滑轮关节(b2PulleyJoint)

package{
    import Box2D.Collision.b2AABB;
    import Box2D.Collision.b2RayCastInput;
    import Box2D.Collision.b2RayCastOutput;
    import Box2D.Collision.Shapes.b2CircleShape;
    import Box2D.Collision.Shapes.b2PolygonShape;
    import Box2D.Collision.Shapes.b2Shape;
    import Box2D.Common.Math.b2Vec2;
    import Box2D.Dynamics.b2Body;
    import Box2D.Dynamics.b2BodyDef;
    import Box2D.Dynamics.b2Fixture;
    import Box2D.Dynamics.b2FixtureDef;
    import Box2D.Dynamics.b2World;
    import flash.display.Sprite;
    import flash.utils.getTimer;
    import Box2D.Dynamics.Joints.b2PulleyJoint;
    import Box2D.Dynamics.Joints.b2PulleyJointDef;

    /**
    * 
    */
    public class Main extends BaseMain{
        
        
        public function Main(){
            super(new b2Vec2(0,10));
        }
        
        override protected function init():void{
            var bodyA:b2Body=this.createBox(50,50,100,400);
            var bodyB:b2Body=this.createCircle(25,700,400);
            
            var jointDef:b2PulleyJointDef=new b2PulleyJointDef();
            
            //悬挂的两个点
            var gaA:b2Vec2=new b2Vec2(100/_pixelToMeter,100/_pixelToMeter);
            var gaB:b2Vec2=new b2Vec2(700/_pixelToMeter,100/_pixelToMeter);
            
            var anchorA:b2Vec2=bodyA.GetWorldCenter();
            var anchorB:b2Vec2=bodyB.GetWorldCenter();
            var r:Number=1;//如果系数是2,那么 length1 的变化会是 length2 的两倍。另外连接 body1 的绳子的约束力将会是连接 body2 绳子的一半。
            jointDef.Initialize(bodyA,bodyB,gaA,gaB,anchorA,anchorB,r);
            var joint:b2PulleyJoint=_world.CreateJoint(jointDef) as b2PulleyJoint;
        }
        
        override protected function stepBefore():void{ 
            
        }
        
        
    };
}

 

源码下载：http://yunpan.cn/c3aI3KPrsUSXy  访问密码 64bc