"math"
-	"runtime"
 )
 
 const (
@@ -37,14 +36,10 @@ type Game struct {
 	canvasRenderTarget ebiten.RenderTargetID
 }
 
-func (g *Game) Update() error {
+func (g *Game) Update(gr ebiten.GraphicsContext) error {
 	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
 		g.count++
 	}
-	return nil
-}
-
-func (g *Game) Draw(gr ebiten.GraphicsContext) error {
 	if g.brushRenderTarget.IsNil() {
 		var err error
 		g.brushRenderTarget, err = ebiten.NewRenderTargetID(1, 1, ebiten.FilterNearest)
@@ -84,13 +79,9 @@ func (g *Game) Draw(gr ebiten.GraphicsContext) error {
 	return nil
 }
 
-func init() {
-	runtime.LockOSThread()
-}
-
 func main() {
-	game := new(Game)
+	g := new(Game)
-	if err := ebiten.Run(game, screenWidth, screenHeight, 2, "Paint (Ebiten Demo)", 60); err != nil {
+	if err := ebiten.Run(g.Update, screenWidth, screenHeight, 2, "Paint (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}
 }

run.go

@@ -17,19 +17,9 @@ limitations under the License.
 package ebiten
 
 import (
-	"os"
-	"os/signal"
 	"runtime"
-	"syscall"
-	"time"
 )
 
-// A Game is the interface that represents a game.
-type Game interface {
-	Update() error
-	Draw(gr GraphicsContext) error
-}
-
 var currentUI *ui
 
 func init() {
@@ -38,7 +28,7 @@ func init() {
 
 // Run runs the game.
 // This function must be called from the main thread.
-func Run(game Game, width, height, scale int, title string, fps int) error {
+func Run(f func(GraphicsContext) error, width, height, scale int, title string) error {
 	ui, err := newUI(width, height, scale, title)
 	if err != nil {
 		return err
@@ -50,27 +40,13 @@ func Run(game Game, width, height, scale int, title string, fps int) error {
 		currentUI = nil
 	}()
 
-	frameTime := time.Duration(int64(time.Second) / int64(fps))
-	tick := time.Tick(frameTime)
-	sigterm := make(chan os.Signal, 1)
-	signal.Notify(sigterm, os.Interrupt, syscall.SIGTERM)
-
 	for {
 		ui.doEvents()
 		if ui.isClosed() {
 			return nil
 		}
-		select {
+		if err := ui.draw(f); err != nil {
-		default:
+			return err
-			if err := ui.draw(game.Draw); err != nil {
-				return err
-			}
-		case <-tick:
-			if err := game.Update(); err != nil {
-				return err
-			}
-		case <-sigterm:
-			return nil
 		}
 	}
 }