On Wed, 28 Feb 2024 at 20:53, Emanuel Han via ntg-context <
ntg-context@ntg.nl> wrote:

> Thank you all for your suggestions and contributions to the wiki.
>
> I don't intend to nag, but when looking at what ConTeXt is producing, I
> need to state that the result is still far away from a properly typeset
> Japanese text.
>
> So the nihongo script which comes with ConTeXt handles *line breaks /
> line wrapping*. But the line break rules defined in it need a rework,
> because they don't follow the standards. The standards are documented here:
> https://www.w3.org/TR/jlreq/#possibilities_for_linebreaking_between_characters
> , and all affected characters are listed here:
> https://www.w3.org/TR/jlreq/tables/table_en3.pdf
>
> We have different rules, depending what kind of character is surpassing
> the text width (or is in its last position).
>
> Rule 1:
>
> Before closing brackets, closing quotation marks, iteration marks, the
> Prolonged sound mark and small Kana, line breaking is prohibited.
>
> ’”）〕］｝〉》」』】ヽヾゝゞ々ーぁぃぅぇぉァィゥェォっゃゅょッャュョ etc.
>
> The actual programmed behaviour by the nihongo script is that, if in the
> position which exceeds the line width,  these characters jump to the next
> line and take the previous character with them. If they're in the last
> position of the line, they stay where they are. This behaviour is correct.
>
> Rule 2:
>
> After opening Brackets and opening quotation marks, line breaking is
> prohibited (but not before).
>
> ‘“（〔［｛〈《「『【
>
> The actual programmed behaviour by the nihongo script is that these
> characters jump to the next line and take the previous character with them.
> This behaviour is wrong. They should jump to the next line without taking
> the previous character with them, just like any regular character. The
> difference to a regular character is that they jump already when still
> within the line length, and they're in the last position of the line. The
> correct behaviour can be seen in LibreOffice Writer in action.
>
> Rule 3:
>
> Comma (tōten), full width comma, full stop
>
> 、，。
>
> The actual programmed behaviour by the nihongo script is that, if in the
> position which exceeds the line width, these characters jump to the next
> line and take the previous character with them. This behaviour is wrong.
> They have to be put back to the end of the previous line, but beyond the
> specified line length. (JIS Z 8125) (Search for "Line adjustment by hanging
> punctuation" under https://www.w3.org/TR/jlreq/ )
> If they're in the last position of the line, they stay where they are. The
> correct behaviour can be seen in LibreOffice Writer in action.
>
> Rules 4, 5, ...:
>
> Combinations of inseparable characters... (see
> https://www.w3.org/TR/jlreq/#possibilities_for_linebreaking_between_character
> ) and eventually more, which I didn't test.
>
> It might be useful to define three scripts nihongo_loose, nihongo_strict
> and nihongo_very_strict which each implement one of the 3 cases described
> here: https://www.w3.org/TR/jlreq/#addendum_a
>
> According the *line gap* (Otared uses \setupwhitespace[big], which is
> exceeding common line gaps), I'd like to quote from
> https://www.w3.org/TR/jlreq/ :
>
> *It is common that the line gap for the kihon-hanmen is set to a value
> between half-em spacing and the one em spacing of the character frame used
> for the kihon-hanmen. Half-em spacing can be chosen in cases where the line
> length is short, but one em spacing or close to it is more appropriate when
> the line length is longer than 35 characters.*
>
> I like the standard line gap which is provided by ConTeXt, which is
> equivalent to \setupwhitespace*[0pt]*. Even when using ruby, it works
> well. I found the best voffset for ruby to be -1.7ex.
>
> The *line adjustment* provided by ConTeXt by default is not meeting the
> needs for Japanese  (and Chinese) text, which follow a grid pattern.
> Especially the last line of a paragraph is squeezed, which is "hurting the
> eye".
>
> When characters need to jump to the next line due to previously discussed
> line breaking rules, ConTeXt seems to apply "Line adjustment by
> inter-character spacing expansion", which is a valid method according to
> https://www.w3.org/TR/jlreq/#line_adjustment , although "Line adjustment
> by inter-character spacing reduction" is preferred.
>
> The last point which ConTeXt is missing, when talking about Japanese
> typesetting, is vertical writing.
>
> I know, this is a lot of work. Hopefully we can achieve with joint efforts
> to make ConTeXt Japanese ready.
>
> If I happen to have made false statements, please accept my apology. I
> tried to be of help as far as I could. I grew up in Japan and know more or
> less how typeset text should look like.
>
> Emanuel
>
>
It would be nice if you can put your notes above into
https://wiki.contextgarden.net/Chinese_Japanese_and_Korean
or in general improve/maintain that page
(e.g. the links about the fonts are broken at the moment)
Perhaps with Jeong Dal ?
Just to say, a few days ago I have seen
https://ken-lunde.medium.com/genuine-han-unification-redux-3912b561ecae
(only webp images, so a bit tricky to make a pdf)

--
luigi