How to make trigger area in Cocos2d - c++

Question

I am doing a Flappy Bird game following some tutorials. To count up the score, I have set PhysicsBody among the score area, but it is just like a Rigibody in Unity, other objects cannot get through it.
You can take reference at https://www.youtube.com/watch?v=3zGTCGgwt_U&list=PLRtjMdoYXLf7GSD9crXIjMQiRuIZ7mUVp&index=12, it is the result that I want. I followed it but I don't know why here comes a difference.
In my situation, the score line blocks my flying bird. As the score lines and pipes are moving backward, my flappy bird is pushed by the score line until it reaches the screen edge and turns out a gameover.
I want something like a Trigger Collider in Unity. Is there any similar thing in cocos2d?
Also attach my code here, it spawns the pipes as well as the score line:
void Pipe::Spawn(Layer* pipeLayer) {
auto upperPipe = Sprite::create("pipe_upper.png");
upperPipe->setAnchorPoint(Vec2(0.5,0));
upperPipe->setScale(spriteScale);
auto upperPipeBody = PhysicsBody::createBox(upperPipe->getContentSize());
upperPipeBody->setDynamic(false);
upperPipeBody->setCollisionBitmask(OBSTACLE_COLLISION_BITMASK);
upperPipeBody->setContactTestBitmask(true);
upperPipe->setPhysicsBody(upperPipeBody);
auto bottomPipe = Sprite::create("pipe_bottom.png");
bottomPipe->setAnchorPoint(Vec2(0.5,1));
bottomPipe->setScale(spriteScale);
auto bottomPipeBody = PhysicsBody::createBox(bottomPipe->getContentSize());
bottomPipeBody->setDynamic(false);
bottomPipeBody->setCollisionBitmask(OBSTACLE_COLLISION_BITMASK);
bottomPipeBody->setContactTestBitmask(true);
bottomPipe->setPhysicsBody(bottomPipeBody);
float randomPosIndex = CCRANDOM_0_1();
if (randomPosIndex < PIPE_BOTTOM_THRESHOLD) {
randomPosIndex = PIPE_BOTTOM_THRESHOLD;
}
else if (randomPosIndex > PIPE_UPPER_THRESHOLD) {
randomPosIndex = PIPE_UPPER_THRESHOLD;
}
float gapHeight = Sprite::create("flappybird1_01.png")->getContentSize().height * spriteScale * PIPE_GAP_INDEX;
Size visibleSize = Director::getInstance()->getVisibleSize();
//setup bottom pipe
bottomPipe->setPosition(Point(visibleSize.width, visibleSize.height * randomPosIndex));
//setup upper pipe
upperPipe->setPosition(Point(visibleSize.width, bottomPipe->getPositionY() + gapHeight));
//setup score area
auto scoreNode = Node::create();
auto scoreNodeBody = PhysicsBody::createBox(Size(1, gapHeight));
scoreNodeBody->setDynamic(false);
scoreNodeBody->setCollisionBitmask(SCORE_COLLISION_BITMASK);
scoreNodeBody->setContactTestBitmask(true);
scoreNode->setPhysicsBody(scoreNodeBody);
scoreNode->setPosition(Point(bottomPipe->getPositionX(), bottomPipe->getPositionY() + gapHeight / 2));
auto bottomPipeAction = RepeatForever::create(MoveBy::create(1, Vec2(-PIPE_MOVE_SPEED, 0)));
auto upperPipeAction = RepeatForever::create(MoveBy::create(1, Vec2(-PIPE_MOVE_SPEED, 0)));
auto scoreNodeAction = RepeatForever::create(MoveBy::create(1, Vec2(-PIPE_MOVE_SPEED, 0)));
bottomPipe->runAction(bottomPipeAction);
upperPipe->runAction(upperPipeAction);
scoreNode->runAction(scoreNodeAction);
pipeLayer->addChild(bottomPipe);
pipeLayer->addChild(upperPipe);
pipeLayer->addChild(scoreNode);
CCLOG("Spawn Pipe");
}

Answer 1

Credits to ryemoss's reference. Simply return false in the collision callback function solves everything!
bool GameScene::onContactBegin(PhysicsContact &contact)
{
PhysicsBody* a = contact.getShapeA()->getBody();
PhysicsBody* b = contact.getShapeB()->getBody();
if ( (a->getCollisionBitmask() == FLAPPYBIRD_COLLISION_BITMASK && b->getCollisionBitmask() == OBSTACLE_COLLISION_BITMASK) ||
(b->getCollisionBitmask() == FLAPPYBIRD_COLLISION_BITMASK && a->getCollisionBitmask() == OBSTACLE_COLLISION_BITMASK)
)
{
auto gameoverScene = GameOverScene::createScene();
Director::getInstance()->replaceScene(TransitionFade::create(SCENE_TRANSITION_DURATION, gameoverScene));
}
else if ((a->getCollisionBitmask() == FLAPPYBIRD_COLLISION_BITMASK && b->getCollisionBitmask() == SCORE_COLLISION_BITMASK) ||
(b->getCollisionBitmask() == FLAPPYBIRD_COLLISION_BITMASK && a->getCollisionBitmask() == SCORE_COLLISION_BITMASK))
{
score++;
CCLOG("Score Count: %i", score);
return false;
}
return true;
}