Data commit

Task/Julia-set/Go/julia-set.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"image/png"
+	"log"
+	"os"
+	"sync"
+)
+
+func main() {
+	const (
+		width, height = 800.0, 600.0
+		maxIter       = 255
+		cX, cY        = -0.7, 0.27015
+		fileName      = "julia.png"
+	)
+	img := image.NewNRGBA(image.Rect(0, 0, width, height))
+
+	var wg sync.WaitGroup
+	wg.Add(width)
+	for x := 0; x < width; x++ {
+		thisx := float64(x)
+		go func() {
+			var tmp, zx, zy float64
+			var i uint8
+			for y := 0.0; y < height; y++ {
+				zx = 1.5 * (thisx - width/2) / (0.5 * width)
+				zy = (y - height/2) / (0.5 * height)
+				i = maxIter
+				for zx*zx+zy*zy < 4.0 && i > 0 {
+					tmp = zx*zx - zy*zy + cX
+					zy = 2.0*zx*zy + cY
+					zx = tmp
+					i--
+				}
+				img.Set(int(thisx), int(y), color.RGBA{i, i, i << 3, 255})
+			}
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+	imgFile, err := os.Create(fileName)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer imgFile.Close()
+	if err := png.Encode(imgFile, img); err != nil {
+		imgFile.Close()
+		log.Fatal(err)
+	}
+}