W3C home > Mailing lists > Public > public-css-archive@w3.org > April 2017

Re: [csswg-drafts] 'line-height: normal' definition should reflect reality of determining based on fonts

From: L. David Baron via GitHub <sysbot+gh@w3.org>
Date: Fri, 21 Apr 2017 05:25:09 +0000
To: public-css-archive@w3.org
Message-ID: <issue_comment.created-296072222-1492752308-sysbot+gh@w3.org>
I'd also note that CSS2 10.8.1 says:
> Still for each glyph, determine the leading L to add, where L = 'line-height' - AD. Half the leading is added above A and the other half below D, giving the glyph and its leading a total height above the baseline of A' = A + L/2 and a total depth of D' = D + L/2.
> The height of the inline box encloses all glyphs and their half-leading on each side and is thus exactly 'line-height'. Boxes of child elements do not influence this height.

This model seems to suggest that if we add external leading from fonts for normal line height, we should probably do so separately for each glyph, i.e., using a per-glyph `line-height` when computing L in the algorithm above.


Gecko's implementation has a number of bugs [described in bug 1358377](https://bugzilla.mozilla.org/show_bug.cgi?id=1358377), so I'm not sure it's particularly useful in determining what to do here.  Information from other implementations may be more useful.

-- 
GitHub Notification of comment by dbaron
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/1254#issuecomment-296072222 using your GitHub account
Received on Friday, 21 April 2017 05:25:16 UTC

This archive was generated by hypermail 2.4.0 : Tuesday, 5 July 2022 06:41:11 UTC