osgEarth教程(三）——搭建MFC桌面端程序框架

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/github_39611196/article/details/87706102

本文主要介绍基于MFC创建osgEarth桌面端程序。

1、新建MFC应用程序DigitalEarth，选择单个文档。

2、实现osgEarth相关功能。

2.1、创建OSGObject.h文件，输入如下代码：

#pragma once

#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgViewer/api/win32/GraphicsWindowWin32>
#include <osgGA/TrackballManipulator>
#include <osgEarth/MapNode>
#include <osgEarthUtil/EarthManipulator>
//#include <osgEarthUtil/SkyNode>

class COSGObject
{
public:
	COSGObject(HWND hWnd);
	~COSGObject(void);

	void InitOSG();
	void InitSceneGraph();
	void InitCameraConfig();
	void PreFrameUpdate();
	void PostFrameUpdate();
	static void Render(void * ptr);

	void InitOsgEarth();

	osgViewer::Viewer *getViewer();
private:
	HWND m_hWnd;
	osgViewer::Viewer * mViewer;
	osg::ref_ptr<osg::Group> mRoot;
	osg::ref_ptr<osgEarth::MapNode> mapNode;
	osg::ref_ptr<osgEarth::Util::EarthManipulator> em;

};

2.2、创建OSGObject.cpp，输入如下代码：

#include "StdAfx.h"
#include "OSGObject.h"


COSGObject::COSGObject(HWND hWnd)
{
	m_hWnd = hWnd;
}


COSGObject::~COSGObject(void)
{
}

void COSGObject::InitOSG()
{
	InitSceneGraph();
	InitCameraConfig();
	InitOsgEarth();

}

void COSGObject::InitSceneGraph()
{
	mRoot = new osg::Group;
	osg::ref_ptr<osg::Node> mp = osgDB::readNodeFile("arcgisonline.earth");
	mRoot->addChild(mp);
	mapNode = dynamic_cast<osgEarth::MapNode*>(mp.get());
	//mRoot->addChild(osgDB::readNodeFile("H:/002.OpenSceneGraph/019.Earth/003.第三讲-VPB用法详解与常见问题处理/vpbtest/TestCommon10/output.ive"));
}

void COSGObject::InitCameraConfig()
{
	RECT rect;
	mViewer = new osgViewer::Viewer;
	::GetWindowRect(m_hWnd, &rect);
	osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
	osg::ref_ptr<osg::Referenced> windata = new osgViewer::GraphicsWindowWin32::WindowData(m_hWnd);
	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->setInheritedWindowPixelFormat = true;
	traits->inheritedWindowData = windata;
	osg::GraphicsContext * gc = osg::GraphicsContext::createGraphicsContext(traits);

	osg::ref_ptr<osg::Camera> camera = new osg::Camera;
	camera->setGraphicsContext(gc);
	camera->setViewport(new osg::Viewport(traits->x, traits->y, traits->width, traits->height));
	camera->setProjectionMatrixAsPerspective(30.0f, static_cast<double>(traits->width) / static_cast<double>(traits->height), 1.0, 1000.0);

	mViewer->setCamera(camera);
	//mViewer->setCameraManipulator(new osgGA::TrackballManipulator);
	mViewer->setSceneData(mRoot);
	mViewer->realize();
	mViewer->getCamera()->setComputeNearFarMode(osg::CullSettings::COMPUTE_NEAR_FAR_USING_PRIMITIVES);
	mViewer->getCamera()->setNearFarRatio(0.000003f);
}

void COSGObject::PreFrameUpdate()
{

}

void COSGObject::PostFrameUpdate()
{

}

void COSGObject::Render(void * ptr)
{
	COSGObject *osg = (COSGObject*)ptr;
	osgViewer::Viewer * viewer = osg->getViewer();
	while (!viewer->done())
	{
		osg->PreFrameUpdate();
		viewer->frame();
		osg->PostFrameUpdate();
	}

	_endthread();
}

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

void COSGObject::InitOsgEarth()
{
	//初始化操作器
	em = new osgEarth::Util::EarthManipulator;
	if (mapNode.valid())
	{
		em->setNode(mapNode);
	}
	em->getSettings()->setArcViewpointTransitions(true);
	mViewer->setCameraManipulator(em);

	////初始化天空
	//osgEarth::Config skyConf;
	//double hours = skyConf.value("hours", 12.0);
	//osg::ref_ptr<osgEarth::Util::SkyNode> sky_node = new osgEarth::Util::SkyNode(mapNode->getMap());
	//sky_node->setDateTime(2012, 1, 27, hours);
	//sky_node->attach(mViewer, 1);
	//sky_node->setAmbientBrightness(1.0, mViewer);
	//mRoot->addChild(sky_node);

}

三、将osgEarth程序运行结果在MFC文档视图中显示。

3.1、修改DigitalEarthView.h为如下代码：

// DigitalEarthView.h : CDigitalEarthView 类的接口
//

#pragma once

#include "DigitalEarthDoc.h"
#include "OSGObject.h"


class CDigitalEarthView : public CView
{
protected: // 仅从序列化创建
	CDigitalEarthView();
	DECLARE_DYNCREATE(CDigitalEarthView)

// 特性
public:
	CDigitalEarthDoc* GetDocument() const;

public:
	COSGObject* mOSG;
	HANDLE mThreadHandle;
// 操作
public:

// 重写
public:
	virtual void OnDraw(CDC* pDC);  // 重写以绘制该视图
	virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
protected:
	virtual BOOL OnPreparePrinting(CPrintInfo* pInfo);
	virtual void OnBeginPrinting(CDC* pDC, CPrintInfo* pInfo);
	virtual void OnEndPrinting(CDC* pDC, CPrintInfo* pInfo);

// 实现
public:
	virtual ~CDigitalEarthView();
#ifdef _DEBUG
	virtual void AssertValid() const;
	virtual void Dump(CDumpContext& dc) const;
#endif

protected:

// 生成的消息映射函数
protected:
	afx_msg void OnFilePrintPreview();
	afx_msg void OnRButtonUp(UINT nFlags, CPoint point);
	afx_msg void OnContextMenu(CWnd* pWnd, CPoint point);
	DECLARE_MESSAGE_MAP()

public:
	afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
	afx_msg BOOL OnEraseBkgnd(CDC* pDC);
	afx_msg void OnDestroy();
	virtual void OnInitialUpdate();
};

#ifndef _DEBUG  // DigitalEarthView.cpp 中的调试版本
inline CDigitalEarthDoc* CDigitalEarthView::GetDocument() const
   { return reinterpret_cast<CDigitalEarthDoc*>(m_pDocument); }
#endif

3.2、修改DigitalEarthView.cpp为如下代码：

// DigitalEarthView.cpp : CDigitalEarthView 类的实现
//

#include "stdafx.h"
// SHARED_HANDLERS 可以在实现预览、缩略图和搜索筛选器句柄的
// ATL 项目中进行定义，并允许与该项目共享文档代码。
#ifndef SHARED_HANDLERS
#include "DigitalEarth.h"
#endif

#include "DigitalEarthDoc.h"
#include "DigitalEarthView.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// CDigitalEarthView

IMPLEMENT_DYNCREATE(CDigitalEarthView, CView)

BEGIN_MESSAGE_MAP(CDigitalEarthView, CView)
	// 标准打印命令
	ON_COMMAND(ID_FILE_PRINT, &CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, &CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, &CView::OnFilePrintPreview)
	ON_WM_CONTEXTMENU()
	ON_WM_RBUTTONUP()
	ON_WM_CREATE()
	ON_WM_ERASEBKGND()
	ON_WM_DESTROY()
END_MESSAGE_MAP()

// CDigitalEarthView 构造/析构

CDigitalEarthView::CDigitalEarthView()
{
	// TODO: 在此处添加构造代码
	mOSG = 0;
	mThreadHandle = 0;
}

CDigitalEarthView::~CDigitalEarthView()
{
}

BOOL CDigitalEarthView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: 在此处通过修改
	//  CREATESTRUCT cs 来修改窗口类或样式

	return CView::PreCreateWindow(cs);
}

// CDigitalEarthView 绘制

void CDigitalEarthView::OnDraw(CDC* /*pDC*/)
{
	CDigitalEarthDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	if (!pDoc)
		return;

	// TODO: 在此处为本机数据添加绘制代码
}


// CDigitalEarthView 打印

BOOL CDigitalEarthView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// 默认准备
	return DoPreparePrinting(pInfo);
}

void CDigitalEarthView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: 添加额外的打印前进行的初始化过程
}

void CDigitalEarthView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: 添加打印后进行的清理过程
}


// CDigitalEarthView 诊断

#ifdef _DEBUG
void CDigitalEarthView::AssertValid() const
{
	CView::AssertValid();
}

void CDigitalEarthView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CDigitalEarthDoc* CDigitalEarthView::GetDocument() const // 非调试版本是内联的
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CDigitalEarthDoc)));
	return (CDigitalEarthDoc*)m_pDocument;
}
#endif //_DEBUG


void CDigitalEarthView::OnRButtonUp(UINT /* nFlags */, CPoint point)
{
	ClientToScreen(&point);
	OnContextMenu(this, point);
}

void CDigitalEarthView::OnContextMenu(CWnd* /* pWnd */, CPoint point)
{
#ifndef SHARED_HANDLERS
	//theApp.GetContextMenuManager()->ShowPopupMenu(IDR_POPUP_EDIT, point.x, point.y, this, TRUE);
#endif
}


// CDigitalEarthView 消息处理程序


int CDigitalEarthView::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
	if (CView::OnCreate(lpCreateStruct) == -1)
		return -1;

	mOSG = new COSGObject(m_hWnd);

	return 0;
}


BOOL CDigitalEarthView::OnEraseBkgnd(CDC* pDC)
{
	if (0 == mOSG)
	{
		return CView::OnEraseBkgnd(pDC);
	}
	else
	{
		return FALSE;
	}

	return CView::OnEraseBkgnd(pDC);
}


void CDigitalEarthView::OnDestroy()
{
	CView::OnDestroy();

	if (mOSG != 0) delete mOSG;
	WaitForSingleObject(mThreadHandle, 1000);

}


void CDigitalEarthView::OnInitialUpdate()
{
	CView::OnInitialUpdate();

	mOSG->InitOSG();
	mThreadHandle = (HANDLE)_beginthread(&COSGObject::Render, 0, mOSG);
}


// CDigitalEarthView 消息处理程序

四、运行程序，即可看到如下结果：

注：若无法运行成功，可参考我的GitHub中的程序进行修改：

GitHub链接：https://github.com/cchangcs/MFC-OsgEarth