[webkit-dev] Using RenderLayer for transforms

[Eric Seidel]

Dave, Simon (and the larger community):

I've been looking at fixing:
https://bugs.webkit.org/show_bug.cgi?id=20769
https://bugs.webkit.org/show_bug.cgi?id=14015
in SVG.  A large part of the mis-match between SVG renderers and the
HTML/CSS rendering tree is the use of transforms.

In SVG, transforms (and clipping) are handled by the renderers
themselves.  the HTML/CSS rendering tree does not handle transforms,
and instead only rectilinear layout using parent-offsets.  Things
which require transforms get a RenderLayer and all the RenderObject
methods remain transform-ignorant.

Is this currently the long-term plan for transforms?  Or will HTML
also be moving to a transform aware rendering tree?

To fix these bugs I will need to sorta "hack" how things like outline
drawing are done, focus ring invalidation, and repaint rect
calculation to take transforms into account inside the renderers.

Thanks.

-eric