On Fri, May 27, 2011 at 10:44 PM, Keith OHara <k-ohara5...@oco.net> wrote:

> One of the special-cases in the LilyPond code is confusing me.
> ( This special-case code is in Page_layout_Problem::get_fixed_spacing(). )
>
> If the flexible-vertical-spacing variable 'stretchability is defined, but
> has
> value 0.0, such as:
>            *-*-spacing = #'((basic-distance . 16)
>                             (stretchability . 0)
>                             (padding . -100)
>                             (minimum-distance . 0))
> then
> a) the staves will not stretch to fill extra space
>   (documented and sensible)
> b) the staves will not compress, making basic-distance serve as
> minimum-distance
>   (not documented, and I don't know if this it is done consistently)
> c) some people expect padding to be ignored, per Carl's comment on issue
> 1654
>   (not documented and I can't find it in the code history)
>
> It seems to me that one could achieve (b) by setting minimum-distance equal
> to
> basic-distance.  It is less cumbersome, however, to say
>  \override VerticalAxisGroup #'staff-staff-spacing #'stretchability = #0.0
> than to look up whatever basic-distance happens to be.
>
> This backdoor really confuses me, however, in cases like the definition of
> Lyrics in egraver-init.ly.
>  \override VerticalAxisGroup #'nonstaff-nonstaff-spacing =
>     #'((basic-distance . 0)
>        (minimum-distance . 2.8)
>        (padding . 0.2)
>        (stretchability . 0))
> Why is basic-distance smaller than minimum-distance?
> What distance should I expect in tight spacing (and a single-line parent
> staff
> like a drum staff) ?
>
>
> What is stretchability = 0 supposed to do ?
>

I don't think it was originally "supposed" to do anything, but it turned out
to be a useful way to force a fixed spacing. With this application in mind,
I think (b) and (c) are both appropriate, and that the distance should be
the maximum of basic-distance and minimum-distance. So in the definition
above, basic-distance could be anything less than 2.8 and the effect would
be the same.

I'm not 100% attached to this, though, so if you want to change something
specific then don't be shy...

Cheers,
Joe
_______________________________________________
lilypond-devel mailing list
lilypond-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/lilypond-devel

Reply via email to