title: Can't get multitouch work on cocos2d-x v3
body: <p>I'm using cocos2d-x v3.3rc0<br>
  I'm trying to handle multi touch, but I only receive only one touch.<br>
  It's behavior is similar with single touch, not multitouch. onTouchesBegan only called once when I touch more than 1 finger.  </p>
  
  <p>Hope someone can help me solve this out.</p>
  
  <p>Here is my code to enable multi touch</p>
  
  <p><strong>ControlLayer.h</strong></p>
  
  <pre><code>#include "cocos2d.h"
  
  class ControlLayer : public cocos2d::Layer{
  
  
  public:
  
      static ControlLayer* create();
      virtual bool init();
  
      void onTouchesBegan(const std::vector&lt;cocos2d::Touch*&gt;&amp; touches, cocos2d::Event *unused_event);
      void onTouchesMoved(const std::vector&lt;cocos2d::Touch*&gt;&amp; touches, cocos2d::Event *unused_event);
      void onTouchesEnded(const std::vector&lt;cocos2d::Touch*&gt;&amp; touches, cocos2d::Event *unused_event);
  
  };
  </code></pre>
  
  <p><strong>ControlLayer.cpp</strong></p>
  
  <pre><code>bool ControlLayer::init(){
  
      if (!Layer::init()){
          return false;
      }
  
      auto touchListener = EventListenerTouchAllAtOnce::create();
      touchListener-&gt;onTouchesBegan = CC_CALLBACK_2(ControlLayer::onTouchesBegan, this);
      touchListener-&gt;onTouchesMoved = CC_CALLBACK_2(ControlLayer::onTouchesMoved, this);
      touchListener-&gt;onTouchesEnded = CC_CALLBACK_2(ControlLayer::onTouchesEnded, this);
  
      Director::getInstance()-&gt;getEventDispatcher()-&gt;addEventListenerWithSceneGraphPriority(touchListener, this);
  
      return true;
  }
  
  void ControlLayer::onTouchesBegan(const std::vector&lt;Touch*&gt;&amp; touches, Event *unused_event){
      CCLOG("onTouchesBegan[%lu]", touches.size());
  }
  void ControlLayer::onTouchesMoved(const std::vector&lt;Touch*&gt;&amp; touches, Event *unused_event){
      CCLOG("onTouchesMoved[%lu]", touches.size());
  }
  void ControlLayer::onTouchesEnded(const std::vector&lt;Touch*&gt;&amp; touches, Event *unused_event){
  
  }
  </code></pre>