[whatwg] context.arc and current point
Ian Hickson
ian at hixie.ch
Tue Mar 1 16:23:44 PST 2011
On Thu, 2 Dec 2010, Andrea Canciani wrote:
>
> What will be the current point after an arc with endAngle-startAngle >
> 2pi?
>
> The specification seems to say that the end point is defined to be the
> point at endAngle, but the path is required to be exactly a circle.
The path is a circle but the end point is unaffected by this; it is
defined as being endAngle aleng the circle's circumference, measured in
radians clockwise from the positive x-axis.
So for example:
c.beginPath();
c.moveTo(20,20);
c.arc(200, 200, 100, 0, 5*Math.PI, false);
c.lineTo(380,380);
c.stroke();
...draws a line from the top left, diagonally down to the right edge of a
circle, and then draws a line from the left edge of that circle diagonally
down to the bottom right.
HTH,
--
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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