Delta3d 2.0中鼠标选取物体的示例代码另外一种方法

忘是亡心i 2022-08-06 11:29 135阅读 0赞

[http://blog.csdn.net/fengerfafa/archive/2008/07/07/2622848.aspx][http_blog.csdn.net_fengerfafa_archive_2008_07_07_2622848.aspx]

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//参考delta3d官方论坛上提供的方法，供交流     
   
// 另请问 " MessageBox(NULL,lpText,NULL,MB\_OK);“第一个参数HWND hWnd用this报错，怎样获取窗口句柄？    
   
   
   
bool  Picker::MBPressed (const dtCore::Mouse \*mouse, dtCore::Mouse::MouseButton button)    
   
\{    
   
    if (button == dtCore::Mouse::MouseButton::MiddleButton)    
   
    \{    
   
       //is there an object picked by the mouse ?    
   
       dtCore::DeltaDrawable\* picked\_object = NULL;    
   
       osg::Vec3 nearPoint,farPoint;    
   
       float x=0, y=0;    
   
       mouse->GetPosition(x, y);//获取鼠标坐标    
   
   
   
       osg::Matrix VPW =GetCamera()->GetOSGCamera()->getViewMatrix()\* //V    
   
                        GetCamera()->GetOSGCamera()->getProjectionMatrix()\*   //P    
   
                        GetCamera()->GetOSGCamera()->getViewport()->computeWindowMatrix();//W    
   
       osg::Matrix inverseVPW;    
   
       inverseVPW.invert(VPW);    
   
   
   
       /\*int xx,yy,w,h;   
   
        GetWindow()->GetPosition(xx, yy, w, h);//获取应用程序窗口大小   
   
        int xLoc = w\*(x+1)/2;   
   
       int yLoc = h\*(y+1)/2;\*/   
   
       int xLoc = GetCamera()->GetOSGCamera()->getViewport()->width()\*(x+1)/2;//width()是视口宽（注意视口不同于窗口），xLoc and yLoc are window (x,y) pixel locations    
   
       int yLoc = GetCamera()->GetOSGCamera()->getViewport()->height()\*(y+1)/2;    
   
       nearPoint.set(xLoc,yLoc, 0.0f);    
   
       farPoint.set(xLoc,yLoc, 1.0f);    
   
       nearPoint=nearPoint\*inverseVPW;    
   
       farPoint=farPoint\*inverseVPW;    
   
   
   
       dtCore::RefPtr<dtCore::Isector> ray = new dtCore::Isector(GetScene());    
   
       osg::Vec3f xyz;    
   
       ray->Reset();    
   
       ray->SetScene(GetScene());    
   
       ray->SetStartPosition(nearPoint);    
   
       ray->SetDirection(farPoint-nearPoint);    
   
   
   
       if(ray->Update())//如果检测到射线与物体相交    
   
       \{    
   
           ray->GetHitPoint(xyz);//光线与第一个物体的相交点坐标    
   
           std::cout<<"Hit Point: "<<xyz.x()<<" "<<xyz.y()<<" "<<xyz.z()<<" Num hits: "<<ray->GetNumberOfHits()<<std::endl;//？？？为什么点中1个输出数目是两个？如果是凹多面体那不有可能大于2次相交？    
   
           picked\_object = ray->GetClosestDeltaDrawable();//光线方向最近的击中物体    
   
           std::cout<<"HIT name:"<<picked\_object->GetName()<<" ID:"<<picked\_object->GetUniqueId().ToString()<<std::endl;    
   
           // 将“const std::string”转换为“LPCTSTR”方法：    
   
           // std::string   str;       
   
           // LPCTSTR   lpstr   =   (LPCTSTR)str.c\_str();//.c\_str()是额外加的    
   
           LPCTSTR lpText = (LPCTSTR)picked\_object->GetName().c\_str();    
   
           MessageBox(NULL,lpText,NULL,MB\_OK);//第一个参数HWND hWnd用this报错，怎样获取窗口句柄？    
   
       \}    
   
       else   
   
           std::cout<<"no Point: "<<std::endl;    
   
       /\*  int xWin = GetCamera()->GetSceneHandler()->GetSceneView()->getViewport()->width()\*(x+1)/2;   
   
       int yWin = GetCamera()->GetSceneHandler()->GetSceneView()->getViewport()->height()\*(y+1)/2;   
   
   
   
       GetCamera()->GetSceneHandler()->GetSceneView()->projectWindowXYIntoObject(xWin,yWin,nearPoint,farPoint);   
   
   
   
       // create the isector   
   
       dtCore::RefPtr<dtCore::Isector> pickRay = new dtCore::Isector(GetScene());   
   
       pickRay->SetStartPosition(nearPoint);   
   
       pickRay->SetDirection(farPoint-nearPoint);   
   
   
   
       // shoot the ray   
   
       if(pickRay->Update())   
   
       \{    
   
       picked\_object = pickRay->GetClosestDeltaDrawable();   
   
       std::cout<<"HIT name:"<<picked\_object->GetName()<<" ID:"<<picked\_object->GetUniqueId().ToString()<<std::endl;   
   
       \}\*/   
   
    \}    
   
    return false;    
   
\}

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