[css3-images] Order of color-stop fixup

Right now, the color-stop fixup rules are:

1. If the first and last color stops don't have a position, make them
0% and 100%.
2. If any color-stop is mis-ordered, shift it so it's not.
3. If any other color-stops don't have a position, evenly distribute them.

Our implementation experience showed that the ordering of #2 and #3
makes it slightly harder to do transitions of gradients.  We'd like to
do as much of the transition on specified values as possible, and
defer computations that need layout information until the very end.
As such, Shane (new CSSWG member, dude who's doing the experimenting
with gradient transitions) suggested I swap steps 2 and 3, and further
make transitions operate *before* step 3, so the fixup is really a
super-final step done *just* before image generation.

Separately, Brian Mantheos brought up what I believe is the same
concern, where he'd prefer to do step 3 before step 2.

I don't have a preference either way.  Both produce smooth
transitions, they just result in slightly different positions for
auto-placed color-stops sometimes.

Does anyone have objections to me swapping these two steps?

~TJ

Received on Thursday, 11 August 2011 23:11:27 UTC