Re: Speed tips, again, for extremely large scores?

[Graham Percival]

On Sat, Jan 30, 2010 at 5:12 PM, Trevor Bača <address@hidden> wrote:
> http://lilypond.org/doc/v2.12/Documentation/user/lilypond-learning/Avoiding-tweaks-with-slower-processing
>
> ... the language in the LM is somewhat ambiguous as to whether
> keep-inside-line settings speed things up or slow things down.
>
> QUESTION: I have to assume that keep-inside-line is relatively expensive and
> that the recommendation in the LM is to *NOT* use the keep-inside-line
> settings, yes?

keep-inside-line is expensive.  The recommendation is to leave it off
(the default) for faster processing.  However, I personally recommend
to turn it on when creating the final version, so that you don't need
to manually add \break commands to avoid text running off the
right-hand side of the page.

James, please prepare a patch to clarify this issue.


> Next, there is a thread here ...
>
>   http://lists.gnu.org/archive/html/lilypond-user/2009-08/msg00057.html

I repeat my previous statement:
http://lists.gnu.org/archive/html/lilypond-user/2009-08/msg00111.html

I'd add some swear-words for emphasis if I thought that would help.


> I guess the reason I'm writing in to ask the question is that I feel that
> something has changed for the worse since the early versions of Lily I used
> on the score in 2005

Since then, we've had
- skyline vertical placement  (you don't need to manually increase the
padding on text scripts!)
- better vertical placement of systems on a page (maybe not
particularly relevant to huge scores when you can only fit one system
per page anyway)

Both of those are expensive.

> (As a postscript, I also have #(define page-breaking ly:minimal-breaking)
> set in the score because I set all breaks and vertical spacing by hand. I
> know that certain changes that Joe's made to dramatically improve vertical
> spacing cane be time consumptive in some cases, so maybe this is a
> precaution to ward against that. However, the setting produces no obvious
> increase in performance, which makes me think that vertical spacing has
> nothing to do with the performance difference I'm experiencing.)

Hmm.  1) are you sure that minimal-breaking is the lowest-CPU option?
Isn't there a naive-breaking, or even a non-automatic-breaking ?  If
you've manually set *all* breaks and pageBreaks, then theoretically
that would save a **ton** of CPU resources.
2) are you certain that you've defined this in the right place?  I'm
not suggesting that *I* know the right place, but I'm not certain if
you're supposed to add this to the top of your file, or inside the
first \book{} block, or put it in every \score block, or what.

Cheers,
- Graham