[SOLVED] Undefined symbols for architecture x86_64:

cocos2d-x C++
1

I’m using Xcode and I define static variable in the header class:
#ifndef MAIN_SCENE_H
#define MAIN_SCENE_H

#include "cocos2d.h"

using namespace cocos2d;

class MainScene : public cocos2d::Scene
{
public:
    static cocos2d::Scene* createScene();

    virtual bool init();
    
    CREATE_FUNC(MainScene);

protected:
    cocos2d::DrawNode* drawNode;
    static cocos2d::Vec2 lastTouchPos;
    
    bool myTouchBegan(cocos2d::Touch *touch, cocos2d::Event *event);
    void myTouchMoved(cocos2d::Touch *touch, cocos2d::Event *event);
};

#endif // __MAIN_SCENE_H__

and I initialize lastTouchPos in the source file:
#include “MainScene.h”
#include “SimpleAudioEngine.h”

USING_NS_CC;

Scene* MainScene::createScene()
{
    return MainScene::create();
}

bool MainScene::init()
{
    if ( !Scene::init() )
    {
        return false;
    }

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

    auto touchListener = EventListenerTouchOneByOne::create();
    touchListener->onTouchBegan = CC_CALLBACK_2(MainScene::myTouchBegan, this);
    touchListener->onTouchMoved = CC_CALLBACK_2(MainScene::myTouchMoved, this);
    
    this->_eventDispatcher->addEventListenerWithSceneGraphPriority(touchListener, this);
    
    drawNode = DrawNode::create();
    this->addChild(drawNode);
    
    return true;
}

bool MainScene::myTouchBegan(cocos2d::Touch *touch, cocos2d::Event *event) {
    MainScene::lastTouchPos = drawNode->convertTouchToNodeSpace(touch);
    return true;
}

void MainScene::myTouchMoved(cocos2d::Touch *touch, cocos2d::Event *event) {
    Vec2 touchPos = drawNode->convertTouchToNodeSpace(touch);
}

and I give this error:
Undefined symbols for architecture x86_64:
“MainScene::lastTouchPos”, referenced from:
MainScene::myTouchBegan(cocos2d::Touch*, cocos2d::Event*) in MainScene.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

2

You should implement

cocos2d::Vec MainScene::lastTouchPos;

in your source file.