[css3-animations] What if different keyframes have different sets of properties?

I can't find anything in http://dev.w3.org/csswg/css3-animations/
that says what to do when different keyframes have different sets of
properties.  For example, how would an implementation handle:
  # @keyframes one {
  #   from { top: 100px; left: 100px; }
  #   50%  { top: 200px; left: 125px; }
  #   to   { top: 100px; }
  # }
What happens to 'left' once the animation is more than 50% complete?
Does left animate at all in this animation?  Whatever the spec says
about this, it's also worth considering how it interacts with the
statement in the "Animation behavior" section:
  # In the case of multiple animations specifying behavior for the
  # same property, the animation defined last will override the
  # previously defined animations. 

Furthermore, is it even allowed to do something like this:
  # @keyframes one {
  #   from { top: 100px; left: 100px; }
  #   50%  { top: 200px; }
  #   to   { top: 100px; left: 300px; }
  # }
It seems relatively obvious how one *could* handle this, but I'd
have no idea how 'left' would animate in this case:
  # @keyframes one {
  #   from { top: 100px; left: 100px; animation-timing-function: ease-out; }
  #   50%  { top: 200px;              animation-timing-function: ease-in; }
  #   to   { top: 100px; left: 300px; }
  # }

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/

Received on Thursday, 17 December 2009 21:18:58 UTC