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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 UTC

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