diff --git a/example/blocks/textures.go b/example/blocks/textures.go
index 9d06bede3..38e4ccf4d 100644
--- a/example/blocks/textures.go
+++ b/example/blocks/textures.go
@@ -34,7 +34,11 @@ func NewTextures(textureFactory graphics.TextureFactory) *Textures {
 		textures:          map[string]graphics.TextureId{},
 		renderTargets:     map[string]graphics.RenderTargetId{},
 	}
-	go textures.loop()
+	go func() {
+		for {
+			textures.loopMain()
+		}
+	}()
 	return textures
 }
 
@@ -52,43 +56,41 @@ func loadImage(path string) (image.Image, error) {
 	return img, nil
 }
 
-func (t *Textures) loop() {
-	for {
-		select {
-		case p := <-t.texturePaths:
-			name := p.name
-			path := p.path
-			go func() {
-				img, err := loadImage(path)
-				if err != nil {
-					panic(err)
-				}
-				id, err := t.textureFactory.CreateTexture(
-					img,
-					graphics.FilterNearest)
-				if err != nil {
-					panic(err)
-				}
-				t.Lock()
-				defer t.Unlock()
-				t.textures[name] = id
-			}()
-		case s := <-t.renderTargetSizes:
-			name := s.name
-			size := s.size
-			go func() {
-				id, err := t.textureFactory.CreateRenderTarget(
-					size.Width,
-					size.Height,
-					graphics.FilterNearest)
-				if err != nil {
-					panic(err)
-				}
-				t.Lock()
-				defer t.Unlock()
-				t.renderTargets[name] = id
-			}()
-		}
+func (t *Textures) loopMain() {
+	select {
+	case p := <-t.texturePaths:
+		name := p.name
+		path := p.path
+		go func() {
+			img, err := loadImage(path)
+			if err != nil {
+				panic(err)
+			}
+			id, err := t.textureFactory.CreateTexture(
+				img,
+				graphics.FilterNearest)
+			if err != nil {
+				panic(err)
+			}
+			t.Lock()
+			defer t.Unlock()
+			t.textures[name] = id
+		}()
+	case s := <-t.renderTargetSizes:
+		name := s.name
+		size := s.size
+		go func() {
+			id, err := t.textureFactory.CreateRenderTarget(
+				size.Width,
+				size.Height,
+				graphics.FilterNearest)
+			if err != nil {
+				panic(err)
+			}
+			t.Lock()
+			defer t.Unlock()
+			t.renderTargets[name] = id
+		}()
 	}
 }
 
diff --git a/graphics/opengl/context.go b/graphics/opengl/context.go
index 1f38fb359..5214d3a6e 100644
--- a/graphics/opengl/context.go
+++ b/graphics/opengl/context.go
@@ -5,6 +5,21 @@ import (
 	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
 )
 
+// #cgo LDFLAGS: -framework OpenGL
+//
+// #include <stdlib.h>
+// #include <OpenGL/gl.h>
+import "C"
+
+func enableAlphaBlending() {
+	C.glEnable(C.GL_TEXTURE_2D)
+	C.glEnable(C.GL_BLEND)
+}
+
+func flush() {
+	C.glFlush()
+}
+
 type Context struct {
 	screenId     graphics.RenderTargetId
 	mainId       graphics.RenderTargetId
diff --git a/graphics/opengl/gl.go b/graphics/opengl/gl.go
deleted file mode 100644
index 12b745eb4..000000000
--- a/graphics/opengl/gl.go
+++ /dev/null
@@ -1,16 +0,0 @@
-package opengl
-
-// #cgo LDFLAGS: -framework OpenGL
-//
-// #include <stdlib.h>
-// #include <OpenGL/gl.h>
-import "C"
-
-func enableAlphaBlending() {
-	C.glEnable(C.GL_TEXTURE_2D)
-	C.glEnable(C.GL_BLEND)
-}
-
-func flush() {
-	C.glFlush()
-}