OSGMFC

在OSG的Demo中找到MFC_OSG类文件。

 #pragma once

 #include <osgViewer/Viewer>
 #include <osgViewer/ViewerEventHandlers>
 #include <osgViewer/api/win32/GraphicsWindowWin32>
 #include <osgGA/TrackballManipulator>
 #include <osgGA/KeySwitchMatrixManipulator>
 #include <osgDB/DatabasePager>
 #include <osgDB/Registry>
 #include <osgDB/ReadFile>
 #include <osgUtil/Optimizer>
 #include <string>

 class cOSG
 {
 public:
     cOSG(HWND hWnd);
     ~cOSG();

     void InitOSG(std::string filename);
     void InitManipulators(void);
     void InitSceneGraph(void);
     void InitCameraConfig(void);
     void SetupWindow(void);
     void SetupCamera(void);
     void PreFrameUpdate(void);
     void PostFrameUpdate(void);
     void Done(bool value) { mDone = value; }
     bool Done(void) { return mDone; }
     static void Render(void* ptr);

     osgViewer::Viewer* getViewer() { return mViewer; }

 private:
     bool mDone;
     std::string m_ModelName;
     HWND m_hWnd;
     osgViewer::Viewer* mViewer;
     osg::ref_ptr<osg::Group> mRoot;
     osg::ref_ptr<osg::Node> mModel;
     osg::ref_ptr<osgGA::TrackballManipulator> trackball;
     osg::ref_ptr<osgGA::KeySwitchMatrixManipulator> keyswitchManipulator;
 };

 class CRenderingThread : public OpenThreads::Thread
 {
 public:
     CRenderingThread( cOSG* ptr );
     virtual ~CRenderingThread();

     virtual void run();

 protected:
     cOSG* _ptr;
     bool _done;
 };

MFC_OSG.h

实现文件：

 // MFC_OSG.cpp : implementation of the cOSG class
 //
 #include "stdafx.h"
 #include "MFC_OSG.h"

 cOSG::cOSG(HWND hWnd) :
    m_hWnd(hWnd)
 {
 }

 cOSG::~cOSG()
 {
     mViewer->setDone(true);
     Sleep();
     mViewer->stopThreading();

     delete mViewer;
 }

 void cOSG::InitOSG(std::string modelname)
 {
     // Store the name of the model to load
     m_ModelName = modelname;

     // Init different parts of OSG
     InitManipulators();
     InitSceneGraph();
     InitCameraConfig();
 }

 void cOSG::InitManipulators(void)
 {
     // Create a trackball manipulator
     trackball = new osgGA::TrackballManipulator();

     // Create a Manipulator Switcher
     keyswitchManipulator = new osgGA::KeySwitchMatrixManipulator;

     // Add our trackball manipulator to the switcher
     keyswitchManipulator->addMatrixManipulator( '', "Trackball", trackball.get());

     // Init the switcher to the first manipulator (in this case the only manipulator)
     keyswitchManipulator->selectMatrixManipulator();  // Zero based index Value
 }

 void cOSG::InitSceneGraph(void)
 {
     // Init the main Root Node/Group
     mRoot  = new osg::Group;

     // Load the Model from the model name
     mModel = osgDB::readNodeFile(m_ModelName);
     if (!mModel) return;

     // Optimize the model
     osgUtil::Optimizer optimizer;
     optimizer.optimize(mModel.get());
     optimizer.reset();

     // Add the model to the scene
     mRoot->addChild(mModel.get());
 }

 void cOSG::InitCameraConfig(void)
 {
     // Local Variable to hold window size data
     RECT rect;

     // Create the viewer for this window
     mViewer = new osgViewer::Viewer();

     // Add a Stats Handler to the viewer
     mViewer->addEventHandler(new osgViewer::StatsHandler);

     // Get the current window size
     ::GetWindowRect(m_hWnd, &rect);

     // Init the GraphicsContext Traits
     osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;

     // Init the Windata Variable that holds the handle for the Window to display OSG in.
     osg::ref_ptr<osg::Referenced> windata = new osgViewer::GraphicsWindowWin32::WindowData(m_hWnd);

     // Setup the traits parameters
     traits->x = ;
     traits->y = ;
     traits->width = rect.right - rect.left;
     traits->height = rect.bottom - rect.top;
     traits->windowDecoration = false;
     traits->doubleBuffer = true;
     traits->sharedContext = ;
     traits->setInheritedWindowPixelFormat = true;
     traits->inheritedWindowData = windata;

     // Create the Graphics Context
     osg::GraphicsContext* gc = osg::GraphicsContext::createGraphicsContext(traits.get());

     // Init Master Camera for this View
     osg::ref_ptr<osg::Camera> camera = mViewer->getCamera();

     // Assign Graphics Context to the Camera
     camera->setGraphicsContext(gc);

     // Set the viewport for the Camera
     camera->setViewport(new osg::Viewport(traits->x, traits->y, traits->width, traits->height));

     // Set projection matrix and camera attribtues
     camera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
     camera->setClearColor(osg::Vec4f(0.2f, 0.2f, 0.4f, 1.0f));
     camera->setProjectionMatrixAsPerspective(
         30.0f, static_cast<double>(traits->width)/static_cast<double>(traits->height), 1.0, 1000.0);

     // Add the Camera to the Viewer
     //mViewer->addSlave(camera.get());
     mViewer->setCamera(camera.get());

     // Add the Camera Manipulator to the Viewer
     mViewer->setCameraManipulator(keyswitchManipulator.get());

     // Set the Scene Data
     mViewer->setSceneData(mRoot.get());

     // Realize the Viewer
     mViewer->realize();

     // Correct aspect ratio
     /*double fovy,aspectRatio,z1,z2;
     mViewer->getCamera()->getProjectionMatrixAsPerspective(fovy,aspectRatio,z1,z2);
     aspectRatio=double(traits->width)/double(traits->height);
     mViewer->getCamera()->setProjectionMatrixAsPerspective(fovy,aspectRatio,z1,z2);*/
 }

 void cOSG::PreFrameUpdate()
 {
     // Due any preframe updates in this routine
 }

 void cOSG::PostFrameUpdate()
 {
     // Due any postframe updates in this routine
 }

 void cOSG::Render(void* ptr)
 {
     cOSG* osg = (cOSG*)ptr;

     osgViewer::Viewer* viewer = osg->getViewer();

     // You have two options for the main viewer loop
     //      viewer->run()   or
     //      while(!viewer->done()) { viewer->frame(); }

     //viewer->run();
     while(!viewer->done())
     {
         osg->PreFrameUpdate();
         viewer->frame();
         osg->PostFrameUpdate();
         //Sleep(10);         // Use this command if you need to allow other processes to have cpu time
     }

     // For some reason this has to be here to avoid issue:
     // if you have multiple OSG windows up
     // and you exit one then all stop rendering
     AfxMessageBox("Exit Rendering Thread");

     _endthread();
 }

 CRenderingThread::CRenderingThread( cOSG* ptr )
 :   OpenThreads::Thread(), _ptr(ptr), _done(false)
 {
 }

 CRenderingThread::~CRenderingThread()
 {
     _done = true;
     while( isRunning() )
         OpenThreads::Thread::YieldCurrentThread();
 }

 void CRenderingThread::run()
 {
     if ( !_ptr )
     {
         _done = true;
         return;
     }

     osgViewer::Viewer* viewer = _ptr->getViewer();
     do
     {
         _ptr->PreFrameUpdate();
         viewer->frame();
         _ptr->PostFrameUpdate();
     } while ( !testCancel() && !viewer->done() && !_done );
 }

MFC_OSG.cpp

新建MFC单文档程序，在视图头文件中添加：

 public:
     cOSG *m_OSG;
     HANDLE m_ThreadHandle;
     afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
     virtual void OnInitialUpdate();

实现代码：

 int COSGMFCView::OnCreate(LPCREATESTRUCT lpCreateStruct)
 {
     if (CView::OnCreate(lpCreateStruct) == -)
         return -;

     // TODO:  在此添加您专用的创建代码
      m_OSG = new cOSG(m_hWnd);

     return ;
 }

 void COSGMFCView::OnInitialUpdate()
 {
     CView::OnInitialUpdate();
     m_OSG->InitOSG("cessna.osg");
     m_ThreadHandle = (HANDLE)_beginthread(&cOSG::Render,,m_OSG);

     // TODO: 在此添加专用代码和/或调用基类
 }