[luatex] LuaTeX file almost 2.5x bigger

[Will Robertson]

On 31/07/2010, at 7:44 PM, Hans Hagen wrote:

> Concerning the badness ... there is some wishful thinking involved I guess ... when hz was introduced in pdftex we did experiments at usergroup meetings (each participant got its own randomized copy so no shared experiences).

Interesting stuff, thanks for the comments.

> - Texies came with remarks about wrong penalties and spacing being set, of limited hyphenation patterns being used, rivers being seen ... basically coming up with reasons why paragraphs next to each other looked different but not per se better.

I doubt very much that I, at least, can spot the difference between two good-enough paragraphs with and without hz. Or even between a local line-breaking algorithm (e.g., Word) and TeX's global-per-paragraph one.

It's in the bad examples that the differences become obvious. E.g., very wide inter-word space is a common sign of poor automatic typesetting that TeX simply wouldn't allow (by default). And overfull lines is an obvious indication of poor automatic typesetting by TeX.

So while enabling hz to remove overfull lines might not be detectable, the fact that it helps to remove them in the first place is a good reason to use it, for me.

(I can take or leave margin kerning; I'm referring mostly to character expansion.)

> When Thanh and I discussed that (at a Dante meeting) with Hermann Zapf he made the remark that probably 99% of the readers would not notice the difference. He also suggested that stretching lines vertically in order to get rid of widow lines was probably more effective. (I must have the tests done afterward somewhere.)

This is a nice idea (as long as you're not interested in grid typesetting). Although with 40 lines per page, say, you'd need to stretch by a bit more than 2.5%, which seems a little high. Perhaps you'd stretch by 1% in combination with reducing the interline space to achieve the rest.

> ps. I tend not to buy books that use expansion and inter character spacing trickery to the extreme as it distracts me too much

Absolutely -- if you notice it then it's not done right. (Which is my one complaint with Jean-luc Doumont's book: all of the hanging punctuation is set completely into the margin, which distracts my eyes a little. I prefer margin kerning to achieve "optical straightness" instead.)

> ps. Keep in mind that with for instance protrusion (and to some extend expansion) changes the solution space so we don't get better output.

Well, better output than it was -- surely :) -- but I understand what you're saying. TeX is optimal in the solution it chooses, so you can't improve on that without expanding the solution space.

Cheers,
-- Will