Re: Whole-note tremolo beams

[Leo Correia de Verdier]

Thanks a lot! 
Here is a first attempt I’ve made, including a lot of problems:
(For instance: only works in absolute mode, doesn’t avoid augmentation dots, 
doesn’t work in other clefs than treble, code could look better)

%%%%%%%%%%%%%%%%%
\version "2.20.0"

\paper { ragged-right = ##f }

wholeNoteTremolo =
#(define-music-function (parser location repeats basic-gap acc-width nc-i nc-ii)
   (integer? (number? 1.3) (number? 0) ly:music? ly:music?)
   (define middle-c-pos #f)
   (define is-note? (lambda (x)
                      (equal? (ly:music-property x 'name) 'NoteEvent)))
   (define is-chord? (lambda (x)
                       (equal? (ly:music-property x 'name) 'EventChord)))
   (define list-same (lambda (lst)
                       (cond ((null? lst) #f)
                         ((null? (cdr lst)) (car lst))
                         ((not (equal? (car lst) (cadr lst))) #f)
                         (else (list-same (cdr lst))))))
   ;doesn't work, doesn't seem to get evaluated.
   #{
     \context Staff \applyContext #(lambda (context)
                                     (begin
                                      (set! middle-c-pos (ly:context-property 
context 'middleCPosition))
                                      (pretty-print middle-c-pos)
                                      ))
   #}
   
   (let*
    ((duration-i (cond ((is-note? nc-i) (duration-of-note nc-i))
                   ((is-chord? nc-i) (list-same (map duration-of-note
                                                  (filter is-note? 
(ly:music-property nc-i 'elements)))))
                   (else #f)))
     (duration-ii (cond ((is-note? nc-ii) (duration-of-note nc-ii))
                    ((is-chord? nc-ii) (list-same (map duration-of-note
                                                    (filter is-note? 
(ly:music-property nc-ii 'elements)))))
                    (else #f)))
     (beam-count (if (and (equal? duration-i duration-ii) duration-i) (- 
(ly:duration-log duration-i) 2)))
     (middle-c-pos -6) ;remove when call to staff works, otherwise it will only 
accept treble clef
     (pitches-i
      (cond ((is-chord? nc-i) (event-chord-pitches nc-i))
        ((is-note? nc-i) (list (ly:music-property nc-i 'pitch)))
        (else #f)))
     (pitch-steps-i (map ly:pitch-steps pitches-i))
     (staff-pos-i (cons (/ (+ middle-c-pos (eval (cons min pitch-steps-i) 
(interaction-environment))) 2)
                    (/ (+ middle-c-pos (eval (cons max pitch-steps-i) 
(interaction-environment))) 2)))
     (pitches-ii
      (cond ((is-chord? nc-ii) (event-chord-pitches nc-ii))
        ((is-note? nc-ii) (list (ly:music-property nc-ii 'pitch)))
        (else #f)))
     (pitch-steps-ii (map ly:pitch-steps pitches-ii))
     (staff-pos-ii (cons (/ (+ middle-c-pos (eval (cons min pitch-steps-ii) 
(interaction-environment))) 2)
                     (/ (+ middle-c-pos (eval (cons max pitch-steps-ii) 
(interaction-environment))) 2)))
     (rising (< (+ (car staff-pos-i) (cdr staff-pos-i)) (+ (car staff-pos-ii) 
(cdr staff-pos-ii))))
     ;this will choose the outmost notes of chords, giving maximal slope, I 
don't know if that's the way 
     ;to calculate beam positions in this case
     (y-pos (if rising (cons (car staff-pos-i) (cdr staff-pos-ii)) (cons (cdr 
staff-pos-i) (car staff-pos-ii)))))

    #{
      \once \override Beam.length-fraction = #1 %should be widened for steeper 
slopes
      %the following two lines are supposed to make the beams shorter and move 
them left, to avoid
      %the accidental, but for some reason seem to move the beam too much
      \once \override Beam.gap = #(+ basic-gap (/ acc-width 2)) %this doesn't 
really work 
      \once \override Beam.extra-offset = #(cons (/ acc-width -2) 0) %this 
doesn't really work
      \once \override Beam.positions =
      #(lambda (grob)
         (let* ((dir (ly:grob-property grob 'direction))
                (length-fraction (ly:grob-property grob 'length-fraction))
                (beam-interval (* length-fraction .37)) ;horrible approximation
                (beam-thickness (ly:grob-property grob 'beam-thickness))
                (half-beams-thickness (* (/ (- beam-count 1) 2) (+ 
beam-interval beam-thickness) dir))
                (slope (- (car y-pos) (cdr y-pos)))
                (beam-damping (* .3 (tanh slope) (abs slope))))
           (cons (+ (car y-pos) half-beams-thickness (- beam-damping))
             (+ (cdr y-pos) half-beams-thickness beam-damping))
           ))
      \repeat tremolo #repeats { #nc-i #nc-ii }
    #}
    ))

{ 
  \wholeNoteTremolo #8 #1.3 #1.5 gis'16 <dis'' b'>
  \wholeNoteTremolo #16 #1.3 #0 <gis b>32 <f' d''>
  \wholeNoteTremolo #4 #1.3 #3.5 <g' d'' g''>8 <bes des' ees'>
  \time 6/4
  \wholeNoteTremolo #12 #1.3 #0 a'16 b’
}
%%%%%%%%%%%%%%%%%
> 19 mars 2020 kl. 12:08 skrev Thomas Morley <address@hidden>:
> 
> Am Do., 19. März 2020 um 11:12 Uhr schrieb Leo Correia de Verdier
> <address@hidden>:
>> 
>> For the sake of clarity, a MWE:
>> 
>> %%%%%%%%%%%
>> 
>> \version "2.20.0"
>> \repeat tremolo 16 {dis'32 dis’’}
>> 
>> %%%%%%%%%%%
>> 
>>> 19 mars 2020 kl. 11:01 skrev Leo Correia de Verdier <address@hidden>:
>>> 
>>> Dear list!
>>> 
>>> I’m working on a piece with a lot of whole note tremolos and was wondering 
>>> if any of you have a nice workaround for the beams (issues 318 and 704). I 
>>> would like them slanted (with the same slope as a regular beam), centered 
>>> between the noteheads and avoiding accidentals on the second note column, 
>>> but if you have code producing any of these results it would be welcome. 
>>> Harm’s code from this tread does unfortunately not seem to work any longer 
>>> http://lilypond.1069038.n5.nabble.com/Tremolos-between-two-whole-notes-tt57577.html#a57580
>>>  . I’ll start hacking something together, but if any of you already have 
>>> invented this wheel it would be nice not to reinvent it.
>>> 
>>> Thanks a lot!
>>> /Leo
>> 
>> 
> 
> Hi,
> 
> here an updated version of my ancient code, along with a function to
> supress warnings.
> 
> \version "2.20.0"
> 
> \paper { line-width = 120 }
> 
> tweakWholeNoteTremolo =
> #(define-music-function (parser location gap y-off-pair)((number? 0.8) pair?)
> #{
>  \once \override Beam.gap = $gap
>  \once \override Beam.positions =
>    #(lambda (grob)
>      (let* ((pos (beam::place-broken-parts-individually grob)))
>        (cons
>          (+ (car pos) (car y-off-pair))
>          (+ (cdr pos) (car y-off-pair) (cdr y-off-pair)))))
> #})
> 
> %--- test
> 
> suppressWarning =
> #(define-void-function (amount message)(number? string?)
>  (for-each
>    (lambda (warning) (ly:expect-warning message))
>    (iota amount 1 1)))
> 
> \suppressWarning 3 "weird stem size"
> 
> \score {
>  \relative c'' {
>  \tweakWholeNoteTremolo #'(-2.4 . 1.2)
>  \repeat tremolo 16  { gis32 dis' }
>  %\break
> 
>  \tweakWholeNoteTremolo #'(-3.6 . 1.7)
>  \repeat tremolo 32  { <e, gis b>64 d' }
> 
>  \tweakWholeNoteTremolo #1.3 #'(4.4 . -3.0)
>  \repeat tremolo 16  { a'32 a, }
> 
>  }
> }
> 
> 
> \new PianoStaff <<
>  \new Staff = "right" {
>    \repeat tremolo 16  {
> 
>    \tweakWholeNoteTremolo #'(11.2 . -19)
>     e'''32
>    \change Staff = "left"
>     a,,
>    }
>  }
>  \new Staff = "left" {
>    \clef bass
>    s1
>  }
>>> 
> 
> It will not avoid possible accidentals at right NoteColumn, though.
> Not saying it would be impossible, rather I've not the time to dive
> into it deeper...
> 
> Cheers,
>  Harm