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[whatwg] Canvas gradients color interpolation - change to premultiplied?

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Sun, 28 Nov 2010 10:04:06 -0800
Message-ID: <AANLkTikTKcJRV-JYJGaD+bidKQB2S936NW4Nq_e7A4AU@mail.gmail.com>
On Fri, Nov 26, 2010 at 8:44 PM, Boris Zbarsky <bzbarsky at mit.edu> wrote:
> On 11/26/10 11:39 PM, Simon Fraser wrote:
>>>
>>> But CSS gradients are already requiring interpolation in premutiplied
>>> space, right?
>>
>> I think you're thinking of CSS Transitions, which we decided should run in
>> premultiplied.
>
> No. ?http://dev.w3.org/csswg/css3-images/#color-stop-syntax currently says:
>
> ?Between two color-stops, the line's color is linearly interpolated
> ?between the colors of the two color-stops, with the interpolation
> ?taking place in premultiplied RGBA space.
>
> and there was related discussion on www-style, iirc.

Note, though, that that's a relatively recent change that I made based
on dbaron's feedback.  That said, in the thread where I made the
change, Simon expressed that he'd like Transitions and Gradients to
work the same way, and I read him as preferring premultiplied.

~TJ
Received on Sunday, 28 November 2010 10:04:06 UTC

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