OSG中的HUD实时显示视点坐标

本文主要是介绍OSG中的HUD实时显示视点坐标，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

/*OSG中的HUD实时显示视点坐标*/

#include <osgDB/ReadFile>

#include <osgViewer/Viewer>

#include <osg/Geode>

#include <osg/Depth>

#include <osg/CameraNode>

#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:  

 

    /**构造函数*/

      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&);

 

      /**LABEL*/

      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纹理正确）

    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::CameraNode::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; 

 

    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;

}

这篇关于OSG中的HUD实时显示视点坐标的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---