Re: Short TextSpanners do not follow beam slope

[Nick Payne]

On 02/09/10 08:37, Neil Puttock wrote:
> On 1 September 2010 04:33, Nick Payne<address@hidden>  wrote:
>    
> > When I look at commercially engraved guitar scores that I have, short text
> > spanners, such as string number indications, follow the slope of a beam. If
> > there are several of them along a sloping beam, they descend or ascend along
> > with the beam so that there is a constant spacing between each spanner and
> > the beam. Lilypond doesn't do this - if the stems are up, the calculation of
> > the vertical height of all spanners seems to be relative to the highest part
> > of the beam, even though some spanners are only above a lower part of the
> > beam. If the stems are down, then the spanners descend or ascend to be the
> > same spacing from the noteheads:
> >      
> You could try tweaking the slope via
>
> '(bound-details right Y)
>
> though you'll also have to force the spanners closer to the beams to
> compensate for the inflexible skylines.
>
> With a bit of clever coding,it might be possible to generate the
> correct bound-details informatio automatically (the code for tuplet
> bracket sloping might provide some inspiration).
>    
Actually, what I meant was not that the spanner line should slope to 
match the beam but that each spanner should be the same distance above 
the part of the beam vertically below it. The following example better 
illustrates things. The first text spanner is positioned about three 
staff units too high because it's height seems to be calculated from the 
highest part of the entire beam and not the highest part of the section 
of the beam that it spans:

\version "2.13.31"

string = #(define-music-function (parser location stringnum dirn shorten 
adjBreak adjEnd)
    (string? number? pair? number? number?)
#{
    \once \override TextSpanner #'bound-details #'left #'text = \markup 
\bold { \teeny \concat { \circle { \finger $stringnum } " " } }
    \once \override TextSpanner #'font-shape = #'upright
    \once \override TextSpanner #'direction = #$dirn
    \once \override TextSpanner #'dash-period = #0.8
    \once \override TextSpanner #'dash-fraction = #0.6
    \once \override TextSpanner #'thickness = #0.8
    \once \override TextSpanner #'bound-details #'right #'text = 
\markup { \draw-line #(cons 0 (/ $dirn -2)) }
    \once \override TextSpanner #'bound-details #'left 
#'stencil-align-dir-y = #CENTER
    \once \override TextSpanner #'bound-details #'left #'padding = 
#(car $shorten)
    \once \override TextSpanner #'bound-details #'right #'padding = 
#(cdr $shorten)
    \once \override TextSpanner #'bound-details #'right-broken 
#'padding = #$adjEnd
    \once \override TextSpanner #'bound-details #'left-broken #'X = 
#$adjBreak
    \once \override TextSpanner #'bound-details #'left-broken #'text = ##f
    \once \override TextSpanner #'bound-details #'right-broken #'text = ##f
#})

\relative c'' {
    \time 9/8
    \override StringNumber #'add-stem-support = ##t
    f16 d b <g\3> <e\4> \string "5" #UP #'(0.25 . -0.75) #7 #0.5 
c\startTextSpan c c c c c c\stopTextSpan
    f' d b <g\3> <e\4> \string "5" #UP #'(0.25 . -0.75) #7 #0.5 
c-\tweak #'extra-offset #'(0 . -2.8)\startTextSpan c c c c c c\stopTextSpan
}

Nick

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