FontStack Class

The fonts of the stack are used first, as without fallback. A character, with the marks and the selectors that follow it, that none of them has is looked for among the installed fonts, in this order: the families of InstalledFontFallbackOptions.PreferredFamilies; for an emoji presented with colors (Unicode Technical Standard #51), the color emoji fonts (Segoe UI Emoji, Apple Color Emoji, Noto Color Emoji); the families the platforms usually use for the script of the character (and, for the Han ideographs, the language of the text), and the fonts of symbols; then every family that has the character, those whose closest face has the weight and the italic of the primary font first, by family name and by file. In a family, the face is the one closest to the style of the primary font, at the instance of that style when it is a variable font (Font.LoadInstalled). A character no font has is drawn with the missing glyph of the primary font.

The Han ideographs have different forms in Chinese, Japanese and Korean: their families are chosen by the language of the text (TextStyle.Language): Microsoft YaHei, PingFang SC or Noto Sans CJK SC for Simplified Chinese and a text without a language, Microsoft JhengHei, PingFang TC or Noto Sans CJK TC for Traditional Chinese, PingFang HK or Noto Sans CJK HK for Hong Kong, Yu Gothic, Hiragino Sans or Noto Sans CJK JP for Japanese, Malgun Gothic, Apple SD Gothic Neo or Noto Sans CJK KR for Korean, then those of Simplified Chinese. The fonts found are kept for each language. InstalledFontFallbackOptions.PreferredFamilies still come first, whatever the language.

The installed fonts differ from one machine to another, and so does a text drawn with this stack: use it when the text matters more than the exact pixels. The characters of a face are read from its file the first time the fallback needs them (SystemFontDescriptor.Covers); a file that cannot be loaded is skipped. The font found for a character is kept by the stack, which its layouts share: each font is loaded once, the same character always gets the same font, and the fonts it loaded live as long as the stack.