Re: [csswg-drafts] [css-inline] Define how to synthesize `ideographic-over` and `ideographic-under` (#10850)

My thoughts on the two original questions here:

>     1. Most fonts, including many CJK fonts, don't have these tables. How should this be synthesized when these are missing?

From metrics present in the first available font (as described in css-inline).

(I think synthesizing by measuring the actual bounds of specific glyphs would problematic for a couple of reasons: the results may be poor for more ornately-styled fonts that do not have such "regular" glyph shapes as a standard Gothic or similar face; and because of the potential interaction with font subsetting, which will be confusing/unpredictable for authors.)

>     2. When the first font in the cascade doesn't have these tables but the second one does, should UA synthesize from the first font, or use the table from the second font?

From the first font. For predictable behavior, these layout metrics should be consistently derived from the primary font specified by the author, not dependent on what fonts happen to be present later in the cascade.


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Received on Thursday, 26 September 2024 09:45:02 UTC