Path: utzoo!attcan!uunet!decwrl!ucbvax!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU (Bob Scheifler)
Newsgroups: comp.windows.x
Subject: Re: X Fonts: 2Byte vs. 16Bit
Message-ID: <9008022356.AA01801@expire.lcs.mit.edu>
Date: 2 Aug 90 23:56:02 GMT
References: <1681@io.UUCP>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 23


    Do 16-bit fonts really exist in X?

Yes.  There is a difference between the encoding form of a font and the
encoding form of the string data.  For drawing text, you can use 1-byte
or 2-byte string data.  Both forms work with all fonts.  For fonts,
the encoding vector can be represented as linear or matrix.  Linear font
encodings are permitted to be up to 65535 glyphs, but this is not expected
to be a normal case, matrix fonts are expected to be normal for large fonts.
There is no 16-bit data format for text strings.  When 2-byte string data
is used with a linear font (regardless of how many glyphs it has), the
linear index is always constructed by using the first byte as the most
significant byte.  String data is never byte swapped.

    Are they (in the VAX case) differently indexed than 2-byte fonts?

I hope I've answered this.

    Are the BDF descriptions different from a 2byte font?

Actually, BDF doesn't specify what encoding to use!  Whether this is a bug
or a feature is unclear.  It is similarly unclear whether bdftosnf always
makes a sensible choice for the encoding.