Re: Cross staff parenthesize

[Thomas Morley]

2017-02-12 14:17 GMT+01:00 Thomas Morley <address@hidden>:
> 2017-02-12 2:59 GMT+01:00 Andrew Bernard <address@hidden>:
>
>> Now I observe the same thing when simply changing staves, no cross staff
>> stemming involved. Is this a bug, or am I using parenthesize incorrectly?
>> The issue is that the parentheses do not enclose the accent properly.
>
> Hi Andrew,
>
> I did some research.
>
> The parantheses are printed with 'parentheses-item::print' for the
> stencil. This procedure uses 'parenthesize-elements'.
> In both procedures ly:relative-group-extent fails to return a sane
> intervall, if \change Staff is in the game.
> I don't no why this happens.
>
> Nevertheless, I tried the fix below getting every extent on his own
> and reducing the results afterwards.
>
> There is some debugging-output returning the values for the proposed
> fix and the original.
>
> Note:
> - It is not tested beyond the given example
> - skylining is still buggy (see the printed output for Fingering and
> StringNumber)
>
> \version "2.19.54"
>
> #(ly:set-option 'debug-skylines #t)
>
> #(define (parenthesize-elements grob . rest)
>   (let* ((refp (if (null? rest)
>                    grob
>                    (car rest)))
>          (elts (ly:grob-array->list (ly:grob-object grob 'elements)))
>          (get-friends
>            (lambda (g)
>              (let ((syms (ly:grob-property g 'parenthesis-friends '()))
>                    (get-friend
>                      (lambda (s)
>                        (let ((f (ly:grob-object g s)))
>                          (cond
>                            ((ly:grob? f) (list f))
>                            ((ly:grob-array? f) (ly:grob-array->list f))
>                            (else '()))))))
>                (append-map get-friend syms))))
>          (friends (apply append elts (map get-friends elts)))
>          (common-ref
>            (ly:grob-common-refpoint grob (ly:grob-parent grob X) X))
>          (x-exts
>            (map
>              (lambda (elt)
>                (ly:grob-robust-relative-extent elt common-ref X))
>              friends))
>          (x-ext
>            (cons
>              (reduce min +inf.0 (map car x-exts))
>              (reduce max -inf.0 (map cdr x-exts))))
>          (x-ext-source
>            (ly:relative-group-extent friends refp X))
>          (stencils (ly:grob-property grob 'stencils))
>          (lp (car stencils))
>          (rp (cadr stencils))
>          (padding (ly:grob-property grob 'padding 0.1)))
>
> (format
>   #t
>   "\n\nThe fix-attempt for 'parenthesize-elements' returns for x-ext: ~a"
>   x-ext)
> (format
>   #t
>   "\nThe source-code for 'parenthesize-elements' returns for x-ext: ~a"
>   x-ext-source)
>
>     (ly:stencil-add
>      (ly:stencil-translate-axis lp (- (car x-ext) padding) X)
>      (ly:stencil-translate-axis rp (+ (cdr x-ext) padding) X))))
>
> #(define-public (parentheses-item::print me)
>   (let* ((elts (ly:grob-object me 'elements))
>          (y-ref (ly:grob-common-refpoint-of-array me elts Y))
>          (x-ref (ly:grob-common-refpoint-of-array me elts X))
>          (stencil (parenthesize-elements me x-ref))
>          (y-exts
>            (map
>              (lambda (elt)
>                (ly:grob-extent elt y-ref Y))
>              (ly:grob-array->list elts)))
>          (elt-y-ext
>            (cons
>              (reduce min +inf.0 (map car y-exts))
>              (reduce max -inf.0 (map cdr y-exts))))
>          (elt-y-ext-source
>            (ly:relative-group-extent elts y-ref Y))
>          (y-center (interval-center elt-y-ext)))
>
> (format
>   #t
>   "\nThe fix-attempt for 'parentheses-item::print' returns for elt-y-ext: ~a"
>   elt-y-ext)
> (format
>   #t
>   "\nThe source-code for 'parentheses-item::print' returns for elt-y-ext: ~a"
>   elt-y-ext-source)
>
>     (ly:stencil-translate
>      stencil
>      (cons
>       (- (ly:grob-relative-coordinate me x-ref X))
>       (- y-center (ly:grob-relative-coordinate me y-ref Y))))))
>
> treble = {
>   \clef treble
>   \time 1/4
>   s4
> }
>
> bass = {
>   \clef bass
>   \time 1/4

%% To avoid:
%% programming error: Grob direction requested while calculation in progress.
%% put in here:

\stemDown

>
>   \override ParenthesesItem.stencil = #parentheses-item::print
>
>   e'16 ^\parenthesize ^> ^\parenthesize ^1 ^\parenthesize ^\3
>   \change Staff = treble

%% And delete it here:

%   \stemDown

>   f' g' a'
> }
>
> \score {
>
>   \new PianoStaff
>   <<
>     \new Staff = "treble" { \treble }
>     \new Staff = "bass" { \bass }
>   >>
>
>   \layout {
>   }
> }
>
>
> HTH a bit,
>   Harm