OSG HUD实时显示视点坐标

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OSG HUD实时显示视点坐标

代码

#include <osgDB/ReadFile>
#include <osgViewer/Viewer>
#include <osg/Geode>
#include <osg/Depth>
#include <osg/Camera>
#include <osgText/Text>
#include <osgGA/TrackballManipulator>

#include <sstream>

#pragma comment( lib, "osgd.lib")//.在Debug版本下的库名都加d,如"osgd.lib"
#pragma comment( lib, "osgDBd.lib")
#pragma comment( lib, "osgViewerd.lib")
#pragma comment( lib, "osgTextd.lib")
#pragma comment( lib, "osgGAd.lib")


using namespace std;

//事件类
class CHUD_viewPoint : public osgGA::GUIEventHandler
{
public:
	CHUD_viewPoint(osgText::Text* updateText):m_text(updateText) {}

	~CHUD_viewPoint() {}

	virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);
	void UpdateText(osgViewer::Viewer* viewer, const osgGA::GUIEventAdapter&);

	void setLabel(const std::string& name)
	{
		if (m_text.get())
		{
			m_text->setText(name);
		}
	}
protected:

	osg::Vec3 m_vPosEye;//视点坐标
	osg::ref_ptr<osgText::Text> m_text;//视点信息，会动态改变

};

bool CHUD_viewPoint::handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
	switch (ea.getEventType())
	{
	case(osgGA::GUIEventAdapter::FRAME):
	{
		osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>(&aa);
		if (viewer)
		{
			osg::Vec3 vCenter, vUp;
			viewer->getCamera()->getViewMatrixAsLookAt(m_vPosEye, vCenter, vUp);//获取视点信息
			UpdateText(viewer, ea);//更新文字信息       
		}
		return true;

	}
	default:
		return false;
	}

}

void CHUD_viewPoint::UpdateText(osgViewer::Viewer* viewer, const osgGA::GUIEventAdapter&)
{
	std::string gdlist = "";
	std::ostringstream os;
	os << "Eye( X: " << m_vPosEye[0] << "     Y: " << m_vPosEye[1] << "      Z: " << m_vPosEye[2] << ")";
	gdlist = os.str();
	setLabel(gdlist);

}

osg::Node* createHUD_viewPoint(osgText::Text* text)
{
	//文字

	//osgText::Text* text = new osgText::Text;   
	//设置字体
	std::string caiyun("fonts /STCAIYUN.TTF");//此处设置的是汉字字体
	text->setFont(caiyun);
	//设置文字显示的位置
	osg::Vec3 position(100.0f, 100.0f, 0.0f);
	text->setPosition(position);
	text->setColor(osg::Vec4(1, 1, 0, 1));
	text->setText(L"");//设置显示的文字
	text->setCharacterSize(15);
	text->setDataVariance(osg::Object::DYNAMIC);//一定要设置字体为动态，否则程序会卡住，死在那里。（参照osgcatch）
												//几何体节点

	osg::Geode* geode = new osg::Geode();
	geode->addDrawable(text);//将文字Text作这drawable加入到Geode节点中

	 //设置状态
	osg::StateSet* stateset = geode->getOrCreateStateSet();
	stateset->setMode(GL_LIGHTING, osg::StateAttribute::OFF);//关闭灯光
	stateset->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);//关闭深度测试
	 //打开GL_BLEND混合模式（以保证Alpha纹理正
	stateset->setMode(GL_BLEND, osg::StateAttribute::ON);
	//相机
	osg::Camera* camera = new osg::Camera;
	//设置透视矩阵
	camera->setProjectionMatrix(osg::Matrix::ortho2D(0, 600, 0, 600));//正交投影   
	//设置绝对参考坐标系，确保视图矩阵不会被上级节点的变换矩阵影响
	camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);

	//视图矩阵为默认的
	camera->setViewMatrix(osg::Matrix::identity());
	//设置背景为透明，否则的话可以设置ClearColor 
	camera->setClearMask(GL_DEPTH_BUFFER_BIT);
	camera->setAllowEventFocus(false);//不响应事件，始终得不到焦点
	//设置渲染顺序，必须在最后渲染
	camera->setRenderOrder(osg::Camera::POST_RENDER);
	camera->addChild(geode);//将要显示的Geode节点加入到相机
	return camera;
};

int main(int argc, char **argv)
{
	osgViewer::Viewer viewer;
	viewer.setUpViewInWindow(100, 100, 1080, 960);
	osg::ref_ptr<osg::Node> model = osgDB::readNodeFile("fountain.osg");
	osg::ref_ptr<osg::Group> root = new osg::Group;
	root->addChild(model.get());//加入某个模型
	osgText::Text* text = new osgText::Text;
	osg::ref_ptr< CHUD_viewPoint> pHUD = new CHUD_viewPoint(text);
	root->addChild(createHUD_viewPoint(text));//加入HUD文字
	viewer.addEventHandler(pHUD.get());
	viewer.setSceneData(root.get());
	viewer.realize();
	viewer.run();
	return 0;
}

效果