- From: Alan Stearns <stearns@adobe.com>
- Date: Thu, 5 Sep 2013 15:57:16 -0700
- To: François REMY <francois.remy.dev@outlook.com>, "www-style@w3.org" <www-style@w3.org>
- CC: Laurence Mclister <lmcliste@adobe.com>

On 9/5/13 3:49 PM, "François REMY" <francois.remy.dev@outlook.com> wrote: >Some clarification of the css-shapes-1 spec (regarding how to interpret a >percentage value used as a circle radius) would be welcome, I guess, for >people trying to implement the spec. > >Indeed, it seems to me it is not specified whether the percentage is >considered from the width direction or from the height direction, or form >any other kind of reference. My own implementation used the width >direction for consistency with ellipse but it would probably just be >better to disallow percentage-defined radius for circles. > >Relevant text from the spec: > > circle([<length>|<percentage>][, [<length>|<percentage>]]{2}) > > The three values values represent cx, cy, and r. > They define the x-axis and y-axis coordinates of the center of the >circle and the radius of the circle. > A negative value for r is invalid. > >For what it's worth, I'm not quite sure why there's a need for circle >function when we could simply consider as a circle an ellipse with 3 >arguments, but I guess it's for the sake of consistency with SVG. > >Best regards, >Francois Look at the last sentence of section 3.2: --- For the radius r of the circle shape, a percentage value is resolved as specified in the SVG recommendation. --- The relevant part of the SVG rec is: --- For any other length value expressed as a percentage of the viewport, the percentage is calculated as the specified percentage of sqrt((actual-width)**2 + (actual-height)**2))/sqrt(2). --- Thanks, Alan

Received on Thursday, 5 September 2013 22:57:42 UTC