Path: utzoo!attcan!uunet!husc6!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU (Bob Scheifler)
Newsgroups: comp.windows.x
Subject: Re: XFontStruct numbers useless?
Message-ID: <8811181451.AA20578@EXPO.LCS.MIT.EDU>
Date: 18 Nov 88 14:51:11 GMT
References: <281@stan.com>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 33


    In particular, how does one determine the total space 
    occupied by a font, in order to size a window to enclose it?

Since I'm not sure exactly what you mean by this, it's hard
to answer exactly.

    How does one
    determine if a font has it's own imbedded interline spacing, as the 9x15
    font appears to?

Read the protocol document; font-ascent and font-descent are logical
extents to be used for line spacing.  These numbers should be viewed
as the font designer's "minimum" line spacing, in a sense.  The
ink metrics of particular characters might or might not stick out
on either side of this; it's up to the font designer.  If you want
to know the ink extents, look at the ink metrics; if you want to
know the logical extents, look at the logical metrics.

    Is there a reliable way to determine if interline whitespace is already
    included in the font, and what it is?

Yes, get your fonts from a reliable source.

    None of the numbers give a reliable hint as
    to how many pixels must be added at the beginning of a string to accomodate
    characters which stick out to the left of their bounding box, or at the end
    for those which stick out to the right.

I don't understand.  Comparing the ink metrics of each character to its
width will give you this information.  If the font has constant character
widths, then comparing the min/max bounds ink metrics against this width
will tell you.