Re: proposed enhancement to vertical stretching logic

[Andrew Hawryluk]

On Wed, Jun 25, 2008 at 2:48 AM, Joe Neeman <address@hidden> wrote:
> On Wed, Jun 25, 2008 at 7:03 AM, Andrew Hawryluk <address@hidden>
> wrote:
>>
>> Reinhold started a recent thread on -user about some problems with the
>> current vertical spacing behaviour, particularly when stretching large
>> systems to fill a page:
>> http://lists.gnu.org/archive/html/lilypond-user/2008-06/msg00309.html
>>
>> To summarize, vertical stretching should be smart enough to add extra
>> space where it is needed most rather than equally distributing it
>> between all the staves.
>>
>> After giving it some thought, I believe that the desired behaviour can
>> be achieved by a system of 'pre-stretched' springs. Since I'm not
>> fluent enough in LP internals to send it as C++, it's in English &
>> pseudocode. It's too big for the email attachment limit, so I have
>> posted it here:
>> http://www.musicbyandrew.ca/springs.pdf
>
> Thanks for the detailed description. I have had a short look and will have a
> longer one once I have access to a printer (I hate trying to read things
> like this on-screen). However, I think that LilyPond´s spring algorithms are
> already close to the ones you are describing. Have a look in
> simple-spacer.cc -- it is reasonably self-contained. Unfortunately, these
> spring algorithms aren´t used in the vertical stretching step, which is
> completely naive; they are only used in horizontal and vertical spacing (ie.
> between systems, not within them). Also, our springs have an ideal length as
> well as parallel (and even overlapping) rods. This allows us to express the
> fact that the "best" spacing (ie. the one with the least force) is not
> necessarily the closest spacing.
>
> Joe
>
>
>

Yes, simple-spacer.cc is very encouraging. I will take a closer look
at it (and springs.cc), but at first glance it appears to do
everything we would need for a 'smart' vertical stretching routine,
and more. Anything we don't have to write is a good thing!

Andrew