diff --git a/.gitignore b/.gitignore
index b25c15b81..915b33024 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
+.DS_Store
 *~
+
diff --git a/example/blocks/game.go b/example/blocks/game.go
new file mode 100644
index 000000000..ff9fbe86e
--- /dev/null
+++ b/example/blocks/game.go
@@ -0,0 +1,158 @@
+package blocks
+
+import (
+	"fmt"
+	"github.com/hajimehoshi/go-ebiten/graphics"
+	"github.com/hajimehoshi/go-ebiten/ui"
+	"image"
+	_ "image/png"
+	"os"
+)
+
+type Size struct {
+	Width  int
+	Height int
+}
+
+var texturePaths = map[string]string{
+	"background": "images/blocks/background.png",
+	"font":       "images/blocks/font.png",
+}
+
+var renderTargetSizes = map[string]Size{
+	"whole": Size{256, 254},
+}
+
+const ScreenWidth = 256
+const ScreenHeight = 240
+
+var drawInfo = struct {
+	textures      map[string]graphics.TextureId
+	renderTargets map[string]graphics.RenderTargetId
+}{
+	textures:      map[string]graphics.TextureId{},
+	renderTargets: map[string]graphics.RenderTargetId{},
+}
+
+type Game struct {
+	sceneManager *SceneManager
+}
+
+func loadImage(path string) (image.Image, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return img, nil
+}
+
+func (game *Game) startLoadingTextures(textureFactory graphics.TextureFactory) {
+	for tag, path := range texturePaths {
+		tag := tag
+		path := path
+		go func() {
+			img, err := loadImage(path)
+			if err != nil {
+				panic(err)
+			}
+			textureFactory.CreateTexture(tag, img, graphics.FilterNearest)
+		}()
+	}
+
+	for tag, size := range renderTargetSizes {
+		tag := tag
+		size := size
+		go func() {
+			textureFactory.CreateRenderTarget(tag, size.Width, size.Height)
+		}()
+	}
+}
+
+func NewGame(textureFactory graphics.TextureFactory) *Game {
+	game := &Game{
+		sceneManager: NewSceneManager(NewTitleScene()),
+	}
+	game.startLoadingTextures(textureFactory)
+	return game
+}
+
+func (game *Game) HandleEvent(e interface{}) {
+	switch e := e.(type) {
+	case graphics.TextureCreatedEvent:
+		if e.Error != nil {
+			panic(e.Error)
+		}
+		drawInfo.textures[e.Tag.(string)] = e.Id
+	case graphics.RenderTargetCreatedEvent:
+		if e.Error != nil {
+			panic(e.Error)
+		}
+		drawInfo.renderTargets[e.Tag.(string)] = e.Id
+	case ui.KeyStateUpdatedEvent:
+		fmt.Printf("%v\n", e.Keys)
+	case ui.MouseStateUpdatedEvent:
+	}
+}
+
+func (game *Game) isInitialized() bool {
+	if len(drawInfo.textures) < len(texturePaths) {
+		return false
+	}
+	if len(drawInfo.renderTargets) < len(renderTargetSizes) {
+		return false
+	}
+	return true
+}
+
+func (game *Game) Update() {
+	if !game.isInitialized() {
+		return
+	}
+	game.sceneManager.Update()
+}
+
+func (game *Game) Draw(context graphics.Context) {
+	if !game.isInitialized() {
+		return
+	}
+	game.sceneManager.Draw(context)
+}
+
+/*func (game *Game) drawText(g graphics.Context, text string, x, y int, clr color.Color) {
+	const letterWidth = 6
+	const letterHeight = 16
+
+	parts := []graphics.TexturePart{}
+	textX := 0
+	textY := 0
+	for _, c := range text {
+		if c == '\n' {
+			textX = 0
+			textY += letterHeight
+			continue
+		}
+		code := int(c)
+		x := (code % 32) * letterWidth
+		y := (code / 32) * letterHeight
+		source := graphics.Rect{x, y, letterWidth, letterHeight}
+		parts = append(parts, graphics.TexturePart{
+			LocationX: textX,
+			LocationY: textY,
+			Source:    source,
+		})
+		textX += letterWidth
+	}
+
+	geometryMatrix := matrix.IdentityGeometry()
+	geometryMatrix.Translate(float64(x), float64(y))
+	colorMatrix := matrix.IdentityColor()
+	colorMatrix.Scale(clr)
+	g.DrawTextureParts(drawInfo.textures["text"], parts,
+		geometryMatrix, colorMatrix)
+}*/
diff --git a/example/blocks/scene_manager.go b/example/blocks/scene_manager.go
new file mode 100644
index 000000000..d2f574f7d
--- /dev/null
+++ b/example/blocks/scene_manager.go
@@ -0,0 +1,43 @@
+package blocks
+
+import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
+)
+
+type GameState struct {
+	SceneManager *SceneManager
+}
+
+type Scene interface {
+	Update(state GameState)
+	Draw(context graphics.Context)
+}
+
+type SceneManager struct {
+	current Scene
+	next    Scene
+}
+
+func NewSceneManager(initScene Scene) *SceneManager {
+	return &SceneManager{
+		current: initScene,
+	}
+}
+
+func (s *SceneManager) Update() {
+	if s.next != nil {
+		s.current = s.next
+		s.next = nil
+	}
+	s.current.Update(GameState{
+		SceneManager: s,
+	})
+}
+
+func (s *SceneManager) Draw(context graphics.Context) {
+	s.current.Draw(context)
+}
+
+func (s *SceneManager) GoTo(scene Scene) {
+	s.next = scene
+}
diff --git a/example/blocks/title_scene.go b/example/blocks/title_scene.go
new file mode 100644
index 000000000..8a6428cef
--- /dev/null
+++ b/example/blocks/title_scene.go
@@ -0,0 +1,81 @@
+package blocks
+
+import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
+	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
+	"image/color"
+)
+
+type TitleScene struct {
+	count int
+}
+
+func NewTitleScene() *TitleScene {
+	return &TitleScene{}
+}
+
+func (s *TitleScene) Update(state GameState) {
+	s.count++
+}
+
+func (s *TitleScene) Draw(context graphics.Context) {
+	drawTitleBackground(context, s.count)
+	drawLogo(context, "BLOCKS")
+}
+
+func drawTitleBackground(context graphics.Context, c int) {
+	const textureWidth = 32
+	const textureHeight = 32
+
+	backgroundTextureId := drawInfo.textures["background"]
+	parts := []graphics.TexturePart{}
+	for j := -1; j < ScreenHeight/textureHeight+1; j++ {
+		for i := 0; i < ScreenWidth/textureWidth+1; i++ {
+			parts = append(parts, graphics.TexturePart{
+				LocationX: i*textureWidth,
+				LocationY: j*textureHeight,
+				Source:    graphics.Rect{0, 0, textureWidth, textureHeight},
+			})
+		}
+	}
+
+	dx := -c % textureWidth / 2
+	dy := c % textureHeight / 2
+	geo := matrix.IdentityGeometry()
+	geo.Translate(float64(dx), float64(dy))
+	context.DrawTextureParts(backgroundTextureId, parts, geo, matrix.IdentityColor())
+}
+
+func drawLogo(context graphics.Context, str string) {
+	const charWidth = 8
+	const charHeight = 8
+	
+	fontTextureId := drawInfo.textures["font"]
+	parts := []graphics.TexturePart{}
+	
+	locationX := 0
+	locationY := 0
+	for _, c := range str {
+		if c == '\n' {
+			locationX = 0
+			locationY += charHeight
+			continue
+		}
+		code := int(c)
+		x := (code % 16) * charWidth
+		y := ((code - 32) / 16) * charHeight
+		parts = append(parts, graphics.TexturePart{
+			LocationX: locationX,
+			LocationY: locationY,
+			Source: graphics.Rect{x, y, charWidth, charHeight},
+		})
+		locationX += charWidth
+	}
+
+	geo := matrix.IdentityGeometry()
+	geo.Scale(4, 4)
+	clr := matrix.IdentityColor()
+	
+	clr.Scale(color.RGBA{0x00, 0x00, 0x60, 0xff})
+	context.DrawTextureParts(fontTextureId, parts, geo, clr)
+}
diff --git a/example/game.go b/example/game.go
deleted file mode 100644
index 88ca1f109..000000000
--- a/example/game.go
+++ /dev/null
@@ -1,183 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"github.com/hajimehoshi/go-ebiten/graphics"
-	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
-	"github.com/hajimehoshi/go-ebiten/ui"
-	"image/color"
-	"math"
-)
-
-var TexturePaths = map[string]string{
-	"ebiten": "images/ebiten.png",
-	"text":   "images/text.png",
-}
-
-type Size struct {
-	Width  int
-	Height int
-}
-
-var RenderTargetSizes = map[string]Size{
-	"whole": Size{256, 254},
-}
-
-type drawInfo struct {
-	textures      map[string]graphics.TextureId
-	renderTargets map[string]graphics.RenderTargetId
-	inputStr      string
-	textureX      int
-	textureY      int
-	textureAngle  float64
-	textureGeo    matrix.Geometry
-}
-
-type Game struct {
-	mouseX     int
-	mouseY     int
-	mousePrevX int
-	mousePrevY int
-	counter    int
-	drawInfo
-}
-
-func NewGame() *Game {
-	return &Game{
-		mouseX:     -1,
-		mouseY:     -1,
-		mousePrevX: -1,
-		mousePrevY: -1,
-		counter:    0,
-		drawInfo: drawInfo{
-			textures:      map[string]graphics.TextureId{},
-			renderTargets: map[string]graphics.RenderTargetId{},
-			textureX:      0,
-			textureY:      0,
-			textureAngle:  0,
-			textureGeo:    matrix.IdentityGeometry(),
-		},
-	}
-}
-
-func (game *Game) HandleEvent(e interface{}) {
-	switch e := e.(type) {
-	case graphics.TextureCreatedEvent:
-		if e.Error != nil {
-			panic(e.Error)
-		}
-		game.textures[e.Tag.(string)] = e.Id
-	case graphics.RenderTargetCreatedEvent:
-		if e.Error != nil {
-			panic(e.Error)
-		}
-		game.renderTargets[e.Tag.(string)] = e.Id
-	case ui.KeyStateUpdatedEvent:
-		fmt.Printf("%v\n", e.Keys)
-	case ui.MouseStateUpdatedEvent:
-		game.mouseX, game.mouseY = e.X, e.Y
-	}
-}
-
-func (game *Game) isInitialized() bool {
-	if len(game.drawInfo.textures) < len(TexturePaths) {
-		return false
-	}
-	if len(game.drawInfo.renderTargets) < len(RenderTargetSizes) {
-		return false
-	}
-	return true
-}
-
-func (game *Game) Update() {
-	if !game.isInitialized() {
-		return
-	}
-
-	const textureWidth = 57
-	const textureHeight = 26
-
-	game.counter++
-	game.drawInfo.inputStr = fmt.Sprintf(`Input State:
-  X: %d
-  Y: %d`, game.mouseX, game.mouseY)
-
-	if game.mousePrevX != -1 && game.mousePrevY != -1 &&
-		game.mouseX != -1 && game.mouseY != -1 {
-		dx, dy := game.mouseX-game.mousePrevX, game.mouseY-game.mousePrevY
-		game.textureX += dx
-		game.textureY += dy
-
-	}
-	game.drawInfo.textureAngle = 2 * math.Pi * float64(game.counter) / 600
-
-	geo := matrix.IdentityGeometry()
-	geo.Translate(-textureWidth/2, -textureHeight/2)
-	geo.Rotate(game.drawInfo.textureAngle)
-	geo.Translate(textureWidth/2, textureHeight/2)
-	geo.Translate(float64(game.textureX), float64(game.textureY))
-
-	game.drawInfo.textureGeo = geo
-
-	// Update for the next frame.
-	game.mousePrevX, game.mousePrevY = game.mouseX, game.mouseY
-}
-
-func (game *Game) Draw(g graphics.Context) {
-	if !game.isInitialized() {
-		return
-	}
-
-	whole := game.drawInfo.renderTargets["whole"]
-	g.SetOffscreen(whole)
-	g.Fill(0x70, 0x90, 0xe0)
-	game.drawTexture(g, game.drawInfo.textureGeo, matrix.IdentityColor())
-	game.drawText(g, game.drawInfo.inputStr, 6, 6, &color.RGBA{0x0, 0x0, 0x0, 0x80})
-	game.drawText(g, game.drawInfo.inputStr, 5, 5, color.White)
-
-	g.ResetOffscreen()
-	g.DrawRenderTarget(whole, matrix.IdentityGeometry(), matrix.IdentityColor())
-	wholeGeo := matrix.IdentityGeometry()
-	wholeGeo.Scale(0.5, 0.5)
-	wholeGeo.Translate(256/2, 240/2)
-	wholeColor := matrix.IdentityColor()
-	wholeColor.Scale(&color.RGBA{0x80, 0x80, 0x80, 0x80})
-	g.DrawRenderTarget(whole, wholeGeo, wholeColor)
-}
-
-func (game *Game) drawText(g graphics.Context, text string, x, y int, clr color.Color) {
-	const letterWidth = 6
-	const letterHeight = 16
-
-	parts := []graphics.TexturePart{}
-	textX := 0
-	textY := 0
-	for _, c := range text {
-		if c == '\n' {
-			textX = 0
-			textY += letterHeight
-			continue
-		}
-		code := int(c)
-		x := (code % 32) * letterWidth
-		y := (code / 32) * letterHeight
-		source := graphics.Rect{x, y, letterWidth, letterHeight}
-		parts = append(parts, graphics.TexturePart{
-			LocationX: textX,
-			LocationY: textY,
-			Source:    source,
-		})
-		textX += letterWidth
-	}
-
-	geometryMatrix := matrix.IdentityGeometry()
-	geometryMatrix.Translate(float64(x), float64(y))
-	colorMatrix := matrix.IdentityColor()
-	colorMatrix.Scale(clr)
-	g.DrawTextureParts(game.drawInfo.textures["text"], parts,
-		geometryMatrix, colorMatrix)
-}
-
-func (game *Game) drawTexture(g graphics.Context, geo matrix.Geometry, color matrix.Color) {
-	g.DrawTexture(game.drawInfo.textures["ebiten"], geo, color)
-}
diff --git a/example/images/blocks/background.png b/example/images/blocks/background.png
new file mode 100644
index 000000000..011b898d6
Binary files /dev/null and b/example/images/blocks/background.png differ
diff --git a/example/images/blocks/blocks.png b/example/images/blocks/blocks.png
new file mode 100644
index 000000000..1f2ede3b3
Binary files /dev/null and b/example/images/blocks/blocks.png differ
diff --git a/example/images/blocks/ebiten.png b/example/images/blocks/ebiten.png
new file mode 100644
index 000000000..72f89c8b2
Binary files /dev/null and b/example/images/blocks/ebiten.png differ
diff --git a/example/images/blocks/font.png b/example/images/blocks/font.png
new file mode 100644
index 000000000..7a76f04f4
Binary files /dev/null and b/example/images/blocks/font.png differ
diff --git a/example/main.go b/example/main.go
index d58566f31..0ea6bae42 100644
--- a/example/main.go
+++ b/example/main.go
@@ -1,38 +1,28 @@
 package main
 
 import (
+	"github.com/hajimehoshi/go-ebiten/example/blocks"
 	"github.com/hajimehoshi/go-ebiten/graphics"
 	"github.com/hajimehoshi/go-ebiten/ui"
 	"github.com/hajimehoshi/go-ebiten/ui/cocoa"
-	"image"
-	_ "image/png"
-	"os"
 	"runtime"
 	"time"
 )
 
+type Game interface {
+	HandleEvent(e interface{})
+	Update()
+	Draw(c graphics.Context)
+}
+
 func init() {
 	runtime.LockOSThread()
 }
 
-func loadImage(path string) (image.Image, error) {
-	file, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-
-	img, _, err := image.Decode(file)
-	if err != nil {
-		return nil, err
-	}
-	return img, nil
-}
-
 func main() {
-	const screenWidth = 256
-	const screenHeight = 240
-	const screenScale = 3
+	const screenWidth = blocks.ScreenWidth
+	const screenHeight = blocks.ScreenHeight
+	const screenScale = 2
 	const fps = 60
 	const title = "Ebiten Demo"
 
@@ -42,33 +32,13 @@ func main() {
 
 	textureFactoryEvents := textureFactory.Events()
 
-	for tag, path := range TexturePaths {
-		tag := tag
-		path := path
-		go func() {
-			img, err := loadImage(path)
-			if err != nil {
-				panic(err)
-			}
-			textureFactory.CreateTexture(tag, img)
-		}()
-	}
-
-	for tag, size := range RenderTargetSizes {
-		tag := tag
-		size := size
-		go func() {
-			textureFactory.CreateRenderTarget(tag, size.Width, size.Height)
-		}()
-	}
-
 	drawing := make(chan *graphics.LazyContext)
 	quit := make(chan struct{})
 	go func() {
 		defer close(quit)
 
 		windowEvents := window.Events()
-		game := NewGame()
+		var game Game = blocks.NewGame(textureFactory)
 		frameTime := time.Duration(int64(time.Second) / int64(fps))
 		tick := time.Tick(frameTime)
 		for {
@@ -76,10 +46,10 @@ func main() {
 			case e := <-textureFactoryEvents:
 				game.HandleEvent(e)
 			case e := <-windowEvents:
+				game.HandleEvent(e)
 				if _, ok := e.(ui.WindowClosedEvent); ok {
 					return
 				}
-				game.HandleEvent(e)
 			case <-tick:
 				game.Update()
 			case context := <-drawing:
diff --git a/graphics/graphics.go b/graphics/graphics.go
index 264695288..f211fa3fd 100644
--- a/graphics/graphics.go
+++ b/graphics/graphics.go
@@ -1,9 +1,5 @@
 package graphics
 
-import (
-	"image/color"
-)
-
 type Rect struct {
 	X      int
 	Y      int
@@ -17,11 +13,12 @@ type TexturePart struct {
 	Source    Rect
 }
 
-type Line struct {
-	X1, Y1 int
-	X2, Y2 int
-	Color  color.Color
-}
+type Filter int
+
+const (
+	FilterNearest Filter = iota
+	FilterLinear
+)
 
 type TextureId int
 
diff --git a/graphics/opengl/context.go b/graphics/opengl/context.go
index 48074e218..b2bb4f6ff 100644
--- a/graphics/opengl/context.go
+++ b/graphics/opengl/context.go
@@ -9,7 +9,6 @@ import (
 	"github.com/hajimehoshi/go-ebiten/graphics"
 	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
 	"github.com/hajimehoshi/go-ebiten/graphics/opengl/offscreen"
-	"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
 	"math"
 )
 
@@ -29,10 +28,11 @@ func newContext(ids *ids, screenWidth, screenHeight, screenScale int) *Context {
 
 	var err error
 	context.screenId, err = ids.CreateRenderTarget(
-		screenWidth, screenHeight, texture.FilterNearest)
+		screenWidth, screenHeight, graphics.FilterNearest)
 	if err != nil {
 		panic("initializing the offscreen failed: " + err.Error())
 	}
+	context.Clear()
 
 	return context
 }
@@ -98,10 +98,6 @@ func (context *Context) DrawRenderTargetParts(
 	context.DrawTextureParts(context.ids.ToTexture(id), parts, geometryMatrix, colorMatrix)
 }
 
-func (context *Context) DrawLines(lines []graphics.Line) {
-	context.offscreen.DrawLines(lines)
-}
-
 func (context *Context) ResetOffscreen() {
 	context.SetOffscreen(context.screenId)
 }
diff --git a/graphics/opengl/device.go b/graphics/opengl/device.go
index f06f1c6a9..9692043a0 100644
--- a/graphics/opengl/device.go
+++ b/graphics/opengl/device.go
@@ -2,7 +2,6 @@ package opengl
 
 import (
 	"github.com/hajimehoshi/go-ebiten/graphics"
-	"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
 	"image"
 )
 
@@ -26,13 +25,13 @@ func (d *Device) Update(context *Context, draw func(graphics.Context)) {
 }
 
 func (d *Device) CreateRenderTarget(width, height int) (graphics.RenderTargetId, error) {
-	renderTargetId, err := d.ids.CreateRenderTarget(width, height, texture.FilterLinear)
+	renderTargetId, err := d.ids.CreateRenderTarget(width, height, graphics.FilterLinear)
 	if err != nil {
 		return 0, err
 	}
 	return renderTargetId, nil
 }
 
-func (d *Device) CreateTexture(img image.Image) (graphics.TextureId, error) {
-	return d.ids.CreateTextureFromImage(img)
+func (d *Device) CreateTexture(img image.Image, filter graphics.Filter) (graphics.TextureId, error) {
+	return d.ids.CreateTexture(img, filter)
 }
diff --git a/graphics/opengl/ids.go b/graphics/opengl/ids.go
index 1db051057..c1c1c024b 100644
--- a/graphics/opengl/ids.go
+++ b/graphics/opengl/ids.go
@@ -50,9 +50,9 @@ func (i *ids) ToTexture(id graphics.RenderTargetId) graphics.TextureId {
 	return i.renderTargetToTexture[id]
 }
 
-func (i *ids) CreateTextureFromImage(img image.Image) (
+func (i *ids) CreateTexture(img image.Image, filter graphics.Filter) (
 	graphics.TextureId, error) {
-	texture, err := texture.CreateFromImage(img)
+	texture, err := texture.CreateFromImage(img, filter)
 	if err != nil {
 		return 0, err
 	}
@@ -64,7 +64,7 @@ func (i *ids) CreateTextureFromImage(img image.Image) (
 	return textureId, nil
 }
 
-func (i *ids) CreateRenderTarget(width, height int, filter texture.Filter) (
+func (i *ids) CreateRenderTarget(width, height int, filter graphics.Filter) (
 	graphics.RenderTargetId, error) {
 	renderTarget, texture, err := rendertarget.Create(width, height, filter)
 	if err != nil {
diff --git a/graphics/opengl/offscreen/offscreen.go b/graphics/opengl/offscreen/offscreen.go
index 344310f84..7d80e223b 100644
--- a/graphics/opengl/offscreen/offscreen.go
+++ b/graphics/opengl/offscreen/offscreen.go
@@ -63,10 +63,6 @@ func (o *Offscreen) DrawTextureParts(texture *gtexture.Texture,
 	texture.DrawParts(parts, &drawable{o, geometryMatrix, colorMatrix})
 }
 
-func (o *Offscreen) DrawLines(lines []graphics.Line) {
-	// TODO: Implement!
-}
-
 type setter struct {
 	offscreen            *Offscreen
 	usingMainFramebuffer bool
diff --git a/graphics/opengl/rendertarget/render_target.go b/graphics/opengl/rendertarget/render_target.go
index c26f879da..a5c5cfe3c 100644
--- a/graphics/opengl/rendertarget/render_target.go
+++ b/graphics/opengl/rendertarget/render_target.go
@@ -5,6 +5,7 @@ package rendertarget
 // #include <OpenGL/gl.h>
 import "C"
 import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
 	"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
 	gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
 )
@@ -43,7 +44,7 @@ func (f *framebufferCreator) Create(native interface{}) interface{} {
 	return createFramebuffer(C.GLuint(native.(texture.Native)))
 }
 
-func Create(width, height int, filter texture.Filter) (
+func Create(width, height int, filter graphics.Filter) (
 	*gtexture.RenderTarget, *gtexture.Texture, error) {
 	tex, err := texture.Create(width, height, filter)
 	if err != nil {
diff --git a/graphics/opengl/texture/texture.go b/graphics/opengl/texture/texture.go
index fbf3b4a55..8947bea97 100644
--- a/graphics/opengl/texture/texture.go
+++ b/graphics/opengl/texture/texture.go
@@ -5,6 +5,7 @@ package texture
 // #include <OpenGL/gl.h>
 import "C"
 import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
 	gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
 	"image"
 	"unsafe"
@@ -12,15 +13,8 @@ import (
 
 type Native C.GLuint
 
-type Filter int
-
-const (
-	FilterLinear Filter = iota
-	FilterNearest
-)
-
 func createNativeTexture(textureWidth, textureHeight int, pixels []uint8,
-	filter Filter) Native {
+	filter graphics.Filter) Native {
 	nativeTexture := C.GLuint(0)
 
 	C.glGenTextures(1, (*C.GLuint)(&nativeTexture))
@@ -33,9 +27,9 @@ func createNativeTexture(textureWidth, textureHeight int, pixels []uint8,
 
 	glFilter := C.GLint(0)
 	switch filter {
-	case FilterLinear:
+	case graphics.FilterLinear:
 		glFilter = C.GL_LINEAR
-	case FilterNearest:
+	case graphics.FilterNearest:
 		glFilter = C.GL_NEAREST
 	default:
 		panic("not reached")
@@ -54,17 +48,12 @@ func createNativeTexture(textureWidth, textureHeight int, pixels []uint8,
 	return Native(nativeTexture)
 }
 
-func create(textureWidth, textureHeight int, filter Filter) (
+func create(textureWidth, textureHeight int, filter graphics.Filter) (
 	interface{}, error) {
 	return createNativeTexture(textureWidth, textureHeight, nil, filter), nil
 }
 
-func createFromImage(img *image.NRGBA) (interface{}, error) {
-	size := img.Bounds().Size()
-	return createNativeTexture(size.X, size.Y, img.Pix, FilterLinear), nil
-}
-
-func Create(width, height int, filter Filter) (*gtexture.Texture, error) {
+func Create(width, height int, filter graphics.Filter) (*gtexture.Texture, error) {
 	native, err := create(gtexture.AdjustSize(width),
 		gtexture.AdjustSize(height), filter)
 	if err != nil {
@@ -73,11 +62,9 @@ func Create(width, height int, filter Filter) (*gtexture.Texture, error) {
 	return gtexture.New(native, width, height), nil
 }
 
-func CreateFromImage(img image.Image) (*gtexture.Texture, error) {
-	native, err := createFromImage(gtexture.AdjustImage(img))
-	if err != nil {
-		return nil, err
-	}
-	size := img.Bounds().Size()
+func CreateFromImage(img image.Image, filter graphics.Filter) (*gtexture.Texture, error) {
+	adjustedImage := gtexture.AdjustImage(img)
+	size := adjustedImage.Bounds().Size()
+	native := createNativeTexture(size.X, size.Y, adjustedImage.Pix, filter)
 	return gtexture.New(native, size.X, size.Y), nil
 }
diff --git a/graphics/texture/texture.go b/graphics/texture/texture.go
index 17e2e6c79..04d5aac67 100644
--- a/graphics/texture/texture.go
+++ b/graphics/texture/texture.go
@@ -36,7 +36,7 @@ func AdjustImage(img image.Image) *image.NRGBA {
 			AdjustSize(height),
 		},
 	}
-	if nrgba := img.(*image.NRGBA); nrgba != nil &&
+	if nrgba, ok := img.(*image.NRGBA); ok &&
 		img.Bounds() == adjustedImageBounds {
 		return nrgba
 	}
diff --git a/graphics/texture_factory.go b/graphics/texture_factory.go
index 7478cc2bb..41a08c7a0 100644
--- a/graphics/texture_factory.go
+++ b/graphics/texture_factory.go
@@ -18,6 +18,6 @@ type RenderTargetCreatedEvent struct {
 
 type TextureFactory interface {
 	CreateRenderTarget(tag interface{}, width, height int)
-	CreateTexture(tag interface{}, img image.Image)
+	CreateTexture(tag interface{}, img image.Image, filter Filter)
 	Events() <-chan interface{}
 }
diff --git a/ui/cocoa/ui.go b/ui/cocoa/ui.go
index 4634f825a..26e969862 100644
--- a/ui/cocoa/ui.go
+++ b/ui/cocoa/ui.go
@@ -15,9 +15,9 @@ import (
 )
 
 type cocoaUI struct {
-	textureFactory *textureFactory
+	textureFactory       *textureFactory
 	textureFactoryEvents chan interface{}
-	graphicsDevice *opengl.Device
+	graphicsDevice       *opengl.Device
 }
 
 var currentUI *cocoaUI
@@ -63,12 +63,12 @@ func (u *cocoaUI) Events() <-chan interface{} {
 	return u.textureFactoryEvents
 }
 
-func (u *cocoaUI) CreateTexture(tag interface{}, img image.Image) {
+func (u *cocoaUI) CreateTexture(tag interface{}, img image.Image, filter graphics.Filter) {
 	go func() {
 		var id graphics.TextureId
 		var err error
 		u.textureFactory.useGLContext(func() {
-			id, err = u.graphicsDevice.CreateTexture(img)
+			id, err = u.graphicsDevice.CreateTexture(img, filter)
 		})
 		if u.textureFactoryEvents == nil {
 			return
diff --git a/ui/cocoa/window.go b/ui/cocoa/window.go
index d16143a3c..d8e9b33a1 100644
--- a/ui/cocoa/window.go
+++ b/ui/cocoa/window.go
@@ -114,12 +114,13 @@ func (w *Window) notify(e interface{}) {
 	}()
 }
 
-/*//export ebiten_ScreenSizeUpdated
-func ebiten_ScreenSizeUpdated(nativeWindow unsafe.Pointer, width, height int) {
-	u := currentUI
-	e := ui.ScreenSizeUpdatedEvent{width, height}
-	u.windowEvents.notifyScreenSizeUpdated(e)
-}*/
+// Now this function is not used anywhere.
+//export ebiten_WindowSizeUpdated
+func ebiten_WindowSizeUpdated(nativeWindow unsafe.Pointer, width, height int) {
+	w := windows[nativeWindow]
+	e := ui.WindowSizeUpdatedEvent{width, height}
+	w.notify(e)
+}
 
 func (w *Window) keyStateUpdatedEvent() ui.KeyStateUpdatedEvent {
 	keys := []ui.Key{}
@@ -132,6 +133,7 @@ func (w *Window) keyStateUpdatedEvent() ui.KeyStateUpdatedEvent {
 }
 
 var cocoaKeyCodeToKey = map[int]ui.Key{
+	49:  ui.KeySpace,
 	123: ui.KeyLeft,
 	124: ui.KeyRight,
 	125: ui.KeyUp,
diff --git a/ui/ui.go b/ui/ui.go
index b3c7af525..489bae92d 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -11,9 +11,10 @@ const (
 	KeyDown
 	KeyLeft
 	KeyRight
+	KeySpace
 )
 
-type ScreenSizeUpdatedEvent struct {
+type WindowSizeUpdatedEvent struct {
 	Width  int
 	Height int
 }