[csswg-drafts] [css-text-decor] Please implement `text-strikethrough-position` key (#9027)

ryanbugden has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-text-decor] Please implement `text-strikethrough-position` key ==
In submitting bug reports to various browsers, and how they are inaccurately rendering `from-font` values for text decoration (with this [test page](https://hex.xyz/misc/text-decoration-test/) by @nicksherman), it started to become clear, that within the dichotomy of underline and strikethroughs (the two linear decorations that font files contain metadata for), there seems to be no way to invoke the font metadata which covers the **strikethrough’s y-position**.

### On the CSS level, how we invoke the values from the font:
✅ **Underline thickness:**  Taken care of by [text-decoration-thickness: from-font;](https://www.w3.org/TR/css-text-decor-4/#text-decoration-thickness-property)
✅ **Strikethrough thickness:** Also taken care of by [text-decoration-thickness: from-font;](https://www.w3.org/TR/css-text-decor-4/#text-decoration-thickness-property)
✅ **Underline position:** Taken care of by [text-underline-position: from-font;](https://www.w3.org/TR/css-text-decor-4/#text-underline-position-property)
❌ **Strikethrough position**

### On the font level, these are the values in the font:
**Underline:** [post table](https://learn.microsoft.com/en-us/typography/opentype/spec/post)
- underlineThickness
- underlinePosition

**Strikethrough:** [OS2 table](https://learn.microsoft.com/en-us/typography/opentype/spec/os2)
- yStrikeoutSize
- yStrikeoutPosition

### Suggestion:
- Implement a `text-strikethrough-position` key, for which there is a possible (and hopefully default) `from-font` value. 
- For this position, look at `OS2` > `yStrikeoutPosition`, and interpret it as the y-position of the top of the stroke.
> The position of the top of the strikeout stroke relative to the baseline in font design units.

Thanks for your consideration!



Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/9027 using your GitHub account


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Received on Tuesday, 4 July 2023 03:17:45 UTC