But, more importantly, the amount of cycles that would be needed to text-wrap most websites is effectively zero. Most websites are simply not typesetting the volumes of text that would be needed for this to be a concern.
Happy to be shown I'm flat wrong on that. What sites are you envisioning this will take a lot of time for?
I've measured this, and no, it's not. What you're missing is the complexities of typesetting Unicode and OpenType, where GSUB/GPOS tables, bidi, ruby text, etc. combine to make typesetting quite complex and expensive. HarfBuzz is 290,000 lines of code for a reason. Typesetting Latin-only text in Times New Roman is quick, sure, but that doesn't cut it nowadays.
I would wager you can find scenarios where it is a large number. My question is if there are sites people use?
Seriously taken, these would all be reasons not to do many of the things Unicode does. And yet here we are.
That all said, if you have measurements, please share. Happy to be proven wrong.
- handling shy hyphens/hyphenation when splitting long words -- working out where to hyphenate so it is readable, then how that affects the available space takes time to compute to ensure that justified text doesn't result in large blocks of whitespace esp. for long words;
- handing text effects like making the first letter large, or the first word(s) larger, like is done in various books;
- reflow due to any changes resulting from text rendering/formatting (e.g. if applying kerning or hyphenation results in/does not result in text wrapping);
- impact of things like kerning and digraphs (e.g. ffi) on text width -- including determining if a word can be split in the middle of one of these or not;
- combining characters, emoji (with zero-width non-joiners), flag Unicode character pairs (including determining valid pairs to determine if/where to split on), etc.;
- mixed direction text (left to right and right to left) handling and positioning;
- the mentioned Ruby text (e.g. https://www.w3.org/International/articles/ruby/styling.en.ht...) -- dealing with both the main text wrapping and the above/below text wrapping, both of which could happen;
- for Chinese/Japanese/Korean ensuring that characters within a word don't have extra space, as those languages don't use spacing to delimit words;
- other things affecting line height such as sub/super script text (mathematical equations, chemical symbols, references, etc.).
Like, I am largely aware that it is a hard problem. So is just rendering text, at large. The added difficulty for justifying text is still not something I expect to impact the vast majority of sites. If you are willing to break your content into multiple pages, I hazard it isn't a significant chunk of time for most content.
Are there edge cases? Absolutely! Most of these are isolated in impact, though. And I do think a focus on whole content optimization is clouding a lot of people's view here. You are not doing yourself any favor by optimizing a full book every time a chapter changes.
There is also the idea that you have to find the absolute best answer for justifying text. Why? One that is low enough on a penalty score is just fine. Akin to the difficulty in finding all tilings of a board, versus just finding a single tiling for a board. Or a single solution to the N-Queens question, versus all solutions. If you just want a single solution, you don't need the raw compute necessary to get them all.
I hardly can open any website w/o some anti-bot check burning my CPU to the ground for 1/2 minute or something (if it doesn't manage to entirely crash my Firefox in the process like cloudflare). I rather would wait for 0.2s text wrapping than that, that's for sure. :)
Try zooming in and out with text-wrap: pretty vs text-wrap: wrap
Are there ereaders that have to typeset the entire text of what you are reading? What is the advantage of making the task harder?
Still, I should acknowledge you provided an example. It surprises me.
As often as the font size changes.
Even the few times I do change text size on my e-readers are largely mistakes. Having gestures to resize is frustrating, in the extreme.
When I'm home, I read books.
Can't speak to Apple Books, but at least Pages.app (and iWork in general) use a separate text engine from TextKit, focused on higher fidelity at the cost of performance -- optical kerning, etc. (Terminal.app also does not use TextKit.)
OpenStep used Display Postscript and was written in Objective-C; WebKit is written in C++.
Rendering text on the web is a different animal all together.
Again, I won't claim it is absolutely free. It is almost certainly negligible in terms of processing power involved with any of the things we are talking about.
* for most webpages. Of course you can come up with giant ebooks or other lengthy content for which this will be more challenging.
And is most of the effort from LaTeX in paragraph layout? Most slowness there, is in Mathematica typesetting, I would think.
Is that the reason the Microsoft Word team tells themselves as well?
We have multi-core, multi-gigahertz CPUs these days: there aren't cycles to spare to do this?
Zooming in a bit, Word also does not kern fonts as well as LaTeX, so it might be missing some logic there that would trickle down into more beautiful word spacing and text flow.
Yes, there can be edge cases where optimizing one section causes another section to be resized. My gut is that that is the exception, not the norm. More, for most of the resizes that will lead folks to do, it will largely result in a "card" being moved up/down in such a way that the contents of that card do not need to be re-optimized.
Yes, you could make this even harder by optimizing what the width of a section should be and flowing another section around it. But how many sites actually do something like that?
To be clear, just because I would hazard that, does not mean I'm right. Would love to see some benchmarks.
A lot of the time folks are sitting and thinking and things are idle. Perhaps Word could 'reflow' text in the background (at least the parts that are off screen)? Also, maybe the saved .docx could perhaps have hints so that on loading things don't have be recalculated?
https://www.youtube.com/watch?v=kzdugwr4Fgk
The Kindle Text Problem - Computerphile
Typesetting all of wikipedia? Probably measurable. Typesetting a single article of wikipedia? Probably not. And I'd wager most sites would be even easier than wikipedia.
"Line Breaking", xxyxyz.org
https://web.archive.org/web/20171021044009/http://xxyxyz.org...
This was on a 4.5 GHz quad core CPU. Single threaded performance of todays top CPUs is only 2-3x faster, but many gamers now have 144Hz+ displays.
What you're complaining about is that the site is not optimized for your reading enjoyment. The site is probably quite well optimized, but your reading enjoyment was not one of the optimizer's priorities. I think we agree about how annoying that is and how prevalent, so the news that new typographical features are coming seems to me like good news for those of us who would appreciate more sites that prioritize us the readers over other possible optimization strategies.
And to be clear, most sites flat out don't need to be optimized. Laying out the content of a single site's page is not something that needs a ton of effort put into it. At least, not a ton in comparison to the power of most machines, nowadays.
This is why, if I open up GMail in the inspector tab, I see upwards of 500+ requests in less than 10 seconds. All to load my inbox, which is almost certainly less than the 5 megs that has been transferred. And I'd assume GMail has to be one of the more optimized sites out there.
Now, to your point, I do think a lot of the discussion around web technologies is akin to low level assembly discussions. The markup and script layout of most sites is optimized for development of the site and the creation of the content far more than it is for display. That we have moved to "webpack" tricks to optimize rendering speaks to that.
You're kidding, right? There are a ton of non-trivial edge cases that have to be considered: break points, hyphenation, other Latin-based languages, etc.
From a Google engineer's paper describing the challenges: https://docs.google.com/document/d/1jJFD8nAUuiUX6ArFZQqQo8yT...
Performance Considerations
While the `text-wrap: pretty` property is an opt-in to accept slower
line breaking, it shouldn’t be too slow, or web developers can’t use
them due to their performance restrictions.
The pinpoint result when it is enabled for all web_tests is in this CL.
Complexity
The score-based algorithm has different characteristics from the
bisection algorithm. The bisection algorithm is O(n * log w) where n is
the number of lines and w is the sum of spaces at the right end. The
score-based algorithm is O(n! + n) where n is the number of break
opportunities, so it will be slower if there are many break
opportunities, such as when hyphenation is enabled.
Also, computing break opportunities are not cheap; it was one of
LayoutNG's optimizations to minimize the number of computing break
opportunities. The score-based algorithm will lose the benefit.
Last 4 Lines
Because computing all break opportunities is expensive, and computing
the score is O(n!) for the number of break opportunities, the number of
break opportunities is critical for the performance. To minimize the
performance impact, the implementation caches 4 lines ahead of the
layout.
Before laying out a line, compute line breaking of 4 lines ahead of the
layout.
If it finds the end of the block or a forced break, compute the score
and optimize line breaks.
Otherwise layout the first line from the greedy line breaking results,
and repeat this for the next line.
The line breaking results are cached, and used if the optimizer decided
not to apply, to minimize the performance impact.
Currently, it applies to the last 4 lines of each paragraph, where
“paragraph” is content in an inline formatting context separated by
forced breaks.
The Length of the Last Line
Because the benefit of the score-based line breaking is most visible
when the last line of the paragraph is short, a performance
optimization is to kick the optimizer in only when the last line is
shorter than a ratio of the available width.
Currently, it applies only when the last line is equal to or less than ⅓
of the available width.
Checking if the last line has only a single word
Checking if the last line has only a single word (i.e. no break
opportunities) requires running the break iterator, but only once.They are still not a sizeable number in comparison to the number of devs that have enabled different text wrap options. Most of which do not give much thought to a setting that did not appreciably slow things down at all.