Tommy Chen tommy351

在 Facebook 上分享 Dcard 文章時，如果沒有指定圖片的話，可能會看到如下的文章摘要：

這張圖片是透過 Go library draw2d 產生的，它有類似 HTML5 canvas 的 API，所以畫一些簡單的圖形都還算小菜一碟，然而在處理文字上就沒這麼得心應手了。

初次嘗試

src, _ := loadBaseImageForPost(post)

	func drawLine(gc *draw2dimg.GraphicContext, str string, maxX float64, maxY float64, x float64, y float64) (bool, float64) {
	// Handle empty line
	if len(strings.TrimSpace(str)) == 0 {
	return false, y + gc.Current.FontSize*lineHeight
	}

	list := []rune(str)
	length := len(list)
	offsetX := x
	offsetY := y

	func drawLine(gc *draw2dimg.GraphicContext, str string, maxX float64, maxY float64, x float64, y float64) (bool, float64) {
	// Handle empty line
	if len(strings.TrimSpace(str)) == 0 {
	return false, y + gc.Current.FontSize*lineHeight
	}

	list := []rune(str)
	length := len(list)
	offsetX := x
	offsetY := y

	func drawLine(gc *draw2dimg.GraphicContext, str string, x float64, y float64) {
	gc.FillStringAt(str, x, y)
	}

	func drawText(gc *draw2dimg.GraphicContext, str string, width float64, height float64, x float64, y float64) {
	str = strings.Trim(str, " \n\r\t")
	lines := strings.Split(str, "\n")
	fontSize := gc.Current.FontSize
	offsetY := y
	wrapLines := []string{}

	draw2d.SetFontFolder("static/fonts")
	draw2d.SetFontNamer(func(fontData draw2d.FontData) string {
	return "WenQuanYiMicroHei.ttf"
	})

	src, _ := loadBaseImageForPost(post)
	img := image.NewRGBA(src.Bounds())
	gc := draw2dimg.NewGraphicContext(img)

	gc.DrawImage(src)

	// Draw title
	gc.SetFillColor(color.RGBA{0xff, 0xff, 0xff, 0xff})
	gc.SetFontSize(26)
	gc.FillStringAt(post.Title, 140, 81.5)

	2016/11/04 16:06:16 open ../resource/font/luxisr.ttf: no such file or directory
	2016/11/04 16:06:16 open ../resource/font/luxisr.ttf: no such file or directory
	2016/11/04 16:06:16 No font set, and no default font available.

	'use strict';

	var highlight = require('highlight.js');
	var Highlights = require('highlights');
	var highlighter = new Highlights();
	var util = require('../lib');
	var fs = require('fs');
	var pathFn = require('path');
	var fixture = fs.readFileSync(pathFn.join(__dirname, 'fixtures', 'q3.js'), 'utf8');

	var input = '';

	process.stdin.resume();
	process.stdin.setEncoding('utf8');

	process.stdin.on('data', function(chunk) {
	input += chunk;
	});

	process.stdin.on('end', function() {