Re: improved lyrics handling

[Han-Wen]

[moved to lilypond-devel]

address@hidden writes:
> 
> > Ah! So you know how encodings work! You're the guy we've been
> > waiting for.  Lily should really read the appropriate font tables,
> > and look up the right Russian or Chinese dimension -- unfortunately,
> > we don't know about the systems involved, and could hardly test if a
> > system works well.
> 
> After some thinking I believe that your approach is doomed to fail,
> and I already know that you don't like my answer :-)
> 
> Without a real text processing engine it is not possible to convert
> input characters to output glyphs.  Well, Latin or Chinese is
> something simple since one input character produces one output
> character, but now consider Indic scripts which don't have this
> property!  If you want LilyPond to become a real success, all
> languages of this world should be supported, especially those which
> don't have proper lyrics support yet.  Right now I'm only talking
> about the input-output problem, not taking into account additional
> typographic subtleties, e.g. no `fi' ligature in Turkish or Portuguese
> -- how shall LilyPond know that?
> 
> In the (hopefully near) future, Omega will be the solution.  John
> Plaice and others are working to convert this TeX extension into a
> library which can then be linked to other programs.  Until this
> project has become mature we really should ask TeX for the metrics of
> the output strings.


OK. I agree with your assessments, however, I am not sure that I agree
with your ideas for implementation.  I think that we will have to
maintain a bare-bones formatting engine in Lily for other reasons than
lyrics.

For getting fully correct lyrics, I propose that we use a different
route; tacking it on top of \lyrics is going to be an engineering
disaster; I am not going to system() a different program from LilyPond
as a standard policy. Linking with Omega might be an option, but given
the activity on their ML, I don't think it is going anywhere in the
near future.

Rather the correct/dimensions lyrics should be generated some kind of
TeX preprocessor; the lyrics could then be dumped as a separate file like

        \lyrics {
                        ...
            \property LyricsVoice.LyricSyllable \set #'X-extent-callback =
                  #'(0.0 . 7.2)
            \property LyricsVoice.LyricSyllable \set #'Y-extent-callback =
                  #'(-1.0 . 1.2)
            "\Zhoung"
            \property LyricsVoice.LyricSyllable \set #'X-extent-callback =
                  #'(0.0 . 4.3)  
            #"\Guo\043\n\t"
                ..

        }

(So \Zhoung is not how it works in TeX, but you get the idea), perhaps
using Scheme, since it makes encoding the strings more standard.

--
Han-Wen Nienhuys   |   address@hidden   |   http://www.cs.uu.nl/~hanwen