Method updateDesignResolutionSize

core/platform/RenderView.cpp:126–176

void RenderView::pollEvents() {}

void RenderView::updateDesignResolutionSize()
{
    if (_screenSize.width > 0 && _screenSize.height > 0 && _designResolutionSize.width > 0 &&
        _designResolutionSize.height > 0)
    {
        _scaleX = (float)_screenSize.width / _designResolutionSize.width;
        _scaleY = (float)_screenSize.height / _designResolutionSize.height;

        if (_resolutionPolicy == ResolutionPolicy::NO_BORDER)
        {
            _scaleX = _scaleY = MAX(_scaleX, _scaleY);
        }

        else if (_resolutionPolicy == ResolutionPolicy::SHOW_ALL)
        {
            _scaleX = _scaleY = MIN(_scaleX, _scaleY);
        }

        else if (_resolutionPolicy == ResolutionPolicy::FIXED_HEIGHT)
        {
            _scaleX                     = _scaleY;
            _designResolutionSize.width = ceilf(_screenSize.width / _scaleX);
        }

        else if (_resolutionPolicy == ResolutionPolicy::FIXED_WIDTH)
        {
            _scaleY                      = _scaleX;
            _designResolutionSize.height = ceilf(_screenSize.height / _scaleY);
        }

        // calculate the rect of viewport
        float viewPortW = _designResolutionSize.width * _scaleX;
        float viewPortH = _designResolutionSize.height * _scaleY;

        _viewPortRect.setRect((_screenSize.width - viewPortW) / 2, (_screenSize.height - viewPortH) / 2, viewPortW,
                              viewPortH);

        // reset director's member variables to fit visible rect
        auto director                   = Director::getInstance();
        director->_winSizeInPoints      = getDesignResolutionSize();
        director->_isStatusLabelUpdated = true;
        director->setProjection(director->getProjection());

        // Github issue #16139
        // A default viewport is needed in order to display the FPS,
        // since the FPS are rendered in the Director, and there is no viewport there.
        // Everything, including the FPS should renderer in the Scene.
        // TODO: minggo
        //        glViewport(0, 0, _screenSize.width, _screenSize.height);
    }
}

void RenderView::setDesignResolutionSize(float width, float height, ResolutionPolicy resolutionPolicy)
{