Hi Aaron,
Am So., 22. Dez. 2019 um 07:06 Uhr schrieb Aaron Hill
<lilyp...@hillvisions.com>:
>
> On 2019-12-21 9:15 am, Kieren MacMillan wrote:
> >> Here is my attempt at hacking the BarLine stencil to add overlapping
> >> ties:
> >
> > This is so cool. Is there an easy way to make the function determine
> > the "current" set of LVs (i.e., the LV configuration from the most
> > recent LV-ed chord) and automagically apply it to the subsequent
> > barlines (e.g., with a \temporary, to be \reverted manually)?
>
> Things get trickier if you need to keep track of past events. But here
> is another approach that uses a Scheme engraver to do the bulk of the
> work:
this is really great stuff.
How about putting it in LSR?
Seems to work with 2.18.2 as well.
After a very quick first glnce over it some remarks:
> %%%%
> \version "2.19.83"
>
> #(begin
> (set-object-property! 'activeLaissezVibrer 'translation-type? list?)
> (set-object-property! 'activeLaissezVibrer 'translation-doc
> "A list of LaissezVibrerTies which should span BarLines.")
> (set! all-translation-properties
> (cons 'activeLaissezVibrer all-translation-properties)))
>
> #(define (SpanLaissezVibrer_engraver context)
> (define (spanLaissezVibrer? grob)
> (let* ((cause (ly:grob-property grob 'cause))
> (class (ly:event-property cause 'class '()))
> (span? (ly:event-property cause 'span #f)))
> (and (memq 'laissez-vibrer-event class) span?)))
> (define (past-events tie)
> (ly:moment<? (car tie) (ly:context-now context)))
> (define (rescale-control-points cp xex)
> (let* ((xmin (apply min (map car cp)))
> (xmax (apply max (map car cp)))
> (xmid (/ (+ xmin xmax) 2))
> (xhw (/ (- xmax xmin) 2)))
(map (lambda (pt) pt <-- this `pt` looks superfluous or am I
overlooking something?
> (let ((t (/ (- (car pt) xmid) xhw)))
> (cons (interval-index xex t) (cdr pt)))) cp)))
> (define ((stencil-proc ties) grob)
> (let* ((bd (ly:item-break-dir grob))
> (orig (ly:bar-line::print grob))
> (xex (ly:stencil-extent orig X))
> (x (interval-index xex 0))
> (w (+ 0.8 (/ (interval-length xex) 2)))
> (tie-xex (cons (- x w) (+ x w))))
Some code-duplication here, iiuc:
> (ly:stencil-add (ly:bar-line::print grob)
> (apply ly:stencil-add
> (map (lambda (tie)
> (let* ((cp-orig (ly:grob-property tie 'control-points))
> (cp-temp (rescale-control-points cp-orig tie-xex))
> (sten '()) (xex '()) (yex '()))
> (ly:grob-set-property! tie 'control-points cp-temp)
> (set! sten (ly:tie::print tie))
> (ly:grob-set-property! tie 'control-points cp-orig)
> (set! xex (ly:stencil-extent sten X))
> (set! yex (ly:stencil-extent sten Y))
> (ly:make-stencil (ly:stencil-expr sten)
> (cons (car xex) (if (> 0 bd) x (cdr xex))) yex)))
> (map cdr ties))))))
> (make-engraver
> (acknowledgers
> ((bar-line-interface engraver grob source-engraver)
> (let ((ties (ly:context-property context
> 'activeLaissezVibrer '())))
> (set! ties (filter past-events ties))
> (if (not (null? ties)) (ly:grob-set-property!
> grob 'stencil (stencil-proc ties)))))
> ((semi-tie-interface engraver grob source-engraver)
> (if (spanLaissezVibrer? grob)
> (ly:context-set-property! context 'activeLaissezVibrer
> (cons (cons (ly:context-now context) grob)
> (ly:context-property context
> 'activeLaissezVibrer '()))))))))
>
> spanLaissezVibrer = #(make-music 'LaissezVibrerEvent 'span #t)
>
> stopSpanLaissezVibrers = \applyContext #(lambda (context)
> (ly:context-set-property! (ly:context-find context 'Staff)
> 'activeLaissezVibrer '()))
>
> Upper = {
> | r2 r8 g'8 b' c''
> | <g' b' c''>1\spanLaissezVibrer
> | R1 \stopSpanLaissezVibrers \bar "||"
> | r8 a' g' e' c'2 \bar "|."
> }
> Lower = {
> | <a, d>1\spanLaissezVibrer
> | R1
> | g8 b <g b>2.^\spanLaissezVibrer
> | R1 \stopSpanLaissezVibrers
> }
> \score {
> \new PianoStaff <<
> \new Staff { \clef "treble" \Upper }
> \new Staff { \clef "bass" \Lower }
> >>
> \layout { \context { \Staff
> \consists \SpanLaissezVibrer_engraver } }
> }
> %%%%
>
> This is quite different from my previous manual approach, but this has
> advantages of exactly matching the vertical positioning of LV ties
> without needing manual intervention.
>
>
> -- Aaron Hill
Thanks,
Harm
