Box2dWeb中有没有办法将对象的position.x输出到console.log()？

Question

我想我的看似简单的问题有一个简单的答案,但我可能完全错了.无论如何,我是box2dWeb的新手,在我的Box2dWeb世界中,我创建了一个地板和一个简单的坠落物体.当我"调试绘制"到我的画布时,我看到盒子掉落了一切.我想要做的就是将我创建的下降对象的x位置输出到browser console.log中,它不能正常工作.console.log只显示我的对象的起始位置,但即使画布中的对象正在下降,该数字也不会更新.经过几个小时的搜索引擎搜索,以及Seth Ladds教程之类的地方,我出现了空洞.我希望有人可以提供帮助.我提供了一些示例代码来帮助自己解释一下.希望能帮助到你.感谢所有回复的人.

  var world;

  function init() {
     var b2Vec2 = Box2D.Common.Math.b2Vec2
      , b2BodyDef = Box2D.Dynamics.b2BodyDef
      , b2Body = Box2D.Dynamics.b2Body
      , b2FixtureDef = Box2D.Dynamics.b2FixtureDef
      , b2Fixture = Box2D.Dynamics.b2Fixture
      , b2World = Box2D.Dynamics.b2World
      , b2MassData = Box2D.Collision.Shapes.b2MassData
      , b2PolygonShape = Box2D.Collision.Shapes.b2PolygonShape
      , b2CircleShape = Box2D.Collision.Shapes.b2CircleShape
      , b2DebugDraw = Box2D.Dynamics.b2DebugDraw
        ;

     world = new b2World(
           new b2Vec2(0, 10) //gravity
        , true //allow sleep
     );

     var fixDef = new b2FixtureDef;
     fixDef.density = 1.0;
     fixDef.friction = 0.5;
     fixDef.restitution = 0.2;

     var bodyDef = new b2BodyDef;

     //create ground
     bodyDef.type = b2Body.b2_staticBody;
     bodyDef.position.x = 9;
     bodyDef.position.y = 13;
     fixDef.shape = new b2PolygonShape;
     fixDef.shape.SetAsBox(10, 0.5);
     world.CreateBody(bodyDef).CreateFixture(fixDef);


        //FIXTURE - define fixture
        crateFixture = new b2FixtureDef;


            //set object attributes
            crateFixture.density = 0.9;
            crateFixture.friction = 0.5;
            crateFixture.restitution = 0.5;


        //BODY - define body  
        crateDef = new b2BodyDef;


            //setup type
            crateDef.type = b2Body.b2_dynamicBody;
            crateDef.position.x = 5;        
            crateDef.position.y = 5;    
            crateDef.angle = 65;


        //SHAPE - define shape
        crateFixture.shape = new b2PolygonShape;


        //define shape
            crateFixture.shape.SetAsBox(2, 2);


        //add to our world
        world.CreateBody(crateDef).CreateFixture(crateFixture);


            //setup debug draw
            var debugDraw = new b2DebugDraw();
    debugDraw.SetSprite(document.getElementById("canvas").getContext("2d"));
    debugDraw.SetDrawScale(30.0);
    debugDraw.SetFillAlpha(0.3);
    debugDraw.SetLineThickness(1.0);
    debugDraw.SetFlags(b2DebugDraw.e_shapeBit | b2DebugDraw.e_jointBit);
    world.SetDebugDraw(debugDraw);

     window.setInterval(update, 1000 / 60);
  };

  function update() {
     world.Step(
           1 / 60 //frame-rate
        , 10 //velocity iterations
        , 10 //position iterations
     );
     world.DrawDebugData();
     world.ClearForces();
     console.log('the crate is located at ' + crateDef.position.x); //position of crate doesnt update
  };

Answer 1

好吧,所以不,谢谢你没有专门针对Box2DWeb的任何真正的文档,我终于搞清楚了.我很快也想感谢Jer In Chicago的回复,谢谢兄弟.无论如何答案:

一旦你将对象添加到你的世界,就像这样:

crateFixture = world.CreateBody(crateBodyDef).CreateFixture(crateFixtureDef);

您可以获取对象的值(在我的情况下是crateBody),如下所示:

console.log('crate X: ' + crateFixture.GetBody().GetPosition().x);
console.log('crate Y: ' + crateFixture.GetBody().GetPosition().y);
console.log('crate Angle: ' + crateFixture.GetBody().GetAngle());

希望这有助于他人!