Re: [css3-images] simplifying radial gradients

On Tuesday 2011-10-11 09:58 -0700, Tab Atkins Jr. wrote:
> On Mon, Oct 10, 2011 at 2:32 PM, Brad Kemper <brad.kemper@gmail.com> wrote:
> > On Oct 7, 2011, at 4:07 PM, "Tab Atkins Jr." <jackalmage@gmail.com> wrote:
> >> Most of the patterns in Lea's gallery don't use any sizing or
> >> positioning at all, only color-stops, and so are equally doable with
> >> either the current syntax or Brad's suggested change.  They would all
> >> need their color-stop positions divided by sqrt(2), though, as Brad's
> >> suggested default sizing behavior is "contain".
> >
> > IIRC, converting them is a matter of multiplying by 1.72 (or thereabouts).
> 
> 1.41, which is approximately sqrt(2).

Converting between 'contain' and 'cover' mathematically is only
possible for ellipse gradients; for 'circle' gradients there's no
single factor since the factor depends on the aspect ratio of the
box.

Unless we're also eliminating circle and making gradients
ellipse-only (where the ellipse is the shape that fits in the
background-size rectangle), I think we should keep 'contain' and
'cover'.  And I tend to think we should have circle gradients.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                           http://www.mozilla.org/   𝄂