OSGEarth嵌入Qt的QGraphicsView框架（二）

上一篇处理了QGraphicsView的鼠标、按键事件，本篇接着嵌入OSGEarth。
新建一继承自EventAdapter（一）的类GraphicsView，完成OSGEarth的嵌入工作。实现思路是QGraphicsView的Viewport用OpenGL来绘制，这样才可以完全OSG的update。而要完成每帧的更新，则需要一个定时器，每隔10ms更新一次，即每10ms调用一次OSG的frame操作。
实现代码：graphicsview.h

class GraphicsView : public EventAdapter{    Q_OBJECTpublic:    GraphicsView(QWidget* parent = 0);    ~GraphicsView();    osgViewer::Viewer* getOSGViewer(){ return m_pViewer; }    osg::Group* getRoot(){ return m_pSceneData; }    osgEarth::MapNode* getMapNode(){ return m_pMapNode; }    const osgEarth::SpatialReference* getSRS(){ return m_pMapSRS; }    osgEarth::Util::EarthManipulator* getManipulator(){ return m_pEarthManipulator; }protected:    // 完成OSG每一帧的update操作    virtual void drawBackground(QPainter *painter, const QRectF& rect);    virtual void timerEvent(QTimerEvent *event);private:    void init();private:    osgEarth::Map* m_pMap;    osg::Group* m_pSceneData;    osg::StateSet* m_pStateSet;    osgViewer::Viewer* m_pViewer;    osgEarth::MapNode* m_pMapNode;    osgEarth::Util::SkyNode* m_pSkyNode;    const osgEarth::SpatialReference* m_pMapSRS;    osgEarth::Util::EarthManipulator* m_pEarthManipulator;};

几个get方法，获取OSGEarth相关的Viewer、Group、MapNode、SpatialReference、EarthManipulator等给外部使用。

实现代码：graphicsview.cpp

GraphicsView::GraphicsView(QWidget *parent){    this->setScene(new QGraphicsScene);    init();}GraphicsView::~GraphicsView(){}void GraphicsView::init(){    // QGraphicsView的Viewport一定要设置为QGLWidget，因为只有这样才能用OpenGL来对OSG进行更新    QGLWidget* glViewPort = new QGLWidget;    glViewPort->setMouseTracking(true);    glViewPort->setMaximumSize(2000, 2000);    this->setViewport(glViewPort);    this->setViewportUpdateMode(QGraphicsView::FullViewportUpdate);    startTimer(10);    osg::Group* pRoot = new osg::Group;    pRoot->setName("root");    m_pSceneData = new osg::Group;    m_pSceneData->setName("SceneData");    m_pStateSet = new osg::StateSet;    m_pStateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::ON);    pRoot->setStateSet(m_pStateSet);    pRoot->addChild(m_pSceneData);    // 使用earth文件的方式进行数据加载，驱动为TMS    osg::Node* node = osgDB::readNodeFile("../LiuPanShui.earth");    if (node)    {        m_pMapNode = osgEarth::MapNode::findMapNode(node);        m_pMapNode->setName("MapNode");        m_pMap = m_pMapNode->getMap();        m_pMapSRS = m_pMapNode->getMapSRS();    }    m_pViewer = new osgViewer::Viewer;    m_pEarthManipulator = new osgEarth::Util::EarthManipulator;    m_pEarthManipulator->getSettings()->setMinMaxPitch(-90.0, -7.0);    m_pViewer->setCameraManipulator(m_pEarthManipulator);    m_pViewer->addEventHandler(new osgViewer::StatsHandler);    m_pViewer->addEventHandler(new osgGA::StateSetManipulator(m_pViewer->getCamera()->getOrCreateStateSet()));    m_pViewer->getCamera()->addCullCallback(new osgEarth::Util::AutoClipPlaneCullCallback(m_pMapNode));    m_pViewer->getCamera()->setNearFarRatio(0.0000002);    m_pViewer->getCamera()->setComputeNearFarMode(osg::CullSettings::COMPUTE_NEAR_FAR_USING_PRIMITIVES);    m_pViewer->setUpViewerAsEmbeddedInWindow(0, 0, width(), height());    m_pViewer->setSceneData(pRoot);    m_pGraphicsWindow = dynamic_cast<osgViewer::GraphicsWindow*>(        m_pViewer->getCamera()->getGraphicsContext());    m_pEarthManipulator->setViewpoint(osgEarth::Util::Viewpoint(        104.81443, 26.60379, 1811.2336, 0.0, -90.0, 5000));    m_pSkyNode = osgEarth::Util::SkyNode::create(m_pMapNode);    m_pSkyNode->setName("SkyNode");    // 设置时间;    osgEarth::DateTime dateTime(2015, 8, 15, 6);    osgEarth::Util::Ephemeris* ephemeris = new osgEarth::Util::Ephemeris;    m_pSkyNode->setEphemeris(ephemeris);    m_pSkyNode->setDateTime(dateTime);    m_pSkyNode->attach(m_pViewer, 0);    m_pSkyNode->setLighting(true);    m_pSkyNode->addChild(m_pMapNode);    pRoot->addChild(m_pSkyNode);}void GraphicsView::timerEvent(QTimerEvent *event){    this->scene()->update();}void GraphicsView::drawBackground(QPainter *painter, const QRectF& rect){    if (painter->paintEngine()->type() != QPaintEngine::OpenGL2)    {        return;    }    // Save the painter state    painter->save();    painter->beginNativePainting();    // OSG帧更新    m_pViewer->frame();    painter->endNativePainting();    painter->restore();}