[css-values-4][css-writing-modes-4] Revisit decision to use 永 instead of 水 as the ic unit

[ziyunfei]

Chrome just implemented the ic unit this week, when I shared this news in Chinese social media, some people are confused about the chosen character 水(water), especially those people who had the handwriting practice experience, they think 永(forever; eternal) is the right choice.

See this Twitter thread: https://twitter.com/intenttoship/status/1555274307735285760

[tiye]

quote https://en.wikipedia.org/wiki/Eight_Principles_of_Yong

It was traditionally believed that the frequent practice of these principles as a beginning calligrapher could ensure beauty in one's writing.

[yisibl]

See #2798

[yisibl]

If CSSWG agrees to this change, I can amend the relevant specification and WPT.

[frivoal]

See #2798

In particular, this comment #2798 (comment) says:

Writing Modes uses 水 as well (used when scaling down the tate-chu-yoko to 1em). If switching to 永, I kinda want to see two specs refer to the same character.

[tabatkins]

And note also in #2798 that the reason we stuck with 水 rather than switching to 永 is solely because it would have been annoying to update Writing Modes, and in practice the two should be roughly identical in font coverage anyway.

But if people keep getting confused about it, it's probably worth going thru the effort of switching the character.

[ziyunfei]

Filed bugs:
https://bugzilla.mozilla.org/show_bug.cgi?id=1783937
https://crbug.com/1351509
https://bugs.webkit.org/show_bug.cgi?id=243746

[VaJoy]

Using 永 is the better choice cuz it is a standard of Asian calligraphy.

I promise almost every devloper in China, Japan, Korea would be confused while using 水 as the unit of ic so please switch to 永 to avoid this disaster.

[gongpeione]

IMO using 永 as the ic unit makes more sense in Chinese and also looks more professional.

[myakura]

Although I'm not strongly against about it, I don't think it's worth the change to the specs and implementations.

#7577 (comment)

and in practice the two should be roughly identical in font coverage anyway.

Speaking of font coverage, they are not the same in web fonts. I don't know how things are going on in #3135 , but if ic requires implementations to download the font, then 永 (U+6C38) has higher chance to cause extra font download compared to 水 (U+6C34):

• In Noto Sans Japanese, 水 (U+6C34) is placed in the 5th most used characters bucket, whereas 永 (U+6C38) is in the 22nd
• In Noto Sans Traditional Chinese, 水 is in the 2nd bucket, and 永 is in the 5th
• In Noto Sans Simplified Chinese, 水 is in the 3rd bucket, and 永 is in the 6th
• In Noto Sans Hong Kong, 水 is in the 2nd bucket, and 永 is in the 5th
• In Noto Sans Korean, 水 is in the 16th bucket, and 永 is in the 39th

[Naeemo]

IMO, using 永 would be a more natural choice.
I would be confused by 水 and try to find out why, but not with 永. 永 is the first thing to practice for properly Chinese handwriting cuz its structure, it's kind of common sense here.

[yisibl]

In fact, the 永 is used in CSS Inline L3. It should also be modified to be consistent from the point of view of consistency of the specification.

The bounding box of 永 (U+6C38) can be used to find the ideographic character face edges.
https://drafts.csswg.org/css-inline-3/#baseline-synthesis-fonts

[foolip]

Is the issue here the belief that 水 was picked by accident because someone conflated it with 永?

@fantasai disconfirmed that in https://twitter.com/fantasai/status/1555385335663759360, and I wonder if the same issue would be raised if the chosen character was instead 口 or something.

I'm not a member of the CSSWG, but the fact that 永 is a kind of reference character in calligraphy doesn't by itself make it a good choice for the ic unit. The kind of analysis that @myakura did in #7577 (comment) seems like a better ground for this kind of decision.

[yisibl]

@myakura @foolip

I'm sorry, but I don't endorse the reasons related to font slicing in Google Web Fonts.

The same problem would exist in the ch unit, which should be proposed to Google Fonts to change to put the characters that are CSS units (0 or 永) further ahead.

I think #3135 about downloading fonts is a separate issue, not related to the proposal of this issue.

---

I'll reproduce Dr. Ken Lunde's(小林剣) suggestion from Twitter: https://twitter.com/ken_lunde/status/1555736774436986880

The reasons why U+6C38 永 is a near-ideal example in this context are because this ideograph 1) includes all of the basic stroke types; 2) is included in the most basic character set for each East Asian region; and 3) is rendered the same regardless of the East Asian region.