Re: Please consider elliptical arc in canvas

That will be fine.
But if a  drawPath-style API is added and "A" command is supported, I think still the ellipse arc api is needed to to keep the two API set of path align.



At 2011-11-14 04:47:33,"Charles Pritchard" <chuck@jumis.com> wrote:

There seems to be consensus that a drawPath-style method can be added to Canvas 2d. So you'd no longer need an svg path implementation.


Would that sufficiently address the issue?


-Charles




On Nov 13, 2011, at 3:27 AM, "Shaofei Cheng" <csf178@163.com> wrote:


Hey guys,
These days I'm working on a simple wrapping of canvas and just noticed that canvas leaks of elliptical canvas.arc APIs for path.


What I want to implement is like the following:


    var canvas = new CanvasWraper(myCanvas);
    canvas.drawPath("M200,300 Q400,50 600,300 T1000,300");


The main purpose is to draw a path in canvas in SVG grammar. Everything goes well except the "A" command. Canvas 2d context do not have a API for arc of ellipse. So in the following picture(which is a sample of SVG). The left graph could be draw with canvas but the right could not.
This path grammar is also supported by silverlight. 


So I suggest to add a elliptical arc API for path. With that we can keep the feature align with SVG.Also I think elliptical arc could be useful for some graphics games. 


(We are able to approx elliptical arc with cubic bezer, but I think the algorithm is too complex for web developers )




Thanks,
Shaofei Cheng