OpenSceneGraph/examples/osgviewerMFC/MFC_OSG.cpp

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


cOSG::cOSG(HWND hWnd) :
   m_hWnd(hWnd)
{
    //
    // We must set the pixelformat before we can create the OSG Rendering Surface
    //
    PIXELFORMATDESCRIPTOR pixelFormat =
    {
        sizeof(PIXELFORMATDESCRIPTOR),
        1,
        PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL,
        PFD_TYPE_RGBA,
        24,
        0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0,
        24,
        0,
        0,
        PFD_MAIN_PLANE,
        0,
        0, 0, 0
    };

    HDC hdc = ::GetDC(m_hWnd);
    if (hdc==0)
    {
        ::DestroyWindow(m_hWnd);
        return;
    }

    int pixelFormatIndex = ::ChoosePixelFormat(hdc, &pixelFormat);
    if (pixelFormatIndex==0)
    {
        ::ReleaseDC(m_hWnd, hdc);
        ::DestroyWindow(m_hWnd);
        return;
    }

    if (!::SetPixelFormat(hdc, pixelFormatIndex, &pixelFormat))
    {
        ::ReleaseDC(m_hWnd, hdc);
        ::DestroyWindow(m_hWnd);
        return;
    }
}

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( '1', "Trackball", trackball.get());

    // Init the switcher to the first manipulator (in this case the only manipulator)
    keyswitchManipulator->selectMatrixManipulator(0);  // 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);

    // 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 = 0;
    traits->y = 0;
    traits->width = rect.right - rect.left;
    traits->height = rect.bottom - rect.top;
    traits->windowDecoration = false;
    traits->doubleBuffer = true;
    traits->sharedContext = 0;
    traits->inheritedWindowData = windata;

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

    // Init a new Camera (Master for this View)
    osg::ref_ptr<osg::Camera> camera = new osg::Camera;

    // 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));

    // Add the Camera to the Viewer
    mViewer->addSlave(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();
}

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");
}