Hello, thank you for your online tutorial, I’ve bought your book “Cocos2d-x Game Developement Essentials” and I am experiencing a problem. I am on a Windows 10 Machine with Cocos-2dx version 3.10 and Android NDK r10e. I want to replace scene from HelloWorldScene to GameMode scene. Here is the code:

 

Android.mk

 

LOCAL_PATH := $(call my-dir)

 

include $(CLEAR_VARS)

 

$(call import-add-path,$(LOCAL_PATH)/../../cocos2d)

$(call import-add-path,$(LOCAL_PATH)/../../cocos2d/external)

$(call import-add-path,$(LOCAL_PATH)/../../cocos2d/cocos)

 

LOCAL_MODULE := cocos2dcpp_shared

 

LOCAL_MODULE_FILENAME := libcocos2dcpp

 

LOCAL_SRC_FILES := hellocpp/main.cpp \

                   ../../Classes/AppDelegate.cpp \

                   ../../Classes/HelloWorldScene.cpp \

                   ../../Classes/GameModeScene.cpp

 

LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../Classes

 

# _COCOS_HEADER_ANDROID_BEGIN

# _COCOS_HEADER_ANDROID_END

 

 

LOCAL_STATIC_LIBRARIES := cocos2dx_static

 

# _COCOS_LIB_ANDROID_BEGIN

# _COCOS_LIB_ANDROID_END

 

include $(BUILD_SHARED_LIBRARY)

 

$(call import-module,.)

 

# _COCOS_LIB_IMPORT_ANDROID_BEGIN

# _COCOS_LIB_IMPORT_ANDROID_END

 

HelloWorldScene.cpp

 

#include "HelloWorldScene.h"

#include "GameModeScene.h"

 

USING_NS_CC;

 

Scene* HelloWorld::createScene()

{

    // 'scene' is an autorelease object

    auto scene = Scene::create();

   

    // 'layer' is an autorelease object

    auto layer = HelloWorld::create();

 

    // add layer as a child to scene

    scene->addChild(layer);

 

    // return the scene

    return scene;

}

 

// on "init" you need to initialize your instance

bool HelloWorld::init()

{

    //////////////////////////////

    // 1. super init first

    if ( !Layer::init() )

    {

        return false;

    }

   

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

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

 

    //creo il menu

    auto play_button = MenuItemImage::create("play.png", "play_pressed.png",CC_CALLBACK_1(HelloWorld::GoToGameMode, this));

    play_button->setPosition(Point(visibleSize.width / 2, (visibleSize.height / 7) * 5));

 

    auto menu = Menu::create(play_button, NULL);

    this->addChild(menu, 1);

   

    return true;

}

 

void HelloWorld::GoToGameMode(cocos2d::Ref *pSender)

{

    auto scene = GameMode::createScene();

 

    Director::getInstance()->replaceScene(scene);

}

 

HelloWorldScene.h

 

#ifndef __HELLOWORLD_SCENE_H__

#define __HELLOWORLD_SCENE_H__

 

#include "cocos2d.h"

 

class HelloWorld : public cocos2d::Layer

{

public:

    static cocos2d::Scene* createScene();

 

    virtual bool init();

   

    // a selector callback

    void menuCloseCallback(cocos2d::Ref* pSender);

   

    void GoToGameMode(Ref *pSender);

 

    // implement the "static create()" method manually

    CREATE_FUNC(HelloWorld);

};

 

#endif // __HELLOWORLD_SCENE_H__

 

 

GameModeScene.h

 

#ifndef __GAMEMODE_SCENE_H__

#define __GAMEMODE_SCENE_H__

 

#include "cocos2d.h"

 

class GameMode : public cocos2d::Layer

{

public:

    static cocos2d::Scene* createScene();

 

    virtual bool init();

   

    // a selector callback

    void menuCloseCallback(cocos2d::Ref* pSender);

   

 

    // implement the "static create()" method manually

    CREATE_FUNC(GameMode);

};

 

#endif // __GAMEMODE_SCENE_H__

 

GameModeScene.cpp

 

#include "GameModeScene.h"

 

 

USING_NS_CC;

 

Scene* GameMode::createScene()

{

    // 'scene' is an autorelease object

    auto scene = Scene::create();

   

    // 'layer' is an autorelease object

    auto layer = GameMode::create();

 

    // add layer as a child to scene

    scene->addChild(layer);

 

    // return the scene

    return scene;

}

 

// on "init" you need to initialize your instance

bool GameMode::init()

{

    //////////////////////////////

    // 1. super init first

    if ( !Layer::init() )

    {

        return false;

    }

   

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

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

 

    return true;

}

 

 

This is the error I experience when i run in the command prompt:

“cd folder of the game” and “cocos.py compile -p android –android-studio”

Error:

jni/../../../Classes/HelloWorldScene.cpp:46: error: undefined reference to 'GameMode::createScene()'

collect2.exe: error: ld returned 1 exit status

make.exe: *** [obj/local/armeabi/libcocos2dcpp.so] Error 1

make.exe: Leaving directory `C:/Users/HK/Documents/Programmazione/Colours/proj.android-studio/app'

Error running command, return code: 2.

 

I know that it’s a basic function but I followed step by step the book and the online tutorials and I always have this error. I have the same error with pushing the scene as well.

 

Thank you