title: What is the use of setDesignResolutionSize in cocos studio?
body: <p>In my appDelegate class i have code something like this, </p>
  
  <blockquote>
    <p>while using cocos studio</p>
  </blockquote>
  
  <pre><code>auto glview = director-&gt;getOpenGLView();
      if(!glview) {
          glview = GLViewImpl::createWithRect("HelloCpp", Rect(0, 0, 960, 640));
          director-&gt;setOpenGLView(glview);
      }
      director-&gt;getOpenGLView()-&gt;setDesignResolutionSize(960, 640, ResolutionPolicy::SHOW_ALL);
  </code></pre>
  
  <p>Where as in a normal cocos2dx project </p>
  
  <blockquote>
    <p>with out cocos studio</p>
  </blockquote>
  
  <p>the code in appDelegate class is like this.</p>
  
  <pre><code>auto glview = director-&gt;getOpenGLView();
      if(!glview) {
          glview = GLViewImpl::create("My Game");
          director-&gt;setOpenGLView(glview);
      }
  </code></pre>
  
  <p>My doubt is, is it mandatory to setDesignResolutionSize, and also should it be the same for every device size???</p>