pic.go

package main

import (
	"image"
	"image/png"
	"os"
)

func Show(f func(int, int) [][]uint8) {
	const (
		dx = 1000
		dy = 1000
	)
	data := f(dx, dy)
	m := image.NewNRGBA(image.Rect(0, 0, dx, dy))
	for y := 0; y < dy; y++ {
		for x := 0; x < dx; x++ {
			v := data[y][x]
			i := y*m.Stride + x*4
			m.Pix[i] = v
			m.Pix[i+1] = v
			m.Pix[i+2] = 255
			m.Pix[i+3] = 255
		}
	}
	ShowImageFile(m)
}

func ShowImageFile(m image.Image) {
	var outImg, _ = os.Create("/tmp/img.png")
	defer outImg.Close()
	err := png.Encode(outImg, m)
	if err != nil {
		panic(err)
	}
}

func Fibb(fibbs []uint64, numiters int) []uint64 {
	if numiters == 0 {
		return fibbs
	}

	currentfibs := fibbs[len(fibbs)-2:]
	a, b := currentfibs[0], currentfibs[1]

	return Fibb(append(fibbs, b, a+b), numiters-1)
}

func Pic(dx, dy int) [][]uint8 {
	var resultPic [][]uint8
	var fibbs = Fibb([]uint64{1, 2}, (dx*dy)-2)

	for i := 0; i < dy; i++ {
		resultPic = append(resultPic, []uint8{})
		for j := 0; j < dx; j++ {
			resultPic[i] = append(resultPic[i], uint8(fibbs[i*j]%255))
		}
	}
	return resultPic
}

func main() {
	Show(Pic)
}

Several code snippets borrowed from the golang.org/x/tour/pic