some redesign

scale_test.go

@@ -21,11 +21,11 @@ func Render(img image.Image, rect image.Rectangle) image.Image {
 func BenchmarkScale(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		err := png.Encode(io.Discard,
-			Scale(Render(
+			Scale(64, Render(
 				texture.New(color.White,
 					color.Black, 2),
 				image.Rect(0, 0, 64, 64),
-			), 64),
+			)),
 		)
 		if err != nil {
 			panic(err)
@@ -51,7 +51,7 @@ func (s SinglePixel) Bounds() image.Rectangle {
 func BenchmarkSinglePixel(b *testing.B) {
 	instance := SinglePixel{}
 	err := png.Encode(io.Discard,
-		Scale(instance, b.N),
+		Scale(b.N, instance),
 	)
 	if err != nil {
 		panic(err)