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Re: [css3-background] vastly different takes on "blur"

From: Simon Fraser <smfr@me.com>
Date: Mon, 21 Jun 2010 21:33:57 -0700
Cc: fantasai <fantasai.lists@inkedblade.net>, Brian Manthos <brianman@microsoft.com>, "www-style@w3.org" <www-style@w3.org>
Message-id: <DB8E1BA2-0155-4972-B5FC-B03567D1AB5E@me.com>
To: Brad Kemper <brad.kemper@gmail.com>
On Jun 21, 2010, at 5:55 pm, Brad Kemper wrote:

> On Jun 21, 2010, at 3:48 PM, fantasai <fantasai.lists@inkedblade.net> wrote:
> 
>> FWIW, I agree with Tab and Simon; it makes more sense to me for the
>> blur value to define the increase in the shadow's size, just like
>> spread.
> 
> I'm just blown away. Absolutely blown away. I can't believe it is even controversial. That we should have a distance measurement for setting an amount of blur, and then we end up with an overall blur width that is twice that distance instead of the distance typed... Words fail me for politely describing how screwed up that is.
> 
> I liken it to PostScript, where a border is drawn down the center of a path: half inside, and half outside. Sure, you may be interested in knowing how much wider that border is going to make your box, but at the end of the day, if you ask for a 19 point border, you get get a 19 point border, not a 38 point border. You don't have to specify 8.5 points to get a 19 point border. Because it is a border you are setting in PostScript, not a distance that the border extends the box width on one side.
> 
> Spread is different. The only noticeable result of spread is the growth of the shadow. The most noticeable result of blur is how much blurrier it became.
> 
> Unbelievable.

If I go into PhotoShop, and add a Drop Shadow effect to an object, setting the spread to 0, and the size to 100, then the shadow projects outside the object by about 100px. This is what Tab, fantasai and I are suggesting that we match.

Is that so wrong?

Simon
Received on Tuesday, 22 June 2010 04:35:15 GMT

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