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) } }
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 }
// 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) } }
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) }
func drawMotionMap(ske0, ske1 *image.NRGBA, m *MotionMap, shift *ShiftMap) (img *image.RGBA) { bounds := ske0.Bounds().Intersect(ske1.Bounds()).Intersect(m.Bounds) if shift != nil { bounds = bounds.Intersect(shift.Bounds) } s := 10 img = image.NewRGBA(image.Rectangle{bounds.Min.Mul(s), bounds.Max.Mul(s)}) gc := draw2d.NewGraphicContext(img) for y := img.Bounds().Min.Y; y < img.Bounds().Max.Y; y++ { for x := img.Bounds().Min.X; x < img.Bounds().Max.X; x++ { c := color.NRGBA{255, 255, 255, 255} if ske0.At(x/s, y/s).(color.NRGBA).A > 0 { c.R = 0 } if ske1.At(x/s, y/s).(color.NRGBA).A > 0 { c.G = 0 } img.Set(x, y, c) } } count := 0 for y := m.Bounds.Min.Y; y < m.Bounds.Max.Y; y++ { for x := m.Bounds.Min.X; x < m.Bounds.Max.X; x++ { v := GetMotion(m, x, y) if v.X != 0 || v.Y != 0 { cx, cy := x*s+s/2, y*s+s/2 dx, dy := v.X*s, v.Y*s gc.SetStrokeColor(color.RGBA{0, 0, 0, 255}) gc.MoveTo(float64(cx), float64(cy)) gc.LineTo(float64(cx+dx), float64(cy+dy)) gc.Stroke() count++ } if shift != nil { sv := GetShift(shift, x, y) if sv.Dx != 0.0 || sv.Dy != 0.0 { cx, cy := x*s+s/2, y*s+s/2 sf := float64(s) //fmt.Println(x, y, sv) gc.SetStrokeColor(color.RGBA{0, 200, 0, 255}) gc.MoveTo(float64(cx), float64(cy)) gc.LineTo(float64(cx)+sv.Dx*sf, float64(cy)+sv.Dy*sf) gc.Stroke() } } } } fmt.Println("count:", count) return }