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Re: position of baseline relative to em square

From: David Lemon <typenerd@slip.net>
Date: Tue, 30 Nov 1999 08:15:04 -0800
Message-Id: <l03130301b469a79489ae@[209.209.14.170]>
To: erik@netscape.com (Erik van der Poel)
Cc: www-font@w3.org
At 11:49 PM -0800 11/29/99, Erik van der Poel wrote:
> However, if CSS wants us to center in terms of the em square, we would
> need to know where the baseline lies in the em square.
>
> As far as I can tell, neither the Windows APIs nor the TrueType file
> give us this info. Is this true?

Although not very clearly specified, the (absolute values of the)
WindowsTypographicAscent and WindowsTypographicDescent in the OS/2 table
should sum to the em square height, positioning the baseline in the em
square. I can't guarantee the general case, but can state that Adobe's
OpenType fonts do exactly that.

- David Lemon
Received on Tuesday, 30 November 1999 11:17:11 UTC

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