PeachDrawing.Core
PeachDrawing.Core.TypefaceFont
TypefaceFont.UnderlineThickness Property
The font’s own real underline-stroke thickness (OpenType post.underlineThickness,
scaled to this font’s size the same way UnderlineOffset is), consulted only when
CSS text-decoration-thickness: from-font is used (CSS Text Decoration 4 §3.3) - the
property’s initial value (auto) deliberately does not read this, to preserve this
engine’s pre-existing fixed decoration-line thickness exactly. Defaults to 1 (this
engine’s own pre-existing hardcoded decoration thickness), mirroring NormalLineHeight’s
pattern of a plain default for every Font except the OpenType-descriptor-backed
adapter, which overrides it with the font’s real metric.
public override double UnderlineThickness { get; }