Add error checks

ebitenutil/loadimage.go

@@ -34,7 +34,9 @@ func NewImageFromFile(path string, filter ebiten.Filter) (*ebiten.Image, image.I
 	if err != nil {
 		return nil, nil, err
 	}
-	defer file.Close()
+	defer func() {
+		_ = file.Close()
+	}()
 	img, _, err := image.Decode(file)
 	if err != nil {
 		return nil, nil, err

examples/2048/2048/board.go

@@ -30,15 +30,17 @@ type Board struct {
 	tasks []task
 }
 
-func NewBoard(size int) *Board {
+func NewBoard(size int) (*Board, error) {
 	b := &Board{
 		size:  size,
 		tiles: map[*Tile]struct{}{},
 	}
 	for i := 0; i < 2; i++ {
-		addRandomTile(b.tiles, b.size)
+		if err := addRandomTile(b.tiles, b.size); err != nil {
+			return nil, err
+		}
 	}
-	return b
+	return b, nil
 }
 
 func (b *Board) tileAt(x, y int) *Tile {

examples/2048/2048/game.go

@@ -37,11 +37,16 @@ type Game struct {
 	boardImage *ebiten.Image
 }
 
-func NewGame() *Game {
+func NewGame() (*Game, error) {
-	return &Game{
+	g := &Game{
 		input: NewInput(),
-		board: NewBoard(boardSize),
 	}
+	var err error
+	g.board, err = NewBoard(boardSize)
+	if err != nil {
+		return nil, err
+	}
+	return g, nil
 }
 
 func (g *Game) Update() error {

examples/2048/2048/tile.go

@@ -346,6 +346,8 @@ func (t *Tile) Draw(boardImage *ebiten.Image) error {
 	h := common.ArcadeFont.TextHeight(str) * scale
 	x = x + (tileSize-w)/2
 	y = y + (tileSize-h)/2
-	common.ArcadeFont.DrawText(boardImage, str, x, y, scale, tileColor(v))
+	if err := common.ArcadeFont.DrawText(boardImage, str, x, y, scale, tileColor(v)); err != nil {
+		return err
+	}
 	return nil
 }

examples/2048/main.go

@@ -22,7 +22,7 @@ import (
 )
 
 var (
-	game = twenty48.NewGame()
+	game *twenty48.Game
 )
 
 func update(screen *ebiten.Image) error {
@@ -39,6 +39,11 @@ func update(screen *ebiten.Image) error {
 }
 
 func main() {
+	var err error
+	game, err = twenty48.NewGame()
+	if err != nil {
+		log.Fatal(err)
+	}
 	if err := ebiten.Run(update, twenty48.ScreenWidth, twenty48.ScreenHeight, 2, "2048 (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}

examples/additive/main.go

@@ -37,14 +37,20 @@ func update(screen *ebiten.Image) error {
 	const ox = 10
 	const oy = 10
 
-	screen.Fill(color.NRGBA{0x00, 0x40, 0x80, 0xff})
+	if err := screen.Fill(color.NRGBA{0x00, 0x40, 0x80, 0xff}); err != nil {
+		return err
+	}
 	op := &ebiten.DrawImageOptions{}
 	op.GeoM.Translate(ox, oy)
-	screen.DrawImage(ebitenImage, op)
+	if err := screen.DrawImage(ebitenImage, op); err != nil {
+		return err
+	}
 	op = &ebiten.DrawImageOptions{}
 	op.GeoM.Translate(ox+float64(w), oy)
 	op.CompositeMode = ebiten.CompositeModeLighter
-	screen.DrawImage(ebitenImage, op)
+	if err := screen.DrawImage(ebitenImage, op); err != nil {
+		return err
+	}
 	return nil
 }
 

internal/loop/run.go

@@ -101,10 +101,7 @@ func Run(g GraphicsContext, width, height int, scale float64, title string, fps
 	}
 	// TODO: Use the error value
 	defer func() {
-		if err != nil {
+		_ = ui.CurrentUI().Terminate()
-			return
-		}
-		err = ui.CurrentUI().Terminate()
 	}()
 
 	n := now()

internal/ui/ui_glfw.go

@@ -90,7 +90,6 @@ func (u *userInterface) main(ch <-chan error) error {
 			return err
 		}
 	}
-	return nil
 }
 
 func (u *userInterface) runOnMainThread(f func() error) error {