Possible error in Elliptical arc implementation notes section from donjordan@cox.net on 2016-12-20 (www-svg@w3.org from December 2016)

From: <donjordan@cox.net>
Date: Tue, 20 Dec 2016 14:24:15 -0800
To: www-svg@w3.org
Message-ID: <20161220172415.XAV3J.438904.imail@fed1rmwml213>

Hello.

I've been implementing a Windows 10 drawing app that is based on the SVG 2 specification. I know it's a moving target.

I'm going through the Elliptical arc implementation notes and there appears to be an error in one of the formulas. Specifically, in the Conversion from endpoint to center parameterization section, (F.6.5.1) the formula for step1, shouldn't the midpoint formula between the points be: (x1 + x2) / 2 and (y1 + y2) / 2?  There are minus signs in the graphic.

Thank you for your time.

Regards,
Don Jordan
Silicon Beach software.

Received on Thursday, 22 December 2016 13:13:13 UTC