func main() { flag.Parse() if *cpuprofile != "" { f, err := os.Create(*cpuprofile) if err != nil { log.Fatal(err) } pprof.StartCPUProfile(f) defer pprof.StopCPUProfile() } g := vector.Vector{X: -5.5, Y: -16, Z: 0}.Normalize() a := vector.Vector{X: 0, Y: 0, Z: 1}.CrossProduct(g).Normalize().Scale(0.002) b := g.CrossProduct(a).Normalize().Scale(0.002) c := a.Add(b).Scale(-256).Add(g) img := image.NewRGBA(image.Rect(0, 0, *width, *height)) const ( R = iota G B A ) pos := 0 invheight := 1.0 / float32(*height-1) s := time.Now() for y := (*height - 1); y >= 0; y-- { fmt.Printf("%.2f%%\r", 100*(1-invheight*float32(y))) for x := (*width - 1); x >= 0; x-- { p := vector.Vector{X: 13, Y: 13, Z: 13} for i := 0; i < 64; i++ { t := a.Scale(Rand() - 0.5).Scale(99).Add(b.Scale(Rand() - 0.5).Scale(99)) orig := vector.Vector{X: 17, Y: 16, Z: 8}.Add(t) dir := t.Scale(-1).Add(a.Scale(Rand() + float64(x)).Add(b.Scale(float64(y) + Rand())).Add(c).Scale(16)).Normalize() p = sampler(orig, dir).Scale(3.5).Add(p) } img.Pix[pos+R] = uint8(p.X) img.Pix[pos+G] = uint8(p.Y) img.Pix[pos+B] = uint8(p.Z) img.Pix[pos+A] = 0xff pos += 4 } } e := time.Since(s) pixels := (*width) * (*height) fmt.Printf("Traced %d pixels in %s, %s/pixel\n", pixels, e, e/time.Duration(pixels)) f, err := os.Create(outimage) if err != nil { log.Fatalln(err) } defer f.Close() if err = png.Encode(f, img); err != nil { log.Fatalln(err) } }
func main() { runtime.GOMAXPROCS(runtime.NumCPU()) flag.Parse() if *cpuprofile != "" { f, err := os.Create(*cpuprofile) if err != nil { log.Fatal(err) } pprof.StartCPUProfile(f) defer pprof.StopCPUProfile() } if *procs < 1 { log.Fatalf("Procs (%v) needs to be >= 1", *procs) } fmt.Printf("P6 %v %v 255 ", *width, *height) bytes := make([]byte, 3**width**height) g := vector.Vector{X: -5.5, Y: -16, Z: 0}.Normalize() a := vector.Vector{X: 0, Y: 0, Z: 1}.CrossProduct(g).Normalize().Scale(0.002) b := g.CrossProduct(a).Normalize().Scale(0.002) c := a.Add(b).Scale(-256).Add(g) rows := make(chan row, *height) var wg sync.WaitGroup wg.Add(*procs) for i := 0; i < *procs; i++ { go worker(a, b, c, bytes, rows, &wg) } for y := (*height - 1); y >= 0; y-- { rows <- row(y) } close(rows) wg.Wait() if _, err := os.Stdout.Write(bytes); err != nil { log.Panic(err) } }