[cairo] CSS/SVG filter effects

[Robert O'Callahan]

CSS3 and SVG support group composition effects of the following form:
1) Render an element and all its children into a temporary buffer (with 
alpha channel)
2) Use some effect to combine the temporary buffer into the canvas 
(e.g., translucent blending or Gaussian blur)

Currently it appears that the temporary buffer should be an image 
surface and we have to figure out a size and resolution for it. Correct?

A related question: many of these effects are convolutions of some 
matrix with the image data. Will hardware accelerated convolution be 
exposed through Cairo? Or will we have to dig into Glitz to get that?

Rob

-- 
Robert O'Callahan <robert at ocallahan.org>
"In the beginning was the Word, and the Word was with God, and the Word
was God. ... The Word became flesh and made his dwelling among us. We
have seen his glory, the glory of the One and Only, who came from the
Father, full of grace and truth." 1 John 1:1,14