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POcreating a class that returns a b2Body issue
 

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  1. POcreating a class that returns a b2Body issue
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    <p>I have to created a class that returns a b2Body, which I am trying to access in the HelloWorldLayer.mm file. See the circle class below:</p> <p>the Circle.h</p> <pre><code>#import &lt;Foundation/Foundation.h&gt; #import "cocos2d.h" #import "Box2D.h" #import "PhysicsSprite.h" #define PTM_RATIO 32 @interface Circle : CCLayer { } +(b2Body *)rCircle; @end </code></pre> <p>and the Circle.mm</p> <pre><code>#import "Circle.h" @implementation Circle +(b2Body *)rCircle { //body and fixture defs for circleSprite b2World *world_; b2BodyDef bodyDef; bodyDef.type = b2_dynamicBody; b2FixtureDef fixtureDef; fixtureDef.density = 0.1; b2PolygonShape polygonShape; fixtureDef.shape = &amp;polygonShape; PhysicsSprite* circleBodySprite = [PhysicsSprite spriteWithFile:@"circleB.png"]; //[self addChild:circleBodySprite z:1]; //body with circle fixture b2CircleShape circleShape; circleShape.m_radius = circleBodySprite.contentSize.width/2 / PTM_RATIO; fixtureDef.shape = &amp;circleShape; b2Body* chainBase = world_-&gt;CreateBody( &amp;bodyDef ); chainBase-&gt;CreateFixture( &amp;fixtureDef ); [circleBodySprite setPhysicsBody:chainBase]; return chainBase; } @end </code></pre> <p>I keep getting EXC_BAD_ACCESS error pointing to the line:</p> <pre><code> b2Body* chainBase = world_-&gt;CreateBody( &amp;bodyDef ); </code></pre> <p>I don't know what I've done wrong. I've also been accessing the <code>b2Body</code> in the HelloWorldLayer.mm in the following way:</p> <pre><code>[Circle rCircle]; </code></pre> <p>Which also gives a <code>EXC_BAD_ACCESS</code> error.</p> <p>I want the class to return a <code>b2Body</code> so I can create a joint in the HelloWorldLayer.mm. </p>
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    1. PTQuestion
    1. USBart
    1. USwilM
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    1. COAm I overlooking something or have you simply not created your `b2World`? `world_ = new b2World()`
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      1. POcreating a class that returns a b2Body issue
      1. USBart
    2. COI don't really understand why I've got to initialize the world as you stated. `world = new b2World(gravity);` I've already done that in the HelloWorldLayer.mm class. Wouldn't that be creating two world's? please explain. I just want my `rCircle` method to return a b2Body which I plan to use in the `HelloWorldLayer.mm` to create a joint with another body.
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      1. POcreating a class that returns a b2Body issue
      1. USwilM
    3. COUnfortunately Objective-C is not my forté, so I don't completely follow it, but I don't see where you set your `world_` to be the one you created. Perhaps someone more versed in the language can help you with that, if that's the problem to begin with.
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      1. USBart
 

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