cocos2d this->getBoundingBox - c++

Question

In a pawn class that inherits from the cocos2d Sprite class, I used this->getBoundingBox() in it's update function. This caused an "Access violation at reading location" error. Then, I swapped "this" with "GAME::PLAYER", a variable in a namespace that references the player and it worked. Why does this->getBoundingBox() cause an error when GAME::PLAYER->getBoundingBox() works perfectly fine? Aren't they supposed to be the same thing? Just to note, "this->" works with any other function but getBoundingBox. Is it something I'm doing wrong? I'm not THAT good with C++
Here's pawn.h
#include <cocos2d.h>
#ifndef PLAYER_CONTROLLER
#define PLAYER_CONTROLLER GAME::PLAYER
class pawn : public cocos2d::Sprite {
public:
pawn();
~pawn();
static pawn* create();
static pawn* create(bool default_moving);
bool moving;
bool right;
int speed;
cocos2d::Rect getBounds();
void step();
void initOptions();
void update(float dt) override;
void move(cocos2d::Vec2 vec);
void moveX(int x);
void moveY(int y);
virtual bool touchBegan(cocos2d::Touch*, cocos2d::Event*);
virtual void touchEnded(cocos2d::Touch*, cocos2d::Event*);
};
namespace GAME {
static pawn* PLAYER;
};
#endif
Here's pawn.cpp
#include "player.h"
#include <cocos2d.h>
pawn::pawn() {
}
pawn::~pawn() {
}
bool pawn::touchBegan(cocos2d::Touch* touch, cocos2d::Event* event) {
this->move(cocos2d::Vec2(5, 0));
this->moving = false;
return true;
}
void pawn::touchEnded(cocos2d::Touch* touch, cocos2d::Event* event) {
this->moving = true;
}
void pawn::step() {
if (this->moving) {
if (this->right) {
this->move(cocos2d::Vec2(this->speed, 0));
}
else {
this->move(cocos2d::Vec2(-this->speed, 0));
}
if (this->getPositionX() < 0) {
this->right = true;
CCLOG("Going right V4");
}
else {
if (this->getPositionX() + this->getContentSize().width > cocos2d::Director::getInstance()->getWinSizeInPixels().width + cocos2d::Director::getInstance()->getVisibleOrigin().x){
this->right = false;
CCLOG("Going left V4");
}
}
}
}
void pawn::move(cocos2d::Vec2 vec) {
PLAYER_CONTROLLER->setPosition(cocos2d::Vec2(PLAYER_CONTROLLER->getPositionX() + vec.x, PLAYER_CONTROLLER->getPositionY() + vec.y));
}
void pawn::moveX(int x) {
}
void pawn::moveY(int y) {
}
void pawn::update(float dt) {
//cocos2d::Rect act = this->getBoundingBox();
this->getPosition();
this->step();
}
cocos2d::Rect pawn::getBounds() {
if (!PLAYER_CONTROLLER) {
CCLOG("Is this the problem?");
}
return PLAYER_CONTROLLER->getBoundingBox();
}
pawn* pawn::create() {
auto character = new pawn();
character->moving = true;
character->right = false;
character->speed = 5;
character->setPositionY(50);
if (PLAYER_CONTROLLER == NULL) {
CCLOG("There is no player, yet.");
CCLOG("Adding player");
PLAYER_CONTROLLER = character;
}
else {
CCLOG("There's already a player");
return NULL;
}
//character->setPositionX(40);
if (character->initWithFile("Base.jpg")){
return character;
}
CC_SAFE_DELETE(character);
return NULL;
}
pawn* pawn::create(bool default_moving) {
pawn* character = new pawn();
character->moving = default_moving;
character->setPositionX(40);
if (character->initWithFile("Base.jpg")){
return character;
}
CC_SAFE_DELETE(character);
return NULL;
}
Is it maybe because I call a pawn method from another class? I use a Collider class to call functions in pawn
Collider.cpp
#include "Collider.h"
#include "player.h"
Collider::Collider() : CollideMode(OVERLAP) {
}
Collider::~Collider() {
}
Collider* Collider::create() {
Collider* col = new Collider;
if (col->initWithFile("Base.jpg")){
col->setAnchorPoint(cocos2d::Vec2(0, 0));
col->setContentSize(cocos2d::Size(100, 100));
return col;
}
CC_SAFE_DELETE(col);
return NULL;
}
void Collider::collision(cocos2d::Vec2 intersect) {
CCLOG("IT IS COLLIDING");
if (intersect.x < intersect.y) {
PLAYER_CONTROLLER->move(cocos2d::Vec2(-intersect.x, 0));
CCLOG("X");
}
else if (intersect.x > intersect.y) {
PLAYER_CONTROLLER->move(cocos2d::Vec2(0, -intersect.y));
CCLOG("Y");
}
}
void Collider::update(float dt) {
//cocos2d::Rect col = this->getBoundingBox();
auto act = PLAYER_CONTROLLER->getBounds();
if (PLAYER_CONTROLLER) {
if (!PLAYER_CONTROLLER) {
CCLOG("There is no player?");
}
}
else {
CCLOG("Not colliding");
}
}

Answer 1

I don't seems any problem with this->getBoundingBox() inside update(float dt) function.
I've created small test :
declaration inside .h file
class MySprite: public Sprite {
public:
bool init() override;
void update(float) override;
CREATE_FUNC(MySprite);
};
Now method definition inside .cpp file
bool MySprite::init(){
if(!Sprite::init())
return false;
scheduleUpdate();
return true;
}
void MySprite::update(float dt){
auto rect=this->getBoundingBox();
CCLOG("Inside Update method of MySprite Bounding rect Width %f & Height %f",rect.size.width,rect.size.height);
}
Then I created an autoreleased object of MySprite and add to parent.
auto mysprite=MySprite::create();
mysprite->setContentSize(Size(10,10));
addChild(mysprite);
Run, Expected result on output console.

Answer 2

I see my mistake. It was the fact that I redefined the namespace "GAME" and it's variable, "GAME::PLAYER" every time I included pawn.h, the other source files that I called the pawn functions from didn't know what GAME::PLAYER or PLAYER_CONTROLLER ( just a macro for GAME::PLAYER ) was, as I had only defined PLAYER_CONTROLLER in pawn.cpp. That's why when you called PLAYER_CONTROLLER->method() in another file, it passed in NULL as "this", and also why PLAYER_CONTROLLER was referring to a different PLAYER_CONTROLLER than the one passed in as "this".
I solved it by using the extern keyword that makes the variables global between all files, which was my original intention.
pawn.h
#include <cocos2d.h>
#ifndef PLAYER_CONTROLLER
#define PLAYER_CONTROLLER GAME::PLAYER
#define INITIALIZE_PLAYER pawn* GAME::PLAYER = NULL
class pawn : public cocos2d::Sprite {
public:
pawn();
~pawn();
static pawn* create();
static pawn* getController();
static pawn* create(bool default_moving);
bool moving;
bool right;
int speed;
cocos2d::Rect getBounds();
void step();
void initOptions();
void update(float dt) override;
void move(cocos2d::Vec2 vec);
void moveX(int x);
void moveY(int y);
virtual bool touchBegan(cocos2d::Touch*, cocos2d::Event*);
virtual void touchEnded(cocos2d::Touch*, cocos2d::Event*);
};
namespace GAME {
extern pawn* PLAYER;
};
#endif
This is why I said I wasn't that good at C++.