Re: tablature.ly

[Marc Hohl]

Neil Puttock schrieb:
> 2009/4/27 Carl D. Sorensen <address@hidden>:
>   
> > Neil,
> >
> > Thanks for your input.  I think it's all really good.
> >
> >
> > On 4/26/09 1:49 PM, "Neil Puttock" <address@hidden> wrote:
> >
> >     
> > > 2009/4/25 Marc Hohl <address@hidden>:
> > >       
> > > > Hello tablature users*,
> > > >         
> > > Like Carl, I'm not a tablature user, so I can only comment on matters of
> > > coding.
> > >
> > > Some suggestions and thoughts follow below:
> > >
> > >       
> > <SNIP>
> >     
> > > >           (font-size (- (* num-strings 1.5) 7))
> > > >           (base-skip (cond ((= 4 num-strings) 1.55)
> > > >                            ((= 5 num-strings) 1.84)
> > > >                            ((= 6 num-strings)  2.00)
> > > >                            ((= 7 num-strings) 2.08)))
> > > >         
> > > Can you rework these so they're not hard-coded?
> > >
> > > Imagine a user doesn't like the default staff-space setting for
> > > TabStaff (1.5).  If they change it, none of these empirical values
> > > will work properly.
> > >       
> > Marc, there are probably at least two ways to do this.  The easiest one
> > would be to take each of these magic numbers and divide them by the default
> > staff-space setting, and then change to something like
> >
> > (base-skip (cond ((= 4 num-strings) (* staff-space 1.03))
> >
> > and so forth.  (1.03 = 1.55/1.5)  And you'd need to find the value of
> > staff-space in order to be able to do this multiplication.
> >     
Ok, as Neil has posted somewhere else in this thread, the formula works 
only with a
fixed staff-space. But I don't know how to find the value of staff-space.
I think it could be done similar to the proposals for the line-count
(see below), but this is far beyond my possibilities - any help is highly
appreciated!
> > The second way would be to try to define fundamental relationships for
> > base-skip, but I'm not sure exactly how you'd do that, so I'm not
> > recommending it right now.
> >
> > <SNIP>
> >     
> > > > calligraphicTabClef = #(define-music-function (parser location tuning)
> > > > (pair?)
> > > >   #{
> > > >      \revert TabStaff.Clef #'stencil
> > > >      \set TabStaff.stringTunings = $tuning
> > > >   #})
> > > >         
> > > On a general note, I'd prefer to keep the string tunings separate from
> > > setting the clef.  To set the traditional tab clef, we have the
> > > command \clef tab, so it would be nice to be able to set the modern
> > > style using e.g. \clef moderntab without having to use a new function.
> > >       
> > I'd also like to do that.  But I don't know how to help Marc do it.  Neil,
> > if you can help him figure it out, I'd appreciate it.
> >
> > There are two issues that I can't address:
> >
> > 1) I wasn't able to figure out how to get stringTunings in a music function
> > or a markup function.   How do we do that?
> >     
>
> You don't need to know stringTunings, since it's possible to access
> 'line-count from any grob which is placed on a StaffSymbol:
>
> (let* ((staff-symbol (ly:grob-object grob 'staff-symbol))
>        (line-count (ly:grob-property staff-symbol 'line-count)))
>
>   
This is way beyond my knowledge of the internals. I simply added these lines
accordingly in my definition of customTabClef:

#(define-markup-command (customTabClef layout props tuning) (pair?)
   (define (square x) (* x x))
   (let* ((staff-symbol (ly:grob-object 'grob 'staff-symbol))
          (num-strings (ly:grob-property staff-symbol 'line-count))
          (font-size (- (* num-strings 1.5) 7))
          (base-skip (square (+ (* num-strings 0.195) 0.4))))
      (interpret-markup layout props
        (markup #:vcenter #:bold
                #:override #'(cons 'font-family 'sans)
                #:fontsize font-size
                #:override #'(cons 'baseline-skip base-skip)
                #:left-align
                #:center-column ("T" "A" "B")))))

but this doesn't work. Lilypond complains with

Unbound variable: grob

How can I assign the right value to this symbolic variable?

Marc

> > 2) I'm not sure how to use a markup, instead of a glyph, as a clef without
> > redefining the 'stencil property, and I don't know how to redefine the
> > 'stencil property by means of  a \clef cleftype command.  If you can show us
> > how to do that, it would be really helpful.
> >     
>
> If we add entries in parser-clef.scm to supported-clefs and
> c0-pitch-alist (either directly or by consing the new entries within
> the tablature file) for the modern tab,
>
> ("moderntab" . ("markup.moderntab" 0 0))
>
> ("markup.moderntab" . 0)
>
> we can override the Clef 'stencil to check 'glyph before calling the
> default print-function.  If the string "markup.moderntab" is found,
> then it's simple to return a stencil for the new tab markup.
>
> There's one potential pitfall: it's expected that each clef type has a
> variant at a smaller size which is obtained by appending "_change" to
> the glyph-name.  You'd probably want to disable this feature by
> setting 'full-size-change = ##t.
>
> Regards,
> Neil
>
>