线关节(Line Joint)

 package{
     import Box2D.Common.Math.b2Vec2;
     import Box2D.Dynamics.b2Body;
     import Box2D.Dynamics.Joints.b2LineJointDef;
     import Box2D.Dynamics.Joints.b2PrismaticJointDef;

     /**
     * 线关节，限制一个刚体只能在一个轴向上移动
     */
     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(25,400,300);
             bodyA.SetType(b2Body.b2_staticBody);

             var jointDef:b2LineJointDef=new b2LineJointDef();
             var anchor:b2Vec2=bodyA.GetWorldCenter();
             var axis:b2Vec2=new b2Vec2(1,0);
             jointDef.Initialize(bodyA,bodyB,anchor,axis);
             _world.CreateJoint(jointDef);

         }

     };
 }

源码下载：http://yunpan.cn/c37xzDJTk4ekb  访问密码 c8c5