/** * Copyright (c) 2008 Bartek Drozdz (http://www.everydayflash.com) * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ package {import flash.display.DisplayObject;import flash.geom.Point;/** * This class can be used as a replacement for the DisplayObject.rotation property. * * It rotates a DisplayObject, but it does not limit itself to rotate around the it's * registration point, instead it can rotate the object around any point. The point is * defined in the objects parent coodrinate system. * * @author Bartek Drozdz (http://www.everydayflash.com) * @version 1.0 */public class Rotator {private var target:DisplayObject;/** * A value that is based on the initial rotation of the display object itself, and * the angle between the registration point of the display object and of the rotator */private var offset:Number;/** * Registration point - the point around which the rotation takse place */private var point:Point;/** * Distance between the registration point of the display object and the registration * point of the rotator */private var dist:Number;/** * Registers a DisplayObject that will be rotated and an registration Point around which it will be rotated. * * @paramtarget DisplayObject to rotate * @paramregistrationPoint Point containing the coodrinates around which the object should be rotated * (in the targets parent coordinate space) If omitted, the displays object x and y coordinates are used */public function Rotator(target:DisplayObject, registrationPoint:Point=null) {this.target = target;setRegistrationPoint(registrationPoint);}/** * Once set in the constructor, the rotation registration point can be modified an any moment * * @paramregistrationPoint, if null defaults to targets x and y coordinates */public function setRegistrationPoint(registrationPoint:Point=null):void {if (registrationPoint == null) point = new Point(target.x, target.y);else point = registrationPoint;var dx:Number = point.x - target.x;var dy:Number = point.y - target.y;dist = Math.sqrt( dx * dx + dy * dy );var a:Number = Math.atan2(dy, dx) * 180 / Math.PI;offset = 180 - a + target.rotation;}/** * Sets the rotation to the angle passed as parameter. * * Since it uses a getter/setter Rotator can easily be used with Tween or Tweener classes. */public function set rotation(angle:Number):void {var tp:Point = new Point(target.x, target.y);var ra:Number = (angle - offset) * Math.PI / 180;target.x = point.x + Math.cos(ra) * dist;target.y = point.y + Math.sin(ra) * dist;target.rotation = angle;}/** * Returns current rotation of the target in degrees */public function get rotation():Number {return target.rotation;}/** * Rotates the target by the angle passed as parameter. * Works the same as Rotator.rotation += angle; * * @param angle angle by which to rotate the target DisplayObject */public function rotateBy(angle:Number):void {var tp:Point = new Point(target.x, target.y);var ra:Number = (target.rotation + angle - offset) * Math.PI / 180;target.x = point.x + Math.cos(ra) * dist;target.y = point.y + Math.sin(ra) * dist;target.rotation = target.rotation + angle;}}}
