W3C

Last Call: Compositing and Blending Level 1

The CSS Working Group and the SVG Working Group have published a Last Call Working Draft of Compositing and Blending Level 1. Compositing describes how shapes of different elements are combined into a single image. Previous versions of SVG and CSS 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 defines a new compositing model that expands upon the Simple Alpha Compositing model by offering additional Porter Duff compositing operators; advanced blending modes which allow control of how colors mix in the areas where shapes overlap; and compositing groups. In addition, this specification defines CSS properties for blending and group isolation, and defines the ‘globalcompositeoperation’ as specified in HTML Canvas 2D Context, Level 2. Comments are welcome by 28 January 2014. Learn more about the Style Activity and the Graphics Activity.