image.go

package main

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

	"github.com/golang/freetype/truetype"
	"golang.org/x/image/font"
	"golang.org/x/image/font/gofont/goregular"
	"golang.org/x/image/math/fixed"
)

const label = "Sorry. We have no imagery here."

const half fixed.Int26_6 = 2 << 4

func main() {
	f, err := truetype.Parse(goregular.TTF)
	if err != nil {
		panic(err)
	}
	face := truetype.NewFace(f, &truetype.Options{
		Size: 20,
	})
	bg := image.NewUniform(color.Gray{200})
	fg := image.NewUniform(color.Gray{100})

	w, h := 500, 500
	x, y := w/2, h/4
	img := image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(img, img.Bounds(), bg, image.ZP, draw.Src)

	drawer := font.Drawer{
		Dst:  img,
		Src:  fg,
		Face: face,
		Dot:  fixed.P(x, y),
	}
	drawer.Dot.X = drawer.Dot.X - drawer.MeasureString(label).Mul(half)
	drawer.DrawString(label)

	if err := png.Encode(os.Stdout, img); err != nil {
		panic(err)
	}
}