Question

我正在使用java，libgdx和box2d

在大班我创造了一个玩家。我想在播放器类中将shape.setAsBox更改为100。换句话说，我想在创建后更改shape.setAsBox。我相信只有这样才能删除夹具并重新创建一个100尺寸的新夹具。我怎样才能做到这一点。

public class main{
  ...
  public main(){
    //create player
    BodyDef bdef = new BodyDef();
    Body body;
    FixtureDef fdef = new FixtureDef();
    PolygonShape shape = new PolygonShape();

    /***Body - Player ***/
    bdef.type = BodyType.DynamicBody;
    bdef.position.set(50 / PPM, 50 / PPM);
    bdef.linearVelocity.set(1.5f, 0);
    body = world.createBody(bdef);

    /*** 1st fixture ***/
    shape.setAsBox(50/ PPM, 50 / PPM);
    fdef.shape = shape;
    fdef.filter.categoryBits = Constants.BIT_PLAYER;
    fdef.filter.maskBits = Constants.BIT_GROUND;
    body.createFixture(fdef).setUserData("player");

    player = new Player(body);
  }

  ....

  public void update(float dt) {
      playerObj.update(dt);
      ...
  }
}

// playyer class

 public class player{
       public player(Body body){
             super(body);
       }

       ....
       public void update(){
             //get player x position
             currentX = this.getBody().getPosition().x;

             // how can I delete old fixture and recreate a new one? 
             // which will has shape.setAsBox = 100.
       }
}

Answer 1

最好（可能是唯一的）方法是实际销毁整个夹具并重新定义它。由于您的播放器只有一个灯具，您可以跟踪它以将其删除，或者只是执行此操作：

    this.getBody().destroyFixture(this.getBody().getFixtureList().first());

然后只需在现有的Body中重新创建一个简单的形状：

    PolygonShape shape;
    FixtureDef fdef;

    // Create box shape
    shape = new PolygonShape();
    shape.setAsBox(100 / PPM, 100 / PPM);

    // Create FixtureDef for player collision box
    fdef = new FixtureDef();
    fdef.shape = shape;
    fdef.filter.categoryBits = Constants.BIT_PLAYER;
    fdef.filter.maskBits = Constants.BIT_GROUND;

    // Create player collision box fixture
    this.getBody().createFixture(fdef).setUserData("player");
    shape.dispose();

如何在创建后更改大小

1 个答案: