Re: [css-compositing] blending in canvas

Hi Jeremie,

thanks for your feedback. It's good to hear from authors!

option 2 is not really a change for existing code.
All it does is define a new property for blending, which is new.

On Thu, Nov 15, 2012 at 2:49 PM, Jeremie Patonnier <
jeremie.patonnier@gmail.com> wrote:

> Hi,
>
> As an author (who's not really aware of compositing and blending
> subtleties), I wish you to avoid 2 and 3. 2 is a change in a well known
> API... it will be confusing and will require again to have polyfills to
> deal with implementation inconsistency, please, spare us that.


option 2 is not really a change for existing code.
All it does is define a new property for blending, which is new.


> 3 is a bit the same... we will have to learn two different way of doing
> the same thing, please, things are hard enough :)
>

I agree


>
> That said, I don't have any opinion between 1 and 4 Except that Canvas is
> out there where CSS B&C is not, so... maybe it worth having CSS to follow
> Canvas.
>
> 2012/11/15 Rik Cabanier <cabanier@gmail.com>
>
>> Maciej still objects because he feels that this is a substantial
>> difference between CSS and Canvas.
>>
>> I think we have a couple of choices:
>> 1. Keep globalCompositeOperator for blending and compositing but
>> collapses the 2 CSS properties into one that takes the same arguments as
>> globalCompositeOperator
>> 2. Keep the 2 CSS properties but split the Canvas properties into
>> globalCompositeOperator and globalBlendOperator
>> 3. Don't change anything and live with them being different.
>> 4. Don't change anything but also define a new CSS shorthand that
>> combines blending and compositing. Canvas is compatible with this shorthand.
>>
>> I'm unsure what approach we should take.
>> option 2 has the issue that we can't implement this correctly in the near
>> term.
>> option 1 has the issue that transitionable blending will be more
>> confusing in the future.
>> option 4 should cover all concerns but introduces yet another keyword.
>>
>> Any comments?
>>
>>  Rik
>>
>> On Wed, Nov 14, 2012 at 11:10 AM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:
>>
>>> On Wed, Nov 14, 2012 at 10:48 AM, Rik Cabanier <cabanier@gmail.com>
>>> wrote:
>>> > Good point!
>>> >
>>> > They are just strings, so we can later define it so you can say:
>>> > mycontext.globalCompositeOperator = "multiply,source-atop"
>>>
>>> I'd use a space-separated pair, but otherwise, yes.  ^_^
>>>
>>> ~TJ
>>>
>>
>>
>
>
> --
> Jeremie
> .............................
> Web : http://jeremie.patonnier.net
> Twitter : @JeremiePat <http://twitter.com/JeremiePat>
>