Box2D Forums

_player = [[[HopperShip alloc] initWithSpriteFrameName:@"SpaceFlier_sm_1.png" maxHp:50 healthBarType:HealthBarTypeGreen] autorelease];
b2BodyDef bodyDef;
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(_player.position.x/PTM_RATIO, _player.position.y/PTM_RATIO);
        shipBody = world->CreateBody(&bodyDef);
        bodyDef.userData = _player;

        b2PolygonShape shape;
        shape.SetAsBox(_player.contentSize.width/2/PTM_RATIO, _player.contentSize.height/2/PTM_RATIO);
       
        b2FixtureDef fixtureDef;
        fixtureDef.shape = &shape;
        fixtureDef.density = 0.0;
        fixtureDef.friction = 0.5;
        fixtureDef.restitution = 0.5;

        shipBody->CreateFixture(&fixtureDef);

target = [WeakAndFastShipTarget target];
        b2BodyDef bodyDef;
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(target.position.x/PTM_RATIO, target.position.y/PTM_RATIO);
        cometBody = world->CreateBody(&bodyDef);
        bodyDef.userData = target;

        b2PolygonShape shape;
        shape.SetAsBox(target.contentSize.width/2/PTM_RATIO, target.contentSize.height/2/PTM_RATIO);
       
        b2FixtureDef fixtureDef;
        fixtureDef.shape = &shape;
        fixtureDef.density = 0.0;
        fixtureDef.friction = 0.5;
        fixtureDef.restitution = 0.5;
       
        cometBody->CreateFixture(&fixtureDef);

- (void)spriteMoveFinished:(id)sender{
    //include finishShoot logic
    CCSprite *sprite = (CCSprite *)sender;//get the passed in sprite
       
    [self removeChild:sprite cleanup:YES];
    NSLog(@"child TRGT removed:OFFSCREEN");
    // hmm already removed it...or is this better?
    [_targets removeObject:sprite];
    NSLog(@"target removed:OFFSCREEN");
   
    //must cycle thru these sprites and get the body to remove it
    //in case the asteroid didnt get shot
   
    //BOX2D REMOVE BODY OF SPRITE
    b2Body *spriteBody = NULL;//create an empty body
    for(b2Body *b=world->GetBodyList(); b!=NULL; b=b->GetNext()) {//loop thru all bodies
        if (b->GetUserData() != NULL) {//if there is a userData attached to the body, which there is...
            //Box2DSprite *sprite = (Box2DSprite *) b->GetUserData();
            CCSprite *curSprite = (CCSprite*) b->GetUserData();//We know the userData we set is the sprite target object, so put it into curSprite
            if (sprite == curSprite) {//if the passed in sprite is the same as the box2d body gotten one....
                spriteBody = b; //put that body into the spriteBody null instance we created and breakOUT
                break;
            }
        }
    }
    if (spriteBody != NULL) {
        [self destroyBody:spriteBody];
    }
   
}

//wrong
world->CreateBody(&bodyDef);
bodyDef.userData = _player; //this setting is ignored

//right
bodyDef.userData = _player;
world->CreateBody(&bodyDef);