JavaScript引用错误找不到变量加闭包蓝调 [英] JavaScript reference error can't find variable plus closure blues

问题描述

一般来说，我收到一些错误。
主要是在safari和android浏览器得到错误

JavaScript参考错误找不到变量

问题中的变量是 b2AABB 。

以下是代码 var worldAABB = new b2AABB（）;

我正在工作与 box2d JavaScript（像素实验室变体）for google闭包。如果你可以给我的闭包依赖，需要一个好的一次，我会很感激它。

 < html> 
< title>调谐隧道Alpha< / title> 
< head> 
<！ -  ===========================  - > 
<！ - 将此零件复制到您的应用程序。 - > 
<！ -  START  - > 
<！ -  ===========================  - > 
 
<！ -  libs  - > 
<！ -  [if IE]>< script type =text / javascriptsrc =lib / excanvas.js>< / script><！[endif]  - > ; 
< script src =prototype.js>< / script> 
<！ - < script src =raphael.js>< / script> - > 
< script src =closure-library / closure / goog / base.js>< / script& 
 
<！ -  box2djs  - > 
< script> 
 goog.addDependency（'../ common / b2Settings.js'，['box2d.Settings']，[]）; 
 goog.addDependency（'../ common / math / b2Vec2.js'，['box2d.Vec2']，[]）; 
 goog.addDependency（'../ common / math / b2Mat22.js'，['box2d.Mat22']，[]）; 
 goog.addDependency（'../ collision / b2Proxy.js'，['box2d.Proxy']，[]）; 
 goog.addDependency（'../ collision / ClipVertex.js'，['box2d.ClipVertex']，[]）; 
 goog.addDependency（'../ common / math / b2Math.js'，['box2d.Math']，[]）; 
 goog.addDependency（'../ collision / b2AABB.js'，['box2d.AABB']，[]）; 
 goog.addDependency（'../ collision / b2Bound.js'，['box2d.Bound']，[]）; 
 goog.addDependency（'../ collision / shapes / b2ShapeDef.js'，['box2d.ShapeDef']，[]）; 
 goog.addDependency（'../ collision / b2BoundValues.js'，['box2d.BoundValues']，[]）; 
 goog.addDependency（'../ collision / b2Pair.js'，['box2d.Pair']，[]）; 
 goog.addDependency（'../ collision / b2PairCallback.js'，['box2d.Callback']，[]）; 
 goog.addDependency（'../ collision / b2BufferedPair.js'，['box2d.BufferedPair']，[]）; 
 goog.addDependency（'../ collision / b2PairManager.js'，['box2d.PairManager']，[]）; 
 goog.addDependency（'../ collision / b2BroadPhase.js'，['box2d.BroadPhase']，[]）; 
 goog.addDependency（'../ collision / b2Collision.js'，['box2d.Collision']，[]）; 
 goog.addDependency（'../ collision / Features.js'，['box2d.Features']，[]）; 
 goog.addDependency（'../ collision / b2ContactID.js'，['box2d.ContactID']，[]）; 
 goog.addDependency（'../ collision / b2ContactPoint.js'，['box2d.ContactPoint']，[]）; 
 goog.addDependency（'../ collision / b2Distance.js'，['box2d.Distance']，[]）; 
 goog.addDependency（'../ collision / b2Manifold.js'，['box2d.Manifold']，[]）; 
 goog.addDependency（'../ collision / b2OBB.js'，['box2d.OBB']，[]）; 
 goog.addDependency（'../ collision / shapes / b2Shape.js'，['box2d.Shape']，[]）; 
 goog.addDependency（'../ collision / shapes / b2BoxDef.js'，['box2d.BoxDef']，[]）; 
 goog.addDependency（'../ collision / shapes / b2CircleDef.js'，['box2d.CircleDef']，[]）; 
 goog.addDependency（'../ collision / shapes / b2CircleShape.js'，['box2d.CircleShape']，[]）; 
 goog.addDependency（'../ collision / shapes / b2MassData.js'，['box2d.MassData']，[]）; 
 goog.addDependency（'../ collision / shapes / b2PolyDef.js'，['box2d.PolyDef']，[]）; 
 goog.addDependency（'../ collision / shapes / b2PolyShape.js'，['box2d.PolyShape']，[]）; 
 goog.addDependency（'../ dynamics / b2Body.js'，['box2d.Body']，[]）; 
 goog.addDependency（'../ dynamics / b2BodyDef.js'，['box2d.BodyDef']，[]）; 
 goog.addDependency（'../ dynamics / b2CollisionFilter.js'，['box2d.ColliationFilter']，[]）; 
 goog.addDependency（'../ dynamics / b2Island.js'，['box2d.Island']，[]）; 
 goog.addDependency（'../ dynamics / b2TimeStep.js'，['box2d.TimeStep']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2ContactNode.js'，['box2d.ContactNode']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2Contact.js'，['box2d.Contact']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2ContactConstraint.js'，['box2d.ContactConstraint']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2ContactConstraintPoint.js'，['box2d.ContactConstraintPoint']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2ContactRegister.js'，['box2d.ContactRegister']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2ContactSolver.js'，['box2d.ContactSolver']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2CircleContact.js'，['box2d.CircleContact']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2Conservative.js'，['box2d.Conservative']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2NullContact.js'，['box2d.NullContact']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2PolyAndCircleContact.js'，['box2d.PolyAndCircleContact']，[]）; 
 goog.addDependency（'../ dynamics / contacts / b2PolyContact.js'，['box2d.PolyContact']，[]）; 
 goog.addDependency（'../ dynamics / b2ContactManager.js'，['box2d.ContactManager']，[]）; 
 goog.addDependency（'../ dynamics / b2World.js'，['box2d.World']，[]）; 
 goog.addDependency（'../ dynamics / b2WorldListener.js'，['box2d.WorldListener']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2JointNode.js'，['box2d.JointNode']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2Joint.js'，['box2d.Joint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2JointDef.js'，['box2d.JointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2DistanceJoint.js'，['box2d.DistanceJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2DistanceJointDef.js'，['box2d.DistanceJointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2Jacobian.js'，['box2d.Jacobian']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2GearJoint.js'，['box2d.GearJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2GearJointDef.js'，['box2d.GearJointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2MouseJoint.js'，['box2d.MouseJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2MouseJointDef.js'，['box2d.MouseJointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2PrismaticJoint.js'，['box2d.PrismaticJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2PrismaticJointDef.js'，['box2d.PrismaticJointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2PulleyJoint.js'，['box2d.PulleyJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2PulleyJointDef.js'，['box2d.PulleyJointDef']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2RevoluteJoint.js'，['box2d.RevoluteJoint']，[]）; 
 goog.addDependency（'../ dynamics / joints / b2RevoluteJointDef.js'，['box2d.RevoluteJointDef']，[]）; 
 goog.require（'goog.dom'）; 
 goog.require（'box2d.Settings'）; 
 goog.require（'box2d.Vec2'）; 
 goog.require（'box2d.Mat22'）; 
 goog.require（'box2d.Proxy'）; 
 goog.require（'box2d.ClipVertex'）; 
 goog.require（'box2d.Math'）; 
 goog.require（'box2dAABB'）; 
 goog.require（'box2d.Bound'）; 
 goog.require（'box2d.ShapeDef'）; 
 goog.require（'box2d.RevoluteJoint'）; 
 goog.require（'box2d.World'）
 goog.require（'box2d.BoundValues'）; 
 goog.require（'box2d.Pair'）; 
 goog.require（'box2d.Callback'）; 
 goog.require（'box2d.BufferedPair'）; 
 goog.require（'box2d.PairManager'）; 
 goog.require（'box2d.BroadPhase'）; 
 goog.require（'box2d.Collision'）; 
 goog.require（'box2d.Features'）; 
 goog.require（'box2d.ContactID'）; 
 goog.require（'box2d.ContactPoint'）; 
 goog.require（'box2d.Distance'）; 
 goog.require（'box2d.Manifold'）; 
 goog.require（'box2d.OBB'）; 
 goog.require（'box2d.Shape'）; 
 goog.require（'box2d.BoxDef'）; 
 goog.require（'box2d.CircleDef'）; 
 goog.require（'box2d.CircleShape'）; 
 goog.requires（'box2d.MassData'）; 
 goog.require（'box2d.PolyDef'）; 
 goog.require（'box2d.PolyShape'）; 
 goog.require（'box2d.Body'）; 
 goog.require（'box2d.BodyDef'）; 
 goog.require（'box2d.CollisionFilter'）
 goog.require（'box2d.Island'）
 goog.require（'box2d.TimeStep'）; 
 goog.require（'box2d.ContactNode'）; 
 goog.require（'box2d.Contact'）; 
 goog.require（'box2d.ContactConstraint'）; 
 goog.require（'box2d.ContactConstraintPoint'）; 
 goog.require（'box2d.ContactRegister'）; 
 goog.require（'box2d.ContactSolver'）; 
 goog.require（'box2d.CircleContact'）; 
 goog.require（'box2d.Conservative'）; 
 goog.require（'box2d.NullContact'）; 
 goog.require（'box2d.PolyAndCircleContact'）; 
 goog.require（'box2d.PolyContact'）; 
 goog.require（'box2d.ContactManager'）; 
 goog.require（'box2d.WorldListener'）; 
 goog.require（'box2d.JointNode'）; 
 goog.require（'box2d.Joint'）; 
 goog.require（'box2d.JointDef'）; 
 goog.require（'box2d.DistanceJoint'）; 
 goog.require（'box2d.DistanceJointDef'）; 
 goog.require（'box2d.Jacobian'）; 
 goog.require（'box2d.GearJoint'）; 
 goog.require（'box2d.GearJointDef'）; 
 goog.require（'box2d.MouseJoint'）; 
 goog.require（'box2d.MouseJointDef'）; 
 goog.require（'box2d.PrismaticJoint'）; 
 goog.require（'box2d.PrismaticJointDef'）; 
 goog.require（'box2d.PulleyJoint'）; 
 goog.require（'box2d.PulleyJointDef'）; 
 goog.require（'box2d.RevoluteJointDef'）; 
< / script> 
<！ -  ===========================  - > 
<！ - 将此零件复制到您的应用程序。 - > 
<！ -  END  - > 
<！ -  ===========================  - > 
< link href =style / box2d.css =stylesheettype =text / css/> 
< / head> 
< body> 
< script> 
 document.observe（dom：loaded，function（）{
 var worldAABB = new b2AABB（）; 
 worldAABB.minVertex.Set（-1000，-1000）; 
 worldAABB.maxVertex.Set（1000，1000）; 
 var gravity = new b2Vec2（0,300）; 
 var doSleep = true; 
 var world = new b2World（worldAABB，gravity， doSleep）; 
 var circleSd = new b2CircleDef（）; 
 circleSd.density = 1.0; 
 circleSd.radius = 20; 
 circleSd.restitution = 1.0; 
 circleSd .friction = 0; 
 var circleBd = new b2BodyDef（）; 
 circleBd.AddShape（circleSd）; 
 circleBd.position.Set（x，y）; 
 var circleBody = world.CreateBody（circleBd）; 
 
 var jointDef = new b2RevoluteJointDef（）; 
 jointDef.anchorPoint.Set（250，200）; 
 jointDef.body1 = world.GetGroundBody ）; 
 jointDef.body2 = circleBody; 
 world.CreateJoint（jointDef）; 
 var timeStep = 1.0 / 60; 
 var iteration = 1; 
 world.Step （timeStep，iteration）; 
 var ctx; 
 var canvasWidth; 
 var canvasHeight; 
 function step（cnt）{
 world.Step（1.0 / 60，1）; 
 ctx.clearRect（0，0，canvasWidth，canvasHeight）; 
 drawWorld（world，ctx）; // see demos / draw_world.js 
 setTimeout（'step（'+（cnt || 0）+'）'，10）; 
} 
 Event.observe（window，'load'，function（）{
 setupWorld（world）; //像你喜欢
 ctx = $（'canvas'）。 getContext（'2d'）; 
 var canvasElm = $（'canvas'）; 
 canvasWidth = parseInt（canvasElm.width）; 
 canvasHeight = parseInt（canvasElm.height）; 
 step（）; 
}）; 
}）; 
< / script> 
< canvas> < / canvas> 
< / body> 
< / html> 
  

解决方案>

我不知道你的闭包/原型环境，但是由于它看起来像你的JS文件可能是异步加载，所有的JS文件是可能的，在dom：loaded事件之前没有加载： / p>

  document.observe（dom：loaded，function（）{
 var worldAABB = new b2AABB（）; 
  

错误发生在这个函数的第一行，这是很可疑的。当JS文件都加载？

所以，我想你需要弄清楚这是一个时间问题的脚本加载或者它是一个依赖问题和所需的脚本永远不会被加载，你可以通过暂时替换整个 document.observe（dom：loaded，function（）{在超时后测试b2AABB的存在：

  document.observe（dom：loaded，function b $ b setTimeout（function（）{
 if（b2AABB）{
 alert（Found it）; 
} else {
 alert（Still not there）; 
} 
}，60 * 1000）; //等待60秒
} 
  

如果60秒后仍然不存在可能永远不可用，你可能有依赖问题。如果在60秒后，您可能有时间问题。

Just in general I'm getting some errors with this. The major one is in safari and the android browser get the error

JavaScript reference error can't find variable

The variable in question is b2AABB.

Here is the code var worldAABB = new b2AABB();
I am working with box2d JavaScript (the pixel lab variant) for google closure. Also if you can give my closure dependencies and requires a good once over I would appreciate it.

<html>
<title>Tune Tunnels Alpha</title>
<head>
<!--=============================-->
<!-- Copy this part to your app. -->
<!-- START       -->
<!--=============================-->

<!-- libs -->
<!--[if IE]><script type="text/javascript" src="lib/excanvas.js"></script><![endif]-->
<script src="prototype.js"></script>
<!-- <script src="raphael.js"></script> -->
<script src="closure-library/closure/goog/base.js"></script>

<!-- box2djs -->
<script>
goog.addDependency('../common/b2Settings.js', ['box2d.Settings'], []);
goog.addDependency('../common/math/b2Vec2.js', ['box2d.Vec2'], []);
goog.addDependency('../common/math/b2Mat22.js', ['box2d.Mat22'], []);
goog.addDependency('../collision/b2Proxy.js', ['box2d.Proxy'], []);
goog.addDependency('../collision/ClipVertex.js', ['box2d.ClipVertex'], []);
goog.addDependency('../common/math/b2Math.js', ['box2d.Math'], []);
goog.addDependency('../collision/b2AABB.js', ['box2d.AABB'], []);
goog.addDependency('../collision/b2Bound.js', ['box2d.Bound'], []);
goog.addDependency('../collision/shapes/b2ShapeDef.js', ['box2d.ShapeDef'], []);
goog.addDependency('../collision/b2BoundValues.js', ['box2d.BoundValues'], []);
goog.addDependency('../collision/b2Pair.js', ['box2d.Pair'], []);
goog.addDependency('../collision/b2PairCallback.js', ['box2d.Callback'], []);
goog.addDependency('../collision/b2BufferedPair.js', ['box2d.BufferedPair'], []);
goog.addDependency('../collision/b2PairManager.js', ['box2d.PairManager'], []);
goog.addDependency('../collision/b2BroadPhase.js', ['box2d.BroadPhase'], []);
goog.addDependency('../collision/b2Collision.js', ['box2d.Collision'], []);
goog.addDependency('../collision/Features.js', ['box2d.Features'], []);
goog.addDependency('../collision/b2ContactID.js', ['box2d.ContactID'], []);
goog.addDependency('../collision/b2ContactPoint.js', ['box2d.ContactPoint'], []);
goog.addDependency('../collision/b2Distance.js', ['box2d.Distance'], []);
goog.addDependency('../collision/b2Manifold.js', ['box2d.Manifold'], []);
goog.addDependency('../collision/b2OBB.js', ['box2d.OBB'], []);
goog.addDependency('../collision/shapes/b2Shape.js', ['box2d.Shape'], []);
goog.addDependency('../collision/shapes/b2BoxDef.js', ['box2d.BoxDef'], []);
goog.addDependency('../collision/shapes/b2CircleDef.js', ['box2d.CircleDef'], []);
goog.addDependency('../collision/shapes/b2CircleShape.js', ['box2d.CircleShape'], []);
goog.addDependency('../collision/shapes/b2MassData.js', ['box2d.MassData'], []);
goog.addDependency('../collision/shapes/b2PolyDef.js', ['box2d.PolyDef'], []);
goog.addDependency('../collision/shapes/b2PolyShape.js', ['box2d.PolyShape'], []);
goog.addDependency('../dynamics/b2Body.js', ['box2d.Body'], []);
goog.addDependency('../dynamics/b2BodyDef.js', ['box2d.BodyDef'], []);
goog.addDependency('../dynamics/b2CollisionFilter.js', ['box2d.CollisionFilter'], []);
goog.addDependency('../dynamics/b2Island.js', ['box2d.Island'], []);
goog.addDependency('../dynamics/b2TimeStep.js', ['box2d.TimeStep'], []);
goog.addDependency('../dynamics/contacts/b2ContactNode.js', ['box2d.ContactNode'], []);
goog.addDependency('../dynamics/contacts/b2Contact.js', ['box2d.Contact'], []);
goog.addDependency('../dynamics/contacts/b2ContactConstraint.js', ['box2d.ContactConstraint'], []);
goog.addDependency('../dynamics/contacts/b2ContactConstraintPoint.js', ['box2d.ContactConstraintPoint'], []);
goog.addDependency('../dynamics/contacts/b2ContactRegister.js', ['box2d.ContactRegister'], []);
goog.addDependency('../dynamics/contacts/b2ContactSolver.js', ['box2d.ContactSolver'], []);
goog.addDependency('../dynamics/contacts/b2CircleContact.js', ['box2d.CircleContact'], []);
goog.addDependency('../dynamics/contacts/b2Conservative.js', ['box2d.Conservative'], []);
goog.addDependency('../dynamics/contacts/b2NullContact.js', ['box2d.NullContact'], []);
goog.addDependency('../dynamics/contacts/b2PolyAndCircleContact.js', ['box2d.PolyAndCircleContact'], []);
goog.addDependency('../dynamics/contacts/b2PolyContact.js', ['box2d.PolyContact'], []);
goog.addDependency('../dynamics/b2ContactManager.js', ['box2d.ContactManager'], []);
goog.addDependency('../dynamics/b2World.js', ['box2d.World'], []);
goog.addDependency('../dynamics/b2WorldListener.js', ['box2d.WorldListener'], []);
goog.addDependency('../dynamics/joints/b2JointNode.js', ['box2d.JointNode'], []);
goog.addDependency('../dynamics/joints/b2Joint.js', ['box2d.Joint'], []);
goog.addDependency('../dynamics/joints/b2JointDef.js', ['box2d.JointDef'], []);
goog.addDependency('../dynamics/joints/b2DistanceJoint.js', ['box2d.DistanceJoint'], []);
goog.addDependency('../dynamics/joints/b2DistanceJointDef.js', ['box2d.DistanceJointDef'], []);
goog.addDependency('../dynamics/joints/b2Jacobian.js', ['box2d.Jacobian'], []);
goog.addDependency('../dynamics/joints/b2GearJoint.js', ['box2d.GearJoint'], []);
goog.addDependency('../dynamics/joints/b2GearJointDef.js', ['box2d.GearJointDef'], []);
goog.addDependency('../dynamics/joints/b2MouseJoint.js', ['box2d.MouseJoint'], []);
goog.addDependency('../dynamics/joints/b2MouseJointDef.js', ['box2d.MouseJointDef'], []);
goog.addDependency('../dynamics/joints/b2PrismaticJoint.js', ['box2d.PrismaticJoint'], []);
goog.addDependency('../dynamics/joints/b2PrismaticJointDef.js', ['box2d.PrismaticJointDef'], []);
goog.addDependency('../dynamics/joints/b2PulleyJoint.js', ['box2d.PulleyJoint'], []);
goog.addDependency('../dynamics/joints/b2PulleyJointDef.js', ['box2d.PulleyJointDef'], []);
goog.addDependency('../dynamics/joints/b2RevoluteJoint.js', ['box2d.RevoluteJoint'], []);
goog.addDependency('../dynamics/joints/b2RevoluteJointDef.js', ['box2d.RevoluteJointDef'], []);
goog.require('goog.dom');
goog.require('box2d.Settings');
goog.require('box2d.Vec2');
goog.require('box2d.Mat22');
goog.require('box2d.Proxy');
goog.require('box2d.ClipVertex');
goog.require('box2d.Math');
goog.require('box2d.AABB');
goog.require('box2d.Bound');
goog.require('box2d.ShapeDef');
goog.require('box2d.RevoluteJoint');
goog.require('box2d.World')
goog.require('box2d.BoundValues');
goog.require('box2d.Pair');
goog.require('box2d.Callback');
goog.require('box2d.BufferedPair');
goog.require('box2d.PairManager');
goog.require('box2d.BroadPhase');
goog.require('box2d.Collision');
goog.require('box2d.Features');
goog.require('box2d.ContactID');
goog.require('box2d.ContactPoint');
goog.require('box2d.Distance');
goog.require('box2d.Manifold');
goog.require('box2d.OBB');
goog.require('box2d.Shape');
goog.require('box2d.BoxDef');
goog.require('box2d.CircleDef');
goog.require('box2d.CircleShape');
goog.require('box2d.MassData');
goog.require('box2d.PolyDef');
goog.require('box2d.PolyShape');
goog.require('box2d.Body');
goog.require('box2d.BodyDef');
goog.require('box2d.CollisionFilter')
goog.require('box2d.Island')
goog.require('box2d.TimeStep');
goog.require('box2d.ContactNode');
goog.require('box2d.Contact');
goog.require('box2d.ContactConstraint');
goog.require('box2d.ContactConstraintPoint');
goog.require('box2d.ContactRegister');
goog.require('box2d.ContactSolver');
goog.require('box2d.CircleContact');
goog.require('box2d.Conservative');
goog.require('box2d.NullContact');
goog.require('box2d.PolyAndCircleContact');
goog.require('box2d.PolyContact');
goog.require('box2d.ContactManager');
goog.require('box2d.WorldListener');
goog.require('box2d.JointNode');
goog.require('box2d.Joint');
goog.require('box2d.JointDef');
goog.require('box2d.DistanceJoint');
goog.require('box2d.DistanceJointDef');
goog.require('box2d.Jacobian');
goog.require('box2d.GearJoint');
goog.require('box2d.GearJointDef');
goog.require('box2d.MouseJoint');
goog.require('box2d.MouseJointDef');
goog.require('box2d.PrismaticJoint');
goog.require('box2d.PrismaticJointDef');
goog.require('box2d.PulleyJoint');
goog.require('box2d.PulleyJointDef');
goog.require('box2d.RevoluteJointDef');
</script>
        <!--=============================-->
        <!-- Copy this part to your app. -->
        <!-- END     -->
        <!--=============================-->
<link href="style/box2d.css" rel="stylesheet" type="text/css" />
</head>
<body>
<script>
document.observe("dom:loaded", function() {
    var worldAABB = new b2AABB();
    worldAABB.minVertex.Set(-1000, -1000);
    worldAABB.maxVertex.Set(1000, 1000);
    var gravity = new b2Vec2(0, 300);
    var doSleep = true;
    var world = new b2World(worldAABB, gravity, doSleep); 
    var circleSd = new b2CircleDef();
    circleSd.density = 1.0;
    circleSd.radius = 20;
    circleSd.restitution = 1.0;
    circleSd.friction = 0;
    var circleBd = new b2BodyDef();
    circleBd.AddShape(circleSd);
    circleBd.position.Set(x,y);
    var circleBody = world.CreateBody(circleBd);

    var jointDef = new b2RevoluteJointDef();
    jointDef.anchorPoint.Set(250, 200);
    jointDef.body1 = world.GetGroundBody();
    jointDef.body2 = circleBody;
    world.CreateJoint(jointDef);
    var timeStep = 1.0/60;
    var iteration = 1;
    world.Step(timeStep, iteration);
    var ctx;
    var canvasWidth; 
    var canvasHeight; 
    function step(cnt) { 
        world.Step(1.0/60, 1);
        ctx.clearRect(0, 0, canvasWidth, canvasHeight);
        drawWorld(world, ctx); // see demos/draw_world.js
        setTimeout('step(' + (cnt || 0) + ')', 10);
    }
    Event.observe(window, 'load', function() {
        setupWorld(world); // as you like
        ctx = $('canvas').getContext('2d');
        var canvasElm = $('canvas');
        canvasWidth = parseInt(canvasElm.width);
        canvasHeight = parseInt(canvasElm.height);
        step();
    });
});
</script>
<canvas> </canvas>
</body>
</html>

解决方案

I don't know your closure/prototype environment, but since it looks like your JS files might be loading asynchronously, is it possible that all your JS files aren't loaded yet before the dom:loaded event fires:

document.observe("dom:loaded", function() {
    var worldAABB = new b2AABB();

The error is occurring on the first line of this function which is pretty suspicious. Is there an event that fires when the JS files are all loaded?

So, I think you need to figure out whether this is a timing issue of script loading or whether it's a dependency problem and the desired scripts are never going to be loaded. You can do that by temporarily replacing the entire document.observe("dom:loaded", function() { with a new function that just tests for the existence of b2AABB after a long timeout:

document.observe("dom:loaded", function() {
  setTimeout(function() {
    if (b2AABB) {
      alert("Found it");
    } else {
      alert("Still not there");
    }
  }, 60 * 1000);  // wait 60 seconds
}

If it's still not present after 60 seconds, then it's probably never going to be available and you probably have a dependency issue. If it is there after 60 seconds, then you probably have a timing issue.

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