Golang image.RGBA64類代碼示例

func Pixel(x, y int, img *image.RGBA64, wg *sync.WaitGroup) {
	var r, g, b, a uint64

	for i := 0; i < *spp; i++ {
		for j := 0; j < *spp; j++ {
			X := (float64(x)+float64(i)/float64(*spp))/float64(*ppp) - float64(*ppi)/2
			Y := float64(*ppi)/2 - (float64(y)+float64(j)/float64(*spp))/float64(*ppp)
			c := Ray(X+*basex, Y+*basey, *basez,
				X/float64(*ppi)*epsilon,
				Y/float64(*ppi)*epsilon,
				epsilon,
				farZ)

			r += uint64(c.R)
			g += uint64(c.G)
			b += uint64(c.B)
			a += uint64(c.A)
		}
	}
	img.SetRGBA64(x, y, color.RGBA64{
		uint16(r / uint64(*spp) / uint64(*spp)),
		uint16(g / uint64(*spp) / uint64(*spp)),
		uint16(b / uint64(*spp) / uint64(*spp)),
		uint16(a / uint64(*spp) / uint64(*spp)),
	})
	wg.Done()
}

func resizeNRGBA64(in *image.NRGBA64, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		row := in.Pix[x*in.Stride:]
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var rgba [4]int64
			var sum int64
			start := offset[y]
			ci := y * filterLength
			for i := 0; i < filterLength; i++ {
				coeff := coeffs[ci+i]
				if coeff != 0 {
					xi := start + i
					switch {
					case uint(xi) < uint(maxX):
						xi *= 8
					case xi >= maxX:
						xi = 8 * maxX
					default:
						xi = 0
					}

					// Forward alpha-premultiplication
					a := int64(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
					r := int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) * a
					r /= 0xffff
					g := int64(uint16(row[xi+2])<<8|uint16(row[xi+3])) * a
					g /= 0xffff
					b := int64(uint16(row[xi+4])<<8|uint16(row[xi+5])) * a
					b /= 0xffff

					rgba[0] += int64(coeff) * r
					rgba[1] += int64(coeff) * g
					rgba[2] += int64(coeff) * b
					rgba[3] += int64(coeff) * a
					sum += int64(coeff)
				}
			}

			xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8

			value := clampUint16(rgba[0] / sum)
			out.Pix[xo+0] = uint8(value >> 8)
			out.Pix[xo+1] = uint8(value)
			value = clampUint16(rgba[1] / sum)
			out.Pix[xo+2] = uint8(value >> 8)
			out.Pix[xo+3] = uint8(value)
			value = clampUint16(rgba[2] / sum)
			out.Pix[xo+4] = uint8(value >> 8)
			out.Pix[xo+5] = uint8(value)
			value = clampUint16(rgba[3] / sum)
			out.Pix[xo+6] = uint8(value >> 8)
			out.Pix[xo+7] = uint8(value)
		}
	}
}

func newAtFuncRGBA64(p *image.RGBA64) AtFunc {
	return func(x, y int) (r, g, b, a uint32) {
		i := p.PixOffset(x, y)
		r = uint32(p.Pix[i+0])<<8 | uint32(p.Pix[i+1])
		g = uint32(p.Pix[i+2])<<8 | uint32(p.Pix[i+3])
		b = uint32(p.Pix[i+4])<<8 | uint32(p.Pix[i+5])
		a = uint32(p.Pix[i+6])<<8 | uint32(p.Pix[i+7])
		return
	}
}

func convertRGBA64(dest *Image, src *image.RGBA64) {
	var x, y, i, si int

	for x = dest.Rect.Min.X; x < dest.Rect.Max.X; x++ {
		for y = dest.Rect.Min.Y; y < dest.Rect.Max.Y; y++ {
			si = src.PixOffset(x, y)
			i = dest.PixOffset(x, y)
			dest.Pix[i+0] = src.Pix[si+4]
			dest.Pix[i+1] = src.Pix[si+2]
			dest.Pix[i+2] = src.Pix[si+0]
			dest.Pix[i+3] = src.Pix[si+6]
		}
	}
}

func (s *Server) decodeRawEncoding(r io.Reader, rect *image.RGBA64) error {
	for y := rect.Rect.Min.Y; y < rect.Rect.Max.Y; y++ {
		for x := rect.Rect.Min.X; x < rect.Rect.Max.X; x++ {
			pixel, err := s.readPixel(r)
			if err != nil {
				log.Println("error reading pixel %d, %d", x, y)
				return err
			}
			rect.Set(x, y, pixel)
		}
	}

	return nil
}

func newSetFuncRGBA64(p *image.RGBA64) SetFunc {
	return func(x, y int, r, g, b, a uint32) {
		i := p.PixOffset(x, y)
		r16, g16, b16, a16 := uint16(r), uint16(g), uint16(b), uint16(a)
		p.Pix[i+0] = uint8(r16 >> 8)
		p.Pix[i+1] = uint8(r16)
		p.Pix[i+2] = uint8(g16 >> 8)
		p.Pix[i+3] = uint8(g16)
		p.Pix[i+4] = uint8(b16 >> 8)
		p.Pix[i+5] = uint8(b16)
		p.Pix[i+6] = uint8(a16 >> 8)
		p.Pix[i+7] = uint8(a16)
	}
}

func resizeGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var rgba [4]int64
			var sum int64
			start := offset[y]
			ci := y * filterLength
			for i := 0; i < filterLength; i++ {
				coeff := coeffs[ci+i]
				if coeff != 0 {
					xi := start + i
					switch {
					case xi < 0:
						xi = 0
					case xi >= maxX:
						xi = maxX
					}

					r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA()

					rgba[0] += int64(coeff) * int64(r)
					rgba[1] += int64(coeff) * int64(g)
					rgba[2] += int64(coeff) * int64(b)
					rgba[3] += int64(coeff) * int64(a)
					sum += int64(coeff)
				}
			}

			offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8

			value := clampUint16(rgba[0] / sum)
			out.Pix[offset+0] = uint8(value >> 8)
			out.Pix[offset+1] = uint8(value)
			value = clampUint16(rgba[1] / sum)
			out.Pix[offset+2] = uint8(value >> 8)
			out.Pix[offset+3] = uint8(value)
			value = clampUint16(rgba[2] / sum)
			out.Pix[offset+4] = uint8(value >> 8)
			out.Pix[offset+5] = uint8(value)
			value = clampUint16(rgba[3] / sum)
			out.Pix[offset+6] = uint8(value >> 8)
			out.Pix[offset+7] = uint8(value)
		}
	}
}

func resizeRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		row := in.Pix[x*in.Stride:]
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var rgba [4]int64
			var sum int64
			start := offset[y]
			ci := (y - newBounds.Min.Y) * filterLength
			for i := 0; i < filterLength; i++ {
				coeff := coeffs[ci+i]
				if coeff != 0 {
					xi := start + i
					switch {
					case xi < 0:
						xi = 0
					case xi >= maxX:
						xi = 8 * maxX
					default:
						xi *= 8
					}
					rgba[0] += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1]))
					rgba[1] += int64(coeff) * int64(uint16(row[xi+2])<<8|uint16(row[xi+3]))
					rgba[2] += int64(coeff) * int64(uint16(row[xi+4])<<8|uint16(row[xi+5]))
					rgba[3] += int64(coeff) * int64(uint16(row[xi+6])<<8|uint16(row[xi+7]))
					sum += int64(coeff)
				}
			}

			xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
			value := clampUint16(rgba[0] / sum)
			out.Pix[xo+0] = uint8(value >> 8)
			out.Pix[xo+1] = uint8(value)
			value = clampUint16(rgba[1] / sum)
			out.Pix[xo+2] = uint8(value >> 8)
			out.Pix[xo+3] = uint8(value)
			value = clampUint16(rgba[2] / sum)
			out.Pix[xo+4] = uint8(value >> 8)
			out.Pix[xo+5] = uint8(value)
			value = clampUint16(rgba[3] / sum)
			out.Pix[xo+6] = uint8(value >> 8)
			out.Pix[xo+7] = uint8(value)
		}
	}
}

func nearestRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		row := in.Pix[x*in.Stride:]
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var rgba [4]float32
			var sum float32
			start := offset[y]
			ci := y * filterLength
			for i := 0; i < filterLength; i++ {
				if coeffs[ci+i] {
					xi := start + i
					switch {
					case uint(xi) < uint(maxX):
						xi *= 8
					case xi >= maxX:
						xi = 8 * maxX
					default:
						xi = 0
					}
					rgba[0] += float32(uint16(row[xi+0])<<8 | uint16(row[xi+1]))
					rgba[1] += float32(uint16(row[xi+2])<<8 | uint16(row[xi+3]))
					rgba[2] += float32(uint16(row[xi+4])<<8 | uint16(row[xi+5]))
					rgba[3] += float32(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
					sum++
				}
			}

			xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
			value := floatToUint16(rgba[0] / sum)
			out.Pix[xo+0] = uint8(value >> 8)
			out.Pix[xo+1] = uint8(value)
			value = floatToUint16(rgba[1] / sum)
			out.Pix[xo+2] = uint8(value >> 8)
			out.Pix[xo+3] = uint8(value)
			value = floatToUint16(rgba[2] / sum)
			out.Pix[xo+4] = uint8(value >> 8)
			out.Pix[xo+5] = uint8(value)
			value = floatToUint16(rgba[3] / sum)
			out.Pix[xo+6] = uint8(value >> 8)
			out.Pix[xo+7] = uint8(value)
		}
	}
}

func nearestGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var rgba [4]float32
			var sum float32
			start := offset[y]
			ci := (y - newBounds.Min.Y) * filterLength
			for i := 0; i < filterLength; i++ {
				if coeffs[ci+i] {
					xi := start + i
					switch {
					case xi < 0:
						xi = 0
					case xi >= maxX:
						xi = maxX
					}
					r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA()
					rgba[0] += float32(r)
					rgba[1] += float32(g)
					rgba[2] += float32(b)
					rgba[3] += float32(a)
					sum++
				}
			}

			offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
			value := floatToUint16(rgba[0] / sum)
			out.Pix[offset+0] = uint8(value >> 8)
			out.Pix[offset+1] = uint8(value)
			value = floatToUint16(rgba[1] / sum)
			out.Pix[offset+2] = uint8(value >> 8)
			out.Pix[offset+3] = uint8(value)
			value = floatToUint16(rgba[2] / sum)
			out.Pix[offset+4] = uint8(value >> 8)
			out.Pix[offset+5] = uint8(value)
			value = floatToUint16(rgba[3] / sum)
			out.Pix[offset+6] = uint8(value >> 8)
			out.Pix[offset+7] = uint8(value)
		}
	}
}

// Resize a rectangle image slice
func resizeSlice(input image.Image, output *image.RGBA64, interp InterpolationFunction, scale, adjust, offset float32, slice image.Rectangle, c chan int) {
	filter := interp(input, float32(clampFactor(scale)))
	var u float32
	var color color.RGBA64
	for y := slice.Min.Y; y < slice.Max.Y; y++ {
		u = scale*(float32(y)+adjust) + offset
		filter.SetKernelWeights(u)
		for x := slice.Min.X; x < slice.Max.X; x++ {
			color = filter.Interpolate(u, x)
			i := output.PixOffset(x, y)
			output.Pix[i+0] = uint8(color.R >> 8)
			output.Pix[i+1] = uint8(color.R)
			output.Pix[i+2] = uint8(color.G >> 8)
			output.Pix[i+3] = uint8(color.G)
			output.Pix[i+4] = uint8(color.B >> 8)
			output.Pix[i+5] = uint8(color.B)
			output.Pix[i+6] = uint8(color.A >> 8)
			output.Pix[i+7] = uint8(color.A)
		}
	}

	c <- 1
}

// decode decodes the IDAT data into an image.
func (d *decoder) decode() (image.Image, error) {
	r, err := zlib.NewReader(d)
	if err != nil {
		return nil, err
	}
	defer r.Close()
	bitsPerPixel := 0
	pixOffset := 0
	var (
		gray     *image.Gray
		rgba     *image.RGBA
		paletted *image.Paletted
		nrgba    *image.NRGBA
		gray16   *image.Gray16
		rgba64   *image.RGBA64
		nrgba64  *image.NRGBA64
		img      image.Image
	)
	switch d.cb {
	case cbG1, cbG2, cbG4, cbG8:
		bitsPerPixel = d.depth
		gray = image.NewGray(image.Rect(0, 0, d.width, d.height))
		img = gray
	case cbGA8:
		bitsPerPixel = 16
		nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
		img = nrgba
	case cbTC8:
		bitsPerPixel = 24
		rgba = image.NewRGBA(image.Rect(0, 0, d.width, d.height))
		img = rgba
	case cbP1, cbP2, cbP4, cbP8:
		bitsPerPixel = d.depth
		paletted = image.NewPaletted(image.Rect(0, 0, d.width, d.height), d.palette)
		img = paletted
	case cbTCA8:
		bitsPerPixel = 32
		nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
		img = nrgba
	case cbG16:
		bitsPerPixel = 16
		gray16 = image.NewGray16(image.Rect(0, 0, d.width, d.height))
		img = gray16
	case cbGA16:
		bitsPerPixel = 32
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
		img = nrgba64
	case cbTC16:
		bitsPerPixel = 48
		rgba64 = image.NewRGBA64(image.Rect(0, 0, d.width, d.height))
		img = rgba64
	case cbTCA16:
		bitsPerPixel = 64
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
		img = nrgba64
	}
	bytesPerPixel := (bitsPerPixel + 7) / 8

	// cr and pr are the bytes for the current and previous row.
	// The +1 is for the per-row filter type, which is at cr[0].
	cr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
	pr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)

	for y := 0; y < d.height; y++ {
		// Read the decompressed bytes.
		_, err := io.ReadFull(r, cr)
		if err != nil {
			return nil, err
		}

		// Apply the filter.
		cdat := cr[1:]
		pdat := pr[1:]
		switch cr[0] {
		case ftNone:
			// No-op.
		case ftSub:
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += cdat[i-bytesPerPixel]
			}
		case ftUp:
			for i, p := range pdat {
				cdat[i] += p
			}
		case ftAverage:
			for i := 0; i < bytesPerPixel; i++ {
				cdat[i] += pdat[i] / 2
			}
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
			}
		case ftPaeth:
			filterPaeth(cdat, pdat, bytesPerPixel)
		default:
			return nil, FormatError("bad filter type")
		}

		// Convert from bytes to colors.
		switch d.cb {
//.........這裏部分代碼省略.........

// readImagePass reads a single image pass, sized according to the pass number.
func (d *decoder) readImagePass(r io.Reader, pass int, allocateOnly bool) (image.Image, error) {
	var bitsPerPixel int = 0
	pixOffset := 0
	var (
		gray     *image.Gray
		rgba     *image.RGBA
		paletted *image.Paletted
		nrgba    *image.NRGBA
		gray16   *image.Gray16
		rgba64   *image.RGBA64
		nrgba64  *image.NRGBA64
		img      image.Image
	)
	width, height := d.width, d.height
	if d.interlace == itAdam7 && !allocateOnly {
		p := interlacing[pass]
		// Add the multiplication factor and subtract one, effectively rounding up.
		width = (width - p.xOffset + p.xFactor - 1) / p.xFactor
		height = (height - p.yOffset + p.yFactor - 1) / p.yFactor
		// A PNG image can't have zero width or height, but for an interlaced
		// image, an individual pass might have zero width or height. If so, we
		// shouldn't even read a per-row filter type byte, so return early.
		if width == 0 || height == 0 {
			return nil, nil
		}
	}
	switch d.cb {
	case cbG1, cbG2, cbG4, cbG8:
		bitsPerPixel = d.depth
		gray = image.NewGray(image.Rect(0, 0, width, height))
		img = gray
	case cbGA8:
		bitsPerPixel = 16
		nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
		img = nrgba
	case cbTC8:
		bitsPerPixel = 24
		rgba = image.NewRGBA(image.Rect(0, 0, width, height))
		img = rgba
	case cbP1, cbP2, cbP4, cbP8:
		bitsPerPixel = d.depth
		paletted = image.NewPaletted(image.Rect(0, 0, width, height), d.palette)
		img = paletted
	case cbTCA8:
		bitsPerPixel = 32
		nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
		img = nrgba
	case cbG16:
		bitsPerPixel = 16
		gray16 = image.NewGray16(image.Rect(0, 0, width, height))
		img = gray16
	case cbGA16:
		bitsPerPixel = 32
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
		img = nrgba64
	case cbTC16:
		bitsPerPixel = 48
		rgba64 = image.NewRGBA64(image.Rect(0, 0, width, height))
		img = rgba64
	case cbTCA16:
		bitsPerPixel = 64
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
		img = nrgba64
	}
	if allocateOnly {
		return img, nil
	}
	bytesPerPixel := (bitsPerPixel + 7) / 8

	// The +1 is for the per-row filter type, which is at cr[0].
	rowSize := 1 + (bitsPerPixel*width+7)/8
	// cr and pr are the bytes for the current and previous row.
	cr := make([]uint8, rowSize)
	pr := make([]uint8, rowSize)

	for y := 0; y < height; y++ {
		// Read the decompressed bytes.
		_, err := io.ReadFull(r, cr)
		if err != nil {
			if err == io.EOF || err == io.ErrUnexpectedEOF {
				return nil, FormatError("not enough pixel data")
			}
			return nil, err
		}

		// Apply the filter.
		cdat := cr[1:]
		pdat := pr[1:]
		switch cr[0] {
		case ftNone:
			// No-op.
		case ftSub:
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += cdat[i-bytesPerPixel]
			}
		case ftUp:
			for i, p := range pdat {
				cdat[i] += p
			}
//.........這裏部分代碼省略.........

func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
	r, err := zlib.NewReader(idat)
	if err != nil {
		return nil, err
	}
	defer r.Close()
	bpp := 0 // Bytes per pixel.
	maxPalette := uint8(0)
	var (
		gray     *image.Gray
		rgba     *image.RGBA
		paletted *image.Paletted
		nrgba    *image.NRGBA
		gray16   *image.Gray16
		rgba64   *image.RGBA64
		nrgba64  *image.NRGBA64
		img      image.Image
	)
	switch d.cb {
	case cbG8:
		bpp = 1
		gray = image.NewGray(d.width, d.height)
		img = gray
	case cbTC8:
		bpp = 3
		rgba = image.NewRGBA(d.width, d.height)
		img = rgba
	case cbP8:
		bpp = 1
		paletted = image.NewPaletted(d.width, d.height, d.palette)
		img = paletted
		maxPalette = uint8(len(d.palette) - 1)
	case cbTCA8:
		bpp = 4
		nrgba = image.NewNRGBA(d.width, d.height)
		img = nrgba
	case cbG16:
		bpp = 2
		gray16 = image.NewGray16(d.width, d.height)
		img = gray16
	case cbTC16:
		bpp = 6
		rgba64 = image.NewRGBA64(d.width, d.height)
		img = rgba64
	case cbTCA16:
		bpp = 8
		nrgba64 = image.NewNRGBA64(d.width, d.height)
		img = nrgba64
	}
	// cr and pr are the bytes for the current and previous row.
	// The +1 is for the per-row filter type, which is at cr[0].
	cr := make([]uint8, 1+bpp*d.width)
	pr := make([]uint8, 1+bpp*d.width)

	for y := 0; y < d.height; y++ {
		// Read the decompressed bytes.
		_, err := io.ReadFull(r, cr)
		if err != nil {
			return nil, err
		}

		// Apply the filter.
		cdat := cr[1:]
		pdat := pr[1:]
		switch cr[0] {
		case ftNone:
			// No-op.
		case ftSub:
			for i := bpp; i < len(cdat); i++ {
				cdat[i] += cdat[i-bpp]
			}
		case ftUp:
			for i := 0; i < len(cdat); i++ {
				cdat[i] += pdat[i]
			}
		case ftAverage:
			for i := 0; i < bpp; i++ {
				cdat[i] += pdat[i] / 2
			}
			for i := bpp; i < len(cdat); i++ {
				cdat[i] += uint8((int(cdat[i-bpp]) + int(pdat[i])) / 2)
			}
		case ftPaeth:
			for i := 0; i < bpp; i++ {
				cdat[i] += paeth(0, pdat[i], 0)
			}
			for i := bpp; i < len(cdat); i++ {
				cdat[i] += paeth(cdat[i-bpp], pdat[i], pdat[i-bpp])
			}
		default:
			return nil, FormatError("bad filter type")
		}

		// Convert from bytes to colors.
		switch d.cb {
		case cbG8:
			for x := 0; x < d.width; x++ {
				gray.Set(x, y, image.GrayColor{cdat[x]})
			}
		case cbTC8:
//.........這裏部分代碼省略.........

// Set a pixel in img by blending c on top of whatever color is
// already there
func blend(pt image.Point, c color.Color, img *image.RGBA64) {
	cc := over(c, img.At(pt.X, pt.Y))
	img.Set(pt.X, pt.Y, cc)
}