Re: [css-compositing][css4-backgrounds] Updated to the blending and compositing

On Sun, Dec 16, 2012 at 9:44 PM, Dirk Schulze <dschulze@adobe.com> wrote:

> +www-style
>
> On Dec 16, 2012, at 8:05 PM, "Rik Cabanier" <cabanier@gmail.com> wrote:
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> On Fri, Dec 14, 2012 at 10:13 AM, Dirk Schulze <dschulze@adobe.com> wrote:
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>>
>> On Dec 11, 2012, at 3:34 PM, Rik Cabanier <cabanier@gmail.com> wrote:
>>
>> >
>> >
>> > On Tue, Dec 11, 2012 at 2:48 PM, Lea Verou <lea@w3.org> wrote:
>> > On Dec 12, 2012, at 00:40, Rik Cabanier wrote:
>> >
>> >> Hi Lea,
>> >>
>> >> thanks for the clarification!
>> >>
>> >> I don't particularly like that this forces you to always specify what
>> part of the element you want to blend.
>> >> Most likely, 99% of blending will just target the element and now
>> those users will have to write either 2 css properties or put 'element' in
>> the shorthand.
>> >
>> > It doesn’t :) `element` would just be the initial value for
>> `mix-blend-area`, just like `normal` is for `mix-blend-mode`. I guess I
>> should’ve mentioned that, but I assumed it was obvious. Mea culpa. :)
>> >
>> > Ah! That makes sense.
>>
>> This wouldn't make it possible to blend at least multiple background
>> images, right? This would be an interesting use case IMO (e.g water mark
>> with a logo).
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>
> I agree that it would be very useful (and probably easy to implement).
> However, I think that one should be in backgrounds and borders with a
> reference to the blending spec.
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> The first questions should be if and how.
>

There is a level 4 draft: http://dev.w3.org/csswg/css4-background/
I'm unsure of its state so I can't tell if blending and compositing in the
background is something that the editors want to tackle.

FYI Compositing has already been implemented in Webkit for several years
with the webkit-background-composite property.



>
> Rik
>
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>>  >
>> >
>> >>
>> >> How about we drop the '-area' property and assume in the shorthand
>> that no area means that that blend should apply to the whole element?
>> >> So your case becomes:
>> >> mix-blend: screen, multiply box-shadow, multiply text-shadow;
>> >
>> > Sounds like what I’m saying, without the longhands. The benefit of
>> having the longhands is potential shorter code when you want the same
>> blending mode to apply to multiple areas (check my example) and individual
>> setting of the two components (area and blending mode), both of which are
>> relatively rare I guess. The downside is more properties. No strong
>> opinions here...
>> >
>> > Yes, I don't think that it's very common to have the same blend mode on
>> all the elements.
>> > I believe that we're in agreement here and will update the spec
>> accordingly unless someone voices an objection.
>> >
>> > Rik
>> >
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>>
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