Developer with some grey hairs

Google Go and the Mandelbrot Set

Learning a new programming language is fun. Here is my version of calculating the mandelbrot set and save the result as a PNG picture with Google Go.

package main

import (   "image";
           "image/png";
           "bufio";
	   "fmt";
	   "os";
           "math";
           "time"; )

func PointIteration( cx, cy, maxValue float64, maxIter uint8) uint8{
     quadValue := float64(0.0);
     iter := uint8(0);
     x := float64(0.0);
     y := float64(0.0);

    for quadValue <= maxValue && iter < maxIter {
        xt:= ( x * x ) - ( y * y) + cx;
        yt:= ( float64(2.0) * x * y ) + cy;
        x = xt;
        y = yt;
        iter++;
        quadValue = ( x * x ) + ( y * y );
    }
    return iter;
}

func main(){
    start := time.Seconds();     

    const pictureSize = 500;
    img := image.NewRGBA(pictureSize,pictureSize);

    f, err := os.Open("mandel.png", os.O_WRONLY|os.O_CREAT, 0666);
    if err != nil {
       fmt.Printf("Can't create picture file\n");
    }

    deltaX := math.Fabs(float64(-2.0 - 1.0)) / float64(pictureSize);
    deltaY := math.Fabs(float64(-1.0 - 1.0)) / float64(pictureSize);

    cx := float64(-2.0);
    for x:=0;x<pictureSize;x++{
        cx+=deltaX;
        cy := float64(-1.0);
        for y:=0;y<pictureSize;y++{
           cy+=deltaY;
           iter := PointIteration(cx,cy,255.0,255);

           color := new(image.NRGBAColor);
           color.A = 255;
           color.R = iter;
           color.G = iter;
           color.B = iter;
           img.Set(x,y,color);
	}
     }

     w := bufio.NewWriter(f);
     png.Encode(w,img);
     w.Flush();

     fmt.Printf("Seconds needed %d\n",time.Seconds() - start);
}

And here the result.

Next step is trying to improve the speed by using goroutines and channels.