On Sun, 2010-06-27 at 06:56 -0400, Boris Shingarov wrote:
Hi Arno,
>> Thanks, I've reverted the patch in the meantime. However, the
>> information that you see in annotate-spacing is actually computed
after
>> line-breaking,
>
> ok, so why can't it then be taken into account for page-breaking?
The problem is that page-breaking does not come *after* page-breaking.
Well, conceptually, it sort of does. But the optimization of breaking
is global over the product space of all line breaking possibilities by
all page breaking possibilities. It is done in the hope to get more
optimal breaks. The downside is that we are forced to use "height
estimations" instead of real heights of things; otherwise we would need
to do page layout for every possible break configuration, which would be
prohibitively expensive.
while I have a
personal bias against scrapping the vertical layout (since I wrote it),
I do think that it is a big improvement over the previous layout
algorithm and I have heard comments to that effect on the lists too.
Also, the page-turn-breaker can't function without some interaction
between line- and page-breaking.
> Since it more than doubles the computation time (often by far) there
> must be something redundant, no?
No, because the height used in page breaking, is not the actual height;
it is just an estimate (often wrong).