# [html5] r1756 - /

whatwg at whatwg.org whatwg at whatwg.org
Thu Jun 12 18:37:40 PDT 2008

```Author: ianh
Date: 2008-06-12 18:37:39 -0700 (Thu, 12 Jun 2008)
New Revision: 1756

Modified:
index
source
Log:
[gow] (2) Clarify arc() for arcs greater than 2pi.

Modified: index
===================================================================
--- index	2008-06-12 23:10:34 UTC (rev 1755)
+++ index	2008-06-13 01:37:39 UTC (rev 1756)
@@ -25,7 +25,7 @@

<h1 id=html-5>HTML 5</h1>

-   <h2 class="no-num no-toc" id=draft>Draft Recommendation — 12 June
+   <h2 class="no-num no-toc" id=draft>Draft Recommendation — 13 June
2008</h2>

<p>You can take part in this work. <a
@@ -19476,18 +19476,24 @@
The arc and its start and end points are defined as follows:

<p>Consider a circle that has its origin at (<var title="">x</var>, <var
-   points at <var title="">startAngle</var> and <var title="">endAngle</var>
-   along the circle's circumference, measured in radians clockwise from the
-   positive x-axis, are the start and end points respectively. The arc is the
-   path along the circumference of this circle from the start point to the
-   end point, going anti-clockwise if the <var title="">anticlockwise</var>
-   argument is true, and clockwise otherwise. Since the points are on the
-   circle, as opposed to being simply angles from zero, the arc can never
-   cover an angle greater than 2π radians. If the two angles are equal, or
-   if the radius is zero, then the arc is defined as being of zero length in
-   both directions.

+  <p>If the absolute magnitude of the difference between the <var
+   title="">startAngle</var> and <var title="">endAngle</var> angles is equal
+   to or greater than 2π, then the arc is the whole circumference of this
+   circle.
+
+  <p>Otherwise, the points at <var title="">startAngle</var> and <var
+   title="">endAngle</var> along this circle's circumference, measured in
+   radians clockwise from the positive x-axis, are the start and end points
+   respectively. The arc is the path along the circumference of this circle
+   from the start point to the end point, going anti-clockwise if the <var
+   title="">anticlockwise</var> argument is true, and clockwise otherwise.
+   Since the points are on the circle, as opposed to being simply angles from
+   zero, the arc can never cover an angle greater than 2π radians. If the
+   two angles are equal, or if the radius is zero, then the arc is defined as
+   being of zero length in both directions.
+
<p>Negative values for <var title="">radius</var> must cause the
implementation to raise an <code>INDEX_SIZE_ERR</code> exception.

Modified: source
===================================================================
--- source	2008-06-12 23:10:34 UTC (rev 1755)
+++ source	2008-06-13 01:37:39 UTC (rev 1756)
@@ -17109,18 +17109,25 @@

<p>Consider a circle that has its origin at (<var title="">x</var>,
<var title="">y</var>) and that has radius <var
-  title="">radius</var>. The points at <var title="">startAngle</var>
-  and <var title="">endAngle</var> along the circle's circumference,
-  measured in radians clockwise from the positive x-axis, are the
-  start and end points respectively. The arc is the path along the
-  circumference of this circle from the start point to the end point,
-  going anti-clockwise if the <var title="">anticlockwise</var>
-  argument is true, and clockwise otherwise. Since the points are on
-  the circle, as opposed to being simply angles from zero, the arc can
-  never cover an angle greater than 2π radians. If the two angles
-  are equal, or if the radius is zero, then the arc is defined as
-  being of zero length in both directions.</p>

+  <p>If the absolute magnitude of the difference between the <var
+  title="">startAngle</var> and <var title="">endAngle</var> angles is
+  equal to or greater than 2π, then the arc is the whole
+  circumference of this circle.</p>
+
+  <p>Otherwise, the points at <var title="">startAngle</var> and <var
+  title="">endAngle</var> along this circle's circumference, measured
+  in radians clockwise from the positive x-axis, are the start and end
+  points respectively. The arc is the path along the circumference of
+  this circle from the start point to the end point, going
+  anti-clockwise if the <var title="">anticlockwise</var> argument is
+  true, and clockwise otherwise. Since the points are on the circle,
+  as opposed to being simply angles from zero, the arc can never cover
+  an angle greater than 2π radians. If the two angles are equal, or
+  if the radius is zero, then the arc is defined as being of zero
+  length in both directions.</p>
+
<p>Negative values for <var title="">radius</var> must cause the
implementation to raise an <code>INDEX_SIZE_ERR</code>
exception.</p>

```