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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [image/] [draw/] [draw_test.go] - Blame information for rev 749

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// 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"
        "testing"
)
 
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 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}},
        // 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")
        }
}

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Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [image/] [draw/] [draw_test.go] - Blame information for rev 749

Line No.	Rev	Author	Line
1	747	jeremybenn	`// Copyright 2010 The Go Authors. All rights reserved.`
2			`// Use of this source code is governed by a BSD-style`
3			`// license that can be found in the LICENSE file.`
4
5			`package draw`
6
7			`import (`
8			`"image"`
9			`"image/color"`
10			`"testing"`
11			`)`
12
13			`func eq(c0, c1 color.Color) bool {`
14			`r0, g0, b0, a0 := c0.RGBA()`
15			`r1, g1, b1, a1 := c1.RGBA()`
16			`return r0 == r1 && g0 == g1 && b0 == b1 && a0 == a1`
17			`}`
18
19			`func fillBlue(alpha int) image.Image {`
20			`return image.NewUniform(color.RGBA{0, 0, uint8(alpha), uint8(alpha)})`
21			`}`
22
23			`func fillAlpha(alpha int) image.Image {`
24			`return image.NewUniform(color.Alpha{uint8(alpha)})`
25			`}`
26
27			`func vgradGreen(alpha int) image.Image {`
28			`m := image.NewRGBA(image.Rect(0, 0, 16, 16))`
29			`for y := 0; y < 16; y++ {`
30			`for x := 0; x < 16; x++ {`
31			`m.Set(x, y, color.RGBA{0, uint8(y * alpha / 15), 0, uint8(alpha)})`
32			`}`
33			`}`
34			`return m`
35			`}`
36
37			`func vgradAlpha(alpha int) image.Image {`
38			`m := image.NewAlpha(image.Rect(0, 0, 16, 16))`
39			`for y := 0; y < 16; y++ {`
40			`for x := 0; x < 16; x++ {`
41			`m.Set(x, y, color.Alpha{uint8(y * alpha / 15)})`
42			`}`
43			`}`
44			`return m`
45			`}`
46
47			`func vgradGreenNRGBA(alpha int) image.Image {`
48			`m := image.NewNRGBA(image.Rect(0, 0, 16, 16))`
49			`for y := 0; y < 16; y++ {`
50			`for x := 0; x < 16; x++ {`
51			`m.Set(x, y, color.RGBA{0, uint8(y * 0x11), 0, uint8(alpha)})`
52			`}`
53			`}`
54			`return m`
55			`}`
56
57			`func vgradCr() image.Image {`
58			`m := &image.YCbCr{`
59			`Y: make([]byte, 16*16),`
60			`Cb: make([]byte, 16*16),`
61			`Cr: make([]byte, 16*16),`
62			`YStride: 16,`
63			`CStride: 16,`
64			`SubsampleRatio: image.YCbCrSubsampleRatio444,`
65			`Rect: image.Rect(0, 0, 16, 16),`
66			`}`
67			`for y := 0; y < 16; y++ {`
68			`for x := 0; x < 16; x++ {`
69			`m.Cr[ym.CStride+x] = uint8(y 0x11)`
70			`}`
71			`}`
72			`return m`
73			`}`
74
75			`func hgradRed(alpha int) Image {`
76			`m := image.NewRGBA(image.Rect(0, 0, 16, 16))`
77			`for y := 0; y < 16; y++ {`
78			`for x := 0; x < 16; x++ {`
79			`m.Set(x, y, color.RGBA{uint8(x * alpha / 15), 0, 0, uint8(alpha)})`
80			`}`
81			`}`
82			`return m`
83			`}`
84
85			`func gradYellow(alpha int) Image {`
86			`m := image.NewRGBA(image.Rect(0, 0, 16, 16))`
87			`for y := 0; y < 16; y++ {`
88			`for x := 0; x < 16; x++ {`
89			`m.Set(x, y, color.RGBA{uint8(x * alpha / 15), uint8(y * alpha / 15), 0, uint8(alpha)})`
90			`}`
91			`}`
92			`return m`
93			`}`
94
95			`type drawTest struct {`
96			`desc string`
97			`src image.Image`
98			`mask image.Image`
99			`op Op`
100			`expected color.Color`
101			`}`
102
103			`var drawTests = []drawTest{`
104			`// Uniform mask (0% opaque).`
105			`{"nop", vgradGreen(255), fillAlpha(0), Over, color.RGBA{136, 0, 0, 255}},`
106			`{"clear", vgradGreen(255), fillAlpha(0), Src, color.RGBA{0, 0, 0, 0}},`
107			`// Uniform mask (100%, 75%, nil) and uniform source.`
108			`// At (x, y) == (8, 8):`
109			`// The destination pixel is {136, 0, 0, 255}.`
110			`// The source pixel is {0, 0, 90, 90}.`
111			`{"fill", fillBlue(90), fillAlpha(255), Over, color.RGBA{88, 0, 90, 255}},`
112			`{"fillSrc", fillBlue(90), fillAlpha(255), Src, color.RGBA{0, 0, 90, 90}},`
113			`{"fillAlpha", fillBlue(90), fillAlpha(192), Over, color.RGBA{100, 0, 68, 255}},`
114			`{"fillAlphaSrc", fillBlue(90), fillAlpha(192), Src, color.RGBA{0, 0, 68, 68}},`
115			`{"fillNil", fillBlue(90), nil, Over, color.RGBA{88, 0, 90, 255}},`
116			`{"fillNilSrc", fillBlue(90), nil, Src, color.RGBA{0, 0, 90, 90}},`
117			`// Uniform mask (100%, 75%, nil) and variable source.`
118			`// At (x, y) == (8, 8):`
119			`// The destination pixel is {136, 0, 0, 255}.`
120			`// The source pixel is {0, 48, 0, 90}.`
121			`{"copy", vgradGreen(90), fillAlpha(255), Over, color.RGBA{88, 48, 0, 255}},`
122			`{"copySrc", vgradGreen(90), fillAlpha(255), Src, color.RGBA{0, 48, 0, 90}},`
123			`{"copyAlpha", vgradGreen(90), fillAlpha(192), Over, color.RGBA{100, 36, 0, 255}},`
124			`{"copyAlphaSrc", vgradGreen(90), fillAlpha(192), Src, color.RGBA{0, 36, 0, 68}},`
125			`{"copyNil", vgradGreen(90), nil, Over, color.RGBA{88, 48, 0, 255}},`
126			`{"copyNilSrc", vgradGreen(90), nil, Src, color.RGBA{0, 48, 0, 90}},`
127			`// Uniform mask (100%, 75%, nil) and variable NRGBA source.`
128			`// At (x, y) == (8, 8):`
129			`// The destination pixel is {136, 0, 0, 255}.`
130			`// The source pixel is {0, 136, 0, 90} in NRGBA-space, which is {0, 48, 0, 90} in RGBA-space.`
131			`// The result pixel is different than in the "copy*" test cases because of rounding errors.`
132			`{"nrgba", vgradGreenNRGBA(90), fillAlpha(255), Over, color.RGBA{88, 46, 0, 255}},`
133			`{"nrgbaSrc", vgradGreenNRGBA(90), fillAlpha(255), Src, color.RGBA{0, 46, 0, 90}},`
134			`{"nrgbaAlpha", vgradGreenNRGBA(90), fillAlpha(192), Over, color.RGBA{100, 34, 0, 255}},`
135			`{"nrgbaAlphaSrc", vgradGreenNRGBA(90), fillAlpha(192), Src, color.RGBA{0, 34, 0, 68}},`
136			`{"nrgbaNil", vgradGreenNRGBA(90), nil, Over, color.RGBA{88, 46, 0, 255}},`
137			`{"nrgbaNilSrc", vgradGreenNRGBA(90), nil, Src, color.RGBA{0, 46, 0, 90}},`
138			`// Uniform mask (100%, 75%, nil) and variable YCbCr source.`
139			`// At (x, y) == (8, 8):`
140			`// The destination pixel is {136, 0, 0, 255}.`
141			`// The source pixel is {0, 0, 136} in YCbCr-space, which is {11, 38, 0, 255} in RGB-space.`
142			`{"ycbcr", vgradCr(), fillAlpha(255), Over, color.RGBA{11, 38, 0, 255}},`
143			`{"ycbcrSrc", vgradCr(), fillAlpha(255), Src, color.RGBA{11, 38, 0, 255}},`
144			`{"ycbcrAlpha", vgradCr(), fillAlpha(192), Over, color.RGBA{42, 28, 0, 255}},`
145			`{"ycbcrAlphaSrc", vgradCr(), fillAlpha(192), Src, color.RGBA{8, 28, 0, 192}},`
146			`{"ycbcrNil", vgradCr(), nil, Over, color.RGBA{11, 38, 0, 255}},`
147			`{"ycbcrNilSrc", vgradCr(), nil, Src, color.RGBA{11, 38, 0, 255}},`
148			`// Variable mask and variable source.`
149			`// At (x, y) == (8, 8):`
150			`// The destination pixel is {136, 0, 0, 255}.`
151			`// The source pixel is {0, 0, 255, 255}.`
152			`// The mask pixel's alpha is 102, or 40%.`
153			`{"generic", fillBlue(255), vgradAlpha(192), Over, color.RGBA{81, 0, 102, 255}},`
154			`{"genericSrc", fillBlue(255), vgradAlpha(192), Src, color.RGBA{0, 0, 102, 102}},`
155			`}`
156
157			`func makeGolden(dst image.Image, r image.Rectangle, src image.Image, sp image.Point, mask image.Image, mp image.Point, op Op) image.Image {`
158			`// Since golden is a newly allocated image, we don't have to check if the`
159			`// input source and mask images and the output golden image overlap.`
160			`b := dst.Bounds()`
161			`sb := src.Bounds()`
162			`mb := image.Rect(-1e9, -1e9, 1e9, 1e9)`
163			`if mask != nil {`
164			`mb = mask.Bounds()`
165			`}`
166			`golden := image.NewRGBA(image.Rect(0, 0, b.Max.X, b.Max.Y))`
167			`for y := r.Min.Y; y < r.Max.Y; y++ {`
168			`sy := y + sp.Y - r.Min.Y`
169			`my := y + mp.Y - r.Min.Y`
170			`for x := r.Min.X; x < r.Max.X; x++ {`
171			`if !(image.Pt(x, y).In(b)) {`
172			`continue`
173			`}`
174			`sx := x + sp.X - r.Min.X`
175			`if !(image.Pt(sx, sy).In(sb)) {`
176			`continue`
177			`}`
178			`mx := x + mp.X - r.Min.X`
179			`if !(image.Pt(mx, my).In(mb)) {`
180			`continue`
181			`}`
182
183			`const M = 1<<16 - 1`
184			`var dr, dg, db, da uint32`
185			`if op == Over {`
186			`dr, dg, db, da = dst.At(x, y).RGBA()`
187			`}`
188			`sr, sg, sb, sa := src.At(sx, sy).RGBA()`
189			`ma := uint32(M)`
190			`if mask != nil {`
191			`_, _, _, ma = mask.At(mx, my).RGBA()`
192			`}`
193			`a := M - (sa * ma / M)`
194			`golden.Set(x, y, color.RGBA64{`
195			`uint16((dra + srma) / M),`
196			`uint16((dga + sgma) / M),`
197			`uint16((dba + sbma) / M),`
198			`uint16((daa + sama) / M),`
199			`})`
200			`}`
201			`}`
202			`return golden.SubImage(b)`
203			`}`
204
205			`func TestDraw(t *testing.T) {`
206			`rr := []image.Rectangle{`
207			`image.Rect(0, 0, 0, 0),`
208			`image.Rect(0, 0, 16, 16),`
209			`image.Rect(3, 5, 12, 10),`
210			`image.Rect(0, 0, 9, 9),`
211			`image.Rect(8, 8, 16, 16),`
212			`image.Rect(8, 0, 9, 16),`
213			`image.Rect(0, 8, 16, 9),`
214			`image.Rect(8, 8, 9, 9),`
215			`image.Rect(8, 8, 8, 8),`
216			`}`
217			`for _, r := range rr {`
218			`loop:`
219			`for _, test := range drawTests {`
220			`dst := hgradRed(255).(*image.RGBA).SubImage(r).(Image)`
221			`// Draw the (src, mask, op) onto a copy of dst using a slow but obviously correct implementation.`
222			`golden := makeGolden(dst, image.Rect(0, 0, 16, 16), test.src, image.ZP, test.mask, image.ZP, test.op)`
223			`b := dst.Bounds()`
224			`if !b.Eq(golden.Bounds()) {`
225			`t.Errorf("draw %v %s: bounds %v versus %v", r, test.desc, dst.Bounds(), golden.Bounds())`
226			`continue`
227			`}`
228			`// Draw the same combination onto the actual dst using the optimized DrawMask implementation.`
229			`DrawMask(dst, image.Rect(0, 0, 16, 16), test.src, image.ZP, test.mask, image.ZP, test.op)`
230			`if image.Pt(8, 8).In(r) {`
231			`// Check that the resultant pixel at (8, 8) matches what we expect`
232			`// (the expected value can be verified by hand).`
233			`if !eq(dst.At(8, 8), test.expected) {`
234			`t.Errorf("draw %v %s: at (8, 8) %v versus %v", r, test.desc, dst.At(8, 8), test.expected)`
235			`continue`
236			`}`
237			`}`
238			`// Check that the resultant dst image matches the golden output.`
239			`for y := b.Min.Y; y < b.Max.Y; y++ {`
240			`for x := b.Min.X; x < b.Max.X; x++ {`
241			`if !eq(dst.At(x, y), golden.At(x, y)) {`
242			`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))`
243			`continue loop`
244			`}`
245			`}`
246			`}`
247			`}`
248			`}`
249			`}`
250
251			`func TestDrawOverlap(t *testing.T) {`
252			`for _, op := range []Op{Over, Src} {`
253			`for yoff := -2; yoff <= 2; yoff++ {`
254			`loop:`
255			`for xoff := -2; xoff <= 2; xoff++ {`
256			`m := gradYellow(127).(*image.RGBA)`
257			`dst := m.SubImage(image.Rect(5, 5, 10, 10)).(*image.RGBA)`
258			`src := m.SubImage(image.Rect(5+xoff, 5+yoff, 10+xoff, 10+yoff)).(*image.RGBA)`
259			`b := dst.Bounds()`
260			`// Draw the (src, mask, op) onto a copy of dst using a slow but obviously correct implementation.`
261			`golden := makeGolden(dst, b, src, src.Bounds().Min, nil, image.ZP, op)`
262			`if !b.Eq(golden.Bounds()) {`
263			`t.Errorf("drawOverlap xoff=%d,yoff=%d: bounds %v versus %v", xoff, yoff, dst.Bounds(), golden.Bounds())`
264			`continue`
265			`}`
266			`// Draw the same combination onto the actual dst using the optimized DrawMask implementation.`
267			`DrawMask(dst, b, src, src.Bounds().Min, nil, image.ZP, op)`
268			`// Check that the resultant dst image matches the golden output.`
269			`for y := b.Min.Y; y < b.Max.Y; y++ {`
270			`for x := b.Min.X; x < b.Max.X; x++ {`
271			`if !eq(dst.At(x, y), golden.At(x, y)) {`
272			`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))`
273			`continue loop`
274			`}`
275			`}`
276			`}`
277			`}`
278			`}`
279			`}`
280			`}`
281
282			`// TestNonZeroSrcPt checks drawing with a non-zero src point parameter.`
283			`func TestNonZeroSrcPt(t *testing.T) {`
284			`a := image.NewRGBA(image.Rect(0, 0, 1, 1))`
285			`b := image.NewRGBA(image.Rect(0, 0, 2, 2))`
286			`b.Set(0, 0, color.RGBA{0, 0, 0, 5})`
287			`b.Set(1, 0, color.RGBA{0, 0, 5, 5})`
288			`b.Set(0, 1, color.RGBA{0, 5, 0, 5})`
289			`b.Set(1, 1, color.RGBA{5, 0, 0, 5})`
290			`Draw(a, image.Rect(0, 0, 1, 1), b, image.Pt(1, 1), Over)`
291			`if !eq(color.RGBA{5, 0, 0, 5}, a.At(0, 0)) {`
292			`t.Errorf("non-zero src pt: want %v got %v", color.RGBA{5, 0, 0, 5}, a.At(0, 0))`
293			`}`
294			`}`
295
296			`func TestFill(t *testing.T) {`
297			`rr := []image.Rectangle{`
298			`image.Rect(0, 0, 0, 0),`
299			`image.Rect(0, 0, 40, 30),`
300			`image.Rect(10, 0, 40, 30),`
301			`image.Rect(0, 20, 40, 30),`
302			`image.Rect(10, 20, 40, 30),`
303			`image.Rect(10, 20, 15, 25),`
304			`image.Rect(10, 0, 35, 30),`
305			`image.Rect(0, 15, 40, 16),`
306			`image.Rect(24, 24, 25, 25),`
307			`image.Rect(23, 23, 26, 26),`
308			`image.Rect(22, 22, 27, 27),`
309			`image.Rect(21, 21, 28, 28),`
310			`image.Rect(20, 20, 29, 29),`
311			`}`
312			`for _, r := range rr {`
313			`m := image.NewRGBA(image.Rect(0, 0, 40, 30)).SubImage(r).(*image.RGBA)`
314			`b := m.Bounds()`
315			`c := color.RGBA{11, 0, 0, 255}`
316			`src := &image.Uniform{C: c}`
317			`check := func(desc string) {`
318			`for y := b.Min.Y; y < b.Max.Y; y++ {`
319			`for x := b.Min.X; x < b.Max.X; x++ {`
320			`if !eq(c, m.At(x, y)) {`
321			`t.Errorf("%s fill: at (%d, %d), sub-image bounds=%v: want %v got %v", desc, x, y, r, c, m.At(x, y))`
322			`return`
323			`}`
324			`}`
325			`}`
326			`}`
327			`// Draw 1 pixel at a time.`
328			`for y := b.Min.Y; y < b.Max.Y; y++ {`
329			`for x := b.Min.X; x < b.Max.X; x++ {`
330			`DrawMask(m, image.Rect(x, y, x+1, y+1), src, image.ZP, nil, image.ZP, Src)`
331			`}`
332			`}`
333			`check("pixel")`
334			`// Draw 1 row at a time.`
335			`c = color.RGBA{0, 22, 0, 255}`
336			`src = &image.Uniform{C: c}`
337			`for y := b.Min.Y; y < b.Max.Y; y++ {`
338			`DrawMask(m, image.Rect(b.Min.X, y, b.Max.X, y+1), src, image.ZP, nil, image.ZP, Src)`
339			`}`
340			`check("row")`
341			`// Draw 1 column at a time.`
342			`c = color.RGBA{0, 0, 33, 255}`
343			`src = &image.Uniform{C: c}`
344			`for x := b.Min.X; x < b.Max.X; x++ {`
345			`DrawMask(m, image.Rect(x, b.Min.Y, x+1, b.Max.Y), src, image.ZP, nil, image.ZP, Src)`
346			`}`
347			`check("column")`
348			`// Draw the whole image at once.`
349			`c = color.RGBA{44, 55, 66, 77}`
350			`src = &image.Uniform{C: c}`
351			`DrawMask(m, b, src, image.ZP, nil, image.ZP, Src)`
352			`check("whole")`
353			`}`
354			`}`