diff options
Diffstat (limited to 'src/image/draw/draw_test.go')
-rw-r--r-- | src/image/draw/draw_test.go | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/src/image/draw/draw_test.go b/src/image/draw/draw_test.go new file mode 100644 index 0000000..9c5a118 --- /dev/null +++ b/src/image/draw/draw_test.go @@ -0,0 +1,520 @@ +// Copyright 2010 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 draw + +import ( + "image" + "image/color" + "image/png" + "os" + "testing" + "testing/quick" +) + +func eq(c0, c1 color.Color) bool { + r0, g0, b0, a0 := c0.RGBA() + r1, g1, b1, a1 := c1.RGBA() + return r0 == r1 && g0 == g1 && b0 == b1 && a0 == a1 +} + +func fillBlue(alpha int) image.Image { + return image.NewUniform(color.RGBA{0, 0, uint8(alpha), uint8(alpha)}) +} + +func fillAlpha(alpha int) image.Image { + return image.NewUniform(color.Alpha{uint8(alpha)}) +} + +func vgradGreen(alpha int) image.Image { + m := image.NewRGBA(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.RGBA{0, uint8(y * alpha / 15), 0, uint8(alpha)}) + } + } + return m +} + +func vgradAlpha(alpha int) image.Image { + m := image.NewAlpha(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.Alpha{uint8(y * alpha / 15)}) + } + } + return m +} + +func vgradGreenNRGBA(alpha int) image.Image { + m := image.NewNRGBA(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.RGBA{0, uint8(y * 0x11), 0, uint8(alpha)}) + } + } + return m +} + +func vgradCr() image.Image { + m := &image.YCbCr{ + Y: make([]byte, 16*16), + Cb: make([]byte, 16*16), + Cr: make([]byte, 16*16), + YStride: 16, + CStride: 16, + SubsampleRatio: image.YCbCrSubsampleRatio444, + Rect: image.Rect(0, 0, 16, 16), + } + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Cr[y*m.CStride+x] = uint8(y * 0x11) + } + } + return m +} + +func vgradGray() image.Image { + m := image.NewGray(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.Gray{uint8(y * 0x11)}) + } + } + return m +} + +func vgradMagenta() image.Image { + m := image.NewCMYK(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.CMYK{0, uint8(y * 0x11), 0, 0x3f}) + } + } + return m +} + +func hgradRed(alpha int) Image { + m := image.NewRGBA(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.RGBA{uint8(x * alpha / 15), 0, 0, uint8(alpha)}) + } + } + return m +} + +func gradYellow(alpha int) Image { + m := image.NewRGBA(image.Rect(0, 0, 16, 16)) + for y := 0; y < 16; y++ { + for x := 0; x < 16; x++ { + m.Set(x, y, color.RGBA{uint8(x * alpha / 15), uint8(y * alpha / 15), 0, uint8(alpha)}) + } + } + return m +} + +type drawTest struct { + desc string + src image.Image + mask image.Image + op Op + expected color.Color +} + +var drawTests = []drawTest{ + // Uniform mask (0% opaque). + {"nop", vgradGreen(255), fillAlpha(0), Over, color.RGBA{136, 0, 0, 255}}, + {"clear", vgradGreen(255), fillAlpha(0), Src, color.RGBA{0, 0, 0, 0}}, + // Uniform mask (100%, 75%, nil) and uniform source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 0, 90, 90}. + {"fill", fillBlue(90), fillAlpha(255), Over, color.RGBA{88, 0, 90, 255}}, + {"fillSrc", fillBlue(90), fillAlpha(255), Src, color.RGBA{0, 0, 90, 90}}, + {"fillAlpha", fillBlue(90), fillAlpha(192), Over, color.RGBA{100, 0, 68, 255}}, + {"fillAlphaSrc", fillBlue(90), fillAlpha(192), Src, color.RGBA{0, 0, 68, 68}}, + {"fillNil", fillBlue(90), nil, Over, color.RGBA{88, 0, 90, 255}}, + {"fillNilSrc", fillBlue(90), nil, Src, color.RGBA{0, 0, 90, 90}}, + // Uniform mask (100%, 75%, nil) and variable source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 48, 0, 90}. + {"copy", vgradGreen(90), fillAlpha(255), Over, color.RGBA{88, 48, 0, 255}}, + {"copySrc", vgradGreen(90), fillAlpha(255), Src, color.RGBA{0, 48, 0, 90}}, + {"copyAlpha", vgradGreen(90), fillAlpha(192), Over, color.RGBA{100, 36, 0, 255}}, + {"copyAlphaSrc", vgradGreen(90), fillAlpha(192), Src, color.RGBA{0, 36, 0, 68}}, + {"copyNil", vgradGreen(90), nil, Over, color.RGBA{88, 48, 0, 255}}, + {"copyNilSrc", vgradGreen(90), nil, Src, color.RGBA{0, 48, 0, 90}}, + // Uniform mask (100%, 75%, nil) and variable NRGBA source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 136, 0, 90} in NRGBA-space, which is {0, 48, 0, 90} in RGBA-space. + // The result pixel is different than in the "copy*" test cases because of rounding errors. + {"nrgba", vgradGreenNRGBA(90), fillAlpha(255), Over, color.RGBA{88, 46, 0, 255}}, + {"nrgbaSrc", vgradGreenNRGBA(90), fillAlpha(255), Src, color.RGBA{0, 46, 0, 90}}, + {"nrgbaAlpha", vgradGreenNRGBA(90), fillAlpha(192), Over, color.RGBA{100, 34, 0, 255}}, + {"nrgbaAlphaSrc", vgradGreenNRGBA(90), fillAlpha(192), Src, color.RGBA{0, 34, 0, 68}}, + {"nrgbaNil", vgradGreenNRGBA(90), nil, Over, color.RGBA{88, 46, 0, 255}}, + {"nrgbaNilSrc", vgradGreenNRGBA(90), nil, Src, color.RGBA{0, 46, 0, 90}}, + // Uniform mask (100%, 75%, nil) and variable YCbCr source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 0, 136} in YCbCr-space, which is {11, 38, 0, 255} in RGB-space. + {"ycbcr", vgradCr(), fillAlpha(255), Over, color.RGBA{11, 38, 0, 255}}, + {"ycbcrSrc", vgradCr(), fillAlpha(255), Src, color.RGBA{11, 38, 0, 255}}, + {"ycbcrAlpha", vgradCr(), fillAlpha(192), Over, color.RGBA{42, 28, 0, 255}}, + {"ycbcrAlphaSrc", vgradCr(), fillAlpha(192), Src, color.RGBA{8, 28, 0, 192}}, + {"ycbcrNil", vgradCr(), nil, Over, color.RGBA{11, 38, 0, 255}}, + {"ycbcrNilSrc", vgradCr(), nil, Src, color.RGBA{11, 38, 0, 255}}, + // Uniform mask (100%, 75%, nil) and variable Gray source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {136} in Gray-space, which is {136, 136, 136, 255} in RGBA-space. + {"gray", vgradGray(), fillAlpha(255), Over, color.RGBA{136, 136, 136, 255}}, + {"graySrc", vgradGray(), fillAlpha(255), Src, color.RGBA{136, 136, 136, 255}}, + {"grayAlpha", vgradGray(), fillAlpha(192), Over, color.RGBA{136, 102, 102, 255}}, + {"grayAlphaSrc", vgradGray(), fillAlpha(192), Src, color.RGBA{102, 102, 102, 192}}, + {"grayNil", vgradGray(), nil, Over, color.RGBA{136, 136, 136, 255}}, + {"grayNilSrc", vgradGray(), nil, Src, color.RGBA{136, 136, 136, 255}}, + // Uniform mask (100%, 75%, nil) and variable CMYK source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 136, 0, 63} in CMYK-space, which is {192, 89, 192} in RGB-space. + {"cmyk", vgradMagenta(), fillAlpha(255), Over, color.RGBA{192, 89, 192, 255}}, + {"cmykSrc", vgradMagenta(), fillAlpha(255), Src, color.RGBA{192, 89, 192, 255}}, + {"cmykAlpha", vgradMagenta(), fillAlpha(192), Over, color.RGBA{178, 67, 145, 255}}, + {"cmykAlphaSrc", vgradMagenta(), fillAlpha(192), Src, color.RGBA{145, 67, 145, 192}}, + {"cmykNil", vgradMagenta(), nil, Over, color.RGBA{192, 89, 192, 255}}, + {"cmykNilSrc", vgradMagenta(), nil, Src, color.RGBA{192, 89, 192, 255}}, + // Variable mask and variable source. + // At (x, y) == (8, 8): + // The destination pixel is {136, 0, 0, 255}. + // The source pixel is {0, 0, 255, 255}. + // The mask pixel's alpha is 102, or 40%. + {"generic", fillBlue(255), vgradAlpha(192), Over, color.RGBA{81, 0, 102, 255}}, + {"genericSrc", fillBlue(255), vgradAlpha(192), Src, color.RGBA{0, 0, 102, 102}}, +} + +func makeGolden(dst image.Image, r image.Rectangle, src image.Image, sp image.Point, mask image.Image, mp image.Point, op Op) image.Image { + // Since golden is a newly allocated image, we don't have to check if the + // input source and mask images and the output golden image overlap. + b := dst.Bounds() + sb := src.Bounds() + mb := image.Rect(-1e9, -1e9, 1e9, 1e9) + if mask != nil { + mb = mask.Bounds() + } + golden := image.NewRGBA(image.Rect(0, 0, b.Max.X, b.Max.Y)) + for y := r.Min.Y; y < r.Max.Y; y++ { + sy := y + sp.Y - r.Min.Y + my := y + mp.Y - r.Min.Y + for x := r.Min.X; x < r.Max.X; x++ { + if !(image.Pt(x, y).In(b)) { + continue + } + sx := x + sp.X - r.Min.X + if !(image.Pt(sx, sy).In(sb)) { + continue + } + mx := x + mp.X - r.Min.X + if !(image.Pt(mx, my).In(mb)) { + continue + } + + const M = 1<<16 - 1 + var dr, dg, db, da uint32 + if op == Over { + dr, dg, db, da = dst.At(x, y).RGBA() + } + sr, sg, sb, sa := src.At(sx, sy).RGBA() + ma := uint32(M) + if mask != nil { + _, _, _, ma = mask.At(mx, my).RGBA() + } + a := M - (sa * ma / M) + golden.Set(x, y, color.RGBA64{ + uint16((dr*a + sr*ma) / M), + uint16((dg*a + sg*ma) / M), + uint16((db*a + sb*ma) / M), + uint16((da*a + sa*ma) / M), + }) + } + } + return golden.SubImage(b) +} + +func TestDraw(t *testing.T) { + rr := []image.Rectangle{ + image.Rect(0, 0, 0, 0), + image.Rect(0, 0, 16, 16), + image.Rect(3, 5, 12, 10), + image.Rect(0, 0, 9, 9), + image.Rect(8, 8, 16, 16), + image.Rect(8, 0, 9, 16), + image.Rect(0, 8, 16, 9), + image.Rect(8, 8, 9, 9), + image.Rect(8, 8, 8, 8), + } + for _, r := range rr { + loop: + for _, test := range drawTests { + dst := hgradRed(255).(*image.RGBA).SubImage(r).(Image) + // Draw the (src, mask, op) onto a copy of dst using a slow but obviously correct implementation. + golden := makeGolden(dst, image.Rect(0, 0, 16, 16), test.src, image.ZP, test.mask, image.ZP, test.op) + b := dst.Bounds() + if !b.Eq(golden.Bounds()) { + t.Errorf("draw %v %s: bounds %v versus %v", r, test.desc, dst.Bounds(), golden.Bounds()) + continue + } + // Draw the same combination onto the actual dst using the optimized DrawMask implementation. + DrawMask(dst, image.Rect(0, 0, 16, 16), test.src, image.ZP, test.mask, image.ZP, test.op) + if image.Pt(8, 8).In(r) { + // Check that the resultant pixel at (8, 8) matches what we expect + // (the expected value can be verified by hand). + if !eq(dst.At(8, 8), test.expected) { + t.Errorf("draw %v %s: at (8, 8) %v versus %v", r, test.desc, dst.At(8, 8), test.expected) + continue + } + } + // Check that the resultant dst image matches the golden output. + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + if !eq(dst.At(x, y), golden.At(x, y)) { + t.Errorf("draw %v %s: at (%d, %d), %v versus golden %v", r, test.desc, x, y, dst.At(x, y), golden.At(x, y)) + continue loop + } + } + } + } + } +} + +func TestDrawOverlap(t *testing.T) { + for _, op := range []Op{Over, Src} { + for yoff := -2; yoff <= 2; yoff++ { + loop: + for xoff := -2; xoff <= 2; xoff++ { + m := gradYellow(127).(*image.RGBA) + dst := m.SubImage(image.Rect(5, 5, 10, 10)).(*image.RGBA) + src := m.SubImage(image.Rect(5+xoff, 5+yoff, 10+xoff, 10+yoff)).(*image.RGBA) + b := dst.Bounds() + // Draw the (src, mask, op) onto a copy of dst using a slow but obviously correct implementation. + golden := makeGolden(dst, b, src, src.Bounds().Min, nil, image.ZP, op) + if !b.Eq(golden.Bounds()) { + t.Errorf("drawOverlap xoff=%d,yoff=%d: bounds %v versus %v", xoff, yoff, dst.Bounds(), golden.Bounds()) + continue + } + // Draw the same combination onto the actual dst using the optimized DrawMask implementation. + DrawMask(dst, b, src, src.Bounds().Min, nil, image.ZP, op) + // Check that the resultant dst image matches the golden output. + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + if !eq(dst.At(x, y), golden.At(x, y)) { + t.Errorf("drawOverlap xoff=%d,yoff=%d: at (%d, %d), %v versus golden %v", xoff, yoff, x, y, dst.At(x, y), golden.At(x, y)) + continue loop + } + } + } + } + } + } +} + +// TestNonZeroSrcPt checks drawing with a non-zero src point parameter. +func TestNonZeroSrcPt(t *testing.T) { + a := image.NewRGBA(image.Rect(0, 0, 1, 1)) + b := image.NewRGBA(image.Rect(0, 0, 2, 2)) + b.Set(0, 0, color.RGBA{0, 0, 0, 5}) + b.Set(1, 0, color.RGBA{0, 0, 5, 5}) + b.Set(0, 1, color.RGBA{0, 5, 0, 5}) + b.Set(1, 1, color.RGBA{5, 0, 0, 5}) + Draw(a, image.Rect(0, 0, 1, 1), b, image.Pt(1, 1), Over) + if !eq(color.RGBA{5, 0, 0, 5}, a.At(0, 0)) { + t.Errorf("non-zero src pt: want %v got %v", color.RGBA{5, 0, 0, 5}, a.At(0, 0)) + } +} + +func TestFill(t *testing.T) { + rr := []image.Rectangle{ + image.Rect(0, 0, 0, 0), + image.Rect(0, 0, 40, 30), + image.Rect(10, 0, 40, 30), + image.Rect(0, 20, 40, 30), + image.Rect(10, 20, 40, 30), + image.Rect(10, 20, 15, 25), + image.Rect(10, 0, 35, 30), + image.Rect(0, 15, 40, 16), + image.Rect(24, 24, 25, 25), + image.Rect(23, 23, 26, 26), + image.Rect(22, 22, 27, 27), + image.Rect(21, 21, 28, 28), + image.Rect(20, 20, 29, 29), + } + for _, r := range rr { + m := image.NewRGBA(image.Rect(0, 0, 40, 30)).SubImage(r).(*image.RGBA) + b := m.Bounds() + c := color.RGBA{11, 0, 0, 255} + src := &image.Uniform{C: c} + check := func(desc string) { + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + if !eq(c, m.At(x, y)) { + t.Errorf("%s fill: at (%d, %d), sub-image bounds=%v: want %v got %v", desc, x, y, r, c, m.At(x, y)) + return + } + } + } + } + // Draw 1 pixel at a time. + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + DrawMask(m, image.Rect(x, y, x+1, y+1), src, image.ZP, nil, image.ZP, Src) + } + } + check("pixel") + // Draw 1 row at a time. + c = color.RGBA{0, 22, 0, 255} + src = &image.Uniform{C: c} + for y := b.Min.Y; y < b.Max.Y; y++ { + DrawMask(m, image.Rect(b.Min.X, y, b.Max.X, y+1), src, image.ZP, nil, image.ZP, Src) + } + check("row") + // Draw 1 column at a time. + c = color.RGBA{0, 0, 33, 255} + src = &image.Uniform{C: c} + for x := b.Min.X; x < b.Max.X; x++ { + DrawMask(m, image.Rect(x, b.Min.Y, x+1, b.Max.Y), src, image.ZP, nil, image.ZP, Src) + } + check("column") + // Draw the whole image at once. + c = color.RGBA{44, 55, 66, 77} + src = &image.Uniform{C: c} + DrawMask(m, b, src, image.ZP, nil, image.ZP, Src) + check("whole") + } +} + +// TestFloydSteinbergCheckerboard tests that the result of Floyd-Steinberg +// error diffusion of a uniform 50% gray source image with a black-and-white +// palette is a checkerboard pattern. +func TestFloydSteinbergCheckerboard(t *testing.T) { + b := image.Rect(0, 0, 640, 480) + // We can't represent 50% exactly, but 0x7fff / 0xffff is close enough. + src := &image.Uniform{color.Gray16{0x7fff}} + dst := image.NewPaletted(b, color.Palette{color.Black, color.White}) + FloydSteinberg.Draw(dst, b, src, image.Point{}) + nErr := 0 + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + got := dst.Pix[dst.PixOffset(x, y)] + want := uint8(x+y) % 2 + if got != want { + t.Errorf("at (%d, %d): got %d, want %d", x, y, got, want) + if nErr++; nErr == 10 { + t.Fatal("there may be more errors") + } + } + } + } +} + +// embeddedPaletted is an Image that behaves like an *image.Paletted but whose +// type is not *image.Paletted. +type embeddedPaletted struct { + *image.Paletted +} + +// TestPaletted tests that the drawPaletted function behaves the same +// regardless of whether dst is an *image.Paletted. +func TestPaletted(t *testing.T) { + f, err := os.Open("../testdata/video-001.png") + if err != nil { + t.Fatalf("open: %v", err) + } + defer f.Close() + video001, err := png.Decode(f) + if err != nil { + t.Fatalf("decode: %v", err) + } + b := video001.Bounds() + + cgaPalette := color.Palette{ + color.RGBA{0x00, 0x00, 0x00, 0xff}, + color.RGBA{0x55, 0xff, 0xff, 0xff}, + color.RGBA{0xff, 0x55, 0xff, 0xff}, + color.RGBA{0xff, 0xff, 0xff, 0xff}, + } + drawers := map[string]Drawer{ + "src": Src, + "floyd-steinberg": FloydSteinberg, + } + sources := map[string]image.Image{ + "uniform": &image.Uniform{color.RGBA{0xff, 0x7f, 0xff, 0xff}}, + "video001": video001, + } + + for dName, d := range drawers { + loop: + for sName, src := range sources { + dst0 := image.NewPaletted(b, cgaPalette) + dst1 := image.NewPaletted(b, cgaPalette) + d.Draw(dst0, b, src, image.Point{}) + d.Draw(embeddedPaletted{dst1}, b, src, image.Point{}) + for y := b.Min.Y; y < b.Max.Y; y++ { + for x := b.Min.X; x < b.Max.X; x++ { + if !eq(dst0.At(x, y), dst1.At(x, y)) { + t.Errorf("%s / %s: at (%d, %d), %v versus %v", + dName, sName, x, y, dst0.At(x, y), dst1.At(x, y)) + continue loop + } + } + } + } + } +} + +func TestSqDiff(t *testing.T) { + // This test is similar to the one from the image/color package, but + // sqDiff in this package accepts int32 instead of uint32, so test it + // for appropriate input. + + // canonical sqDiff implementation + orig := func(x, y int32) uint32 { + var d uint32 + if x > y { + d = uint32(x - y) + } else { + d = uint32(y - x) + } + return (d * d) >> 2 + } + testCases := []int32{ + 0, + 1, + 2, + 0x0fffd, + 0x0fffe, + 0x0ffff, + 0x10000, + 0x10001, + 0x10002, + 0x7ffffffd, + 0x7ffffffe, + 0x7fffffff, + -0x7ffffffd, + -0x7ffffffe, + -0x80000000, + } + for _, x := range testCases { + for _, y := range testCases { + if got, want := sqDiff(x, y), orig(x, y); got != want { + t.Fatalf("sqDiff(%#x, %#x): got %d, want %d", x, y, got, want) + } + } + } + if err := quick.CheckEqual(orig, sqDiff, &quick.Config{MaxCountScale: 10}); err != nil { + t.Fatal(err) + } +} |