Re: Tie settings question

[David Nalesnik]

Hi Karol,

On Tue, Oct 25, 2016 at 9:35 AM, Karol Majewski <address@hidden> wrote:
> OK, I'm trying to write something like this in scheme:
>
> if (stem-direction == UP && tie-direction == UP && note-has-a-dot == true)
> {
>   \once \override Tie.details.skyline-padding = #5
>   \once \override Tie.Y-offset = #-0.25
> }
>
> Please, David or Harm, correct my mistakes. So far I've got this:
>
> raiseTie =
> #(lambda
>   (grob)
>   (let*
>     ((ties
>         (ly:grob-array->list
>           (ly:grob-object grob 'ties)))

"tie" is not a defined variable.  When you bind "tie-dir" to a
procedure, it will be evaluated, so "tie" has to be defined.

>       (tie-dir
>         (ly:grob-property tie 'direction))
>       (notehead
>         (ly:spanner-bound
>           (car ties) LEFT))
>       (stem
>         (ly:grob-object notehead 'stem))
>       (stem-dir
>         (ly:grob-property stem 'direction))
>       (flag
>         (ly:grob-object stem 'flag))

grob = TieColumn.  TieColumn grobs store no reference to augmentation
dots.  'dot is a part of the rhythmic-head-interface
(http://lilypond.org/doc/v2.19/Documentation/internals/rhythmic_002dhead_002dinterface)
which is supported by NoteHead.

>       (dot (ly:grob-object grob 'dot)))
>     (if

Again, "tie" is not defined.

>       (and (= stem-dir 1) (= tie-dir 1) (ly:grob? dot))
>       (begin

"tie" is bound locally here.  It is only usable within the lambda expression.

>         (for-each
>           (lambda
>             (tie)
>             (ly:grob-set-nested-property! tie '(details skyline-padding) 5)) 
> ties)
>         (for-each
>           (lambda
>             (tie)
>             (ly:grob-set-property! tie 'Y-offset -0.25)) ties)))))
>
> \layout {
>   \context {
>     \Score
>     \override TieColumn.before-line-breaking = #raiseTie
>   }
> }
>
>

Try this:
raiseTie =
#(lambda (grob)
   (let* ((ties (ly:grob-array->list (ly:grob-object grob 'ties)))
          (notehead (ly:spanner-bound (car ties) LEFT))
          (stem (ly:grob-object notehead 'stem))
          (stem-dir (ly:grob-property stem 'direction))
          (flag (ly:grob-object stem 'flag))
          (dot (ly:grob-object notehead 'dot)))
     (if (and (= stem-dir 1)(ly:grob? dot))
         (for-each
          (lambda (tie)
            (let ((tie-dir (ly:grob-property tie 'direction)))
              (if (= tie-dir 1)
                  (begin
                   (ly:grob-set-nested-property! tie '(details
skyline-padding) 5)
                   (ly:grob-set-property! tie 'Y-offset -0.25)))))
          ties))))

\layout {
  \context {
    \Score
    \override TieColumn.before-line-breaking = #raiseTie
  }
}

{
  \time 3/8 \voiceOne
  g'4~ g'8~
  g'4~ g'8~
  g'4.~
  g'4~ g'8
}

%%%%

I hope this helps.  You'll probably need to retool it to incorporate
the features you began the thread with, but this should give you an
idea of the principles involved.

David