- From: Chris Lilley <chris@w3.org>
- Date: Mon, 7 Feb 2011 18:06:21 +0100
- To: Simon Fraser <smfr@me.com>
- CC: Vynce Montgomery <vynce.montgomery@gmail.com>, www-style@w3.org
On Monday, February 7, 2011, 5:54:30 PM, Simon wrote: SF> On Jan 18, 2011, at 6:51 pm, Vynce Montgomery wrote: >> I dunno what you guys are doing with transform >> (a) please make rotate() positive for counter-clockwise, as it is in >> mathematics. This is the opposite of what the (not yet standardized) >> prototypes in webkit, mozilla, and opera do, but it's still correct. SF> The clockwise direction was chosen to match SVG: SF> <http://www.w3.org/TR/SVG/coords.html#RotationDefined> SF> In addition, on a web page the coordinate system is top-down, so SF> a clockwise direction is arguably more sensible. In fact that was why SVG chose a Y-down coordinate system in the first place, because Web pages have a Y-down, top-right-origin coordinate system. Having chosen that, the direction of rotation (always from positive x axis = 0 degrees to positive y axis = 90 degrees, in mathematics)follows naturally. -- Chris Lilley Technical Director, Interaction Domain W3C Graphics Activity Lead, Fonts Activity Lead Co-Chair, W3C Hypertext CG Member, CSS, WebFonts, SVG Working Groups
Received on Monday, 7 February 2011 17:06:24 UTC