Re: [css-color] more detailed proposal for "compositing-space"

On Fri, Mar 25, 2016 at 8:21 AM, Simon Fraser <smfr@me.com> wrote:

> On Mar 23, 2016, at 10:45 pm, Rik Cabanier <cabanier@gmail.com> wrote:
>
> On Tue, Mar 22, 2016 at 10:15 PM, Florian Rivoal <florian@rivoal.net>
> wrote:
>
>>
>> On Mar 23, 2016, at 12:58, Rik Cabanier <cabanier@gmail.com> wrote:
>>
>> All,
>>
>> here is a more detailed proposal for the compositing-space CSS property.
>>
>> * compositing-space is a non-inherited property that creates a stacking
>> context if a color space is specified.
>>
>> * It takes the current values:
>> - "default": the default value which doesn't create a new space
>> - "uncalibrated": composite in the color space of the output device
>> - "sRGB"/"P3"/"BT.2020": composite in the specified standard color space
>> then map to the output device
>> - "url(path.to.a.icc.profile)": composite with the supplied profile ,
>> then map to the output space
>>
>> * The root element has a value of "uncalibrated" by default.
>>
>> * The value is not animatable
>>
>> * Applies to all elements. In SVG, it applies to container elements,
>> graphics elements and graphics referencing elements
>>
>>
>> I agree about the overall idea, syntax, and choice of the default value
>> in general and on the root element.
>>
>
> Thanks for the feedback. I agree with all of your points.
>
>
>> For the url notation, I think you should be able to point to an icc
>> profile or to an image with an embedded profile. Or preferably, we add a
>> layer of indirection, and icc profiles or images with embedded profiles can
>> be turned into named color spaces that can be used by this property using
>> @color-profile.
>>
>> Also, I hope we can make it so that "composite in the .... color space"
>> means not only compositing and blending, but any kind of color math,
>> including for example gradients.
>>
>
> Yes. it should apply to everything.
>
>
>> I would add "CIELab" to the list of predefined names. As discussed
>> elsewhere, composition/color math in that space gives pretty results, and
>> even if that's subjective, using CIELab as a working space is a thing that
>> exists and is sometime desired, and that would be the natural way to ask
>> for it.
>>
>
>  After getting feedback, I agree it's a reasonable option.
> I worry that the implementation cost is too high and the feature too
> advanced for most users.
>
>
> This is true. For WebKit we don’t have control over the colorspace in
> which compositing takes place. This proposal just isn’t readily
> implementable.
>

Since Apple controls the operating system, your rendering engineers could
implement it so you can take advantage of it :-)