Support multi-byte fonts

[k1LoW]

Hi @goccy !

This is feature request.

I want to use go-graphviz with multi-byte fonts.

Example DOT and current render results

Example DOT

digraph "blog" {
  // Config
  graph [rankdir=TB, layout=dot, fontname="Arial"];
  node [shape=record, fontsize=14, margin=0.6, fontname="Arial"];
  edge [fontsize=10, labelfloat=false, splines=none, fontname="Arial"];

  // Tables
  "users" [shape=none, label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="6">
                 <tr><td bgcolor="#EFEFEF"><font face="Arial Bold" point-size="18">users</font> <font color="#666666">[BASE TABLE]</font><br /><font color="#333333">ユーザテーブル</font></td></tr>
                 <tr><td port="id" align="left">id <font color="#666666">[int(11)]</font></td></tr>
                 <tr><td port="username" align="left">username <font color="#666666">[varchar(50)]</font></td></tr>
                 <tr><td port="password" align="left">password <font color="#666666">[varchar(50)]</font></td></tr>
                 <tr><td port="email" align="left">email <font color="#666666">[varchar(355)]</font> ex. user@example.com</td></tr>
                 <tr><td port="created" align="left">created <font color="#666666">[timestamp]</font></td></tr>
                 <tr><td port="updated" align="left">updated <font color="#666666">[timestamp]</font></td></tr>
              </table>>];
  "posts" [shape=none, label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="6">
                 <tr><td bgcolor="#EFEFEF"><font face="Arial Bold" point-size="18">posts</font> <font color="#666666">[BASE TABLE]</font><br /><font color="#333333">投稿テーブル</font></td></tr>
                 <tr><td port="id" align="left">id <font color="#666666">[bigint(20)]</font></td></tr>
                 <tr><td port="user_id" align="left">user_id <font color="#666666">[int(11)]</font></td></tr>
                 <tr><td port="title" align="left">title <font color="#666666">[varchar(255)]</font></td></tr>
                 <tr><td port="body" align="left">body <font color="#666666">[text]</font> post body</td></tr>
                 <tr><td port="post_type" align="left">post_type <font color="#666666">[enum(&#39;public&#39;,&#39;private&#39;,&#39;draft&#39;)]</font> public/private/draft</td></tr>
                 <tr><td port="created" align="left">created <font color="#666666">[datetime]</font></td></tr>
                 <tr><td port="updated" align="left">updated <font color="#666666">[datetime]</font></td></tr>
              </table>>];

  // Relations
  "posts":"user_id" -> "users":"id" [dir=back, arrowtail=crow, style ="dashed", taillabel=<<table cellpadding="5" border="0" cellborder="0"><tr><td>ユーザと投稿の関連</td></tr></table>>];
}

Render results

Graphviz 2.44.0 via Homebrew	goccy/go-graphviz/cmd/dot

Best Regards.

[goccy]

Thank you for the reporting !!
I will fix it as soon as possible !

[k1LoW]

THANK YOU!!!! 🤩

[goccy]

Currently, multibyte characters can already be used in the following way .

import (
    "github.com/golang/freetype/truetype"
    "golang.org/x/image/font"
)

	ftBinary, _ := ioutil.ReadFile("/path/to/Japanese-Font.ttf")
	ft, _ := truetype.Parse(ftBinary)

	g := graphviz.New()
	g.SetFontFace(func(size float64) (font.Face, error) {
		opt := &truetype.Options{
			Size:              size,
			DPI:               0,
			Hinting:           0,
			GlyphCacheEntries: 0,
			SubPixelsX:        0,
			SubPixelsY:        0,
		}
		return truetype.NewFace(ft, opt), nil
	})

[goccy]

On the other hand, I try to set a font.Face from the font name automatically .

[k1LoW]

Currently, multibyte characters can already be used in the following way .

@goccy Thank you for your support !

On the other hand, I try to set a font.Face from the font name automatically .

I'm looking forward to the automatic font settings !