RE: breaking cleanups

[Joe Neeman]

On Thu, 2006-09-07 at 15:57 +0100, Anthony Youngman wrote:
> One thing I'd jump on with "negative == no compression". It's been
> commented elsewhere that the stuff I normally set (band parts) tends to
> be very loosely spaced. If you've got a configurable compression
> parameter, might it be an idea to make a negative value force expansion?

I'm not quite sure what you mean by this. My negative <=> compression
was purely a comment on lilypond's internal algorithms. We calculate the
force required to squeeze or stretch a line.
Force negative => compression
Force positive => stretching

The compression penalty doesn't relate to expansion at all, it just says
"how bad is compression?". A large penalty would mean that compression
is very bad. A negative penalty would say that compression is good
(which wouldn't really make sense).

If you want your music loosely spaced, just configure SpacingSpanner to
give you longer springs. It's in the manual somewhere, probably under
"Horizontal Spacing". The idea of the line breaking algorithm, btw, is
that the "best possible spacing" is one where the force is zero. If you
want your music more widely spaced, the correct way to go about it is to
change your springs so that they will be long when the force is zero, as
opposed to trying to make the line breaker prefer stretching.

> 
> (Just an idea, I could probably (and easily) force the same sort of
> effect by forcing the number of systems - it's just that by default lily
> typically sets pieces in maybe half to two thirds the space used by the
> printed part I'm copying. Well annoying when the result is two thirds of
> a side on a double-page spread is just empty space in the lily
> version...)

The new page breaker should help here. It takes page spacing into
account when choosing line breaks. If you don't mind testing the
development version, I would appreciate the feedback (but you should
wait for 2.9.18 as it has many bugfixes and the new page breaker will be
enabled by default).

Hope that helps,
Joe