How to remove a sprite/b2body after a delay of time? - ios

Question

Thanks advance for your time!
I'm doing a project with box2d. When I first touch the screen, a bird will be created in the box2d world, as follows
- (void)createBird
{
//init bird
bird = [CCSprite spriteWithFile:#"bird.png"];
bird.scale = 23/[bird boundingBox].size.width;
bird.position = center;
[self addChild:bird z:12];
}
Then, if the touch ends, the bird will be given a force
//add box2d body
b2BodyDef birdBodyDef;
birdBodyDef.type=b2_dynamicBody;
birdBodyDef.userData = (__bridge void*)bird;
birdBodyDef.position.Set(bird.position.x/PTM_RATIO,bird.position.y/PTM_RATIO);
birdBody=world->CreateBody(&birdBodyDef);
//create circle shape
b2CircleShape birdShape;
birdShape.m_radius=([bird boundingBox].size.width-6)/PTM_RATIO/2;
// Create shape definitio and add to body
b2FixtureDef birdFixtureDef;
birdFixtureDef.shape=&birdShape;
birdFixtureDef.density=1.6f;
birdFixtureDef.friction=0.3f;
birdFixtureDef.restitution=0.3f;
birdFixture = birdBody -> CreateFixture(&birdFixtureDef);
// Apply force
b2Vec2 force = b2Vec2(-2.0f*distance,-2.0f*distance);
birdBody->ApplyForce(force,birdBody->GetWorldCenter());
birdBody->SetLinearDamping(0.2f);
Then, when I touch the screen again, another bird will be created with the "createBird" method.
I want to delete the first bird after it has been created for 5 seconds. But at that time, the "CCSprite *bird" and "b2Body *birdBody" will be pointing to the second bird, so how can I delete the first one?
Thanks!

Answer 1

I'm not sure I understand your question exactly, but this might help. Call before you create the new bird.
if ( bird ) {
id delayTimeAction = [CCDelayTime actionWithDuration:5.0];
id removeMySprite = [CCCallFuncND actionWithTarget:bird selector:#selector(removeFromParentAndCleanup:) data:(void*)NO];
[bird runAction:[CCSequence actions: delayTimeAction, removeMySprite, nil]];
}
edit:
init an array
NSMutableArray *birds = [NSMutableArray new];
Then call this in create bird function
[birds addObject:newBird];
if ( [birds count] > 1 ) {
oldBird = [birds firstObject];
//Call remove function on oldBird
[birds removeObject:oldBird];
}

Answer 2

One way would be giving your bird tag and then saving them into an Nsmutuable dictionary.
Keep traversing that dictionary and then after your bool variable for destroy is been set destroy the body.....
I have done the same thing using classes.... The fact is you will need to destroy body any case. (Else you will face fps issues later)