Cocos2d-x crash due to ccLayer->schedule(schedule_selector(...), ...);

Question

I have Android development background. A few days ago, I started to learn Cocos2d-x for game development. I was creating a simple splash screen and some menu screen but got stuck on some app crash issue. I want Splash Scene to stay for 3 seconds and to load MenuScene after that. So I tried to use schedule method to replace the scenes. But I am getting crash when it comes to execute the scheduled task. Here are my simple classes;

Splash.h class:

#ifndef SPLASHSCREEN_H_
#define SPLASHSCREEN_H_

#include <layers_scenes_transitions_nodes/CCLayer.h>
#include <cocos2d.h>

/**
 * Splash Screen for the game
 *
 */

USING_NS_CC;

class SplashScreen: public cocos2d::CCLayer {
public:
    SplashScreen();
    virtual ~SplashScreen();
    virtual bool init();
    static cocos2d::CCScene* newInstance();
    void endSplash(float dt);

    // implement the "static node()" method manually
    CREATE_FUNC(SplashScreen);


};

#endif

SplashScreen.cpp:

    #define COCOS2D_DEBUG 1

#include "SplashScreen.h"
#include "GeneralMenuScreen.h"


USING_NS_CC;

SplashScreen::SplashScreen() {
    // TODO Auto-generated constructor stub

}

SplashScreen::~SplashScreen() {
    // TODO Auto-generated destructor stub
}

bool SplashScreen::init() {

    if(! CCLayer::init() ) {
        return false;
    }
    CCSize windowSize = CCDirector::sharedDirector()->getVisibleSize();
    CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();

    CCSprite* background = CCSprite::create("background.png");
    background->setPosition(ccp(origin.x + windowSize.width/2, origin.y + windowSize.height/2));
    this->addChild(background);

    CCLabelTTF* loadingText = CCLabelTTF::create("Loading...", "Arial", 36);
    loadingText->setAnchorPoint(ccp(0,0));
    loadingText->setPosition(ccp(origin.x + windowSize.width/2 - loadingText->getContentSize().width/2, origin.y + windowSize.height/2 - loadingText->getContentSize().height/2));
    this->addChild(loadingText);

    /*  this->schedule(schedule_selector(SplashScreen::endSplash), 5.0);        */
CCDirector::sharedDirector()->getScheduler()->scheduleSelector(schedule_selector(SplashScreen::endSplash), this , 5, false, 0, 0 );

/*   CCTimer* ccTimer = CCTimer::timerWithTarget(this, schedule_selector(SplashScreen::endSplash), 5.0f);
ccTimer->update(1.0);       */


/* CCDelayTime* startDelay = CCDelayTime::create(5.0);
CCCallFunc *showHearts = CCCallFunc::create(this, callfunc_selector(SplashScreen::endSplash));
CCSequence* seq = CCSequence::create(startDelay, showHearts);
background->runAction(seq);*/

    return true;

}


CCScene* SplashScreen::newInstance() {

    // 'scene' is an autorelease object
    CCScene* scene = CCScene::create();

    // 'layer' is an autorelease object
    SplashScreen* splashScreen = SplashScreen::create();

    scene->addChild(splashScreen);

    return scene;

}

void SplashScreen::endSplash(float dt) {

    //CCLOG("FilePath = %f", dt);
    CCScene* menuScreen = GeneralMenuScreen::newInstance();
    CCDirector::sharedDirector()->replaceScene(menuScreen);

}

GeneralMenuScreen.cpp:

#include "GeneralMenuScreen.h"

USING_NS_CC;

GeneralMenuScreen::GeneralMenuScreen() {

}

GeneralMenuScreen::~GeneralMenuScreen() {

}

CCScene* GeneralMenuScreen::newInstance() {

    CCScene* scene = CCScene::create();
    GeneralMenuScreen* layer = GeneralMenuScreen::create();
    scene->addChild(layer);

    return scene;

}

bool GeneralMenuScreen::init() {

    if( ! CCLayer::init()) {
        return false;
    }

    CCSize windowSize = CCDirector::sharedDirector()->getVisibleSize();
    CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();

    CCSprite* background = CCSprite::create("background.png");
    background->setPosition(ccp(origin.x + windowSize.width/2, origin.y + windowSize.height/2));
    this->addChild(background);

    int margin = 10;

    CCLabelTTF* playLabel = CCLabelTTF::create("PLAY", "Arial", 36);
    CCMenuItemLabel* menuPlay = CCMenuItemLabel::create(playLabel);
    menuPlay->setPosition(origin.x + windowSize.width/2 - menuPlay->getContentSize().width/2, origin.y + windowSize.height/2 + menuPlay->getContentSize().height + margin/2 );

    CCMenu* menu = CCMenu::create(menuPlay);
    menu->setPosition(CCPointZero);
    this->addChild(menu);


    return true;


}

The splash screen runs but after 3 secods, the endSplash method is not being called and app crashed. I have never programmed in C/C++. Any idea where I am going wrong? And also, is there any way to debug the cocos2d-x apps using some debugger like we have in android/ios?

score 0 · Accepted Answer · answered Dec 02 '13 at 09:23

0

You can use gdb for debugging.

What are you writing those getInstance methods for? Pair of create + init should suffice in most cases.

Maybe try using CCDirector::sharedDirector()->getScheduler()->scheduleSelector or just run action calling some method on your object: http://www.cocos2d-x.org/reference/native-cpp/V3.0alpha0/d3/d32/classcocos2d_1_1_call_func.html . It is easier to manager actions running on your objects than to deal with a scheduler IMO.

When having such errors you may want to try placing some asserts checking if objects aren't dead (check if not nullptr and retaincount). And off course run it with debugger to see where the explosion happens. Right now I cannot find errors in your code, I'll try to run it later at home.

answered Dec 02 '13 at 09:23

kuhar

338
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I have tried different timer related things but nothing is working. I am very frustrated now. Please see the question again. I have added different approaches I used. – Khawar Raza Dec 02 '13 at 14:55
The endSplash function is never called whatever method I use. – Khawar Raza Dec 02 '13 at 14:56
Well, the problem is solved but in a strange way. Firstly I was developing for Android platform. Then I ported my code to XCode. Same thing happened there. this->schedule() was also not working. So i replaced it with CCDirector::sharedDirector()->getScheduler()->scheduleSelector() and it worked :) Don't know what was the problem. And also I got the extra feature of debugging app with XCode because XCode can debug your Cocos2d-x code like we do in Eclipse for Android. – Khawar Raza Dec 05 '13 at 18:01

kuhar · Answer 2 · 2013-12-02T19:41:46.487

0

So after a little investigation:

constructor of a CCObject should be private (read as: pretty much always must be)
in CCObject.h it is a good idea to replace defualt c-like castring with static_cast --> you'll avoid many hours of debugging selectors
your code works for me under VC12 (but I used pushScene instead of replaceScene) --> are you using master branch of cocos?

edited Dec 02 '13 at 19:41

answered Dec 02 '13 at 19:00

kuhar

338
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score 0 · Answer 3 · answered Dec 03 '13 at 04:55

Instead of this...

CCDirector::sharedDirector()->getScheduler()->scheduleSelector(schedule_selector(SplashScreen::endSplash), this , 5, false, 0, 0 );

Try this..

this->scheduleOnce(schedule_selector(SplashScreen::endSplash),delayTime);

where delayTime =3 or anything.

score 0 · Answer 4 · answered Dec 05 '13 at 11:53

0

Use this it will work for you

schedule(SEL_SCHEDULE(&SplashScreen::endSplash), 5);

answered Dec 05 '13 at 11:53

Singhak

8,508
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This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. – Voonic Dec 05 '13 at 12:14
Ok I will remmber next time – Singhak Dec 06 '13 at 06:15

Cocos2d-x crash due to ccLayer->schedule(schedule_selector(...), ...);

4 Answers4