Пример #1
0
func hexToColorNRGBA(hex string) color.NRGBA {
	c := color.NRGBA{}

	getIntensity := func(str string) uint8 {
		if u, err := hexToUint8(str); err == nil {
			return u
		}

		return 0
	}

	if len(hex) >= 6 {
		c.R = getIntensity(hex[0:2])
		c.G = getIntensity(hex[2:4])
		c.B = getIntensity(hex[4:6])
	}

	if len(hex) == 8 {
		c.A = getIntensity(hex[6:8])
	} else {
		c.A = 255
	}

	return c
}
Пример #2
0
func writeImagePng(filename string, pixels []float32, xres, yres int) {
	outImage := image.NewNRGBA(image.Rect(0, 0, xres, yres))

	to_byte := func(v float32) uint8 {
		// apply gamma and convert to 0..255
		return uint8(Clamp(255.0*math.Pow(float64(v), 1.0/2.2), 0.0, 255.0))
	}

	for y := 0; y < yres; y++ {
		for x := 0; x < xres; x++ {
			var fcolor color.NRGBA
			fcolor.R = to_byte(pixels[3*(y*xres+x)+0])
			fcolor.G = to_byte(pixels[3*(y*xres+x)+1])
			fcolor.B = to_byte(pixels[3*(y*xres+x)+2])
			fcolor.A = 0xff
			outImage.Set(x, y, fcolor)
		}
	}
	f, err := os.Create(filename)
	defer f.Close()

	if err != nil {
		Error("Error writing PNG \"%s\"", filename)
	} else {
		png.Encode(f, outImage)
	}
}
Пример #3
0
// render one row of pixels by calculating a colour for each pixel.
// The image pixel row number is r. Fill the pixel colour into the
// image after the colour has been calculated.
func (r row) render(rt *rtrace, a, b, c lin.V3, img *image.NRGBA, seed *uint32) {
	rgba := color.NRGBA{0, 0, 0, 255}
	t, v1, v2 := lin.NewV3(), lin.NewV3(), lin.NewV3() // temp vectors.
	colour, orig, dir := lin.NewV3(), lin.NewV3(), lin.NewV3()
	for x := (rt.iw - 1); x >= 0; x-- {
		colour.SetS(13, 13, 13) // Use a very dark default colour.

		// Cast 64 rays per pixel for blur (stochastic sampling) and soft-shadows.
		for cnt := 0; cnt < 64; cnt++ {

			// Add randomness to the camera origin 17,16,8
			t.Scale(&a, rnd(seed)-0.5).Scale(t, 99).Add(t, v1.Scale(&b, rnd(seed)-0.5).Scale(v1, 99))
			orig.SetS(17, 16, 8).Add(orig, t)

			// Add randomness to the camera direction.
			rnda := rnd(seed) + float64(x)
			rndb := float64(r) + rnd(seed)
			dir.Scale(t, -1)
			dir.Add(dir, v1.Scale(&a, rnda).Add(v1, v2.Scale(&b, rndb)).Add(v1, &c).Scale(v1, 16))
			dir.Unit()

			// accumulate the colour from each of the 64 rays.
			sample := rt.sample(*orig, *dir, seed)
			colour = sample.Scale(&sample, 3.5).Add(&sample, colour)
		}

		// set the final pixel colour in the image.
		rgba.R = byte(colour.X) // red
		rgba.G = byte(colour.Y) // green
		rgba.B = byte(colour.Z) // blue
		img.SetNRGBA(rt.iw-x, int(r), rgba)
	}
}
Пример #4
0
func setRandomBrightness(c *color.NRGBA, max uint8) {
	minc := min3(c.R, c.G, c.B)
	maxc := max3(c.R, c.G, c.B)
	if maxc > max {
		return
	}
	n := rand.Intn(int(max-maxc)) - int(minc)
	c.R = uint8(int(c.R) + n)
	c.G = uint8(int(c.G) + n)
	c.B = uint8(int(c.B) + n)
}