Solution to golang tour slices exercise (https://tour.golang.org/moretypes/18)

gistfile1.txt

package main

import "golang.org/x/tour/pic"
import "math"

func makePic(f func(x, y int) uint8) func(dx, dy int) [][]uint8 {
	pic := func(dx, dy int) [][]uint8 {
		// 2d array of pixel values
		p := make([][]uint8, dy)
		for y := range p {
			p[y] = make([]uint8, dx)

			for x := range p[y] {
				p[y][x] = f(x, y)
			}
		}

		return p
	}

	return pic
}

func a(x, y int) uint8 {
	return uint8((x+y)/2)
}

func b(x, y int) uint8 {
	return uint8(y - int(16 * math.Sin(float64(x*2))) - 130)
}

func c(x, y int) uint8 {
	return (uint8(x) << (uint8(y)/32))
}

func main() {
	pic.Show(makePic(c))
}