ActionScript 3.0 Cookbook: Solutions for Flash Platform and Flex Application Developers

Problem

You want to draw an arc.

Solution

Use the Pen.drawArc( ) method.

Discussion

An arc is a part of the outline from a circle. Drawing an arc with the curveTo( ) method is rather difficult for various reasons. However, by using the Pen.drawArc( ) method, you can quickly draw an arc of any radius and length. The drawArc( ) method accepts the following parameters:

x

The x coordinate of the arc center (the center of the circle).

y

The y coordinate of the arc center.

radius

The radius of the arc.

arc

The angle measurement of the arc, specified in degrees.

startingAngle

The starting angle of the arc. The default value is 0.

radialLines

A Boolean value that indicates whether to draw the radial lines that connect the arc to the center. The default is false. When set to true, the arc looks like a slice.

The following draws an arc with radial lines; the radius is 50, the arc angle is 80 degrees, and the starting angle is 20 degrees:

var pen:Pen = new Pen(graphics); pen.drawArc(100, 100, 50, 80, 20, true);