Re: setting the number of pages for a score

[Joe Neeman]

> > Yes, I think that might be possible without too much work. Maybe we 
> > could allow the user to specify a global page-break-system-extent. We 
> > then do the page breaking assuming all music systems have that 
> > Y-extent. For 95% of the music I would use this for, that would be 
> > acceptable since Y-extents don't vary too much. I think the main 
> > problem would be if there are sections with more or less staves than 
> > other sections. But this could work in the meantime.
>
>
> Come to think of it, wouldn't it also be easy to make a 
> Constrained_page_breaker, ie. a page-breaking routine that is 
> constrained to put the final result in X pages? That still wouldn't be 
> an optimal solution to the complete problem, but it would come a long 
> way to automating the current page break tweaking hassle.

You mean a Constrained_page_breaker without the 
Constrained_line_breaker? I think this still leaves a couple problems. 
First, if page turns necessitate uneven spacing, doing without a 
Constrained_line_breaker means that the lines will be evenly spaced, but 
some pages might be spaced much wider than other pages. With a 
Constrained_line_breaker, the uneven spacing will be divided between 
horizontal and vertical spacing, which I think looks nicer.

Second, sometimes when page turns are few and far between, the 
Gourlay_breaker will divide it into too many systems. So if I put a 
\pageBreak where the end of the second page should be, the page breaker 
has no option but to space the systems on 3 pages instead of 2. And then 
I have to twiddle with SpacingSpanner and recompile lots of times.

Anyway, I hope to have a (preliminary) version of the page/line breaker 
combination up later today, so people can at least see the design and 
ideas in it.

Joe