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Re: Linear gradients, Transforms and angles...

From: David Singer <singer@apple.com>
Date: Wed, 22 Sep 2010 16:36:20 -0700
Cc: Chris Marrin <cmarrin@apple.com>, Simon Fraser <smfr@me.com>, DanielGlazman <daniel.glazman@disruptive-innovations.com>, "L. DavidBaron" <dbaron@dbaron.org>, "Tab Atkins Jr." <jackalmage@gmail.com>, www-style list <www-style@w3.org>
Message-Id: <1887B3BE-B2F2-4781-91F9-59A1F15C512E@apple.com>
To: Brad Kemper <brad.kemper@gmail.com>

On Sep 22, 2010, at 13:20 , Brad Kemper wrote:
>> I think many people, if asked, "on a cartesian grid, what is the relationship between a vector along the Y-axis and a vector at 90 degrees?" would say that they are the same,
> 
> Really? I think most would look at you funny and say, "What the heck are you talking about? Speak English, man!" (well, maybe not most; maybe just English speakers would say that). Maybe if you were asking people in a math class or something...
> 
> 

>> and surprise might not be enough if told that the Y axis is at MINUS 90 degrees.  They may need astonishment.
>> 
>> David Singer
>> Multimedia and Software Standards, Apple Inc.
> 
> I've not heard of any astonishment from people setting gradient directions in Adobe products or in your own company's products (Pages, Keynote).



CSS is a language in which you express geometric concepts textually, not wysiwyg.  The idea that you can work in a language expressing geometric concepts without understanding geometry is odd, to say the least.  I could not find a way to ask Photoshop for a gradient at a specified angle (it seems you always click and drag), but the sample preset gradients in the drop-down are actually at 45 -- from top left to bottom right.  These programs are all wysiswyg and the user doesn't have to program in a coordinate system, so the CSS consistency issue does not arise.

I think users want rotations (transforms) and gradients to be consistent -- that two, at 45, go the same way.  They want to learn one, well-defined, coordinate space, not have to remember that there are two somewhat intuitive, but different, conventions at work depending on what they are working with.

> 

David Singer
Multimedia and Software Standards, Apple Inc.
Received on Wednesday, 22 September 2010 23:37:26 GMT

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