- From: Ian Hickson <ian@hixie.ch>
- Date: Fri, 14 Mar 2014 20:50:41 +0000 (UTC)
- To: Justin Novosad <junov@google.com>
- Cc: WHATWG List <whatwg@whatwg.org>
On Fri, 7 Feb 2014, Justin Novosad wrote: > > > > > > Current text: If the point (x0, y0) is equal to the point (x1, y1), > > > or if the point (x1, y1) is equal to the point (x2, y2), or if both > > > radiusX and radiusY are zero, then the method must add the point > > > (x1, y1) to the subpath, and connect that point to the previous > > > point (x0, y0) by a straight line. > > With arcTo, the first point (x0, y0) may have been added to the current > subpath using a different CTM. So to bring it into the local space of > the current primitive, we need an invertible CTM. What I don't understand is why you can't draw the curve in the transformed space instead of the 1:1 coordinate space. You have to transform it eventually, right? And the points will end up simply transformed. So you can easily compare the points in the transformed space. All the transforms are affine, so what's a straight line isn't impacted. Can't you just draw the transformed arc instead of first drawing the circular arc and then transforming it? Maybe what I'm saying is obviously dumb for some reason, but I'm not understanding why, if so... (not that I'm a graphics guy, obviously). -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Friday, 14 March 2014 20:51:45 UTC