package {
    // Represents a polygon that can be drawn to the screen
    public class @ax-actionscript-lib-drawing-Polygon extends actionscript_lib_drawing_BasicShape {
      // The polygon's points.
      //  To reduce memory consumption, the points are stored in two integer 
      //  arrays rather than one array of flash.geom.Point objects.
      private var xpoints:Array;
      private var ypoints:Array;
      
      // Constructor
      public function @ax-actionscript-lib-drawing-Polygon (xpoints:Array = null, ypoints:Array = null) {
        super();
        setPoints(xpoints, ypoints);
      }
  
      // The polygon drawing routine
      override protected function drawShape ():void { 
        // Draw lines to each point in the polygon
        graphics.moveTo(xpoints[0], ypoints[0]);
        for (var i:int = 1; i < xpoints.length; i++) {
          graphics.lineTo(xpoints[i], ypoints[i]);
        }
        // Close the shape by returning to the first point
        graphics.lineTo(xpoints[0], ypoints[0]);
      }
      
      // Assigns the polygon's points
      public function setPoints (newXPoints:Array, newYPoints:Array):void {
        if (newXPoints == null || newYPoints == null) {
          return;
        }
        
        if (newXPoints.length != newYPoints.length) {
          throw new Error("setPoints() requires a matching " 
                          + "number of x and y points");
        }
        
        xpoints = newXPoints;
        ypoints = newYPoints;
        
        // Assigning new points to the polygon changes its shape, 
        // so it must be redrawn at the next render opportunity.
        setChanged();
      }  
    }
  }