On Jan 6, 2011, at 3:48 PM, Rik Cabanier wrote:
> It looks like people want Adobe PDF/Flash style blending in addition to filters. J
> It would be great if we could even add blending to the HTML imaging model. PDF style blending is probably overkill but Flash style should be sufficient.
> (ps filters and blending are very different concepts. I think it will be a lot harder to implement blending than filters)
>
> Adobe has ample documentation and knowledge about this so we can certainly help out here.
Applying blend modes that require reading the destination pixels imposes severe constraints on the rendering model used by the browsers, and I think we should, initially at least, stay away from graphical operations that require reading the destination pixels.
The rendering pipeline used by modern browsers is now much more complex than simply drawing into a bitmap. They may use islands of OpenGL content, and other OS-supplied, GPU-based rendering frameworks to present parts of the content like video and plug-ins. Supporting blending in such an environment, while maintaining acceptable rendering performance may not be possible.
Simon