Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU (Bob Scheifler)
Newsgroups: comp.windows.x
Subject: Re: Request for help
Message-ID: <8903201332.AA21104@EXPIRE.LCS.MIT.EDU>
Date: 20 Mar 89 13:32:49 GMT
References: <8903170848.AA03413@gs3.gmd.de>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 26


    1) Would someone be so kind to explain the difference and the usage of the
    16-bit elems that can be passed to the draw-glyph(s) function?

Do you understand the 8-bit case?  If so, then the 16-bit case is identical,
except that a larger index space is used.  The way you display glyphs is to
specify indices into a font array/matrix.  The font array might have a size
that can be encoded in 8 bits, or it might have a size that can be encoded in
16 bits.  The font matrix has a size for which each dimension can be encoded in
8 bits.  However, this size is essentially orthogonal to the encoding size you
use in a draw-glyphs/PolyText request.  Think of this as the difference between
using a variable of type (integer 0 255) and (integer 0 65535), or (for C folk)
using a variable of type unsigned char and unsigned short.  What matters are
the values you pass, not the number of bytes they occupy.

    2) Is there a way to implement 'multiple-font-strings' on the CLX base? My
    lisp (Lucid CL) has char-font-limit equal to 1, but perhaps by shadowing
    and redefining some functions it could be possible to use the ability of
    different fonts in X.

Fonts are (pardon me) a mess in CL; char-font seems pretty useless as a decent
abstraction.  I doubt there is any way in Lucid to up the limit.  You will note
that draw-glyphs is not restricted to taking a string, but rather can take any
sequence.  This allows you the freedom to use any "multi" representation you
want, and provide the appropriate :translate routine to decompose it into
fonts and glyph indices.