Re: radial-gradient() proposal

On Fri, Nov 6, 2009 at 5:06 PM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
> On Fri, Nov 6, 2009 at 2:57 PM, Brendan Kenny <bckenny@gmail.com> wrote:
>> I sketched a quick diagram that might help (with apologies for the lengthy url)
>>
>> http://lh6.ggpht.com/_K6wA3xN79Qs/SvSmsPplRKI/AAAAAAAAAcc/QtG6Jt4I-ys/s800/gradient-angle.png
>
> If anyone was unclear on exactly what my "starting-point is the point
> on the gradient-line where a line drawn perpendicular..." language
> meant, there you go.
>
> (Mind if I steal that image?  It may be useful to put into the spec,
> since it illustrates *precisely* the language I'm using.)

Please do. Let me know if I can make a change or if you want the
original illustrator file.

>
>> Note that this is the default behavior for Illustrator gradients when
>> an angle is given but not end points: it assumes you want to
>> completely fill the selected shape and that the color stops at 0 and
>> 100% should occur at the last pixels possible. That behavior is
>> equivalent to Tab's recommendation for the <angle> parameter, as long
>> as no background position is specified, and what I think one would
>> expect if just an angle was specified (ignoring for now the formula
>> for specifying how to select a "starting" corner based on the angle).
>
> Well, the default corner would be pretty much in all cases what you'd
> select with that type of behavior.
>
>> Incidentally, if you change the Illustrator artboard to have its
>> origin in the top left and have y increase downwards, selecting a
>> linear gradient with angle 60 degrees puts the 100% colorstop 60
>> degrees clockwise from 0 degrees, exactly as you'd expect if you think
>> of the angle as rotating a direction arrow in screen space. For what
>> that's worth.
>
> I'm beginning a survey now, and we'll be expanding it this weekend, to
> see what makes the most sense for people.  No sense arguing when we
> can get hard data.  ^_^  So moratorium on discussing angles?
>

Probably a great idea =]