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From: mouse@LARRY.MCRCIM.MCGILL.EDU
Newsgroups: comp.windows.x
Subject: Re:  Font question
Message-ID: <9012300832.AA10050@Larry.McRCIM.McGill.EDU>
Date: 30 Dec 90 08:32:19 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 32

> Why do some variable width fonts have negative lbearings?  I could
> not find any documentation that mentions the reasoning behind this.

> If you look at the font
> "-adobe-courier-bold-r-normal--18-180-75-75-m-110-*",
> the 'A' and the 'm' have negative lbearings.  Is there a reason for
> this?

That's not a variable-width font, or at least shouldn't be; it claims
to be monospaced (the -m-).  (It doesn't claim -c-, for charactercell;
that would be wrong for a font with some negative lbearings.)

A negative lbearing indicates that some of the character's ink lies to
the left of the character's reference point.  That's all.  In the case
of the Courier A, I would guess that the serif on the left slanting
vertical sticks out far enough to fall to the left of the refpt.

As an example of a reasonable use for a (large) negative lbearing....

Imagine, if you will, an A with a swash tail on the left-hand stroke.
Such a tail will extend far to the left and below the reference point;
thus, the depth will be >>0 and the lbearing will be <<0....[%]

[%] << and >> in the math meaning of "much less than" and "much greater
    than", not the C sense of left and right shift.  (I know this seems
    obvious, but I also know how little difference that makes on the
    net.)

					der Mouse

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