Re: Translating stencils

[Michael Käppler]

Hi Harm,
many thanks for your advice!
The \table command was completely new to me.
Here is my current state of work:

#(define (mm->staff-spaces mm)
   (let ((ss (ly:output-def-lookup $defaultpaper 'staff-space)))
     (/ mm ss)))

#(define musiclist (list
                    #{ { \clef bass e'4 } #}
                    #{ { \clef treble a'2 } #}
                    #{ { \key as \major \clef alto es' } #}
                    #{ { \clef bass e'4 } #}
                    #{ { \clef treble a'2 } #}
                    #{ { \key as \major \clef alto es' } #}
                    #{ { \clef bass e'4 } #}
                    #{ { \clef treble a'2 } #}
                    #{ { \key as \major \clef alto es' } #}
                    ))

\layout {
  indent = #0
  \context {
    \Staff
    \remove "Time_signature_engraver"
    \remove "Bar_engraver"
    \override StaffSymbol #'width = #(mm->staff-spaces 20)
  }
}

#(define (make-score music)
   (let* ((score (scorify-music music))
          (layout (ly:output-def-clone $defaultlayout)))
     (ly:score-add-output-def! score layout)
     score))

#(define-markup-command (scoretomarkup layout props s)
   (ly:score?)
   (interpret-markup layout props (make-score-markup s)))

#(define-markup-list-command (scores-to-markup-list layout props scores)
   (list?)
   (map (lambda (s) (interpret-markup layout props s))
     (map make-score-markup scores)))

#(define scores (map make-score musiclist))

\markuplist { \table #'(0 0 0) \scores-to-markup-list \scores }

Some new questions arose:
1. Is there an easier way of converting a list of music expressions into
markups? Did I miss some built-in function
that would do the job, too?
2. I stumbled upon some functions I was not able to find in the source code.
First I wanted to see how the built-in \score markup-function does it's job.
I saw that it calls a function called score-lines-markup-list, which I
was unable to find in the repository.
Or take (make-score-markup) which I had seen in an older thread.
But a "git grep make-score-markup" returns nothing.
What am I missing?

Thank you,
Michael

Am 23.09.2019 um 23:14 schrieb Thomas Morley:
> Am Mo., 23. Sept. 2019 um 18:04 Uhr schrieb Michael Käppler <address@hidden>:
> > Hi all,
> > I'm trying to understand the way one can translate / stack stencils in
> > LilyPond.
> > Consider the following code:
> >
> > #(define-markup-command (draw-line-mod layout props startpos endpos)
> >      (number-pair? number-pair?)
> >      #:properties ((thickness 1))
> >
> >     (let ((th (* (ly:output-def-lookup layout 'line-thickness)
> >                  thickness))
> >           (startx (car startpos))
> >           (starty (cdr startpos))
> >           (endx (car endpos))
> >           (endy (cdr endpos)))
> >       (make-line-stencil th startx starty endx endy)))
> >
> > #(define hlineone (markup #:draw-line-mod '(0 . 0) '(10 . 0)))
> > #(define hlinetwo (markup #:draw-line-mod '(0 . 10) '(10 . 10)))
> >
> > #(define vlineone (markup #:draw-line-mod '(0 . 0) '(0 . 10)))
> > #(define vlinetwo (markup #:draw-line-mod '(10 . 0) '(10 . 10)))
> >
> > \markup \hlineone
> > % \markup \hlinetwo
> > % \markup \vlineone
> > % \markup \vlinetwo
> >
> > The ordinary draw-line markup function calls (make-line-stencil) with
> > startx/starty 0 0.
> > So I wrote the custom draw-line-mod function to figure out what happens
> > when I set the startx / starty to different values.
> > What I understand is that these values do not specify "absolute
> > coordinates" somewhere on the paper, but are somehow relative
> > to each other. But how exactly?
> >
> > \markup \hlinetwo gives a line positioned exactly like \hlineone, though
> > the stencil has different starty.
> > \markup \vlinetwo, however,  gives a line starting at a different
> > vertical position than \vlineone.
> >
> > Eventually I want to draw a kind of grid with horizontal and vertical
> > lines, placing little "scores" in them.
> > Attached is an example of what I want to achieve. But I do not want a
> > quick solution, instead I would be glad to understand
> > the stencil positioning better than now.
> >
> > Kind regards,
> > Michael
> If I understand correctly:
> If you place a bunch of stencils on a page, then lilyponds
> spacing-engine will drop in and white space may be disregarded. See:
>
> \paper { markup-markup-spacing.padding = 5 }
>
> \markup \hlineone
> \markup \hlinetwo
> \markup \vlineone
> \markup \vlinetwo
>
> And compare with:
>
> \markup {
>    \hlineone
>    \hlinetwo
>    \vlineone
>    \vlinetwo
> }
>
> With the latter you can observe all the different settings (relative
> to the previous stencil)
>
> For your final goal, checkout the table-markup-list-command.
> No lines implemented there, but probably a starting point.
>
> Cheers,
>    Harm