void GameLogic::isHit(int mousePressX, int mousePressY)
{
for each(BallObject* ball in ballList) {
for (it = ballList.begin(); it != ballList.end();)
{
bool isHit = ball->EvaluateHit(mousePressX, mousePressY);
if (isHit == true)
{
mScore++;
ballList.remove(ball);
}
else
{
++it;
}
}
}
I am trying to remove ball from "ballList" while playing game via click on surface(ball should dissapear). Program is running correctly until click. When I click, it gives an error from the title. How does it right?
void GameLogic::isHit(int mousePressX, int mousePressY)
{
// iterate all the balls in the list...
for (it = ballList.begin(); it != ballList.end();)
{
bool isHit = (*it)->EvaluateHit(mousePressX, mousePressY);
if (isHit == true)
{
mScore++;
// This invalidates iterators, and is linear in complexity
// (it iterates the list too, but you're already doing that)
// ballList.remove(ball);
// erase the ball at this iteration, save off the result
// so you can continue iterating
it = ballList.erase(it);
}
else
{
// if the ball wasn't hit, increment the iterator normally
++it;
}
}
}
Related
I am new to c++ and am currently learning sfml.
I have set up a system that adds one 'Snowpile' object to the vector. But when I keep hitting errors like "can't increment vector past iterator past end" or that it's outside the scope.
std::vector<Snowpile*> snowpiles;
I want it to check every snowpile for the removed2 bool, and delete the ones that do have it.
for (auto s_it = snowpiles.begin(); s_it != snowpiles.end(); s_it++) {
int sindex = std::distance(snowpiles.begin(), s_it);
if (snowpiles[sindex]->getSprite_S().getGlobalBounds().intersects(player.getSpriteP().getGlobalBounds()) && snowpiles[sindex]->melting == false) {
snowpiles[sindex]->melting = true;
}
else if (snowpiles[sindex]->getSprite_S().getGlobalBounds().intersects(player.getSpriteP().getGlobalBounds()) && snowpiles[sindex]->melting == true) {
snowpiles[sindex]->melting = true;
}
else if (!snowpiles[sindex]->getSprite_S().getGlobalBounds().intersects(player.getSpriteP().getGlobalBounds()) && snowpiles[sindex]->melting == true) {
snowpiles[sindex]->melting = false;
}
snowpiles[sindex]->meltedrem(sindex, snowpiles, m_win);
if (snowpiles[sindex]->removed2 == true)
{
cout << "Detected removed 2 at " << sindex << endl;
//delete snowpiles[sindex];
snowpiles.erase(snowpiles.begin() + sindex - 1);
}
}
The melting parts determine whether the player is on top of a snowpile. The meltdrem functions checks for bool 'melting' == true and then proceeds to start the timer. After a few seconds (+ animations) it sets the bool removed2 to true.
I know that at the program at least sees the bools changing, so thats not it.
Am I simply using vector wrong, or do I need to change something in my loop?
The loop is located in the while(window.isOpen()) loop in int main.
For starters it is unclear why there is used the expression
snowpiles.erase(snowpiles.begin() + sindex - 1);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
instead of
snowpiles.erase(snowpiles.begin() + sindex);
^^^^^^^^^^^^^^^^^^^^^^^^^^
if in a comment you wrote
//delete snowpiles[sindex];
You need to increase the iterator in the for loop only when a current object was not removed.
Change the loop the following way
for (auto s_it = snowpiles.begin(); s_it != snowpiles.end(); ) {
//...
if (snowpiles[sindex]->removed2 == true)
{
cout << "Detected removed 2 at " << sindex << endl;
//delete snowpiles[sindex];
s_it = snowpiles.erase( s_it );
}
else
{
++s_it;
}
}
void head_insert(DomesticPtr& head, string firstNameD, string lastNameD, string province, float cgpaD, int researchScoreD, int idD)
{
DomesticPtr temp_ptr;
DomesticPtr temp2;
temp_ptr= new DomesticStudent(head, firstNameD, lastNameD, province,cgpaD,researchScoreD,idD);
temp2 = head->getLink();
temp2==temp_ptr;
head=temp_ptr;
if (head->getLink() == NULL)
return;
else
{
bubblesort(head);
}
}
void bubblesort(DomesticStudent* head)
{
int rsd;
int cgpad;
int p;
DomesticPtr tempc, tempd, tempe;
tempd=head;
tempe= head->getLink();
{
while(tempd != NULL)
{
rsd=compareResearchScore(tempd, tempe);
if (rsd==1)
{
tempc=head;
head->next=head;
head=tempc;
}// if
else if (rsd==0)
{
cgpad= compareCGPA(tempe,tempd);
if (cgpad==1)
{
tempc=head;
head->next=head;
head=tempc;
}// if (cgpad[k]>cgpad[k+1])
else if(cgpad==0)
{
p=compareProvince(tempd,tempe);
if(p==1)
{
tempc=head;
head->next=head;
head=tempc;
}// if (p[k]>p[k+1])
}//
}// else if cgpad[k]
}// else if rsd[k]
// }
// }
tempd = tempe;
}
int compareResearchScore(DomesticPtr RSA, DomesticPtr RSB)
{
if (RSB == NULL || RSA==NULL )
{
return 0;
}
if (RSA->researchScoreD==RSB->researchScoreD) //compares if is the same for domesetic students returns value for bubble sort
{
return 0;
}
if (RSA->researchScoreD > RSB->researchScoreD)
{
return 1;
}
if (RSA->researchScoreD< RSB->researchScoreD)
{
return -1;
}
}
I'm trying to to have my linked list sorted every time a new node is inserted. It compiles but every time I try to run the program it is stuck on the point that I am trying to print my list. I have a destructor but no copy constructor or assignment operator.
The head_insert calls the sort function and the sort function calls the compare function to receive an integer output so that it can make a swap. I want to compare research, the cgpa, and then province. Any input would be much appreciated, this is for a project so I wouldn't like any blocks of code but if you could point me in the right direction or multiple directions.
I'm having an incredibly difficult time programming Space Invaders for a class. I am supposed to use a list to store my "missiles" and a list to store my "aliens" as well. I press space bar to load in a new alien, and when the two contact, I am attempting to delete both of them, and I can't even get past deleting the "alien". I get a variety of bugs when more than one missile is fired, and the missiles work fine if this function is commented out. I am forced to pass a list of missiles into another class that already contains a list of aliens and delete both.
Here is the offending code:
bool AlienMgr::checkHit(PlayerMgr& playerMgr)
{
bool hit = false; // If the player hits an alien, switches to true and is returned.
list<Missile*>::iterator missileIter;
list<Missile*> missileList = playerMgr.getMissiles();
int missileCount;
FloatRect missileBounds;
FloatRect alienBounds;
iter = myAliens.begin();
while (!myAliens.empty() && iter != myAliens.end())
{
alienBounds = (*iter)->getGlobalBounds();
if (!missileList.empty() && !hit)
{
for (missileIter = missileList.begin(); missileIter != missileList.end() && !hit; missileIter++)
{
missileBounds = (*missileIter)->getMissileBounds();
if (alienBounds.intersects(missileBounds))
{
delete (*iter);
iter = myAliens.erase(iter);
cout << "HIT" << endl;
}
else
{
iter++;
}
}
}
else
{
iter++;
}
}
return hit;
}
You have several problems in your code. I've tried to clean them up. Also, I hope you can use c++ 11.
bool AlienMgr::checkHit(PlayerMgr& playerMgr)
{
bool hit = false; // If the player hits an alien, switches to true and is returned.
list<Missile*> missileList = playerMgr.getMissiles();
int missileCount;
FloatRect missileBounds;
FloatRect alienBounds;
// iter == myAliens.end() if it's empty
for (auto iter = myAliens.begin(); iter != myAliens.end();)
{
bool hitDetected = false;
alienBounds = (*iter)->getGlobalBounds();
// remove all missiles intersecting current alien and set flag
missileList.remove_if([&](Missile* missile)
{
if (!alienBounds.intersects(missile->getMissileBounds()))
return false;
hitDetected = true;
delete missile;
return true;
});
if (hitDetected)
{
hit = true;
delete (*iter);
iter = myAliens.erase(iter);
cout << "HIT" << endl;
else
{
iter++;
}
}
return hit;
}
However, there are more critical problems. Your code is too c++98'ish.
I would advise several improvements:
Use std::vector instead of std::list (it's really hard to find case when list will be faster)
Use smart pointers instead of manual memory management (code would be much simple and easier to understand)
I have a bullet class. and I try to instantiate it by the following code:
I always get an assertion that there is a memory that is in use.. why?
In another class called ship:
if (g_Input.isKeyDown(s3eKeySpace))// && Canfire)
{
Bullet *bullet = new Bullet();
bullet->Init(SHIP_BULLET);
bullet->setPosition(Position.x, Position.y - 20);
Bullets->push_back(bullet);
Canfire = false;
}
This is called each frame which causes memory still in usage:
for (list<Bullet*>::iterator it = Bullets->begin(); it != Bullets->end();)
{
(*it)->Update(dt);
if ((*it)->IsDestroyed)
{
Canfire = true;
it = Bullets->erase(it);
}
else
{
it++;
Canfire = false;
}
}
the destructor of the Ship class
Ship::~Ship()
{
for (std::list<Bullet*>::iterator it = Bullets->begin(); it != Bullets->end(); ++it)
delete *it;
delete Bullets;
}
class Bullet
{
public:
Bullet();
~Bullet();
public:
void Init(BulletTypes bulletType);
void Update(float dt);
void Render();
CIw2DImage* Image; // curr image
}
void Bullet::Init(BulletTypes bulletType)
{
BulletType = bulletType;
if (BulletType == SHIP_BULLET)
{
Image = Iw2DCreateImage("textures/ship_bullet.png");
if (Image == nullptr)
return;
}
}
Bullet::~Bullet()
{
delete Image;
}
Executing this code causes the leak:
for (list<Bullet*>::iterator it = Bullets->begin(); it != Bullets->end();)
{
(*it)->Update(dt);
if ((*it)->IsDestroyed)
{
Canfire = true;
it = Bullets->erase(it);
}
else
{
it++;
Canfire = false;
}
}
What is going on is basically you removing a dynamically allocated element from a container, losing any reference to it thus you cannot free its memory anymore. Calling Ship destructor only frees the elements that are currently in the list, excluding the ones removed in the iteration, obviously.
I suggest this as a fix:
for (list<Bullet*>::iterator it = Bullets->begin(); it != Bullets->end();)
{
(*it)->Update(dt);
if ((*it)->IsDestroyed)
{
Canfire = true;
delete *it; // it now points to invalid address
it = Bullets->erase(it);
}
else
{
it++;
Canfire = false;
}
}
Another option would be to store all removed bullets in some other container in class Ship in case that a Bullet can be referenced after it was destroyed. Problem with this idea is that you have alot of destroyed bullets taking up memory and have to come up with a solution on how to remove them once they really prove useless.
If you get stuck with that, using std::shared_ptrs instead of raw pointers in the list could solve your issue (for slight performance penalty).
I'm getting a "incompatible vector iterator" error to what i believe is a invalid iterator
void Bomb::CreateExplosion(Game_Manager* EGame_Manager)
{
for(irr::f32 iteration = 0; iteration < BlastRadius; iteration++) //up direction blast
{
***//PROGRAM CRASHES AT THIS LINE-->*** for(EGame_Manager->getEntityManager()->GetEntityIterator() = EGame_Manager->getEntityManager()->GetEntityList().begin(); EGame_Manager->getEntityManager()->GetEntityIterator() != EGame_Manager->getEntityManager()->GetEntityList().end(); ++EGame_Manager->getEntityManager()->GetEntityIterator())
{
if(CheckForCollision(UpExplosion->getTransformedBoundingBox(), (*EGame_Manager->getEntityManager()->GetEntityIterator())->GetEntityNode()->getTransformedBoundingBox()) == true)//check for collision against the unbreakable blocks (entity.type equals 0)
{
if((*EGame_Manager->getEntityManager()->GetEntityIterator())->GetType() == unbreakableblock)
{
break;
}
else if((*EGame_Manager->getEntityManager()->GetEntityIterator())->GetType() == gameplayer)
{
(*EGame_Manager->getEntityManager()->GetEntityIterator())->SetLives(this->GetLives() -1);
break;
}
else if((*EGame_Manager->getEntityManager()->GetEntityIterator())->GetType() == gameitem)
{
break;
}
}
else
{
UpExplosion->setScale(irr::core::vector3df(1,1,iteration)); //standard width of UpExplosion, iterated height of the UpExplosion
}
}
}
CreateExplosion is called by Bomb::UpdateEntity() which is called by EntityManager::UpdateList() which then loops through the vector<*Entity> List calling each Entity's respective Update function.
This function adds the Entities to the vector I'm not sure if it causes the problem
EntityManager::AddEntity(Entity* addtoList)
{
List.push_back(addtolist);
addtolist->GetEntityNode()->setID(List.size());
EntityIterator = List.begin();
}
Also the instance of the Bomb class that calls these functions is declared in the Player class if that helps with anything. And I can post more code if needed.