(Moderator: jchaffraix, Scribe: dpranke)

(Notes in progress)

How can we get more people hacking on rendering?

• accelerated compositing is tied to a layer (a very old concept)
  • can we make layers better or faster?

• can we talk about security and the impact of specific design decisions in the render tree (inferno, bethdakin?)

• jchaffraix: from study tables, thinks layers are the wrong abstraction
  • as a general rule, the render object knows what its own structure should be
    • because layers are generic, they don't know and have to do more work
    • they do too much
      • repainting
      • clipping
      • compositing
      • stacking
      • scrolling

• eseidel: layers are designed to allow the rendering tree to be lightweight
  • layers exist to handle the more "advanced" features of rendering
  • smfr: layers designed to solve problems like scrolling and clipping that affect a set of render objects in one go

• eseidel: what are the problems we're trying to solve?
  • (??) need render layers to support z-index (for svg 2.0 and z-stacking not in document order)
  • jamesr: we want to composited into svg
  • enne: rendering / layers are hard to test
  • dave barton: mathml is very painful - math layout is bottom-up from the children of the node, not top-down left-to-right on the page
  • jamesr / jchaffraix: tables are very similar
  • eseidel: if you call setNeedsLayout(False), you should be able to do whatever you want inside your own elements
    • jchaffraix: this means we don't reuse other code
    • eseidel: there are other layout models other than the renderboxmodel
    • eseidel: also there's computePreferredWidths()
    • dave barton: this is kinda what he does in mathml
    • jamesr: maybe mathml shouldn't be deriving from renderboxmodelobject?
    • dave barton: but we do use a lot of it - maybe this is more a question about writing your own render object and should be in the other talk?