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androidc++cocos2d-x

C++ cocos-2d-x undefined error


first ever question here on SO in my numerous years of coding. I've recently started trying to get into C++ to work with cocos-2d-x for mobile development and have hit a wall pretty much immediately.

My new project comes with AppDelegate and HelloWorld classes, I've then added my own GameScene class which I've tried to instanciate from AppDelegate, however, every time I do this, I get an 'undefined error' message.

Here's the code I've got so far, as you can see, the code I've got in my GameScene.cpp file is just a copy-paste of the hello world file...which I can confirm does work.

GameScene.cpp

#include "GameScene.h"

USING_NS_CC;



cocos2d::Scene* GameScene::createScene()
{
    // 'scene' is an autorelease object
    auto scene = Scene::create();

    // 'layer' is an autorelease object
    auto layer = GameScene::create();
    scene->addChild(layer);

    return scene;
}



// on "init" you need to initialize your instance
bool GameScene::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }

    Size visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();

    // add a label shows "Built on"
    auto label = Label::createWithTTF("Built on", "fonts/Marker Felt.ttf", 24);
    label->setPosition(Vec2(origin.x + visibleSize.width/2,
                            origin.y + visibleSize.height - label->getContentSize().height));
    this->addChild(label, 1);

    // add "HelloWorld" splash screen"
    auto sprite = Sprite::create("HelloWorld.png");
    sprite->setPosition(Vec2(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));
    this->addChild(sprite, 0);

    return true;
}

GameScene.h

#ifndef __GAME_SCENE_H__
#define __GAME_SCENE_H__

#include "cocos2d.h"

class GameScene : public cocos2d::Layer
{
public:
    // there's no 'id' in cpp, so we recommend returning the class instance pointer
    static cocos2d::Scene* createScene();

    // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
    virtual bool init();

    // implement the "static create()" method manually
    CREATE_FUNC(GameScene);
};

#endif // __GAME_SCENE_H__

AppDelegate.cpp

#include "AppDelegate.h"
#include "HelloWorldScene.h"
#include "GameScene.h"

USING_NS_CC;

static cocos2d::Size designResolutionSize = cocos2d::Size(480, 320);
static cocos2d::Size smallResolutionSize = cocos2d::Size(480, 320);
static cocos2d::Size mediumResolutionSize = cocos2d::Size(1024, 768);
static cocos2d::Size largeResolutionSize = cocos2d::Size(2048, 1536);

AppDelegate::AppDelegate() {

}

AppDelegate::~AppDelegate() 
{
}

//if you want a different context,just modify the value of glContextAttrs
//it will takes effect on all platforms
void AppDelegate::initGLContextAttrs()
{
    //set OpenGL context attributions,now can only set six attributions:
    //red,green,blue,alpha,depth,stencil
    GLContextAttrs glContextAttrs = {8, 8, 8, 8, 24, 8};

    GLView::setGLContextAttrs(glContextAttrs);
}

// If you want to use packages manager to install more packages, 
// don't modify or remove this function
static int register_all_packages()
{
    return 0; //flag for packages manager
}

bool AppDelegate::applicationDidFinishLaunching() {
    // initialize director
    auto director = Director::getInstance();
    auto glview = director->getOpenGLView();
    if(!glview) {
        glview = GLViewImpl::create("My Game");
        director->setOpenGLView(glview);
    }

    // turn on display FPS
    director->setDisplayStats(true);

    // set FPS. the default value is 1.0/60 if you don't call this
    director->setAnimationInterval(1.0 / 60);

    // Set the design resolution
    glview->setDesignResolutionSize(designResolutionSize.width, designResolutionSize.height, ResolutionPolicy::NO_BORDER);
    Size frameSize = glview->getFrameSize();
    // if the frame's height is larger than the height of medium size.
    if (frameSize.height > mediumResolutionSize.height)
    {        
        director->setContentScaleFactor(MIN(largeResolutionSize.height/designResolutionSize.height, largeResolutionSize.width/designResolutionSize.width));
    }
    // if the frame's height is larger than the height of small size.
    else if (frameSize.height > smallResolutionSize.height)
    {        
        director->setContentScaleFactor(MIN(mediumResolutionSize.height/designResolutionSize.height, mediumResolutionSize.width/designResolutionSize.width));
    }
    // if the frame's height is smaller than the height of medium size.
    else
    {        
        director->setContentScaleFactor(MIN(smallResolutionSize.height/designResolutionSize.height, smallResolutionSize.width/designResolutionSize.width));
    }

    register_all_packages();

    // create a scene. it's an autorelease object
    auto scene = GameScene::createScene();

    // run
    director->runWithScene(scene);

    return true;
}

// This function will be called when the app is inactive. When comes a phone call,it's be invoked too
void AppDelegate::applicationDidEnterBackground() {
    Director::getInstance()->stopAnimation();

    // if you use SimpleAudioEngine, it must be pause
    // SimpleAudioEngine::getInstance()->pauseBackgroundMusic();
}

// this function will be called when the app is active again
void AppDelegate::applicationWillEnterForeground() {
    Director::getInstance()->startAnimation();

    // if you use SimpleAudioEngine, it must resume here
    // SimpleAudioEngine::getInstance()->resumeBackgroundMusic();
}

AppDelegate.h

#ifndef  _APP_DELEGATE_H_
#define  _APP_DELEGATE_H_

#include "cocos2d.h"

/**
@brief    The cocos2d Application.

The reason for implement as private inheritance is to hide some interface call by Director.
*/
class  AppDelegate : private cocos2d::Application
{
public:
    AppDelegate();
    virtual ~AppDelegate();

    virtual void initGLContextAttrs();

    /**
    @brief    Implement Director and Scene init code here.
    @return true    Initialize success, app continue.
    @return false   Initialize failed, app terminate.
    */
    virtual bool applicationDidFinishLaunching();

    /**
    @brief  The function be called when the application enter background
    @param  the pointer of the application
    */
    virtual void applicationDidEnterBackground();

    /**
    @brief  The function be called when the application enter foreground
    @param  the pointer of the application
    */
    virtual void applicationWillEnterForeground();
};

#endif // _APP_DELEGATE_H_

I've tried doing as much debugging as I can though am not really getting anywhere, although I am starting to suspect that possibly the GameScene.cpp file isn't being included in the compile...I put an error line ("blahblahblah;") in each file and the compiler didn't show anything about the error in GameScene.cpp. So if this is the problem, then how do I make sure it is included? I'm currently editing my code in Notepad++ and building by calling the build_native.py file which was created in the proj.android folder of my cocos project.


Solution

  • I've done some further hunting for answers on this and found this:

    Adding cpp files to cocos2d-x project android project

    Having added my GameScene.cpp file to the android.mk file, it is now compiling, therefore I'm going to mark this as resolved.