Re: [csswg-drafts] [css-fonts-5] Text Fitting: Scaling of things based on font-size (#12888)

> In practice, almost no fonts use these non-linear capabilities. Rare edge-cases should not prevent us from solving 99+ common use cases.

As Tab was saying however - we don't know if a font is going to do something weird - until we've shaped it. As a simple concrete example just `font-family: sans-serif` can map to *many* different fonts depending on the operating system.

> I don't fully the complexity and “guessing” problem, as it is evident that for majority of use cases, including scaling of em-based values and handling optical sizing, we can cover it in a finite number of steps as shown in...

Just on a practical level, the text layout engine doesn't work how you describe (as Tab discussed above - 2nd paragraph onwards). While what you presented may work for a well-behaved font, it doesn't work in the general case, and we shouldn't disable the feature entirely if a developer just happens to use a particular font, and/or a glyph that is missing, etc.


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Received on Wednesday, 12 November 2025 20:36:25 UTC