PeachDrawing.Text
PeachDrawing.Text.Layout.RunStyle
RunStyle.Fallback Property
What to ask for a typeface when Typeface has no glyph for a character (see CreateFallback(TypefaceQuery)), or null to draw the missing-glyph shape. It is asked once for each user-perceived character the face cannot draw, with that character’s first code point, and answers null when it has nothing better; the character and the marks that follow it are then set in the typeface it returns, at the run’s size. Runs are equal only when their fallbacks are the same delegate, and text in runs that differ is shaped and broken separately, so a caller that sets a fallback on many runs should make it once and share it.
public System.Func<System.Text.Rune,PeachDrawing.Text.Typeface?>? Fallback { get; init; }