Re: Two questions about vertical layout and lyrics spacing

[Janek Warchoł]

On Wed, Mar 21, 2012 at 9:46 AM, Frank Steinmetzger <address@hidden> wrote:
> On Sat, Mar 17, 2012 at 01:53:10PM -0700, Joe Neeman wrote:
>> There are two competing desires here [...]. Could you suggest, therefore, an
>> extra parameter (or a modification to the [vertical spacing] algorithm) that 
>> would give you the
>> trade-off you want?
>
> Well, what came to my mind, being a (quite) seasoned user who's done a few
> dozens scores for my choir, in different styles and arrangements, is a
> variable to guide lily in its decisions, just like two-sided or ragged-* do.
>
> So for example a variable called spacing-priority with a few possible values,
> such as system-distance (what 2.14 does now), system-padding (what I would
> need in padding.png), or system-lyrics-padding (for the lyrics.png
> situation).  Internally, I guess, setting this variable would just imply some
> other default values for the spacing alists, as Keith proposed.
>
> The reason behind this approach is that, while lilypond should do as much as
> possible automagically (which it is generally very good at), it just cannot
> predict every possible situation.  So we're giving it a hint as to the
> direction in which to go.

I am convinced that this is a wrong approach, because it complicates
things (trying to create more options and exceptions to the current
rules).  Instead, i think we should create different spacing rules
that better reflect human judgement of good spacing.

I suggest that the vertical spacing alrogithm should calculate the
area between the objects (staves, systems, lyrics etc).  See here how
it would work: http://www.freeimagehosting.net/tsr21

Please also look at these two scores of Tota pulchra es Maria:
www.anonstorage.net/PStorage/871.tota-pulchra-default.pdf
www.anonstorage.net/PStorage/993.tota-pulchra-reduced-padding.pdf

In the first one (created with all default spacing settings), there
are places where a single dynamic object pushes the staves far apart
(marked with light blue).  See pages 2 and 4 - there is too much space
between the staves, especially compared with space between systems.
It is important to keep systems visually separate - the last page is
completely illegible in this regard.
When i reduce padding between a lyric line and the staff below it, the
spacing between systems is definitely improved.  However, some lyrics
are now too close to the staves below them (because of the reduced
padding) - see the other pdf file, light blue markings again.  This
problem isn't very big, but it's noticeable (especially when a lyric
line gets closer to the unrelated staff than to the related staff).
I think that's impossible to achieve the desired effect (very small
padding between lyrics and a single sticking-out dynamic, but overall
not too small distance between lyrics and unrealted staff) with
current spacing system.
The area system, however, will be able to produce desired result,
because it takes into account the amount of actual overall whitespace
between objects, instead of focusing on the points where objects
(staff and lyrics) are closest to themselves.

How do you like it?

cheers,
Janek