void Player::physicsSetUp()
{
	//listen to contacts
	auto contactListener = EventListenerPhysicsContact::create();
	contactListener->onContactBegin = CC_CALLBACK_1(Player::onContactBegin, this);
	contactListener->onContactSeperate = CC_CALLBACK_1(Player::onContactSeperate, this);
	_eventDispatcher->addEventListenerWithSceneGraphPriority(contactListener, this);

	//physics body
	auto playerPhysicsBody = PhysicsBody::createBox(Size(getBoundingBox().size.width, getBoundingBox().size.height*0.25));
	playerPhysicsBody->setPositionOffset(Point(0, -getBoundingBox().size.height*0.35));
	playerPhysicsBody->setContactTestBitmask(PLAYER_CONTACT_MASK);
	playerPhysicsBody->setRotationEnable(false);
	setPhysicsBody(playerPhysicsBody);
}