\version "2.19.82"

%% After
%% http://lilypond.1069038.n5.nabble.com/Glissando-on-single-note-in-chords-tt34672.html#a34676

%% Printing Glissando between Fingerings is initialized by the new introduced 
%% subproperty:
%%   Glissando.details.finger-slides (a boolean, default is #f)
%%
%% Which Glissando between Finerings is printed (as a line)
%%   could be selected via 'glissandoMap' or the provided 'connectGliss'
%%
%% Selecting which Glissando should become a bow is done with (not selected
%% ones are dropped):
%%   Glissando.details.bow-glissando-indices (a number-list, default #f)
%%
%% The bow is further customizable modifing the newly introduced
%%   Glissando.bound-details.left.y-padding (a numerical value, default is 1)
%%   Glissando.bound-details.right.y-padding (a numerical value, default is 1)
%%
%% The other known subproperties may still be modified.

#(define (replace-gliss-with-tie which)
  (lambda (grob)
    (let* ((gliss-count (ly:grob-property grob 'glissando-index))
           (sign 
             (lambda (x)
               (if (= x 0)
                   0
                   (if (< x 0) -1 1)))))
      (if (member gliss-count which) 
          (let* ((sys (ly:grob-system grob))
                 (left-bound (ly:spanner-bound grob LEFT))
                 (left-coord (ly:grob-relative-coordinate left-bound sys X))
                 (right-bound (ly:spanner-bound grob right))
                 (right-coord (ly:grob-relative-coordinate right-bound sys X))
                 (left-bound-info (ly:grob-property grob 'left-bound-info))
                 (left-padding (assoc-get 'padding left-bound-info))
                 (Y-left (assoc-get 'Y left-bound-info))
                 (X-left (assoc-get 'X left-bound-info))
                 (y-left-padding (assoc-get 'y-padding left-bound-info 1))
                 (right-bound-info (ly:grob-property grob 'right-bound-info))
                 (Y-right (assoc-get 'Y right-bound-info))
                 (right-padding (assoc-get 'padding right-bound-info))
                 (X-right (assoc-get 'X right-bound-info))
                 (y-right-padding (assoc-get 'y-padding right-bound-info 1))
                 (thick (ly:grob-property grob 'thickness 0.12)))
              (make-tie-stencil 
                (cons (- X-left left-coord left-padding) 
                      (+ Y-left (* y-left-padding (sign Y-left))))
                (cons (- X-right left-coord (- right-padding)) 
                      (+ Y-right (* y-right-padding (sign Y-left))))
                thick
                (if (negative? Y-left) DOWN UP)))
          #f))))
   
fingeringSlideEngraver =
#(lambda (context)
   (let ((glissandi '())
         (fingerings '()))
     (make-engraver
       (acknowledgers
         ((glissando-interface engraver grob source-engraver)
           (let* ((details (ly:grob-property grob 'details))
                  (slides? (assoc-get 'finger-slides details #f))
                  (which-bow-gliss
                    (assoc-get 'bow-glissando-indices details #f)))
             (if slides?
                 (set! glissandi (cons grob glissandi)))
             (if (and which-bow-gliss slides? (pair? fingerings))
                 (ly:grob-set-property! grob 'stencil 
                   (replace-gliss-with-tie which-bow-gliss)))))
         ((finger-interface engraver grob source-engraver)
           (set! fingerings (cons grob fingerings))))
       ((stop-translation-timestep translator)
         (for-each 
           (lambda (gliss)
             (for-each 
               (lambda (finger)
                 (if (eq? (ly:spanner-bound gliss LEFT)
                          (ly:grob-parent finger X))
                     (ly:spanner-set-bound! gliss LEFT finger))
                 (if (eq? (ly:spanner-bound gliss RIGHT)
                          (ly:grob-parent finger X))
                     (begin
                       (ly:spanner-set-bound! gliss RIGHT finger)
                       (set! glissandi 
                             (remove (lambda (x) (eq? x gliss)) glissandi)))))
               fingerings))
           glissandi)
         (set! fingerings '())))))
         
\layout {
  \context {
    \Voice
    \consists \fingeringSlideEngraver
  }
}

%% \set glissandoMap = #'(pair-1 pair-2) ended with \unset glissandoMap is
%% more flexible but not really needed for the fingeringSlideEngraver, thus:
connectGliss =
#(define-music-function (which)(number-list?)
  #{ \set glissandoMap = #(map (lambda (w) (cons w w)) which) #})

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXAMPLES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%{
m = \relative c'' {
  <fis-2 d'-4>4\glissando
  <g,-2 d'-4>
  
  <fis-1 d'-3>4\glissando
  <g'-1 d'-3>
  \bar "||"
}

{
  %% default behaviour
  \m
  %% activate slides for fingerings
  \override Glissando.details.finger-slides = ##t
  \m
  %% select certain glissandos, drop the other
  \connectGliss 0
  \m
  \connectGliss 1
  \m
  \unset glissandoMap
  \break
  %% bowed slides, select with the provided list, unsuitable list-settings
  %% will be ignored
  \override Glissando.details.bow-glissando-indices = #'(0 1)
  \m
  \override Glissando.details.bow-glissando-indices = #'(0)
  \m
  \override Glissando.details.bow-glissando-indices = #'(1)
  \m
  
  %% line-breaks and skipping NoteColumns
  \override Glissando.details.bow-glissando-indices = #'(0 1)
  \override Glissando.breakable = ##t
  \override Glissando.after-line-breaking = ##f
  <fis''-2 d'''-4>1\glissando
  \once \override NoteColumn.glissando-skip = ##t
  <g'-2 d''-4>
  \break
  <fis''-1 d'''-3>1
}

{
  \voiceOne
  \acciaccatura {
    e''16 
    \override Glissando.details.finger-slides = ##t
    \override Glissando.details.bow-glissando-indices = #'(0 1)
    % some custom-tweakings
    \once \override Glissando.bound-details.left.padding = 0.3
    \once \override Glissando.bound-details.left.y-padding = 0.7
    \once \override Glissando.bound-details.right.y-padding = 0.8
    <f''-1>\glissando
  }
  <e''-1>8
  
  <fis'' d'''>1\glissando
  <g' d''>
}