Lilypond: Variable page break penalty - lilypond

Question

In my use of Lilypond, I often face the same kind of problems: Say I have four scores (3-4 lines each) that fit in two pages but not necessarily in one.
I refuse to have page breaks within scores. If possible, I want all the scores on the same page. When it's not possible however, I would like the page break to occur between the first and second scores. If that is not possible either, between the second and the third. And only if that's really necessary between the third and the fourth. That is, by order of preference, | representing the page break:
1 2 3 4 |
1 | 2 3 4
1 2 | 3 4
1 2 3 | 4
Is there a way to achieve that without trying and adding the page breaks myself? Maybe by having page-break penalties going in increasing order after each score (but remaining smaller than the penalty for adding a new page)?
Thank you by advance for your help.

Answer 1

You should use ly:page-turn-breaking (see Optimal page turning in the documentation). You'll probably have to play also with \pageTurn, \noPageTurn, \allowPageTurn in order to have the best control.
Here's a minimal example:
\version "2.19.82"
\header {
title = "Page turn breaking"
}
\paper {
% The default page breaking will make Score 1 end at beginning of page 2.
% The following option prevents this and keeps Score 1 all in the first page.
page-breaking = #ly:page-turn-breaking
}
\score {
\header { piece = "Score 1" }
\new Staff {
\clef "treble_8"
\repeat unfold 14 { c'1*4 }
}
\layout {
indent = 0
system-count = 14
}
}
\score {
\header { piece = "Score 2" }
\new Staff {
\clef "treble_8"
\repeat unfold 13 { e'2 f }
}
\layout {
indent = 0
system-count = 13
}
}