Re: [css-compositing] Isolation groups

On Mon, 2013-12-09 at 09:40 -0800, Rik Cabanier wrote:
> 
> 
> 
> On Mon, Dec 9, 2013 at 6:07 AM, Tavmjong Bah <tavmjong@free.fr> wrote:
>         
>         Hi,
>         
>         I have a few questions about the spec:
>         
>         Section 3.3: I don't understand how blending creates an
>         isolation group.
>         If I set 'mix-mode-blend' on a circle and the circle gets
>         blended with
>         the background, what is the isolation group? An example would
>         really
>         help.
> 
> 
> there's an example in the section on
> isolation: http://dev.w3.org/fxtf/compositing-1/#isolationblending
> It is the circle that becomes the isolated group so if there's
> blending inside the content that has the blend-mode, it will be
> isolated to that content.

In the example, 'isolation' is a property of the group, correct?. What I
don't understand is how an SVG circle can have blending inside. It seems
to me that the 'isolation' property is not applicable to SVG graphics
elements (unless or until we allow graphics elements to contain other
elements... and maybe <text> which can wrap <tspan>s which could
overlap).


>         Example 4: It appears that the three circles are being blended
>         in one
>         isolation group and then put over the gray background. What is
>         causing
>         the circles to be isolated? If the SVG is referenced from an
>         <img> then
>         it should be isolated but if it is included inline then it
>         should not
>         be(?). If I try the SVG in Chrome the circles are never
>         isolated, no
>         matter what I do (stand-alone SVG, external SVG, inline). Is
>         this due to
>         a lack of isolation support in Chrome?
> 
> 
> Can you post your example online (codepen, jsfiddle)?
> There should be a difference since if you link them using <img>, the
> SVG should be rasterized.

See: http://tavmjong.free.fr/SVG/BLENDING/blending.html

Tav

Received on Tuesday, 10 December 2013 13:31:17 UTC