Re: new spacing test/example

[Joe Neeman]

On Mon, 2009-07-13 at 11:28 -0400, Kieren MacMillan wrote:
> Hello all (and especially Joe):
> 
> Now that my most recent musical "crisis" is over — the premiere of my  
> newest (Lilypond-v2.12-engraved) commission is this Friday!

Congratulations!

>  — I'm  
> revisiting some recent scores, to see what v2.13 can do for me.  ;)
> 
> I have a choral score which I want to reengrave and then use as a  
> public example of the new spacing engine Joe has devised. So I'm  
> looking for the very best way (read: least tweaking required) to set  
> up the score.

For a start, you will need to checkout the dev/jneeman branch from git,
since I haven't merged it yet (hopefully I will in a couple weeks, but
that's what I thought a couple of weeks ago, too). After that, it should
ideally work without any tweaking. In fact, I would encourage you to
report any tweaks that might be useful as default settings; I haven't
put much thought into the defaults so they probably aren't very good.

> The final output will be as follows:
>    1. Octavo choral paper size (7in x 10.5in).
>    2. Two systems per page, each system consisting of a ChoirStaff  
> (containing four voice staves each with its own lyric line) and  
> slightly reduced PianoStaff (a rehearsal reduction of the a cappella  
> choir parts).
>    3. Non-frenched score, i.e., all six staves will appear in every  
> system.
> 
> So far, so good. However, I want to use ragged-bottom = ##f and have  
> the (new) vertical spacing engine spread the staves "nicely".
> 
> Notes:
>    1. With ragged-bottom = ##t, I have between 0.5 and 1.5 inches of  
> extra space between the bottom of the second system and the footer  
> (with page number).
>    2. When I simply say ragged-bottom = ##f, all of the space gets  
> put between the two systems — this looks even worse than the ragged  
> bottom version.
>    3. I want any extra space to be "pleasingly" distributed primarily  
> (e.g., 50%) between the two systems and secondarily (e.g. the  
> remaining 50%) within the systems.

This happens by default in the new spacing code, although maybe not with
those proportions. The variables that control spacing are all alists and
their elements are described in scm/define-grob-properties.scm (search
for "next-staff-spacing" and please let me know if the documentation is
unclear). These alists go in several places (which should probably get a
few paragraphs in the docs, but I haven't written them yet):

between-system-spacing in the \paper block controls the spacing between
systems

next-staff-spacing on Staff.VerticalAxisGroup controls the spacing to
the next staff

between-staff-spacing on {PianoStaff,GrandStaff,etc}.StaffGrouper
controls the spacing between staves of the same PianoStaff, GrandStaff,
etc

after-last-staff-spacing on {PianoStaff,GrandStaff,etc}.StaffGrouper
does what the name suggests

>    4. I want each lyric lines to stick pretty closely to the  
> associated music staff above it.

It will by default. You can set VerticalAxisGroup 'staff-affinity if you
want to change the position of Lyrics between staves (default is UP)

>    5. I want the separation of the two piano staves to stay pretty  
> well (or maybe completely) fixed.

This is not on by default, should it be? You can try something like
\override PianoStaff.StaffGrouper #'between-staff-spacing
#'stretchability = #2

Hope that gets you started. Examples, docs and feedback are much
appreciated.
Cheers,
Joe