おせえよ

mand.go

package main

import (
    "math/cmplx"
    "image"
    "image/color"
    "image/png"
    "os"
    "fmt"
    "time"
)

func square(c complex128) complex128 {
    a := real(c)
    b := imag(c)
    return complex(a * a - b * b, 2.0 * a * b)
}

func mand (c complex128, max_iter uint8) (bool, uint8) {
    z := 0 + 0i
    z1 := 0 + 0i
    var n uint8 = 0
    for ; n < max_iter; n++ {
        z1 = square(z) + c
        if cmplx.Abs(z) > 2 {
            return true, n
        }
        z = z1
    }
    return false, n;
}

func main() {
    t := time.Now()

    width := 640
    height := 640

    img := image.NewRGBA(image.Rect(0, 0, width, height))

    for imy := 0; imy < height; imy++ {
        for imx := 0; imx < width; imx++ {

            vx := float64(imx - width  / 2) / float64(width / 2) * 2.0
            vy := float64(imy - height / 2) / float64(height / 2) * 2.0
            c := complex(vx, vy)

            divergence, speed := mand(c, 0xFF);

            if (!divergence) {
                img.SetRGBA(imx, imy, color.RGBA{0, 0, 0, 0xFF})
            } else {
                img.SetRGBA(imx, imy, color.RGBA{speed, speed, speed, 0xFF})
            }

        }
    }

    f, _ := os.Create("out2.png")
    defer f.Close()
    png.Encode(f, img)

    fmt.Println(time.Now().Sub(t))
}