Re: missing glissando features (bugs?)

[Marc Hohl]

Neil Puttock schrieb:
> 2009/5/11 Marc Hohl <address@hidden>:
>
>   
> >    (if (and (= left-staff-position right-staff-position)
> >             (< (ly:pitch-semitones right-pitch) (ly:pitch-semitones
> > left-pitch)))
> >                -1
> >                 1 )))
> >     
>
> This will apply an extra-dy of 1 for glissandos which aren't on the
> same staff-position.
>
>   
No, it doesn't; at least in my test files. I have attached an example 
where the
default and the corrected behaviour are compared, please have a look at it.

Marc
> > Here I'm stuck, 'cause when I override the value for extra-dy manually, as
> > in
> >
> > dytest = \relative c {
> >  \set TabStaff.minimumFret = #2
> >  \override Glissando #'extra-dy = #0
> >  c4 \glissando cis \glissando c2
> > }
> >
> > \score {
> >   \new TabStaff { \clef "tab" \dytest } }
> >           the glissando line doesn't look as expected, it is parallel to the
> > staff lines and therefore
> > invisible. So, strange as it seems, the value "1" must be right here.
> >     
>
> The default value for 'extra-dy is set to 0.75 for all glissandos,
> even if they're on different lines; see the context definition in
> engraver-init.ly.
>
> Though I suggested using cond/else, it's probably easier to use nested
> if clauses: if the staff-positions are equal, compare the pitches,
> otherwise return a default value of 0.
>
>      (if (= left-staff-position right-staff-position)
>          (if (< (ly:pitch-semitones right-pitch) (ly:pitch-semitones 
> left-pitch))
>              -1
>              1)
>
>          ;; not on same staff-position -> no extra-dy
>          0))
>
>   
> > Just for the record: I think it would be reasonable to move the
> > glissando::calc-tab-extra-dy
> > call to tablature.ly, so all files are backwards compatible and tablature
> > users can profit from
> > the nicer glissando lines :-)
> >     
>
> It would make an excellent addition to the file.
>
> Regards,
> Neil
>
>   

\version "2.12.2"

\paper {
   indent = 0
   ragged-right = ##f
}


#(define (glissando::calc-extra-dy grob)
   (let* ((original (ly:grob-original grob))
          (left-bound (ly:spanner-bound original LEFT))
          (right-bound (ly:spanner-bound original RIGHT))
          (left-pitch (ly:event-property (event-cause left-bound) 'pitch))
          (right-pitch (ly:event-property (event-cause right-bound) 'pitch)))

     (if (and (= (ly:pitch-octave left-pitch) (ly:pitch-octave right-pitch))
              (= (ly:pitch-notename left-pitch) (ly:pitch-notename 
right-pitch)))
         (- (ly:pitch-alteration right-pitch) (ly:pitch-alteration left-pitch))
         0 )))

#(define (glissando::calc-tab-extra-dy grob)
   (let* ((original (ly:grob-original grob))
          (left-bound (ly:spanner-bound original LEFT))
          (right-bound (ly:spanner-bound original RIGHT))
          (left-pitch (ly:event-property (event-cause left-bound) 'pitch))
          (right-pitch (ly:event-property (event-cause right-bound) 'pitch))
          (left-staff-position (ly:grob-property left-bound 'staff-position))
          (right-staff-position (ly:grob-property right-bound 'staff-position)))

     (if (and (= left-staff-position right-staff-position)
              (< (ly:pitch-semitones right-pitch) (ly:pitch-semitones 
left-pitch)))
         -1
          1 )))

noten = \relative c {
   c4 \glissando cis
   c4 \glissando cis
   c4 \glissando ces
   c4 \glissando ces
   c4 \glissando d \glissando e \glissando f
}

tabs = \relative c {
   \set TabStaff.minimumFret = #2
   c4 \glissando cis \glissando c2
   c4 \glissando ces \glissando c2
   c4 \glissando c \glissando c2
   c4 \glissando d \glissando c2
   c4 \glissando d \glissando c2
   c'4 \glissando d \glissando e, \glissando f 
   \bar "|."
}

\score {
    \new Staff { \clef "G_8" 
                 \noten \break
                 \override Glissando #'extra-dy = #glissando::calc-extra-dy
                 \noten }
}

\score {
    \new TabStaff { \clef "tab"
                    \tabs \break
                    \override Glissando #'extra-dy = 
#glissando::calc-tab-extra-dy
                    \tabs }
}