旋转关节(Revolute Joint)

package{

    import Box2D.Common.Math.b2Vec2;

    import Box2D.Dynamics.b2Body;

    import Box2D.Dynamics.Joints.b2RevoluteJointDef;

    import Box2D.Dynamics.Joints.b2RevoluteJoint;

    /**

    * 旋转关节，指定刚体只能绕着某一个锚点旋转

    */

    public class Main extends BaseMain{

        public function Main(){

            super(new b2Vec2(0,10));

        }

        override protected function init():void{

            var bodyA:b2Body=this.createBox(50,50,400,300);

            var bodyB:b2Body=this.createCircle(25,500,300);

            bodyA.SetType(b2Body.b2_staticBody);

            var jointDef:b2RevoluteJointDef=new b2RevoluteJointDef();

            var anchor:b2Vec2=bodyA.GetWorldCenter();

            jointDef.Initialize(bodyA,bodyB,anchor);

            //限制在一个弧度范围内可以转动,,,,,,,,bodyB的位置需要放在bodyA0弧度的位置

            //jointDef.enableLimit=true;

            //jointDef.lowerAngle=45*0.01745;

            //jointDef.upperAngle=135*0.01745;

            //马达速度

            //jointDef.motorSpeed=4;

            //jointDef.maxMotorTorque=400;//必须赋值,否则他的默认值为:0

            //jointDef.enableMotor=true;

            _world.CreateJoint(jointDef);

        }

    };

}

源码下载：http://pan.baidu.com/s/1cmT6oe