W3C home > Mailing lists > Public > whatwg@whatwg.org > August 2013

[whatwg] Path API feedback

From: Ian Hickson <ian@hixie.ch>
Date: Tue, 20 Aug 2013 22:36:23 +0000 (UTC)
To: Rik Cabanier <cabanier@gmail.com>
Message-ID: <alpine.DEB.2.00.1308202232540.27209@ps20323.dreamhostps.com>
Cc: whatwg@lists.whatwg.org
On Fri, 26 Apr 2013, Rik Cabanier wrote:
> 
> I think an author would expect that 'addPathByStrokingPath' and other 
> path methods render as if you stroked/outlined directly on the canvas 
> context. Same goes for 'addPath'.
> 
> I believe very few people actually want the current behavior that's in 
> the spec.

I don't know how true that is.

It seems logical to me that this:

   context.beginPath();
   context.rect(0,0,100,100);
   context.rect(50,50,150,150);
   context.fill();

...should do the same as this:

   var p1 = new Path();
   p1.rect(0,0,100,100);
   var p2 = new Path();s
   p2.rect(50,50,150,150);
   var p = new Path();
   p.addPath(p1);
   p.addPath(p2);
   context.fill(p);

...for any combination of path commands where I've put the rect()s.


> > > I think the spec needs to mention that
> > > - sections of the path where both edges are filled should be removed
> > > - winding needs to be done so eofill and fill give the same result
> >
> > I've filed a bug for adding something like this:
> >
> >    https://www.w3.org/Bugs/Public/show_bug.cgi?id=21835
> >
> > I'm not sure exactly what the algorithm should be (as we discussed on 
> > IRC today), so if anyone has any input here, please don't hesitate to 
> > comment.
> 
> I can help if needed. I know the skia people are working on this as 
> well.
> 
> The algorithm is fairly straightforward to describe in prose. 
> Implementation is very hard though...

Please do add such help as comments on the bug, that would be very 
helpful.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Tuesday, 20 August 2013 22:36:52 UTC

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