/**
* Adds to the receiver a circular or elliptical arc that lies within the specified rectangular
* area.
*
* <p>The resulting arc begins at <code>startAngle</code> and extends for <code>arcAngle</code>
* degrees. Angles are interpreted such that 0 degrees is at the 3 o'clock position. A positive
* value indicates a counter-clockwise rotation while a negative value indicates a clockwise
* rotation.
*
* <p>The center of the arc is the center of the rectangle whose origin is (<code>x</code>, <code>
* y</code>) and whose size is specified by the <code>width</code> and <code>height</code>
* arguments.
*
* <p>The resulting arc covers an area <code>width + 1</code> pixels wide by <code>height + 1
* </code> pixels tall.
*
* @param x the x coordinate of the upper-left corner of the arc
* @param y the y coordinate of the upper-left corner of the arc
* @param width the width of the arc
* @param height the height of the arc
* @param startAngle the beginning angle
* @param arcAngle the angular extent of the arc, relative to the start angle
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </ul>
*/
public void addArc(
float x, float y, float width, float height, float startAngle, float arcAngle) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
NSAffineTransform transform = NSAffineTransform.transform();
transform.translateXBy(x + width / 2f, y + height / 2f);
transform.scaleXBy(width / 2f, height / 2f);
NSBezierPath path = NSBezierPath.bezierPath();
NSPoint center = new NSPoint();
float sAngle = -startAngle;
float eAngle = -(startAngle + arcAngle);
path.appendBezierPathWithArcWithCenter_radius_startAngle_endAngle_clockwise_(
center, 1, sAngle, eAngle, arcAngle > 0);
path.transformUsingAffineTransform(transform);
handle.appendBezierPath(path);
}
