Re: Adding text to slurs

[Urs Liska]

Hi Pablo,


Am 04.11.2018 um 09:36 schrieb Pablo Cordal:
> Hi to everyone from Spain,
>
> I have got a special need with lilypond. I need to add text to slurs 
> for educational purposes, I'm a music teacher and I'd like to add 
> information to musical phrases.

I have recently written a function (with extensive help from this list) 
that should be exactly what you need. It places a markup centered above 
or below (depending on the direction) of a slur:

\version "2.19.82"

% "Annotate" a slur with a horizontally centered markup.
% The vertical position of the markup is determined both by
% (uses the greater of) the mozart.markup-staff-padding option and
% the min-padding argument.
%
% NOTE: As this function is an after-line-breaking callback it can't
% provide any collision handling for the added markup. This may result
% in collisions with other score elements, or it can cause the added
% markup to be cut off at the paper border. For the latter case the
% function \forceTopCropping from the paper-top-padding tool can be used.


annotatedSlur =
#(define-event-function (min-padding text)((number? 1) markup?)
   "Create a slur with an attached markup."
   #{
     -\tweak after-line-breaking
     #(lambda (grob)
        (let*
         ((dir (ly:grob-property grob 'direction))
          ;; staff-padding from the options
          (staff-padding (getOption '(mozart markup-staff-padding)))
          ;; The original slur stencil
          (stencil (ly:slur::print grob))
          ;; A new stencil for the markup
          (markup-stencil (grob-interpret-markup grob text))
          ;; Y-extent of the original slur for later reference
          (slur-extent (ly:grob-property grob 'Y-extent))
          ;; total height of slur
          (slur-height (- (cdr slur-extent) (car slur-extent)))
          ;; absolute distance of outer slur edge from middle staffline
          (outer-slur-edge-abs
           (abs (if (> dir 0) (cdr slur-extent) (car slur-extent))))
          ;; Y-extent of the added markup stencil
          (markup-extent (ly:stencil-extent markup-stencil Y))
          ;; total height of markup
          (markup-height (- (cdr markup-extent) (car markup-extent)))
          ;; height of lower extender or X height, depending on direction
          (markup-inner-height
           (if (> dir 0)
               (* -1 (car markup-extent))
               (cdr markup-extent)))
          ;; offset because staff-padding *below* staff is increased by 1
          (direction-offset (if (> dir 0) 0 -1))
          ;; padding between slur and markup, based on both the min-padding
          ;; argument and the global mozart.markup-staff-padding option
          (effective-padding
           (max
            (- (+ staff-padding 2)
              markup-inner-height
              direction-offset
              outer-slur-edge-abs)
            min-padding))
          ;; necessary horizontal shift to center the markup against the slur
          (hshift (- (interval-center (ly:stencil-extent stencil X))
                    (interval-center (ly:stencil-extent markup-stencil X))))
          ;; combined stencil from slur and text
          (new-stencil
           (ly:stencil-combine-at-edge stencil Y dir
             (ly:stencil-translate-axis markup-stencil hshift X)
             effective-padding)))
         ;; enclose the *new* stencil by the modified Y-extent
         ;; NOTE: this only makes the whole thing *clickable*, it doesn't
         ;; help with pushing the staff towards the bottom of the page.
         (ly:grob-set-property! grob 'Y-extent
           (if (> dir 0)
               (cons
                (car slur-extent)
                (+ (car slur-extent) slur-height effective-padding 
markup-height))
               (cons
                (- (car slur-extent) effective-padding markup-height)
                (cdr slur-extent))))
         (ly:grob-set-property! grob 'stencil new-stencil)))
     % NOTE: this is a slur-event, not a misplaced parenthesis
     (
   #})

You would use it like

{
  c'1 ^\annotatedSlur "My text" c' ) c' _\annotatedSlur 4 "My padded text" c' )
}

HTH
Urs