Re: [csswg-drafts] [css-color-4] Device-independent color definitions (#8065)

Yes, recent edits were driven by the early clamping discussion in #7677 but as you note, impact this issue as well.

> So, just to clarify, is the following true?
* `lab(-10 0 0)` should serialize to `lab(0 0 0)`
* `lab(110 0 0)` should serialize to `lab(100 0 0)`

Yes. From [Specifying Lab and LCH: the `lab()` and `lch()` functional notations](https://drafts.csswg.org/css-color-4/#specifying-lab-lch)

>> Values less than 0% or 0 must be clamped to 0% at parsed-value time; values greater than 100% or 100 are clamped to 100% at parsed-value time.

> And how does hue serialize? Does it use number or degree? Is it clamped to 0..360?
How should lch(-10% -10% 360deg) serialize?

From [Representing Cylindrical-coordinate Hues: the `<hue>` syntax](https://drafts.csswg.org/css-color-4/#hue-syntax):

>> Because this value is so often given in degrees, the argument can also be given as a number, which is interpreted as a number of degrees and is the [canonical unit](https://drafts.csswg.org/css-values-4/#canonical-unit).

>> This number is normalized to the range [0,360].

So `<hue>` serializes as number (of degrees), which follows on from the  [CSSWG resolution on color components in Color 5](https://github.com/w3c/csswg-drafts/issues/7876#issuecomment-1379264467) which also went with number. 

I'm actually unclear whether this should be [0, 360) which seems better but I saw some use of [0, 360] in other threads so cautiosly went with that. But now we removed the `specified` option from [Hue Interpolation](https://drafts.csswg.org/css-color-4/#hue-interpolation) I think [0, 360) makes more sense and preserves the 1:1 colorimetric identity between different syntactic forms.

-- 
GitHub Notification of comment by svgeesus
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/8065#issuecomment-1398485995 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Friday, 20 January 2023 14:42:09 UTC