Fix 2732: Extract the full page geometry in lilypond-book

Fix 2732: Extract the full page geometry in lilypond-book

So far, lilypond-book tried to extract the line-width from the latex settings,
but not the full page geometry (height, width, margins). Instead, it simply used
the extracted line-with with the default paper size.

If the latex paper size is larger than the lilypond default paper size, then the
line-width will be larger than the page. Lilypond detects this and ignores the
wrong line-width.

The proper solution is to extract the full page geometry from the latex document
and use that for the lilypond snippet, too (unless an explicit papersize or
line-width was given, of course...)

As a side-effect, we now have some more snippet options:
-) paper-width
-) left-margin

-) paper-height
-) top-margin
-) bottom-margin

The latter options only have an effect on vertical stretching of multi-staff groups.

This patch also fixes a small mis-calculation of the text-width for multi-column
texts (the columnsep was subtracted only once rather than once per separation...)

[dak, 2012-08-12 13:24:37]

http://codereview.appspot.com/6454139/diff/1/python/book_latex.py
File python/book_latex.py (right):

http://codereview.appspot.com/6454139/diff/1/python/book_latex.py#newcode262
python/book_latex.py:262: textwidth = (textwidth + columnsep) / columns -
columnsep
Why not use the value of \columnwidth in the first place here?  Note that this
does not help with full-width figures:
\begin{figure*}
...
\end{figure*}

http://codereview.appspot.com/6454139/diff/1/python/book_snippets.py
File python/book_snippets.py (right):

http://codereview.appspot.com/6454139/diff/1/python/book_snippets.py#newcode128
python/book_snippets.py:128: MARGIN_LEFT: r'''left-margin = %(left-margin)s''',
I have a hard time imagining the margins to make any sense since TeX applies
them to the included material anyway.

[Reinhold, 2012-08-24 13:13:39]

http://codereview.appspot.com/6454139/diff/1/python/book_latex.py
File python/book_latex.py (right):

http://codereview.appspot.com/6454139/diff/1/python/book_latex.py#newcode262
python/book_latex.py:262: textwidth = (textwidth + columnsep) / columns -
columnsep
On 2012/08/12 13:24:37, dak wrote:
> Why not use the value of \columnwidth in the first place here?  

Good idea, I wasn't aware that this length existed. You are right, this is much
better.

> Note that this
> does not help with full-width figures:
> \begin{figure*}
> ...
> \end{figure*}

For those you'll have to specify an explicit line-width parameter to the snippet
anyway.

http://codereview.appspot.com/6454139/diff/1/python/book_snippets.py
File python/book_snippets.py (right):

http://codereview.appspot.com/6454139/diff/1/python/book_snippets.py#newcode128
python/book_snippets.py:128: MARGIN_LEFT: r'''left-margin = %(left-margin)s''',
On 2012/08/12 13:24:37, dak wrote:
> I have a hard time imagining the margins to make any sense since TeX applies
> them to the included material anyway.

Neither do I. I just figured it might not be wrong if the lilypond snippet uses
the exact same position on the paper as the latex document (i.e. don't center
the line-width on the paper, but use the latex left-/right margins). But then, I
can't think of a situation where lilypond would give a different cropped result
for different margins, but same line-width...

The top-/bottom-margins might have an influence for vertical
stretching/compressing of multi-staff systems in a snippet. If the latex margins
are quite large, without top-/bottom margins lilypond would create a snippet
image that is too high for the latex textheight.

However, I don't think that these margin settings should be documented. They are
not meant to be used as snippet options manually, only for the auto-extracted
page geometry.