diff --git a/example/game.go b/example/game.go
index 328fca6d2..b08f75dde 100644
--- a/example/game.go
+++ b/example/game.go
@@ -122,7 +122,7 @@ func (game *Game) Update() {
 	game.inputPrevX, game.inputPrevY = game.inputX, game.inputY
 }
 
-func (game *Game) Draw(g graphics.Canvas) {
+func (game *Game) Draw(g graphics.Context) {
 	if !game.isInitialized() {
 		return
 	}
@@ -144,7 +144,7 @@ func (game *Game) Draw(g graphics.Canvas) {
 	g.DrawRenderTarget(whole, wholeGeo, wholeColor)
 }
 
-func (game *Game) drawText(g graphics.Canvas, text string, x, y int, clr color.Color) {
+func (game *Game) drawText(g graphics.Context, text string, x, y int, clr color.Color) {
 	const letterWidth = 6
 	const letterHeight = 16
 
@@ -177,6 +177,6 @@ func (game *Game) drawText(g graphics.Canvas, text string, x, y int, clr color.C
 		geometryMatrix, colorMatrix)
 }
 
-func (game *Game) drawTexture(g graphics.Canvas, geo matrix.Geometry, color matrix.Color) {
+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/main.go b/example/main.go
index ef59847a9..18aa6e4b5 100644
--- a/example/main.go
+++ b/example/main.go
@@ -62,7 +62,7 @@ func main() {
 		}()
 	}
 
-	drawing := make(chan *graphics.LazyCanvas)
+	drawing := make(chan *graphics.LazyContext)
 	quit := make(chan struct{})
 	go func() {
 		defer close(quit)
@@ -89,9 +89,9 @@ func main() {
 				return
 			case <-tick:
 				game.Update()
-			case canvas := <-drawing:
-				game.Draw(canvas)
-				drawing <- canvas
+			case context := <-drawing:
+				game.Draw(context)
+				drawing <- context
 			}
 		}
 	}()
@@ -100,11 +100,11 @@ func main() {
 		ui.PollEvents()
 		select {
 		default:
-			drawing <- graphics.NewLazyCanvas()
-			canvas := <-drawing
+			drawing <- graphics.NewLazyContext()
+			context := <-drawing
 
-			window.Draw(func(actualCanvas graphics.Canvas) {
-				canvas.Flush(actualCanvas)
+			window.Draw(func(actualContext graphics.Context) {
+				context.Flush(actualContext)
 			})
 			after := time.After(time.Duration(int64(time.Second) / 120))
 			ui.PollEvents()
diff --git a/graphics/canvas.go b/graphics/context.go
similarity index 59%
rename from graphics/canvas.go
rename to graphics/context.go
index 782bb5030..9b7b26279 100644
--- a/graphics/canvas.go
+++ b/graphics/context.go
@@ -4,7 +4,7 @@ import (
 	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
 )
 
-type Canvas interface {
+type Context interface {
 	Clear()
 	Fill(r, g, b uint8)
 	// TODO: Refacotring
@@ -27,81 +27,81 @@ type Canvas interface {
 	SetOffscreen(id RenderTargetId)
 }
 
-type LazyCanvas struct {
-	funcs []func(Canvas)
+type LazyContext struct {
+	funcs []func(Context)
 }
 
-func NewLazyCanvas() *LazyCanvas {
-	return &LazyCanvas{
-		funcs: []func(Canvas){},
+func NewLazyContext() *LazyContext {
+	return &LazyContext{
+		funcs: []func(Context){},
 	}
 }
 
-func (c *LazyCanvas) Flush(actual Canvas) {
+func (c *LazyContext) Flush(actual Context) {
 	for _, f := range c.funcs {
 		f(actual)
 	}
-	c.funcs = []func(Canvas){}
+	c.funcs = []func(Context){}
 }
 
-func (c *LazyCanvas) Clear() {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+func (c *LazyContext) Clear() {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.Clear()
 	})
 }
 
-func (c *LazyCanvas) Fill(r, g, b uint8) {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+func (c *LazyContext) Fill(r, g, b uint8) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.Fill(r, g, b)
 	})
 }
 
-func (c *LazyCanvas) DrawTexture(id TextureId,
+func (c *LazyContext) DrawTexture(id TextureId,
 	geometryMatrix matrix.Geometry,
 	colorMatrix matrix.Color) {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.DrawTexture(id, geometryMatrix, colorMatrix)
 	})
 }
 
-func (c *LazyCanvas) DrawRenderTarget(id RenderTargetId,
+func (c *LazyContext) DrawRenderTarget(id RenderTargetId,
 	geometryMatrix matrix.Geometry,
 	colorMatrix matrix.Color) {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.DrawRenderTarget(id, geometryMatrix, colorMatrix)
 	})
 }
 
-func (c *LazyCanvas) DrawTextureParts(id TextureId,
+func (c *LazyContext) DrawTextureParts(id TextureId,
 	parts []TexturePart,
 	geometryMatrix matrix.Geometry,
 	colorMatrix matrix.Color) {
 	parts2 := make([]TexturePart, len(parts))
 	copy(parts2, parts)
-	c.funcs = append(c.funcs, func(actual Canvas) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.DrawTextureParts(id, parts2, geometryMatrix, colorMatrix)
 	})
 }
 
-func (c *LazyCanvas) DrawRenderTargetParts(id RenderTargetId,
+func (c *LazyContext) DrawRenderTargetParts(id RenderTargetId,
 	parts []TexturePart,
 	geometryMatrix matrix.Geometry,
 	colorMatrix matrix.Color) {
 	parts2 := make([]TexturePart, len(parts))
 	copy(parts2, parts)
-	c.funcs = append(c.funcs, func(actual Canvas) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.DrawRenderTargetParts(id, parts2, geometryMatrix, colorMatrix)
 	})
 }
 
-func (c *LazyCanvas) ResetOffscreen() {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+func (c *LazyContext) ResetOffscreen() {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.ResetOffscreen()
 	})
 }
 
-func (c *LazyCanvas) SetOffscreen(id RenderTargetId) {
-	c.funcs = append(c.funcs, func(actual Canvas) {
+func (c *LazyContext) SetOffscreen(id RenderTargetId) {
+	c.funcs = append(c.funcs, func(actual Context) {
 		actual.SetOffscreen(id)
 	})
 }
diff --git a/graphics/opengl/canvas.go b/graphics/opengl/context.go
similarity index 51%
rename from graphics/opengl/canvas.go
rename to graphics/opengl/context.go
index 32401c4d2..48074e218 100644
--- a/graphics/opengl/canvas.go
+++ b/graphics/opengl/context.go
@@ -13,56 +13,56 @@ import (
 	"math"
 )
 
-type Canvas struct {
+type Context struct {
 	screenId    graphics.RenderTargetId
 	ids         *ids
 	offscreen   *offscreen.Offscreen
 	screenScale int
 }
 
-func newCanvas(ids *ids, screenWidth, screenHeight, screenScale int) *Canvas {
-	canvas := &Canvas{
+func newContext(ids *ids, screenWidth, screenHeight, screenScale int) *Context {
+	context := &Context{
 		ids:         ids,
 		offscreen:   offscreen.New(screenWidth, screenHeight, screenScale),
 		screenScale: screenScale,
 	}
 
 	var err error
-	canvas.screenId, err = ids.CreateRenderTarget(
+	context.screenId, err = ids.CreateRenderTarget(
 		screenWidth, screenHeight, texture.FilterNearest)
 	if err != nil {
 		panic("initializing the offscreen failed: " + err.Error())
 	}
 
-	return canvas
+	return context
 }
 
-func (canvas *Canvas) update(draw func(graphics.Canvas)) {
+func (context *Context) update(draw func(graphics.Context)) {
 	C.glEnable(C.GL_TEXTURE_2D)
 	C.glEnable(C.GL_BLEND)
 
-	canvas.ResetOffscreen()
-	canvas.Clear()
+	context.ResetOffscreen()
+	context.Clear()
 
-	draw(canvas)
+	draw(context)
 
 	C.glFlush()
-	canvas.offscreen.SetMainFramebuffer()
-	canvas.Clear()
+	context.offscreen.SetMainFramebuffer()
+	context.Clear()
 
-	scale := float64(canvas.screenScale)
+	scale := float64(context.screenScale)
 	geometryMatrix := matrix.IdentityGeometry()
 	geometryMatrix.Scale(scale, scale)
-	canvas.DrawRenderTarget(canvas.screenId,
+	context.DrawRenderTarget(context.screenId,
 		geometryMatrix, matrix.IdentityColor())
 	C.glFlush()
 }
 
-func (canvas *Canvas) Clear() {
-	canvas.Fill(0, 0, 0)
+func (context *Context) Clear() {
+	context.Fill(0, 0, 0)
 }
 
-func (canvas *Canvas) Fill(r, g, b uint8) {
+func (context *Context) Fill(r, g, b uint8) {
 	const max = float64(math.MaxUint8)
 	C.glClearColor(
 		C.GLclampf(float64(r)/max),
@@ -72,41 +72,41 @@ func (canvas *Canvas) Fill(r, g, b uint8) {
 	C.glClear(C.GL_COLOR_BUFFER_BIT)
 }
 
-func (canvas *Canvas) DrawTexture(
+func (context *Context) DrawTexture(
 	id graphics.TextureId,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	tex := canvas.ids.TextureAt(id)
-	canvas.offscreen.DrawTexture(tex, geometryMatrix, colorMatrix)
+	tex := context.ids.TextureAt(id)
+	context.offscreen.DrawTexture(tex, geometryMatrix, colorMatrix)
 }
 
-func (canvas *Canvas) DrawRenderTarget(
+func (context *Context) DrawRenderTarget(
 	id graphics.RenderTargetId,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	canvas.DrawTexture(canvas.ids.ToTexture(id), geometryMatrix, colorMatrix)
+	context.DrawTexture(context.ids.ToTexture(id), geometryMatrix, colorMatrix)
 }
 
-func (canvas *Canvas) DrawTextureParts(
+func (context *Context) DrawTextureParts(
 	id graphics.TextureId, parts []graphics.TexturePart,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	tex := canvas.ids.TextureAt(id)
-	canvas.offscreen.DrawTextureParts(tex, parts, geometryMatrix, colorMatrix)
+	tex := context.ids.TextureAt(id)
+	context.offscreen.DrawTextureParts(tex, parts, geometryMatrix, colorMatrix)
 }
 
-func (canvas *Canvas) DrawRenderTargetParts(
+func (context *Context) DrawRenderTargetParts(
 	id graphics.RenderTargetId, parts []graphics.TexturePart,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	canvas.DrawTextureParts(canvas.ids.ToTexture(id), parts, geometryMatrix, colorMatrix)
+	context.DrawTextureParts(context.ids.ToTexture(id), parts, geometryMatrix, colorMatrix)
 }
 
-func (canvas *Canvas) DrawLines(lines []graphics.Line) {
-	canvas.offscreen.DrawLines(lines)
+func (context *Context) DrawLines(lines []graphics.Line) {
+	context.offscreen.DrawLines(lines)
 }
 
-func (canvas *Canvas) ResetOffscreen() {
-	canvas.SetOffscreen(canvas.screenId)
+func (context *Context) ResetOffscreen() {
+	context.SetOffscreen(context.screenId)
 }
 
-func (canvas *Canvas) SetOffscreen(renderTargetId graphics.RenderTargetId) {
-	renderTarget := canvas.ids.RenderTargetAt(renderTargetId)
-	canvas.offscreen.Set(renderTarget)
+func (context *Context) SetOffscreen(renderTargetId graphics.RenderTargetId) {
+	renderTarget := context.ids.RenderTargetAt(renderTargetId)
+	context.offscreen.Set(renderTarget)
 }
diff --git a/graphics/opengl/device.go b/graphics/opengl/device.go
index 2fc3a51c6..f06f1c6a9 100644
--- a/graphics/opengl/device.go
+++ b/graphics/opengl/device.go
@@ -17,12 +17,12 @@ func NewDevice() *Device {
 	return device
 }
 
-func (d *Device) CreateCanvas(screenWidth, screenHeight, screenScale int) *Canvas {
-	return newCanvas(d.ids, screenWidth, screenHeight, screenScale)
+func (d *Device) CreateContext(screenWidth, screenHeight, screenScale int) *Context {
+	return newContext(d.ids, screenWidth, screenHeight, screenScale)
 }
 
-func (d *Device) Update(canvas *Canvas, draw func(graphics.Canvas)) {
-	canvas.update(draw)
+func (d *Device) Update(context *Context, draw func(graphics.Context)) {
+	context.update(draw)
 }
 
 func (d *Device) CreateRenderTarget(width, height int) (graphics.RenderTargetId, error) {
diff --git a/ui/cocoa/texture_factory.go b/ui/cocoa/texture_factory.go
index 3f9c3f0ae..f4425bd8b 100644
--- a/ui/cocoa/texture_factory.go
+++ b/ui/cocoa/texture_factory.go
@@ -45,7 +45,7 @@ func (t *textureFactory) loop() {
 	}
 }
 
-func (t *textureFactory) useContext(f func()) {
+func (t *textureFactory) useGLContext(f func()) {
 	t.funcs <- f
 	<-t.funcsDone
 }
diff --git a/ui/cocoa/ui.go b/ui/cocoa/ui.go
index 9bfff9124..6fb2be9ec 100644
--- a/ui/cocoa/ui.go
+++ b/ui/cocoa/ui.go
@@ -31,7 +31,7 @@ func getCurrentUI() *cocoaUI {
 	C.StartApplication()
 
 	currentUI.textureFactory = runTextureFactory()
-	currentUI.textureFactory.useContext(func() {
+	currentUI.textureFactory.useGLContext(func() {
 		currentUI.graphicsDevice = opengl.NewDevice()
 	})
 
@@ -66,7 +66,7 @@ func (u *cocoaUI) CreateTexture(tag interface{}, img image.Image) {
 	go func() {
 		var id graphics.TextureId
 		var err error
-		u.textureFactory.useContext(func() {
+		u.textureFactory.useGLContext(func() {
 			id, err = u.graphicsDevice.CreateTexture(img)
 		})
 		e := graphics.TextureCreatedEvent{
@@ -82,7 +82,7 @@ func (u *cocoaUI) CreateRenderTarget(tag interface{}, width, height int) {
 	go func() {
 		var id graphics.RenderTargetId
 		var err error
-		u.textureFactory.useContext(func() {
+		u.textureFactory.useGLContext(func() {
 			id, err = u.graphicsDevice.CreateRenderTarget(width, height)
 		})
 		e := graphics.RenderTargetCreatedEvent{
diff --git a/ui/cocoa/window.go b/ui/cocoa/window.go
index 245e23d46..f99a38beb 100644
--- a/ui/cocoa/window.go
+++ b/ui/cocoa/window.go
@@ -27,7 +27,7 @@ type Window struct {
 	screenScale  int
 	closed       bool
 	native       unsafe.Pointer
-	canvas       *opengl.Canvas
+	context       *opengl.Context
 	funcs        chan func()
 	funcsDone    chan struct{}
 	windowEvents
@@ -62,8 +62,8 @@ func runWindow(ui *cocoaUI, width, height, scale int, title string, sharedContex
 		w.loop()
 	}()
 	<-ch
-	w.useContext(func() {
-		w.canvas = ui.graphicsDevice.CreateCanvas(width, height, scale)
+	w.useGLContext(func() {
+		w.context = ui.graphicsDevice.CreateContext(width, height, scale)
 	})
 	return w
 }
@@ -81,16 +81,16 @@ func (w *Window) loop() {
 	}
 }
 
-func (w *Window) Draw(f func(graphics.Canvas)) {
+func (w *Window) Draw(f func(graphics.Context)) {
 	if w.closed {
 		return
 	}
-	w.useContext(func() {
-		w.ui.graphicsDevice.Update(w.canvas, f)
+	w.useGLContext(func() {
+		w.ui.graphicsDevice.Update(w.context, f)
 	})
 }
 
-func (w *Window) useContext(f func()) {
+func (w *Window) useGLContext(f func()) {
 	w.funcs <- f
 	<-w.funcsDone
 }
diff --git a/ui/ui.go b/ui/ui.go
index 3c7455b96..8e73209ee 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -29,6 +29,6 @@ type WindowEvents interface {
 }
 
 type Window interface {
-	Draw(func(graphics.Canvas))
+	Draw(func(graphics.Context))
 	WindowEvents
 }