Hey, I was trying to write sth cool with cocos2d and i get stuck. DebugDrawing doesnt show anything ;/
I spent 4h looking for solution. I think it could be sth wrong with my implementation. ;/
<canvas id="gameCanvas" width="560" height="450"></canvas>
<script type="text/javascript">
window.onload = function(){
cc.game.onStart = function () {
cc.LoaderScene.preload(["pics/HelloWorld.png"],
function () {
var MyScene = cc.Layer.extend({
ctor: function(){
this._super();
var screenSize = cc.director.getWinSize();
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;
this.world = new b2World(new b2Vec2(0, -10), true);
this.world.SetContinuousPhysics(true);
var fixDef = new b2FixtureDef;
fixDef.density = 1.0;
fixDef.friction = 0.5;
fixDef.restitution = 0.2;
var bodyDef = new b2BodyDef;
bodyDef.type = b2Body.b2_staticBody;
bodyDef.position.x = 9;
bodyDef.position.y = 13;
fixDef.shape = new b2PolygonShape;
fixDef.shape.SetAsBox(10, 0.5);
this.world.CreateBody(bodyDef).CreateFixture(fixDef);
bodyDef.type = b2Body.b2_dynamicBody;
for (var i = 0; i < 10; ++i) {
if (Math.random() > 0.5) {
fixDef.shape = new b2PolygonShape;
fixDef.shape.SetAsBox(
Math.random() + 0.1
, Math.random() + 0.1
);
} else {
fixDef.shape = new b2CircleShape(
Math.random() + 0.1
);
}
bodyDef.position.x = Math.random() * 10;
bodyDef.position.y = Math.random() * 10;
this.world.CreateBody(bodyDef).CreateFixture(fixDef);
}
var debugDraw = new Box2D.Dynamics.b2DebugDraw();
debugDraw.SetSprite(document.getElementById("gameCanvas").getContext("2d"));
debugDraw.SetDrawScale(30.0);
debugDraw.SetFillAlpha(0.3);
debugDraw.SetLineThickness(1.0);
debugDraw.SetFlags(Box2D.Dynamics.b2DebugDraw.e_shapeBit | Box2D.Dynamics.b2DebugDraw.e_jointBit);
this.world.SetDebugDraw(debugDraw);
this.world.DrawDebugData();
this.update();
this.scheduleUpdate();
},
update: function () {
var dt = 1 / 60;
var velocityIterations = 6;
var positionIterations = 2;
this.world.Step(dt, velocityIterations, positionIterations);
},
});
cc.director.runScene(new MyScene());
}, this);
};
cc.game.run("gameCanvas");
};
</script>
What could be wrong 
i am very new in cocos2dhtml . Thanks for help 