Re: Half-note stem length Function help

[Thomas Morley]

Hi Carl,

2016-12-18 6:20 GMT+01:00 Carl Williams <address@hidden>:
> For those interested,
>
> I made some improvements to the solution for this. It now accounts for
> whether the stems are up or down, so as to match what is commonly done in
> modern tablature.

I really doubt about "commonly" ;)
I've seen so many different styles...

>
> I intend to make a tablature template incorporating this solution here also,
> http://lists.gnu.org/archive/html/bug-lilypond/2016-12/msg00022.html.
>
> %%%%%%%%%%%%%%%%
> \version "2.18.2"
>
> halve-half-stems =
> \override Stem.before-line-breaking =
>   #(lambda (grob)
>     (if (= 1 (ly:grob-property grob 'duration-log))
>       (if (= DOWN (ly:grob-property grob 'direction))
>         (and
>           (ly:grob-set-property! grob 'stem-begin-position
>             (- (ly:grob-property grob 'stem-begin-position)
>               (/ (ly:grob-property grob 'length) 2)
>             )
>           )
>           (ly:grob-set-property! grob 'length
>             (/ (ly:grob-property grob 'length) 2)
>           )
>         )
>         (ly:grob-set-property! grob 'length
>           (/ (ly:grob-property grob 'length) 2)
>         )
>       )
>     )
>   )

No point in calling the same over and over again. How about:

halve-half-stems =
\override Stem.before-line-breaking =
  #(lambda (grob)
    (if (= 1 (ly:grob-property grob 'duration-log))
        (let ((half-orig-lngth (/ (ly:grob-property grob 'length) 2)))
          (if (= DOWN (ly:grob-property grob 'direction))
              (ly:grob-set-property! grob 'stem-begin-position
                (- (ly:grob-property grob 'stem-begin-position)
                   half-orig-lngth)))
          (ly:grob-set-property! grob 'length half-orig-lngth))))

>
> %%%%%%%%%%%%%%%%
> %% EXAMPLES
> %%%%%%%%%%%%%%%%
>
> \new TabStaff \with {
>   stringTunings = #ukulele-tuning
>   \tabFullNotation
>   \stemUp
>   \halve-half-stems
> }
>   \relative c' {
>   \partial 2.. a'8 a4 a2 |
>   a1 |
>   \stemDown
>   \partial 2.. g8\4 g4\4 g2\4 |
>   g1\4 |
> }
> \new TabStaff \with {
>   stringTunings = #ukulele-tuning
>   \tabFullNotation
>   \revert Stem.stencil
>   \revert Stem.X-extent
>   \stemUp
>   \halve-half-stems
> }
>   \relative c' {
>   \partial 2.. a'8 a4 a2 |
>   a1 |
>   \stemDown
>   \partial 2.. g8\4 g4\4 g2\4 |
>   g1\4 |
> }
> %%%%%%%%%%%%%%%%

Cheers,
  Harm