box2d - box2d 2.2 b2Body GetGroundBody 方法不见了

Question

我尝试使用旧 box2d < =2.1 编写的休闲教程我无法理解如何将 b2Body 的 GetGroundBody 方法替换为 box2d >= 2.2

var jointDef:b2MouseJointDef=new b2MouseJointDef();
jointDef.bodyA=world.GetGroundBody();   // what does it need to be now?
jointDef.bodyB=touchedBody;
jointDef.target=mouseToWorld();
jointDef.maxForce=1000*touchedBody.GetMass();
mouseJoint=world.CreateJoint(jointDef) as b2MouseJoint;

Answer 1

您可以使自己的静态主体充当地面主体。