Re: Controlling hairpin length - revisited!

[David Sumbler]

On Wed, 2016-10-12 at 14:10 -0400, Kieren MacMillan wrote:
> Hi David,
> 
> > 
> > But I realise that often what I need in order to get satisfactory
> > hairpins is more space between the note heads, and simply moving
> > the
> > ends of the hairpin does not reposition the relevant notes.
> Have you tried adjusting the minimum-length?
> 
> %%%  SNIPPET BEGINS
> \version "2.18.2"
> \language "english"
> 
> after =
> #(define-music-function (parser location t e m)
>      (ly:duration? ly:music? ly:music?)
>      #{
>          \context Bottom <<
>              #m
>              { \skip $t <> -\tweak extra-spacing-width #empty-
> interval $e }
>          >>
>      #})
> 
> testing = \relative e'' {
>   \override Hairpin.minimum-length = #5
>   e8 cs ds d \after 4 \> \after 4 \mf cs2\< ~ cs4 d8(\p cs)
> }
> 
> \score { \testing }
> %%%  SNIPPET ENDS
> 
> Hope that helps!
> Kieren.

Thanks, that's brilliant.  With this and Hairpin.shorten-pair I should
be able to solve most or all of the problems I often find with
hairpins.

I have read all the material in the list archive relating to this
function.  Even so I don't really understand how it works.  I have a
reasonable understanding of basic Scheme, but much less of the internal
working of Lilypond and how Lilypond and Scheme interract (and yes, I
have read the Extending manual more than once).  Still, I think I
understand how to use the function, which is the main thing.

If anyone has the patience to explain the workings of the function I'd
be very interested. If not, I shan't blame you!

David