diff --git a/internal/restorable/vertices.go b/internal/graphicsutil/vertices.go
similarity index 99%
rename from internal/restorable/vertices.go
rename to internal/graphicsutil/vertices.go
index 1d0a797f4..0f0088e3b 100644
--- a/internal/restorable/vertices.go
+++ b/internal/graphicsutil/vertices.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package restorable
+package graphicsutil
 
 import (
 	"github.com/hajimehoshi/ebiten/internal/affine"
diff --git a/internal/restorable/image.go b/internal/restorable/image.go
index 92cb7d854..8a8de0c5f 100644
--- a/internal/restorable/image.go
+++ b/internal/restorable/image.go
@@ -21,6 +21,7 @@ import (
 
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
+	"github.com/hajimehoshi/ebiten/internal/graphicsutil"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
@@ -148,7 +149,7 @@ func (i *Image) ReplacePixels(pixels []byte, x, y, width, height int) {
 		geom := (*affine.GeoM)(nil).Scale(float64(width)/float64(w), float64(height)/float64(h))
 		geom = geom.Translate(float64(x), float64(y))
 		colorm := (*affine.ColorM)(nil).Scale(0, 0, 0, 0)
-		vs := QuadVertices(w, h, 0, 0, w, h, geom)
+		vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, geom)
 		i.image.DrawImage(dummyImage.image, vs, quadIndices, colorm, opengl.CompositeModeCopy, graphics.FilterNearest)
 	}
 
diff --git a/internal/restorable/images_test.go b/internal/restorable/images_test.go
index 86426356a..d36f71985 100644
--- a/internal/restorable/images_test.go
+++ b/internal/restorable/images_test.go
@@ -24,6 +24,7 @@ import (
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
+	"github.com/hajimehoshi/ebiten/internal/graphicsutil"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	. "github.com/hajimehoshi/ebiten/internal/restorable"
 	"github.com/hajimehoshi/ebiten/internal/testflock"
@@ -122,7 +123,7 @@ func TestRestoreChain(t *testing.T) {
 	fill(imgs[0], clr.R, clr.G, clr.B, clr.A)
 	for i := 0; i < num-1; i++ {
 		w, h := imgs[i].Size()
-		vs := QuadVertices(w, h, 0, 0, 1, 1, nil)
+		vs := graphicsutil.QuadVertices(w, h, 0, 0, 1, 1, nil)
 		imgs[i+1].DrawImage(imgs[i], vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	}
 	if err := ResolveStaleImages(); err != nil {
@@ -165,7 +166,7 @@ func TestRestoreChain2(t *testing.T) {
 	clr8 := color.RGBA{0x00, 0x00, 0xff, 0xff}
 	fill(imgs[8], clr8.R, clr8.G, clr8.B, clr8.A)
 
-	vs := QuadVertices(w, h, 0, 0, w, h, nil)
+	vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, nil)
 	imgs[8].DrawImage(imgs[7], vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	imgs[9].DrawImage(imgs[8], vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	for i := 0; i < 7; i++ {
@@ -212,7 +213,7 @@ func TestRestoreOverrideSource(t *testing.T) {
 	clr0 := color.RGBA{0x00, 0x00, 0x00, 0xff}
 	clr1 := color.RGBA{0x00, 0x00, 0x01, 0xff}
 	fill(img1, clr0.R, clr0.G, clr0.B, clr0.A)
-	vs := QuadVertices(w, h, 0, 0, w, h, nil)
+	vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, nil)
 	img2.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
 	img3.DrawImage(img2, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
 	fill(img0, clr1.R, clr1.G, clr1.B, clr1.A)
@@ -298,23 +299,23 @@ func TestRestoreComplexGraph(t *testing.T) {
 		img1.Dispose()
 		img0.Dispose()
 	}()
-	vs := QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
+	vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
 	img3.DrawImage(img0, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
 	img3.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
 	img4.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(2, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(2, 0))
 	img4.DrawImage(img2, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
 	img5.DrawImage(img3, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
 	img6.DrawImage(img3, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
 	img6.DrawImage(img4, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(0, 0))
 	img7.DrawImage(img2, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
-	vs = QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(2, 0))
+	vs = graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(2, 0))
 	img7.DrawImage(img3, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
 	if err := ResolveStaleImages(); err != nil {
 		t.Fatal(err)
@@ -407,7 +408,7 @@ func TestRestoreRecursive(t *testing.T) {
 		img1.Dispose()
 		img0.Dispose()
 	}()
-	vs := QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
+	vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, (*affine.GeoM)(nil).Translate(1, 0))
 	img1.DrawImage(img0, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
 	img0.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeSourceOver, graphics.FilterNearest)
 	if err := ResolveStaleImages(); err != nil {
@@ -504,7 +505,7 @@ func TestDrawImageAndReplacePixels(t *testing.T) {
 	img1 := NewImage(2, 1, false)
 	defer img1.Dispose()
 
-	vs := QuadVertices(1, 1, 0, 0, 1, 1, nil)
+	vs := graphicsutil.QuadVertices(1, 1, 0, 0, 1, 1, nil)
 	img1.DrawImage(img0, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	img1.ReplacePixels([]byte{0xff, 0xff, 0xff, 0xff}, 1, 0, 1, 1)
 
@@ -540,7 +541,7 @@ func TestDispose(t *testing.T) {
 	img2 := newImageFromImage(base2)
 	defer img2.Dispose()
 
-	vs := QuadVertices(1, 1, 0, 0, 1, 1, nil)
+	vs := graphicsutil.QuadVertices(1, 1, 0, 0, 1, 1, nil)
 	img1.DrawImage(img2, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	img0.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	img1.Dispose()
@@ -572,7 +573,7 @@ func TestDoubleResolve(t *testing.T) {
 	base.Pix[3] = 0xff
 	img1 := newImageFromImage(base)
 
-	vs := QuadVertices(1, 1, 0, 0, 1, 1, nil)
+	vs := graphicsutil.QuadVertices(1, 1, 0, 0, 1, 1, nil)
 	img0.DrawImage(img1, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	img0.ReplacePixels([]uint8{0x00, 0xff, 0x00, 0xff}, 1, 1, 1, 1)
 	// Now img0 is stale.
diff --git a/internal/shareable/shareable.go b/internal/shareable/shareable.go
index efc3e4d50..c82a75848 100644
--- a/internal/shareable/shareable.go
+++ b/internal/shareable/shareable.go
@@ -23,6 +23,7 @@ import (
 
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
+	"github.com/hajimehoshi/ebiten/internal/graphicsutil"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"github.com/hajimehoshi/ebiten/internal/packing"
 	"github.com/hajimehoshi/ebiten/internal/restorable"
@@ -66,7 +67,7 @@ func (b *backend) TryAlloc(width, height int) (*packing.Node, bool) {
 	newImg := restorable.NewImage(s, s, false)
 	oldImg := b.restorable
 	w, h := oldImg.Size()
-	vs := restorable.QuadVertices(w, h, 0, 0, w, h, nil)
+	vs := graphicsutil.QuadVertices(w, h, 0, 0, w, h, nil)
 	newImg.DrawImage(oldImg, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 	oldImg.Dispose()
 	b.restorable = newImg
@@ -110,7 +111,7 @@ func (i *Image) ensureNotShared() {
 	x, y, w, h := i.region()
 	newImg := restorable.NewImage(w, h, false)
 	vw, vh := i.backend.restorable.Size()
-	vs := restorable.QuadVertices(vw, vh, x, y, x+w, y+h, nil)
+	vs := graphicsutil.QuadVertices(vw, vh, x, y, x+w, y+h, nil)
 	newImg.DrawImage(i.backend.restorable, vs, quadIndices, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
 
 	i.dispose(false)
@@ -162,7 +163,7 @@ func (i *Image) DrawImage(img *Image, sx0, sy0, sx1, sy1 int, geom *affine.GeoM,
 	sx1 += dx
 	sy1 += dy
 	w, h := img.backend.restorable.Size()
-	vs := restorable.QuadVertices(w, h, sx0, sy0, sx1, sy1, geom)
+	vs := graphicsutil.QuadVertices(w, h, sx0, sy0, sx1, sy1, geom)
 	i.backend.restorable.DrawImage(img.backend.restorable, vs, quadIndices, colorm, mode, filter)
 }