Golang image.NewRGBA函數代碼示例

// NewDrawableSize returns a new draw.Image with the same type as p and the given bounds.
// If p is not a draw.Image, another type is used.
func NewDrawableSize(p image.Image, r image.Rectangle) draw.Image {
	switch p := p.(type) {
	case *image.RGBA:
		return image.NewRGBA(r)
	case *image.RGBA64:
		return image.NewRGBA64(r)
	case *image.NRGBA:
		return image.NewNRGBA(r)
	case *image.NRGBA64:
		return image.NewNRGBA64(r)
	case *image.Alpha:
		return image.NewAlpha(r)
	case *image.Alpha16:
		return image.NewAlpha16(r)
	case *image.Gray:
		return image.NewGray(r)
	case *image.Gray16:
		return image.NewGray16(r)
	case *image.Paletted:
		pl := make(color.Palette, len(p.Palette))
		copy(pl, p.Palette)
		return image.NewPaletted(r, pl)
	case *image.CMYK:
		return image.NewCMYK(r)
	default:
		return image.NewRGBA(r)
	}
}

// Save saves the texture as a PNG image.
func (a *TextureAtlas) Save(file string) (err error) {
	fd, err := os.Create(file)
	if err != nil {
		return
	}

	defer fd.Close()

	rect := image.Rect(0, 0, a.width, a.height)

	switch a.depth {
	case 1:
		img := image.NewAlpha(rect)
		copy(img.Pix, a.data)
		err = png.Encode(fd, img)

	case 3:
		img := image.NewRGBA(rect)
		copy(img.Pix, a.data)
		err = png.Encode(fd, img)

	case 4:
		img := image.NewRGBA(rect)
		copy(img.Pix, a.data)
		err = png.Encode(fd, img)
	}

	return
}

// Smart crop given image file & write it to io.Writer
func smartCrop(w io.Writer, r io.Reader, size []int) error {
	img, mimetype, err := image.Decode(r)
	if size == nil || err != nil {
		io.Copy(w, r)
		return nil
	}

	size = setMaxSize(fitToActualSize(&img, size))
	crop, err := smartcrop.SmartCrop(&img, size[0], size[1])
	if err != nil {
		io.Copy(w, r)
		return nil
	}

	croppedBuffer := image.NewRGBA(image.Rect(0, 0, crop.Width, crop.Height))
	draw.Draw(
		croppedBuffer,
		croppedBuffer.Bounds(),
		img,
		image.Point{crop.X, crop.Y},
		draw.Src,
	)

	dst := image.NewRGBA(image.Rect(0, 0, size[0], size[1]))
	graphics.Scale(dst, croppedBuffer)
	return writeByMimetype(w, dst, mimetype)
}

func main() {
	rand.Seed(time.Now().UTC().UnixNano())
	var templatePath string
	if len(os.Args) == 1 {
		templatePath = "tux.png"
	} else {
		templatePath = os.Args[1]
	}
	template, err := readTemplate(templatePath)
	if err != nil {
		panic(err)
	}
	templateBounds := template.Bounds()
	sourceHeight := templateBounds.Max.Y
	sourceWidth := templateBounds.Max.X
	cypherHeight := sourceHeight * 2
	cypherWidth := sourceWidth * 2

	image1 := image.NewRGBA(image.Rect(0, 0, cypherWidth, cypherHeight))
	image2 := image.NewRGBA(image.Rect(0, 0, cypherWidth, cypherHeight))
	for x := 0; x <= sourceWidth; x++ {
		for y := 0; y <= sourceHeight; y++ {
			setPixel(x, y, template.At(x, y), image1, image2)
		}
	}

	writeCypers(image1, image2)
}

func NewPPU(console *Console) *PPU {
	ppu := PPU{Memory: NewPPUMemory(console), console: console}
	ppu.front = image.NewRGBA(image.Rect(0, 0, 256, 240))
	ppu.back = image.NewRGBA(image.Rect(0, 0, 256, 240))
	ppu.Reset()
	return &ppu
}

func makePngShield(w io.Writer, d Data) {
	// render text to determine how wide the image has to be
	// we leave 6 pixels at the start and end, and 3 for each in the middle
	v, vw := renderString(d.Vendor, c)
	s, sw := renderString(d.Status, c)
	imageWidth := op + vw + ip*2 + sw + op

	img := image.NewRGBA(image.Rect(0, 0, imageWidth, h))
	draw.Draw(img, img.Bounds(), &image.Uniform{C: d.Color}, image.ZP, draw.Src)

	rect := image.Rect(0, 0, op+vw+ip, h)
	draw.Draw(img, rect, &image.Uniform{C: Grey}, image.ZP, draw.Src)

	dst := image.NewRGBA(image.Rect(0, 0, imageWidth, h))

	mask := image.NewRGBA(image.Rect(0, 0, imageWidth, h))
	buildMask(mask, imageWidth, edge, draw.Src)
	draw.DrawMask(dst, dst.Bounds(), img, image.ZP, mask, image.ZP, draw.Over)

	buildMask(dst, imageWidth, gradient, draw.Over)

	draw.Draw(dst, dst.Bounds(), v, image.Point{-op, 0}, draw.Over)

	draw.Draw(dst, dst.Bounds(), s, image.Point{-(op + vw + ip*2), 0}, draw.Over)

	png.Encode(w, dst)
}

func (ff *FontFace) GetImage(text string) (img draw.Image, err error) {
	var (
		src image.Image
		bg  image.Image
		dst draw.Image
		pt  fixed.Point26_6
		w   int
		h   int
	)
	src = image.NewUniform(ff.fg)
	bg = image.NewUniform(ff.bg)
	w = int(float32(len(text)) * ff.charw)
	h = int(ff.charh)
	dst = image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(dst, dst.Bounds(), bg, image.ZP, draw.Src)
	ff.context.SetSrc(src)
	ff.context.SetDst(dst)
	ff.context.SetClip(dst.Bounds())
	pt = freetype.Pt(0, int(ff.charh+ff.offy))
	if pt, err = ff.context.DrawString(text, pt); err != nil {
		return
	}
	img = image.NewRGBA(image.Rect(0, 0, int(pt.X/64), int(pt.Y/64)))
	draw.Draw(img, img.Bounds(), dst, image.Pt(0, -int(ff.offy)), draw.Src)
	return
}

func (ff *FontFace) GetText(text string) (t *Texture, err error) {
	var (
		src       image.Image
		bg        image.Image
		dst       draw.Image
		shortened draw.Image
		pt        fixed.Point26_6
		w         int
		h         int
	)
	src = image.NewUniform(ff.fg)
	bg = image.NewUniform(ff.bg)
	w = int(float32(len(text)) * ff.charw)
	h = int(ff.charh)
	dst = image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(dst, dst.Bounds(), bg, image.ZP, draw.Src)
	ff.context.SetSrc(src)
	ff.context.SetDst(dst)
	ff.context.SetClip(dst.Bounds())
	pt = freetype.Pt(0, int(ff.charh))
	if pt, err = ff.context.DrawString(text, pt); err != nil {
		return
	}
	// if err = WritePNG("hello.png", dst); err != nil {
	// 	return
	// }
	shortened = image.NewRGBA(image.Rect(0, 0, int(pt.X/64), h))
	draw.Draw(shortened, shortened.Bounds(), dst, image.ZP, draw.Src)
	t, err = GetTexture(shortened, gl.NEAREST)
	return
}

// TestNegativeWeights tests that scaling by a kernel that produces negative
// weights, such as the Catmull-Rom kernel, doesn't produce an invalid color
// according to Go's alpha-premultiplied model.
func TestNegativeWeights(t *testing.T) {
	check := func(m *image.RGBA) error {
		b := m.Bounds()
		for y := b.Min.Y; y < b.Max.Y; y++ {
			for x := b.Min.X; x < b.Max.X; x++ {
				if c := m.RGBAAt(x, y); c.R > c.A || c.G > c.A || c.B > c.A {
					return fmt.Errorf("invalid color.RGBA at (%d, %d): %v", x, y, c)
				}
			}
		}
		return nil
	}

	src := image.NewRGBA(image.Rect(0, 0, 16, 16))
	for y := 0; y < 16; y++ {
		for x := 0; x < 16; x++ {
			a := y * 0x11
			src.Set(x, y, color.RGBA{
				R: uint8(x * 0x11 * a / 0xff),
				A: uint8(a),
			})
		}
	}
	if err := check(src); err != nil {
		t.Fatalf("src image: %v", err)
	}

	dst := image.NewRGBA(image.Rect(0, 0, 32, 32))
	CatmullRom.Scale(dst, dst.Bounds(), src, src.Bounds(), Over, nil)
	if err := check(dst); err != nil {
		t.Fatalf("dst image: %v", err)
	}
}

func main() {
	m := image.NewRGBA(image.Rect(0, 0, 500, 500))

	blue := color.RGBA{59, 148, 217, 255}
	white := color.RGBA{255, 255, 255, 255}
	black := color.RGBA{0, 0, 0, 255}

	draw.Draw(m, m.Bounds(), &image.Uniform{blue}, image.ZP, draw.Src)

	filename := "egg_mask.png"

	f, err := os.Open(filename)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	src, err := png.Decode(f)
	if err != nil {
		panic(err)
	}

	mask := image.NewRGBA(image.Rect(0, 0, 500, 500))
	draw.Draw(mask, mask.Bounds(), &image.Uniform{white}, image.ZP, draw.Src)

	draw.DrawMask(m, m.Bounds(), src, image.ZP, mask, image.ZP, draw.Over)

	for i := m.Bounds().Min.X; i < m.Bounds().Max.X; i++ {
		m.Set(i, m.Bounds().Max.Y/2, black) // to change a single pixel
	}

	w, _ := os.Create("defaultegg.png")
	defer w.Close()
	png.Encode(w, m)
}

func TestSrcMask(t *testing.T) {
	srcMask := image.NewRGBA(image.Rect(0, 0, 23, 1))
	srcMask.SetRGBA(19, 0, color.RGBA{0x00, 0x00, 0x00, 0x7f})
	srcMask.SetRGBA(20, 0, color.RGBA{0x00, 0x00, 0x00, 0xff})
	srcMask.SetRGBA(21, 0, color.RGBA{0x00, 0x00, 0x00, 0x3f})
	srcMask.SetRGBA(22, 0, color.RGBA{0x00, 0x00, 0x00, 0x00})
	red := image.NewUniform(color.RGBA{0xff, 0x00, 0x00, 0xff})
	blue := image.NewUniform(color.RGBA{0x00, 0x00, 0xff, 0xff})
	dst := image.NewRGBA(image.Rect(0, 0, 6, 1))
	Copy(dst, image.Point{}, blue, dst.Bounds(), Src, nil)
	NearestNeighbor.Scale(dst, dst.Bounds(), red, image.Rect(0, 0, 3, 1), Over, &Options{
		SrcMask:  srcMask,
		SrcMaskP: image.Point{20, 0},
	})
	got := [6]color.RGBA{
		dst.RGBAAt(0, 0),
		dst.RGBAAt(1, 0),
		dst.RGBAAt(2, 0),
		dst.RGBAAt(3, 0),
		dst.RGBAAt(4, 0),
		dst.RGBAAt(5, 0),
	}
	want := [6]color.RGBA{
		{0xff, 0x00, 0x00, 0xff},
		{0xff, 0x00, 0x00, 0xff},
		{0x3f, 0x00, 0xc0, 0xff},
		{0x3f, 0x00, 0xc0, 0xff},
		{0x00, 0x00, 0xff, 0xff},
		{0x00, 0x00, 0xff, 0xff},
	}
	if got != want {
		t.Errorf("\ngot  %v\nwant %v", got, want)
	}
}

func (jw *JsonWed) ImportOverlays(wed *Wed) error {
	jw.Overlays = make([]jsonWedOverlay, 0)
	jw.TileIndices = make([]int, len(wed.TileIndices))
	for idx, overlay := range wed.Overlays {
		if overlay.Name.String() != "" {
			ov := jsonWedOverlay{}
			ov.Width = int(overlay.Width)
			ov.Height = int(overlay.Height)
			ov.Name = overlay.Name.String()
			ov.Flags = int(overlay.LayerFlags)

			ov.Tilemap = make([]jsonWedTilemap, len(wed.Tilemaps[idx]))
			for tmIdx, tilemap := range wed.Tilemaps[idx] {
				ov.Tilemap[tmIdx].Id = int(tilemap.TileIndexLookupIndex)
				ov.Tilemap[tmIdx].Count = int(tilemap.TileIndexLookupCount)
				ov.Tilemap[tmIdx].Alt = int(tilemap.AlternateTileIndex)
				ov.Tilemap[tmIdx].Flags = int(tilemap.Flags)
				ov.Tilemap[tmIdx].AnimSpeed = int(tilemap.AnimSpeed)
				ov.Tilemap[tmIdx].WFlags = int(tilemap.WFlags)
			}

			tisFile, err := os.Open(overlay.Name.String() + ".tis")
			if err != nil {
				return fmt.Errorf("unable to open overlay: %s %v", overlay.Name.String(), err)
			}
			defer tisFile.Close()

			cwd, err := os.Getwd()
			if err != nil {
				return fmt.Errorf("unable to get working directory: %v", err)
			}
			tis, err := OpenTis(tisFile, overlay.Name.String(), cwd)
			if err != nil {
				return fmt.Errorf("unable to open tis: %v", err)
			}
			ov.Tis = tis
			img := image.NewRGBA(image.Rect(0, 0, 64*ov.Width, 64*ov.Height))
			closedimg := image.NewRGBA(image.Rect(0, 0, 64*ov.Width, 64*ov.Height))
			for y := 0; y < int(ov.Height); y++ {
				for x := 0; x < int(ov.Width); x++ {
					tileNum := y*int(ov.Width) + x
					tileImg := tis.SubImage(tileNum)
					draw.Draw(img, image.Rect(x*64, y*64, x*64+64, y*64+64), tileImg, image.Pt(0, 0), draw.Src)
					if ov.Tilemap[tileNum].Alt != -1 {
						tileImg = tis.SubImage(ov.Tilemap[tileNum].Alt)
						draw.Draw(closedimg, image.Rect(x*64, y*64, x*64+64, y*64+64), tileImg, image.Pt(0, 0), draw.Src)
					}
				}
			}
			ov.BackgroundImg = img
			ov.ClosedImage = closedimg

			jw.Overlays = append(jw.Overlays, ov)
		}
	}
	for idx, ti := range wed.TileIndices {
		jw.TileIndices[idx] = int(ti)
	}
	return nil
}

func maskFor(in image.Image) image.Image {
	b := in.Bounds()

	// thumb size, corresponds to first convert command
	thumbWidth := int(b.Dx() / 5)
	thumbHeight := int(b.Dy() / 5)

	thumb := image.NewRGBA(image.Rect(0, 0, thumbWidth, thumbHeight))
	final := image.NewRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))

	// fill black (xc:black)
	// draw white rectangle  (1,1 : thumbWidth-1,thumbHeight-1)
	for y := 0; y < thumbHeight; y++ {
		for x := 0; x < thumbWidth; x++ {
			if (y > 0 && y < thumbHeight-1) && (x > 0 && x < thumbWidth-1) {
				thumb.Set(x, y, color.White)
			} else {
				thumb.Set(x, y, color.Black)
			}
		}
	}

	// apply Gaussian blur with radius=7, sigma=15
	graphics.Blur(thumb, thumb, &graphics.BlurOptions{2, 7})

	// now resize to original image size
	resized := resize.Resize(uint(b.Dx()), uint(b.Dy()), thumb, resize.Bilinear)

	// with gaussian blur radius=0, sigma=5
	graphics.Blur(final, resized, &graphics.BlurOptions{5, 0})

	return final
}

// Adjust adjusts the two images aligning ther centers. The background
// of the smaller image is filled with FillColor. The returned images
// are of the same size.
func (c Centerer) Adjust(img1, img2 image.Image) (image.Image, image.Image) {
	img1Rect := img1.Bounds()
	img2Rect := img2.Bounds()
	backgroundRect := img1Rect.Union(img2Rect)

	dstImg1 := image.NewRGBA(backgroundRect)
	dstImg2 := image.NewRGBA(backgroundRect)

	// Fill destination images with FillColor
	draw.Draw(dstImg1, dstImg1.Bounds(), &image.Uniform{c.FillColor}, image.ZP, draw.Src)
	draw.Draw(dstImg2, dstImg2.Bounds(), &image.Uniform{c.FillColor}, image.ZP, draw.Src)

	// Copy img1 to the center of dstImg1
	dp := image.Point{
		(backgroundRect.Max.X-backgroundRect.Min.X)/2 - (img1Rect.Max.X-img1Rect.Min.X)/2,
		(backgroundRect.Max.Y-backgroundRect.Min.Y)/2 - (img1Rect.Max.Y-img1Rect.Min.Y)/2,
	}
	r := image.Rectangle{dp, dp.Add(img1Rect.Size())}
	draw.Draw(dstImg1, r, img1, image.ZP, draw.Src)

	// Copy img2 to the center of dstImg2
	dp = image.Point{
		(backgroundRect.Max.X-backgroundRect.Min.X)/2 - (img2Rect.Max.X-img2Rect.Min.X)/2,
		(backgroundRect.Max.Y-backgroundRect.Min.Y)/2 - (img2Rect.Max.Y-img2Rect.Min.Y)/2,
	}
	r = image.Rectangle{dp, dp.Add(img2Rect.Size())}
	draw.Draw(dstImg2, r, img2, image.ZP, draw.Src)

	return dstImg1, dstImg2
}

func TestGMProcess(t *testing.T) {
	buffer := new(bytes.Buffer)
	png.Encode(buffer, image.NewRGBA(image.Rect(0, 0, 200, 200)))

	gm := NewGMProcessor()
	params, _ := ParseParams("r_100x100,c_50x50,g_c,q_50")
	img, err := gm.Process(params, "text.png", buffer)
	assert.NoError(t, err)
	assert.NotNil(t, img)
	assert.True(t, img.Len() > 0)

	buffer = new(bytes.Buffer)
	png.Encode(buffer, image.NewRGBA(image.Rect(0, 0, 200, 200)))
	params, _ = ParseParams("r_100x0,c_50x50,g_c,q_50")
	img, err = gm.Process(params, "text.png", buffer)
	assert.NoError(t, err)
	assert.NotNil(t, img)
	assert.True(t, img.Len() > 0)

	buffer = new(bytes.Buffer)
	png.Encode(buffer, image.NewRGBA(image.Rect(0, 0, 200, 200)))
	params, _ = ParseParams("r_0x100,c_50x50,g_c,q_50")
	img, err = gm.Process(params, "text.png", buffer)
	assert.NoError(t, err)
	assert.NotNil(t, img)
	assert.True(t, img.Len() > 0)
}