57 lines
1.4 KiB
Go
57 lines
1.4 KiB
Go
package main
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import (
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"bytes"
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"image"
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"image/jpeg"
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"testing"
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)
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// testPhoto returns a JPEG-decoded (so *image.YCbCr, 4:2:0) image with an odd
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// size and a non-zero origin to exercise the plane offset arithmetic.
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func testPhoto(t testing.TB, w, h int) *image.YCbCr {
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t.Helper()
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src := image.NewRGBA(image.Rect(0, 0, w, h))
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for i := range src.Pix {
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src.Pix[i] = uint8(i*7 + i/w)
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}
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var buf bytes.Buffer
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if err := jpeg.Encode(&buf, src, &jpeg.Options{Quality: 90}); err != nil {
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t.Fatal(err)
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}
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img, err := jpeg.Decode(&buf)
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if err != nil {
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t.Fatal(err)
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}
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return img.(*image.YCbCr).SubImage(image.Rect(3, 5, w, h)).(*image.YCbCr)
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}
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func TestResizeBoxYCbCrMatchesGeneric(t *testing.T) {
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src := testPhoto(t, 1001, 667)
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fast := resizeBox(src, 120).(*image.RGBA)
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// Hide the concrete type so resizeBox takes the generic At() path.
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slow := resizeBox(struct{ image.Image }{src}, 120).(*image.RGBA)
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if fast.Bounds() != slow.Bounds() {
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t.Fatalf("bounds %v != %v", fast.Bounds(), slow.Bounds())
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}
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for i := range fast.Pix {
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if fast.Pix[i] != slow.Pix[i] {
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t.Fatalf("pixel byte %d: fast %d, generic %d", i, fast.Pix[i], slow.Pix[i])
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}
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}
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}
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func BenchmarkResizeBox(b *testing.B) {
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src := testPhoto(b, 4000, 3000)
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b.Run("ycbcr", func(b *testing.B) {
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for i := 0; i < b.N; i++ {
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resizeBox(src, 300)
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}
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})
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b.Run("generic", func(b *testing.B) {
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for i := 0; i < b.N; i++ {
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resizeBox(struct{ image.Image }{src}, 300)
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}
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})
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}
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