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PObody null when accessed from another method
 

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    <p>I have a contact listener that handles contact between two box2d bodies. I am accessing the bodies from the Contacter in the HelloWorldLayer since box2d recommends that contacting bodies should be saved and changes implemented after the timestep. Please see the code below:</p> <p>Contacter.h:</p> <pre><code>#import "CCPhysicsSprite.h" @interface Contacter : CCPhysicsSprite { } @property(nonatomic, assign) NSMutableArray* arrayOfBodies; @property(nonatomic, assign) CCPhysicsSprite* spriteToDestroy; -(void)physicsSpritesContact:(CCPhysicsSprite*)onePhysicsSprite otherSprite:(CCPhysicsSprite*)twoPhysicsSprite; @end </code></pre> <p>Contacter.mm:</p> <pre><code>#import "Contacter.h" #import "Box2D.h" @implementation Contacter @synthesize arrayOfBodies = _arrayOfBodies; @synthesize spriteToDestroy = _spriteToDestroy; -(void)destroyBodies:(b2Body*)body { _arrayOfBodies = [[NSMutableArray alloc] init]; NSValue *bodyValue = [NSValue valueWithPointer:body]; [_arrayOfBodies addObject:bodyValue]; } -(void)physicsSpritesContact:(CCPhysicsSprite*)onePhysicsSprite otherSprite: (CCPhysicsSprite*)twoPhysicsSprite; { int firstTag = onePhysicsSprite.tag; int secondTag = twoPhysicsSprite.tag; if (((firstTag == 90) &amp;&amp; (secondTag == 101 )) || ((firstTag == 101) &amp;&amp; (secondTag == 90))) { if (tag1 == 90) { [self destroyBodies:onePhysicsSprite.b2Body];// adds body to array to be destroyed spriteToDestroy = onePhysicsSprite; // taking note of sprite to be destroyed } else if (tag2 == 90) { [self destroyBodies:twoPhysicsSprite.b2Body]; spriteToDestroy = twoPhysicsSprite; } } </code></pre> <p>}</p> <p>The following method within HelloWorldLayer.mm is called in the update method:</p> <pre><code>-(void)removeDestroyedBodiesAndSprites { bodyContact = [Contacter node]; if ([bodyContact arrayOfBodies]) { for (NSValue* bodyValue in [bodyContact arrayOfBodies]) { b2Body *removeBody; removeBody = (b2Body*)[bodyValue pointerValue]; world-&gt;DestroyBody(removeBody); removeBody = NULL; [self removeChild:[bodyContact spriteToDestroy]]; } } } </code></pre> <p>There is contact but the sprite is not removed and body is not destroyed in removeDestroyedBodiesAndSprites. After testing with a CCLOG I found that the for loop was not satisfied meaning that the arrayOfBodies could be null. Which is surprising since the contact was established. I would appreciate your assistance.</p> <p><strong>UPDATED</strong></p> <p>Below is the contact listener:</p> <p>TestContactListener.h:</p> <pre><code>#import &lt;Foundation/Foundation.h&gt; #import "cocos2d.h" #import "Box2D.h" #import "GameObjects.h" #import "Contacter.h" class TestContactListener : public b2ContactListener { public: Contacter* contacter; void BeginContact(b2Contact* contact); }; </code></pre> <p>TestContactListener.mm:</p> <pre><code>#import "TestContactListener.h" void TestContactListener:: BeginContact(b2Contact *contact) { contacter = [Contacter node]; b2Fixture *fixtureA = contact-&gt;GetFixtureA(); b2Fixture *fixtureB = contact-&gt;GetFixtureB(); b2Body *fixtureABody = fixtureA-&gt;GetBody(); b2Body *fixtureBBody = fixtureB-&gt;GetBody(); CCPhysicsSprite* physicsSprite = (CCPhysicsSprite*)fixtureABody-&gt;GetUserData(); CCPhysicsSprite* physicsSprite2 = (CCPhysicsSprite*)fixtureBBody-&gt;GetUserData(); [contacter physicsSpritesContact:physicsSprite otherSprite:physicsSprite2]; } </code></pre>
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