日本語OpenTypeを画像に描画

drawJapaneseOpentype.go

package main

import (
	"fmt"
	"golang.org/x/image/font"
	"golang.org/x/image/font/opentype"
	"golang.org/x/image/math/fixed"
	"image"
	"image/color"
	"image/png"
	"io/ioutil"
	"log"
	"os"
)

func main() {
	const (
		width        = 360
		height       = 36
		startingDotX = 6
		startingDotY = 28
	)
	fontdata,_:=ioutil.ReadFile("Chalk-JP.otf")
	f, err := opentype.Parse(fontdata)
	if err != nil {
		log.Fatalf("Parse: %v", err)
	}
	face, err := opentype.NewFace(f, &opentype.FaceOptions{
		Size:    32,
		DPI:     72,
		Hinting: font.HintingNone,
	})
	if err != nil {
		log.Fatalf("NewFace: %v", err)
	}

	dst := image.NewGray(image.Rect(0, 0, width, height))
	d := font.Drawer{
		Dst:  dst,
		Src:  image.White,
		Face: face,
		Dot:  fixed.P(startingDotX, startingDotY),
	}
	fmt.Printf("The dot is at %v\n", d.Dot)
	d.DrawString("我思う、故に")
	fmt.Printf("The dot is at %v\n", d.Dot)
	d.Src = image.NewUniform(color.Gray{0x7F})
	d.DrawString("我在り")
	fmt.Printf("The dot is at %v\n", d.Dot)

	pOutput, err := os.Create("./new.png")
	if err != nil {
		panic(err)
	}
	defer pOutput.Close()

	err = png.Encode(pOutput, dst)
	if err != nil {
		panic(err)
	}

}