- From: Brad Kemper <brad.kemper@gmail.com>
- Date: Wed, 4 Nov 2009 22:17:11 -0800
- To: Simon Fraser <smfr@me.com>
- Cc: www-style list <www-style@w3.org>, "Tab Atkins Jr." <jackalmage@gmail.com>, Brendan Kenny <bckenny@gmail.com>
- Message-Id: <AA30F294-C8C8-4E2F-B473-0779269C564F@gmail.com>
[cc'ing my reply to whole list, assuming you meant to do the same...] I think that clockwise rotation makes total sense when actually rotating something, instead of indicating a linear direction. But for linear directions, I think that there is not really anything that is turning. Thus using .25turn instead of 90deg for a linear-gradient direction feels a little unnatural to me (even though it means the same to CSS), because nothing is turning aside from a point of reference. For just indication a straight direction, the protractor directions seem most intuitive. Like this (showing degrees and radians, and with 0 going to the right, and 90 going straight up): http://en.wikipedia.org/wiki/File:Degree-Radian_Conversion.svg Here is a Java applet from a math site, which shows directional arrows, and the resulting angles: http://www.mathopenref.com/degrees.html On Nov 4, 2009, at 7:51 PM, Simon Fraser wrote: > Unfortunately this gives angles which are backwards from transforms > (where positive angles result in clockwise rotation). > > Simon > > On Nov 4, 2009, at 6:34 pm, Brad Kemper wrote: > >> It would if it were degrees of clockwise rotation, instead of just >> indicating a linear direction. There is nothing turning here, just >> an angle to indicate a straight direction. In geometry convention, >> 90 degrees as a linear direction is straight up. >> >> On Nov 4, 2009, at 6:14 PM, Brendan Kenny <bckenny@gmail.com> wrote: >> >>> Wouldn't 90 degrees point straight down, since +y points down? >>> >>> On Wed, Nov 4, 2009 at 8:05 PM, Brad Kemper >>> <brad.kemper@gmail.com> wrote: >>>> >>>> On Nov 4, 2009, at 5:41 PM, Simon Fraser <smfr@me.com> wrote: >>>> >>>>> 0deg being up (I think; the current proposal doesn't say), >>>> >>>> 0deg is left-to-right. Like on a protractor, where 0 points to >>>> the right, >>>> 180 points to the left, and 90 points straight up. >>>> >
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Received on Thursday, 5 November 2009 06:17:55 UTC