Re: [css-compositing] How do 'alpha-compositing' and 'blend-mode' interact?

On Sat, Jul 21, 2012 at 11:21 AM, Maciej Stachowiak <> wrote:

> How do 'alpha-compositing' and 'blend-mode' interact if you have set both?
> I was unable to determine this from the spec. Does it actually make sense
> to specify both to non-default values at the same time?

Yes, it does in certain use cases.
Say for instance, you have text that is blending with a video underneath,
but I also want the text to clip the video. (see for instance the Marvel
trailer :

> I was unable to understand what their relationship is supposed to be.
> Some other comments:
> - The property values for the 'alpha-compositing' operator are
> inconsistent with the values for HTML5 Canvas: <
> I suggest making them match if there is no compelling advantage to the new
> names, otherwise this will be needlessly confusing to authors.
> - Consider renaming 'alpha-compositing' to 'composite-operator' for
> similar reasons.
> Regards,
> Maciej

Received on Sunday, 22 July 2012 06:40:40 UTC