Adding upstream version 1.20.14.upstream/1.20.14upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 407 insertions, 0 deletions

diff --git a/src/image/png/writer_test.go b/src/image/png/writer_test.go
new file mode 100644
index 0000000..6dac8ec
--- /dev/null
+++ b/src/image/png/writer_test.go
@@ -0,0 +1,407 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package png
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/color"
+	"image/draw"
+	"io"
+	"testing"
+)
+
+func diff(m0, m1 image.Image) error {
+	b0, b1 := m0.Bounds(), m1.Bounds()
+	if !b0.Size().Eq(b1.Size()) {
+		return fmt.Errorf("dimensions differ: %v vs %v", b0, b1)
+	}
+	dx := b1.Min.X - b0.Min.X
+	dy := b1.Min.Y - b0.Min.Y
+	for y := b0.Min.Y; y < b0.Max.Y; y++ {
+		for x := b0.Min.X; x < b0.Max.X; x++ {
+			c0 := m0.At(x, y)
+			c1 := m1.At(x+dx, y+dy)
+			r0, g0, b0, a0 := c0.RGBA()
+			r1, g1, b1, a1 := c1.RGBA()
+			if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 {
+				return fmt.Errorf("colors differ at (%d, %d): %T%v vs %T%v", x, y, c0, c0, c1, c1)
+			}
+		}
+	}
+	return nil
+}
+
+func encodeDecode(m image.Image) (image.Image, error) {
+	var b bytes.Buffer
+	err := Encode(&b, m)
+	if err != nil {
+		return nil, err
+	}
+	return Decode(&b)
+}
+
+func convertToNRGBA(m image.Image) *image.NRGBA {
+	b := m.Bounds()
+	ret := image.NewNRGBA(b)
+	draw.Draw(ret, b, m, b.Min, draw.Src)
+	return ret
+}
+
+func TestWriter(t *testing.T) {
+	// The filenames variable is declared in reader_test.go.
+	names := filenames
+	if testing.Short() {
+		names = filenamesShort
+	}
+	for _, fn := range names {
+		qfn := "testdata/pngsuite/" + fn + ".png"
+		// Read the image.
+		m0, err := readPNG(qfn)
+		if err != nil {
+			t.Error(fn, err)
+			continue
+		}
+		// Read the image again, encode it, and decode it.
+		m1, err := readPNG(qfn)
+		if err != nil {
+			t.Error(fn, err)
+			continue
+		}
+		m2, err := encodeDecode(m1)
+		if err != nil {
+			t.Error(fn, err)
+			continue
+		}
+		// Compare the two.
+		err = diff(m0, m2)
+		if err != nil {
+			t.Error(fn, err)
+			continue
+		}
+	}
+}
+
+func TestWriterPaletted(t *testing.T) {
+	const width, height = 32, 16
+
+	testCases := []struct {
+		plen     int
+		bitdepth uint8
+		datalen  int
+	}{
+
+		{
+			plen:     256,
+			bitdepth: 8,
+			datalen:  (1 + width) * height,
+		},
+
+		{
+			plen:     128,
+			bitdepth: 8,
+			datalen:  (1 + width) * height,
+		},
+
+		{
+			plen:     16,
+			bitdepth: 4,
+			datalen:  (1 + width/2) * height,
+		},
+
+		{
+			plen:     4,
+			bitdepth: 2,
+			datalen:  (1 + width/4) * height,
+		},
+
+		{
+			plen:     2,
+			bitdepth: 1,
+			datalen:  (1 + width/8) * height,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("plen-%d", tc.plen), func(t *testing.T) {
+			// Create a paletted image with the correct palette length
+			palette := make(color.Palette, tc.plen)
+			for i := range palette {
+				palette[i] = color.NRGBA{
+					R: uint8(i),
+					G: uint8(i),
+					B: uint8(i),
+					A: 255,
+				}
+			}
+			m0 := image.NewPaletted(image.Rect(0, 0, width, height), palette)
+
+			i := 0
+			for y := 0; y < height; y++ {
+				for x := 0; x < width; x++ {
+					m0.SetColorIndex(x, y, uint8(i%tc.plen))
+					i++
+				}
+			}
+
+			// Encode the image
+			var b bytes.Buffer
+			if err := Encode(&b, m0); err != nil {
+				t.Error(err)
+				return
+			}
+			const chunkFieldsLength = 12 // 4 bytes for length, name and crc
+			data := b.Bytes()
+			i = len(pngHeader)
+
+			for i < len(data)-chunkFieldsLength {
+				length := binary.BigEndian.Uint32(data[i : i+4])
+				name := string(data[i+4 : i+8])
+
+				switch name {
+				case "IHDR":
+					bitdepth := data[i+8+8]
+					if bitdepth != tc.bitdepth {
+						t.Errorf("got bitdepth %d, want %d", bitdepth, tc.bitdepth)
+					}
+				case "IDAT":
+					// Uncompress the image data
+					r, err := zlib.NewReader(bytes.NewReader(data[i+8 : i+8+int(length)]))
+					if err != nil {
+						t.Error(err)
+						return
+					}
+					n, err := io.Copy(io.Discard, r)
+					if err != nil {
+						t.Errorf("got error while reading image data: %v", err)
+					}
+					if n != int64(tc.datalen) {
+						t.Errorf("got uncompressed data length %d, want %d", n, tc.datalen)
+					}
+				}
+
+				i += chunkFieldsLength + int(length)
+			}
+		})
+
+	}
+}
+
+func TestWriterLevels(t *testing.T) {
+	m := image.NewNRGBA(image.Rect(0, 0, 100, 100))
+
+	var b1, b2 bytes.Buffer
+	if err := (&Encoder{}).Encode(&b1, m); err != nil {
+		t.Fatal(err)
+	}
+	noenc := &Encoder{CompressionLevel: NoCompression}
+	if err := noenc.Encode(&b2, m); err != nil {
+		t.Fatal(err)
+	}
+
+	if b2.Len() <= b1.Len() {
+		t.Error("DefaultCompression encoding was larger than NoCompression encoding")
+	}
+	if _, err := Decode(&b1); err != nil {
+		t.Error("cannot decode DefaultCompression")
+	}
+	if _, err := Decode(&b2); err != nil {
+		t.Error("cannot decode NoCompression")
+	}
+}
+
+func TestSubImage(t *testing.T) {
+	m0 := image.NewRGBA(image.Rect(0, 0, 256, 256))
+	for y := 0; y < 256; y++ {
+		for x := 0; x < 256; x++ {
+			m0.Set(x, y, color.RGBA{uint8(x), uint8(y), 0, 255})
+		}
+	}
+	m0 = m0.SubImage(image.Rect(50, 30, 250, 130)).(*image.RGBA)
+	m1, err := encodeDecode(m0)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	err = diff(m0, m1)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+}
+
+func TestWriteRGBA(t *testing.T) {
+	const width, height = 640, 480
+	transparentImg := image.NewRGBA(image.Rect(0, 0, width, height))
+	opaqueImg := image.NewRGBA(image.Rect(0, 0, width, height))
+	mixedImg := image.NewRGBA(image.Rect(0, 0, width, height))
+	translucentImg := image.NewRGBA(image.Rect(0, 0, width, height))
+	for y := 0; y < height; y++ {
+		for x := 0; x < width; x++ {
+			opaqueColor := color.RGBA{uint8(x), uint8(y), uint8(y + x), 255}
+			translucentColor := color.RGBA{uint8(x) % 128, uint8(y) % 128, uint8(y+x) % 128, 128}
+			opaqueImg.Set(x, y, opaqueColor)
+			translucentImg.Set(x, y, translucentColor)
+			if y%2 == 0 {
+				mixedImg.Set(x, y, opaqueColor)
+			}
+		}
+	}
+
+	testCases := []struct {
+		name string
+		img  image.Image
+	}{
+		{"Transparent RGBA", transparentImg},
+		{"Opaque RGBA", opaqueImg},
+		{"50/50 Transparent/Opaque RGBA", mixedImg},
+		{"RGBA with variable alpha", translucentImg},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			m0 := tc.img
+			m1, err := encodeDecode(m0)
+			if err != nil {
+				t.Fatal(err)
+			}
+			err = diff(convertToNRGBA(m0), m1)
+			if err != nil {
+				t.Error(err)
+			}
+		})
+	}
+}
+
+func BenchmarkEncodeGray(b *testing.B) {
+	img := image.NewGray(image.Rect(0, 0, 640, 480))
+	b.SetBytes(640 * 480 * 1)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}
+
+type pool struct {
+	b *EncoderBuffer
+}
+
+func (p *pool) Get() *EncoderBuffer {
+	return p.b
+}
+
+func (p *pool) Put(b *EncoderBuffer) {
+	p.b = b
+}
+
+func BenchmarkEncodeGrayWithBufferPool(b *testing.B) {
+	img := image.NewGray(image.Rect(0, 0, 640, 480))
+	e := Encoder{
+		BufferPool: &pool{},
+	}
+	b.SetBytes(640 * 480 * 1)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		e.Encode(io.Discard, img)
+	}
+}
+
+func BenchmarkEncodeNRGBOpaque(b *testing.B) {
+	img := image.NewNRGBA(image.Rect(0, 0, 640, 480))
+	// Set all pixels to 0xFF alpha to force opaque mode.
+	bo := img.Bounds()
+	for y := bo.Min.Y; y < bo.Max.Y; y++ {
+		for x := bo.Min.X; x < bo.Max.X; x++ {
+			img.Set(x, y, color.NRGBA{0, 0, 0, 255})
+		}
+	}
+	if !img.Opaque() {
+		b.Fatal("expected image to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}
+
+func BenchmarkEncodeNRGBA(b *testing.B) {
+	img := image.NewNRGBA(image.Rect(0, 0, 640, 480))
+	if img.Opaque() {
+		b.Fatal("expected image not to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}
+
+func BenchmarkEncodePaletted(b *testing.B) {
+	img := image.NewPaletted(image.Rect(0, 0, 640, 480), color.Palette{
+		color.RGBA{0, 0, 0, 255},
+		color.RGBA{255, 255, 255, 255},
+	})
+	b.SetBytes(640 * 480 * 1)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}
+
+func BenchmarkEncodeRGBOpaque(b *testing.B) {
+	img := image.NewRGBA(image.Rect(0, 0, 640, 480))
+	// Set all pixels to 0xFF alpha to force opaque mode.
+	bo := img.Bounds()
+	for y := bo.Min.Y; y < bo.Max.Y; y++ {
+		for x := bo.Min.X; x < bo.Max.X; x++ {
+			img.Set(x, y, color.RGBA{0, 0, 0, 255})
+		}
+	}
+	if !img.Opaque() {
+		b.Fatal("expected image to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}
+
+func BenchmarkEncodeRGBA(b *testing.B) {
+	const width, height = 640, 480
+	img := image.NewRGBA(image.Rect(0, 0, width, height))
+	for y := 0; y < height; y++ {
+		for x := 0; x < width; x++ {
+			percent := (x + y) % 100
+			switch {
+			case percent < 10: // 10% of pixels are translucent (have alpha >0 and <255)
+				img.Set(x, y, color.NRGBA{uint8(x), uint8(y), uint8(x * y), uint8(percent)})
+			case percent < 40: // 30% of pixels are transparent (have alpha == 0)
+				img.Set(x, y, color.NRGBA{uint8(x), uint8(y), uint8(x * y), 0})
+			default: // 60% of pixels are opaque (have alpha == 255)
+				img.Set(x, y, color.NRGBA{uint8(x), uint8(y), uint8(x * y), 255})
+			}
+		}
+	}
+	if img.Opaque() {
+		b.Fatal("expected image not to be opaque")
+	}
+	b.SetBytes(width * height * 4)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(io.Discard, img)
+	}
+}