image/gif: have BenchmarkEncodeRealisticRGBA convert to RGBA

Change-Id: I98f5d987b92a29dcff06ae23b92f293cc7d6c02f
Reviewed-on: https://go-review.googlesource.com/c/go/+/252597
Reviewed-by: David Symonds <dsymonds@golang.org>

diff --git a/src/image/gif/writer_test.go b/src/image/gif/writer_test.go
index 5d1b2c439ee6d9a0c111053d2a8c1df12099156c..1e622b3674e428b75497a51a7e2df1f882c442dc 100644 (file)
--- a/src/image/gif/writer_test.go
+++ b/src/image/gif/writer_test.go
@@ -658,27 +658,27 @@ func TestEncodeWrappedImage(t *testing.T) {
 }
 
 func BenchmarkEncodeRandomPaletted(b *testing.B) {
-       img := image.NewPaletted(image.Rect(0, 0, 640, 480), palette.Plan9)
+       paletted := image.NewPaletted(image.Rect(0, 0, 640, 480), palette.Plan9)
        rnd := rand.New(rand.NewSource(123))
-       for i := range img.Pix {
-               img.Pix[i] = uint8(rnd.Intn(256))
+       for i := range paletted.Pix {
+               paletted.Pix[i] = uint8(rnd.Intn(256))
        }
 
        b.SetBytes(640 * 480 * 1)
        b.ReportAllocs()
        b.ResetTimer()
        for i := 0; i < b.N; i++ {
-               Encode(ioutil.Discard, img, nil)
+               Encode(ioutil.Discard, paletted, nil)
        }
 }
 
 func BenchmarkEncodeRandomRGBA(b *testing.B) {
-       img := image.NewRGBA(image.Rect(0, 0, 640, 480))
-       bo := img.Bounds()
+       rgba := image.NewRGBA(image.Rect(0, 0, 640, 480))
+       bo := rgba.Bounds()
        rnd := rand.New(rand.NewSource(123))
        for y := bo.Min.Y; y < bo.Max.Y; y++ {
                for x := bo.Min.X; x < bo.Max.X; x++ {
-                       img.SetRGBA(x, y, color.RGBA{
+                       rgba.SetRGBA(x, y, color.RGBA{
                                uint8(rnd.Intn(256)),
                                uint8(rnd.Intn(256)),
                                uint8(rnd.Intn(256)),
@@ -691,24 +691,24 @@ func BenchmarkEncodeRandomRGBA(b *testing.B) {
        b.ReportAllocs()
        b.ResetTimer()
        for i := 0; i < b.N; i++ {
-               Encode(ioutil.Discard, img, nil)
+               Encode(ioutil.Discard, rgba, nil)
        }
 }
 
 func BenchmarkEncodeRealisticPaletted(b *testing.B) {
-       rgba, err := readImg("../testdata/video-001.png")
+       img, err := readImg("../testdata/video-001.png")
        if err != nil {
                b.Fatalf("readImg: %v", err)
        }
-       bo := rgba.Bounds()
-       img := image.NewPaletted(bo, palette.Plan9)
-       draw.Draw(img, bo, rgba, bo.Min, draw.Src)
+       bo := img.Bounds()
+       paletted := image.NewPaletted(bo, palette.Plan9)
+       draw.Draw(paletted, bo, img, bo.Min, draw.Src)
 
        b.SetBytes(int64(bo.Dx() * bo.Dy() * 1))
        b.ReportAllocs()
        b.ResetTimer()
        for i := 0; i < b.N; i++ {
-               Encode(ioutil.Discard, img, nil)
+               Encode(ioutil.Discard, paletted, nil)
        }
 }
 
@@ -718,11 +718,17 @@ func BenchmarkEncodeRealisticRGBA(b *testing.B) {
                b.Fatalf("readImg: %v", err)
        }
        bo := img.Bounds()
+       // Converting img to rgba is redundant for video-001.png, which is already
+       // in the RGBA format, but for those copy/pasting this benchmark (but
+       // changing the source image), the conversion ensures that we're still
+       // benchmarking encoding an RGBA image.
+       rgba := image.NewRGBA(bo)
+       draw.Draw(rgba, bo, img, bo.Min, draw.Src)
 
        b.SetBytes(int64(bo.Dx() * bo.Dy() * 4))
        b.ReportAllocs()
        b.ResetTimer()
        for i := 0; i < b.N; i++ {
-               Encode(ioutil.Discard, img, nil)
+               Encode(ioutil.Discard, rgba, nil)
        }
 }