Drawing in Go?

draw.go

package main

import (
	"image"
	"image/draw"
	"image/png"
	"os"

	"github.com/golang/freetype/raster"
	"golang.org/x/image/math/fixed"
)

func SavePNG(path string, im image.Image) error {
	file, err := os.Create(path)
	if err != nil {
		return err
	}
	defer file.Close()
	return png.Encode(file, im)
}

func main() {
	const width = 1024
	const height = 1024
	im := image.NewRGBA(image.Rect(0, 0, width, height))
	draw.Draw(im, im.Bounds(), image.White, image.ZP, draw.Src)
	painter := raster.NewRGBAPainter(im)
	painter.SetColor(image.Black)
	r := raster.NewRasterizer(width, height)
	r.UseNonZeroWinding = true
	var path raster.Path
	path.Start(fixed.P(20, 40))
	path.Add1(fixed.P(width-20, height-40))
	path.Add1(fixed.P(width/2, 40))
	r.AddStroke(path, fixed.I(16), raster.RoundCapper, raster.RoundJoiner)
	r.Rasterize(painter)
	SavePNG("out.png", im)
}