Re: [css compositing]

On Sat, 2013-10-19 at 14:12 -0700, Rik Cabanier wrote:
> Hi Tav,
> only section 2 and 3 are normative.
> The rest of the document describes what compositing and blending is in
> general terms.
> What makes you think it's meant to apply to SVG?

In the abstract it says:

"Previous versions of SVG used Simple Alpha Compositing. In this model,
each element is rendered into its own buffer and is then merged with its
backdrop using the Porter Duff source-over operator. This specification
will define a new compositing model that expands upon the Simple Alpha
Compositing model by offering:

  * additional Porter Duff compositing operators;"

I read this as to say that this specification will expand the previous
version of SVG (i.e. 1.1) to include additional compositing operators.
This abstract makes no sense if SVG is not getting the new compositing
operators. Why mention SVG at all? The SVG Compositing Specification
which is the origin of this specification did include the 'comp-op'


> On Sat, Oct 19, 2013 at 6:51 AM, Tavmjong Bah <>
> wrote:
>         I am a bit confused when reading the spec. As I read it, the
>         whole
>         discussion of Porter Duff Compositing Operators is irrelevant
>         for SVG,
>         only applying to Canvas. Is this correct? The Abstract would
>         lead one to
>         think otherwise.
>         Also, would it be usefule for the feComposite filter to
>         include all the
>         Porter Duff compositing operators?
> Apart from 'clear' (which could be done through other means), it seems
> like you can implement all PD operators with filters. Which one do you
> think is missing?

Received on Sunday, 20 October 2013 03:20:39 UTC