Re: [compositing-1] please move non-separable effects to Level 2

On Fri, Apr 18, 2014 at 3:56 AM, Robert O'Callahan <robert@ocallahan.org>wrote:

> On Fri, Apr 18, 2014 at 6:15 PM, Rik Cabanier <cabanier@gmail.com> wrote:
>
>> How do you feel about making the non-sep blend modes optional for now?
>>  I can see Dean's view of wanting to support the whole spec so WebKit
>> doesn't get called out for only supporting a subset.
>>
>
> Is that really what Dean is concerned about? I did not think so.
>

>From Dean's email:

If they are not moved, we’ll probably put the prefix back on, because *we
don’t want to ship a non-prefixed incorrect implementation.*


It's clear at this point that the CSS Blending spec will need to change.
The spec is in CR and we have feedback from a browser vendor that they
can't implement certain features because of a technical reason. Having a
spec that is interoperable is (to me at least) more important than one that
is more complete but only partly implemented.
Either the subset is removed, or it is made optional.

For level 2 of the spec, I will put the non-sep blend modes back in, likely
alongside the missing Photoshop blend modes.

If it's any consolation, these blend modes are not that popular (Adobe
never bothered to support them for CMYK or spot colors) and one of them can
be approximated with a luminosity mask