Microsoft YaHei rendering issue

[mikegoatly]

Hi, thanks for the great library!

I've noticed that there is additional space rendered after the unicode ’ character (U+2019) when I use the Semi.Avalonia theme:

---

It looks like this is caused by an bug in the Microsoft YaHei font because I can replicate it in MS Word as well, however it renders correctly if I use Microsoft YaHei UI:

Might it be possible to use the Microsoft YaHei UI font instead of Microsoft YaHei?

[rabbitism]

I can't reproduce the issue, maybe I installed some fonts that has higher priority than MS YaHei.
However, FontFamily is just a regular resource in Semi.Avalonia. It's quite easy to override it globally in your project.

[mikegoatly]

Thanks @rabbitism, that works for my needs.

For what it's worth, I've done a bit more searching and found this issue mentioned in other places, although none are Avalonia specific:

This one did replace YaHei with YaHei UI
This one indicated the order fonts were applied fixed the issue, and moving Chinese fonts to later in the font list helped.

I tried that last one out, and with DefaultFontFamily defined as:

  <!-- Current order defined in Semi.Avalonia is:
     Inter, -apple-system, BlinkMacSystemFont, PingFang SC,
     Microsoft YaHei, Segoe UI, Hiragino Sans GB, Helvetica Neue, 
     Helvetica, Arial, sans-serif
  -->
  <FontFamily x:Key="DefaultFontFamily">
      Inter, -apple-system, BlinkMacSystemFont, Segoe UI, 
      Helvetica Neue, Helvetica, Arial, sans-serif, PingFang SC,
      Microsoft YaHei, Hiragino Sans GB
  </FontFamily>

Did actually make the issue go away for me. I don't know what impact it will have when rendering Chinese text though if YaHei was providing better glyphs than a font that now has higher precidence, e.g. Segoe UI or Arial.

[rabbitism]

We have a commercial markdown rendering library, so I happened to learn a bit about this topic. You can check this for the detailed implementation of typeface lookup. https://github.com/AvaloniaUI/Avalonia/blob/dc19c39df5b9c1cf69c29625da44ffa245dc44e5/src/Avalonia.Base/Media/FontManager.cs#L254