OSG物体随鼠标移动(即点移动)

OSG物体随鼠标移动(即点移动)

一.流程图:

 

 

 

 

 

 

二.点移动过程详解:

如下图所示:

可让物体移动平面D与显示器窗口平面M平行.

鼠标只在显示器窗口M上移动,当鼠标点到A点时,会看到物体的A’点被选中,当鼠标点从A移动到B时,实际的物体的移动也是只有平面D,此时对应物体实际点就为D平面上的B’.其中AB与A’B’两线是平行的.其实这归根到底还是基本的视锥体问题.平面D可由点A’和该平面的法线n确定:A’可由pointer.getLocalIntersectPoint()获得,是世界坐标系;n即为视线方向: pointer.getEyeDir().然后设置拖动的投影面为平面D即可,表示物体在平面D内移动: _projector->setPlane( *pplnPTPush);.

代码如下:

#include <osgDB/ReadFile>

#include <osgViewer/Viewer>

 

#include <osgManipulator/Command>

#include <osgManipulator/CommandManager> 

#include <osgManipulator/Translate2DDragger>

#include <osgText/Text>

 

#include <iostream>

#include <string>

 

 

#include <osg/ShapeDrawable>

 

#pragma comment( lib, "osgd.lib"); //此库用于Debug版本下

#pragma comment( lib, "osgDBd.lib");

#pragma comment( lib, "osgViewerd.lib");

 

#pragma comment( lib, "osgmanipulatord.lib");

#pragma comment( lib, "osgTextd.lib");

#pragma comment( lib, "osgGAd.lib");

 

using namespace std;

using namespace osgManipulator;

 

 

osg::ref_ptr< osg::Group > g_pRoot= new osg::Group();

 

class CDraggerPoint: public osgManipulator::Translate2DDragger

{

public:

 

    void setupDefaultGeometry()

    {

 

 

       osg::ref_ptr< osg::Geometry   > pGeom= new osg::Geometry();

 

       osg::ref_ptr< osg::Geode    > pGeoSphere= new osg::Geode();

 

       osg::ref_ptr< osg::Vec3Array > pVertices= new osg::Vec3Array(  3);

 

   

       int t= 2;

       (*pVertices)[ 0].set( 0, 0+ t, 0);

       (*pVertices)[ 1].set( 0, 0+ t, -2);

       (*pVertices)[ 2].set( 2, 0+ t, 0);

 

       pGeom->setVertexArray( pVertices.get() );

 

       osg::ref_ptr< osg::DrawElementsUInt> pTri= new osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES , 0);

 

       pTri->push_back( 0);

       pTri->push_back( 1);

       pTri->push_back( 2);

       pGeom->addPrimitiveSet( pTri.get());

 

       pGeoSphere->addDrawable( pGeom.get());

       addChild( pGeoSphere.get());

 

    }

 

    virtual bool handle(const PointerInfo& pointer, const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)

    {

       // Check if the dragger node is in the nodepath.

       if (!pointer.contains(this)) return false;

 

       switch (ea.getEventType())

       {

           // Pick start.

       case (osgGA::GUIEventAdapter::PUSH):

           {

               // Get the LocalToWorld matrix for this node and set it for the projector.

              osg::NodePath nodePathToRoot;

              computeNodePathToRoot(*this,nodePathToRoot);

              osg::Matrix localToWorld = osg::computeLocalToWorld(nodePathToRoot);

              _projector->setLocalToWorld(localToWorld);

 

              //设置点移动平面,点即鼠标与物体交点(世界坐标系),法线为//视线方向

              osg::Plane* pplnPTPush= new osg::Plane( pointer.getEyeDir(),  pointer.getLocalIntersectPoint()/** _projector->getLocalToWorld()*/);

              _projector->setPlane( *pplnPTPush);

 

              if (_projector->project(pointer, _startProjectedPoint))

              {

                  // Generate the motion command.

                  osg::ref_ptr<TranslateInPlaneCommand> cmd = new TranslateInPlaneCommand(_projector->getPlane());

 

                  cmd->setStage(MotionCommand::START);

                  cmd->setReferencePoint(_startProjectedPoint);

                  cmd->setLocalToWorldAndWorldToLocal(_projector->getLocalToWorld(),_projector->getWorldToLocal());

 

                  // Dispatch command.

                  if (_commandManager)

                  {

                     _commandManager->addSelectionsToCommand(*cmd, *getParentDragger());

                     _commandManager->dispatch(*cmd);

                  }

 

                 

              //在该点处添加一个球

              osg::ref_ptr< osg::Shape> sphere = new osg::Sphere( _startProjectedPoint* _projector->getLocalToWorld(), 0.08f);

              osg::ref_ptr<osg::ShapeDrawable> sphereDrawable = new osg::ShapeDrawable(sphere);

              osg::ref_ptr<osg::Geode> sphereGeode = new osg::Geode();

              sphereGeode->addDrawable(sphereDrawable);

 

              g_pRoot->addChild( sphereGeode);

 

 

 

                  // Set color to pick color.

                  setMaterialColor(_pickColor,*this);

                  getOrCreateStateSet()->setAttributeAndModes(_polygonOffset.get(), osg::StateAttribute::ON);

 

                  aa.requestRedraw();

              }

              return true;

           }

 

           // Pick move.

       case (osgGA::GUIEventAdapter::DRAG):

           {

 

              osg::Vec3d projectedPoint;

              if (_projector->project(pointer, projectedPoint))

              {

                  // Generate the motion command.

                  osg::ref_ptr<TranslateInPlaneCommand> cmd = new TranslateInPlaneCommand(_projector->getPlane());

 

                  cmd->setStage(MotionCommand::MOVE);

                  cmd->setLocalToWorldAndWorldToLocal(_projector->getLocalToWorld(),_projector->getWorldToLocal());

                  cmd->setTranslation(projectedPoint - _startProjectedPoint);

                  cmd->setReferencePoint(_startProjectedPoint);

 

                  // Dispatch command.

                  if (_commandManager)

                  {

                     _commandManager->addSelectionsToCommand(*cmd, *getParentDragger());

                     _commandManager->dispatch(*cmd);

                  }

 

 

                  osg::ref_ptr< osg::Shape> sphere = new osg::Sphere( projectedPoint* _projector->getLocalToWorld(), 0.08f);

              osg::ref_ptr<osg::ShapeDrawable> sphereDrawable = new osg::ShapeDrawable(sphere);

              osg::ref_ptr<osg::Geode> sphereGeode = new osg::Geode();

              sphereGeode->addDrawable(sphereDrawable);

 

              g_pRoot->addChild( sphereGeode);

 

 

                  aa.requestRedraw();

              }

              return true;

           }

 

           // Pick finish.

       case (osgGA::GUIEventAdapter::RELEASE):

           {

 

               osg::ref_ptr<TranslateInPlaneCommand> cmd = new TranslateInPlaneCommand(_projector->getPlane());

 

              cmd->setStage(MotionCommand::FINISH);

              cmd->setReferencePoint(_startProjectedPoint);

               cmd->setLocalToWorldAndWorldToLocal(_projector->getLocalToWorld(),_projector->getWorldToLocal());

 

 

              // Dispatch command.

              if (_commandManager)

              {

                  _commandManager->addSelectionsToCommand(*cmd, *getParentDragger());

                  _commandManager->dispatch(*cmd);

              }

 

              // Reset color.

              setMaterialColor(_color,*this);

              getOrCreateStateSet()->removeAttribute(_polygonOffset.get());

 

              aa.requestRedraw();

 

              return true;

           }

       default:

           return false;

       }

    }

 

};

 

 

class PickModeHandler : public osgGA::GUIEventHandler

{

public:

    enum Modes

    {

       VIEW = 0,

       PICK

    };

 

    PickModeHandler():

       _mode(VIEW),

           _activeDragger(0)

       {

       }       

 

       bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa,

           osg::Object*, osg::NodeVisitor*)

       {

           osgViewer::View* view = dynamic_cast<osgViewer::View*>(&aa);

           if (!view) return false;

 

          

 

           if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Tab &&

              ea.getEventType() == osgGA::GUIEventAdapter::KEYDOWN &&

              _activeDragger == 0)

           {

              _mode = ! _mode;

           }

 

           if (VIEW == _mode) return false;

 

           switch (ea.getEventType())

           {

           case osgGA::GUIEventAdapter::PUSH:

              {

                  osgUtil::LineSegmentIntersector::Intersections intersections;

 

                  _pointer.reset();

                  if (view->computeIntersections(ea.getX(),ea.getY(),intersections))

                  {

                     _pointer.setCamera(view->getCamera());

                     _pointer.setMousePosition(ea.getX(), ea.getY());

 

                     for(osgUtil::LineSegmentIntersector::Intersections::iterator hitr = intersections.begin();

                         hitr != intersections.end(); ++hitr)

                     {

                         _pointer.addIntersection(hitr->nodePath, hitr->getLocalIntersectPoint());

                     }

                     for (osg::NodePath::iterator itr = _pointer._hitList.front().first.begin();

                         itr != _pointer._hitList.front().first.end();

                         ++itr)

                     {

                         osgManipulator::Dragger* dragger = dynamic_cast<osgManipulator::Dragger*>(*itr);

                         if (dragger)

                         {

 

                            dragger->handle(_pointer, ea, aa);

                            _activeDragger = dragger;

                        

                            break;

                         }                   

                     }

                  }

             

              }

           case osgGA::GUIEventAdapter::DRAG:

           case osgGA::GUIEventAdapter::RELEASE:

              {

                  if (_activeDragger)

                  {

                     _pointer._hitIter = _pointer._hitList.begin();

                     _pointer.setCamera(view->getCamera());

                     _pointer.setMousePosition(ea.getX(), ea.getY());

 

                     _activeDragger->handle(_pointer, ea, aa);

                  }

                  break;

              }

           default:

              break;

           }

 

           if (ea.getEventType() == osgGA::GUIEventAdapter::RELEASE)

           {

              _activeDragger = 0;

              _pointer.reset();

           }

 

           return true;

       }

      

 

 

private:

    unsigned int _mode;

    osgManipulator::Dragger* _activeDragger;

    osgManipulator::PointerInfo _pointer;

};

 

 

 

 

 

osgManipulator::Dragger* createDragger(const std::string& name)

{

    osgManipulator::Dragger* dragger = 0;

 

    CDraggerPoint* d = new CDraggerPoint();

    d->setupDefaultGeometry();

    dragger = d;

 

    return dragger;

}

 

 

osg::Node* addDraggerToScene(osg::Node* scene, osgManipulator::CommandManager* cmdMgr, const std::string& name)

{

    scene->getOrCreateStateSet()->setMode(GL_NORMALIZE, osg::StateAttribute::ON);

 

    osgManipulator::Selection* selection = new osgManipulator::Selection;

    selection->addChild(scene);

 

    osgManipulator::Dragger* dragger = createDragger(name);

    dragger->setName( name);

 

    osg::Group* root = new osg::Group;

    root->addChild(dragger);

    root->addChild(selection);

 

    cmdMgr->connect(*dragger, *selection);

 

    return root;

}

 

 

 

int main()

{

 

    osg::ref_ptr< osg::Geode    > pGeoSphere= new osg::Geode();

 

    osg::ref_ptr< osg::Geometry   > pGeom= new osg::Geometry();

 

    osg::ref_ptr< osg::Vec3Array > pVertices= new osg::Vec3Array(  3);

 

    (*pVertices)[ 0].set( 0+ 2, 0- 2, 0);

    (*pVertices)[ 1].set( 0 , 0- 2, 2);

    (*pVertices)[ 2].set( 0, 0- 2, 0);

    pGeom->setVertexArray( pVertices.get() );

 

    osg::ref_ptr< osg::DrawElementsUInt> pTri= new osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES , 0);

 

    pTri->push_back( 0);

    pTri->push_back( 1);

    pTri->push_back( 2);

    pGeom->addPrimitiveSet( pTri.get());

 

    pGeoSphere->addDrawable( pGeom.get());

 

    //g_pRoot->addChild( pGeoSphere.get());//将非dragger的物体加入

 

    osgViewer::Viewer viewer;

 

    //cmdManager

    osg::ref_ptr<osgManipulator::CommandManager> cmdMgr = new osgManipulator::CommandManager;

 

    osg::ref_ptr< osg::Geode    > pGeoSphereDragger= new osg::Geode();

    g_pRoot->addChild(addDraggerToScene( pGeoSphereDragger.get(),cmdMgr,"Translate2DDragger") );

 

    viewer.setSceneData(  g_pRoot);

 

    viewer.addEventHandler(new PickModeHandler());

 

 

    return viewer.run(); 

 

}