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Re: [css3-background]Positioning of box-shadow blurs?

From: fantasai <fantasai.lists@inkedblade.net>
Date: Tue, 04 May 2010 18:13:47 -0700
Message-ID: <4BE0C64B.4040709@inkedblade.net>
To: Brad Kemper <brad.kemper@gmail.com>
CC: Brian Manthos <brianman@microsoft.com>, "Tab Atkins Jr." <jackalmage@gmail.com>, Alex Meiburg <timeroot.alex@gmail.com>, "www-style@w3.org" <www-style@w3.org>
On 04/29/2010 10:39 AM, Brad Kemper wrote:
>
> Oh yeah. How about this:
>
> # The third length is a blur radius. Negative values are not allowed. The
> blurring region should be an area the width of this value, running along and
> centered on the edge of the shadow shape (a shape that otherwise mimics
> the shape of the border box, including any border-radius, absent the
> application of spread radius).  The shadow should should transition from
> the shadow color on the inner edge of this region, to transparent at the
> outer edge of this region. If the blur radius is 0, the shadow has a sharp
> edge, otherwise the larger the value, the more the edge of the shadow is
> blurred.  The exact algorithm is not specified.
>
> #The fourth length is a spread radius. Positive values cause the shadow
> to grow in all directions by the specified radius. Negative values cause
> the shadow to shrink. The shadow should not change shape when a
> spread radius is applied: sharp corners should remain sharp ***prior to the
> application of blur radius***.

Ok, here's my attempt at integrating the various bits of feedback on Brad's
proposed text. :) Let me know what you think.

   | The third length is a blur radius. Negative values are not
   | allowed. The blur radius is perpendicular to and centered on the
   | shadow's edge and defines a gradient color transition ranging from
   | the full shadow color at the radius endpoint inside the shadow to
   | fully transparent at the endpoint outside it: if the blur radius
   | is 0, the shadow's edge is sharp, otherwise the larger the value,
   | the more the shadow is blurred. The exact algorithm for the blur
   | transition is not specified.
   | ...
   | If both a blur radius and a spread radius are defined, the blur
   | is applied to the resulting shape after the spread is applied.

How's that?

~fantasai
Received on Wednesday, 5 May 2010 01:14:22 GMT

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