W3C home > Mailing lists > Public > www-style@w3.org > November 2009

Re: radial-gradient() proposal

From: Simon Fraser <smfr@me.com>
Date: Thu, 05 Nov 2009 08:41:32 -0800
Cc: Brendan Kenny <bckenny@gmail.com>, www-style list <www-style@w3.org>, "Tab Atkins Jr." <jackalmage@gmail.com>
Message-id: <928A5363-B158-4C2E-B847-934A9956E528@me.com>
To: Brad Kemper <brad.kemper@gmail.com>
On Nov 5, 2009, at 7:19 am, Brad Kemper wrote:

> On Nov 5, 2009, at 6:53 AM, Simon Fraser wrote:
>
>> I'd be OK dropping angles from linear gradients. You can always get  
>> a fixed
>> angle by specifying two points in pixel coordinates; what you lose  
>> is the ability
>> to have a fixed angle gradient that automatically fills the box.  
>> I'm not sure if this
>> would be a common use case.
>
> Sorry, but I could not disagree more. I'd say by far, specifying the  
> angle would be the easiest, easiest to read and understand, and most  
> common way to want to specify a linear gradient.

That may be true in image editors where you're generating fixed-size  
images. I'm not convinced it's so true for dynamic gradients on web  
pages.

> I personally loath the "4 offsets" way of specifying beginning and  
> ending endpoints, because it adds so much unneeded verbosity, and  
> decreases clarity and understanding.

It's two points, not four offsets, and those can be abbreviated  
according to background-position rules.

The "two point" method of creating gradients is also very familiar to  
designers from the gradient tool in apps like PhotoShop; it's exactly  
what you do when you drag out a line with the gradient tool.

> In practice, most blends (and I do mean almost all) will be either  
> from edge-to-edge (or corner-to-corner), or will start or end some  
> distance from one of those edges or corners in a way that can be  
> specified more clearly and succinctly in the stops.

Don't forget that CSS gradients are used for more than just background- 
image; they are a generic type of generated image that might be used  
in a lot of other places (list-image, border-image, as masks,  
potentially as inputs to filters). I don't want gradients to be so  
tied to background-image that it makes them impossible to use  
elsewhere, for example in places where background-position is not an  
option for adjusting the location of the gradient.

> I do not find anything even slightly confusing about using angles to  
> specify a linear angle in the way they've been diagrammed in  
> geometry classes since forever. I would find it completely counter- 
> intuitive to have 0deg or 90deg represent any other directions than  
> that for gradients. For rotations, I can appreciate both sides of  
> the argument, but if one really has to change I would prefer it to  
> be rotation to match gradients, and not the other way around.

I tried some apps to see what the convention is. The Adobe apps  
(PhotoShop, Illustrator) use the 90deg as "up" rule. In Omnigraffle  
90deg was "down". Does anyone else have other apps to try?

Simon
Received on Thursday, 5 November 2009 16:42:35 GMT

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