Re: [css-images] Negative implications of linear gradient color space choice in CSS

On Tue, Jan 26, 2016 at 10:48 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
> On Mon, Jan 25, 2016 at 3:29 PM, Xidorn Quan <quanxunzhen@gmail.com> wrote:
>> On Tue, Jan 26, 2016 at 6:22 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
>>> On Mon, Jan 25, 2016 at 11:17 AM, Rik Cabanier <cabanier@gmail.com> wrote:
>>>> On Mon, Jan 25, 2016 at 10:58 AM, Tab Atkins Jr. <jackalmage@gmail.com>
>>>> wrote:
>>>>> On Mon, Jan 25, 2016 at 10:53 AM, Rik Cabanier <cabanier@gmail.com> wrote:
>>>>> > Are you worried about the computed value of the 'transparent' keyword in
>>>>> > the
>>>>> > gradient? If so, that one doesn't resolve to an rgba color.
>>>>>
>>>>> Sure it does.  (Or it should be doing so, for consistency - colors
>>>>> should be computed in computed values.)
>>>>
>>>> It does not. I tried Edge, Safari 9, latest Chrome and Firefox.
>>>
>>> Then that's a bug, either in the specs or the implementations.  There
>>> is absolutely no reason a color should serialize differently based on
>>> whether it's bare or wrapped in a gradient function.
>>
>> Given all impls current agree with the same behavior here, I guess we
>> can probably make 'transparent' a keyword value in gradient function
>> to simulate premultiplied effect, and revert the general cases to
>> non-premultiplied...
>
> If and only if there's not a significant number of gradients out there
> that currently write out transparent with rgba() syntax, or that use
> near-transparent colors that'll significant change behavior here.

Yeah, sure. This needs to be proven first before any spec change on this.

> And we (Blink) must store the input string somewhere so we can output
> it back literally, because I *know* that we parse that into an
> #AARRGGBB 4-byte int and operate on it like that.  So it doesn't
> matter whether you type "transparent" or "rgba(0,0,0,0)", you get
> 0x00000000 either way.

It seems Gecko does so as well. But we already have an additional bit
for interpolation hint, so I guess we are not very concerned about
adding another bit for transparent keyword if the spec changes that
way.

- Xidorn

Received on Tuesday, 26 January 2016 00:09:15 UTC