W3C home > Mailing lists > Public > www-style@w3.org > September 2010

Re: Linear gradients, Transforms and angles...

From: Brad Kemper <brad.kemper@gmail.com>
Date: Mon, 20 Sep 2010 19:29:42 -0700
Message-Id: <704F232B-4EBC-4381-B445-9FC7B7B6F896@gmail.com>
Cc: Simon Fraser <smfr@me.com>, Daniel Glazman <daniel.glazman@disruptive-innovations.com>, "L. DavidBaron" <dbaron@dbaron.org>, "Tab Atkins Jr." <jackalmage@gmail.com>, www-style list <www-style@w3.org>
To: Chris Marrin <cmarrin@apple.com>


On Sep 20, 2010, at 2:01 PM, Chris Marrin <cmarrin@apple.com> wrote:

>> This author's expectations are that 90deg should be upward for a linear direction specified in degrees. All my prior experience in life before learning how programmers think reinforce that expectation. 
> 
> Angle is a concept that I believe is fairly new to CSS, so I don't think there is much of a precedent here.

Yes, but there is an long-time, pre-CSS precedent for specifying linear directions in the manner printed on traditional protractors. 

> Using the math we are using in CSS transforms,

[...]

>  means positive rotation angles go clockwise.
> 
>    -webkit-transform: rotate(10deg)
> 
> results in a clockwise rotation of the element to which it is applied. This is true in both WebKit and Firefox

That's fine. My point is that designers do not think of a linear direction as being the same as a rotation. At least I don't. So something that is entirely sensible for specifying an amount of rotation (an amount of turning in a circular direction) is not necessarily appropriate or relevant to specifying a straight, linear direction. To me it is counter-intuitive to do so, as it confuses two entirely different types of direction. 

When I walk north, I do not think of myself as pointing a default of east and then turning -90 degrees before starting forward. I just walk straight in the direction I want to go. 
Received on Tuesday, 21 September 2010 02:30:26 GMT

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