[luatex] Interfere with page breaking to balance pages

[Stephan Hennig]

Am 18.10.2012 10:42, schrieb Paul Isambert:

> Similar to the linebreak callbacks, I've been thinking about the following:
> 
> - A pre_shipout would take whatever box is passed to \shipout and return a
> similar one; returning nothing would cancel shipout, i.e. it'd be a dead cycle.
>
> - A shipout callback would take what the preceding returns, and return PDF code
> representing the page,

Plus allow transferring a table of page boxes from pre_shipout to
shipout to make shuffling pages in the former hook easy.  Or balancing
as in Patricks case, or anything that requires looking at more than one
page at a time and is simple enough that you don't need to write a
customized output routine.

Best regards,
Stephan Hennig