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Re: [CSS4 color][CSS4 transition] color pre-multiplied vs non pre-multiplied

From: Alan Gresley <alan@css-class.com>
Date: Fri, 01 Feb 2013 16:28:48 +1100
Message-ID: <510B5290.20300@css-class.com>
To: Rik Cabanier <cabanier@gmail.com>
CC: fantasai <fantasai.lists@inkedblade.net>, "www-style@w3.org" <www-style@w3.org>
On 1/02/2013 3:48 PM, Rik Cabanier wrote:
> On Thu, Jan 31, 2013 at 8:31 PM, Alan Gresley <alan@css-class.com> wrote:
>
>> On 1/02/2013 2:25 PM, Rik Cabanier wrote:
>>
>>> So, can we fix the spec?
>>>
>>
>> Yes. Changing the part here [1] regarding example 23 and the second note
>> that discusses premultiplied color space.
>>
>> Giving an example of how to create a gradient from color to
>> transparent-color like so:
>>
>>    linear-gradient(red, rgba(255,0,0,0))
>>
>>    linear-gradient(red, rgba(255,0,0,0) 50%, rgba(0,0,255,0) 50%, blue)
>>
>>
>> Possibly consider a new way to trigger transparent-color:
>>
>>    linear-gradient(red, pre-transparent)
>>
>>    linear-gradient(red, pre-transparent, blue)
>>
>>
>>   I volunteer to fix the implementation in FF and WK.
>>>
>>
>>
>> What would you fix in FF and what is WK?
>>
>
> FF = mozilla :-)
> WK = WebKit
>
> I would fix that transparent has a special meaning (meaning a transparent
> version of the previous and next stop color)

Well then there is nothing to fix in regards to those implementations. 
FF (with prefix and un-prefixed) and WebKit all show gradients in non 
pre-multiplied colorspace [1] (check in both Chrome and Safari). It's 
Opera and IE10 that does different.

It is the spec that needs to be changed.


Regarding transitioning, I happy for the ship to have sailed.


1. http://css-class.com/test/temp/color-transparent.htm


-- 
Alan Gresley
http://css-3d.org/
http://css-class.com/
Received on Friday, 1 February 2013 05:29:20 GMT

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