[osg][osgEarth][原]基于OE自定义自由飞行漫游器（初级版）

由于受够了OE的漫游器，想搞个可以在全球飞行的漫游器，所以就做了一个：

请无视我的起名规则······

类头文件：EarthWalkManipulator.h

#pragma once
//南水之源  20180101
#include <osgGA/CameraManipulator>
#include <osgEarth/MapNode>
#include <osgEarth/Viewpoint>
#include <osgEarth/GeoData>

class EarthWalkManipulator :public osgGA::CameraManipulator
{
public:
    EarthWalkManipulator();
    ~EarthWalkManipulator();

    //所有漫游器都必须实现的4个纯虚函数
    virtual void setByMatrix(const osg::Matrixd& matrix) {}  //设置相机的位置姿态矩阵
    virtual void setByInverseMatrix(const osg::Matrixd& matrix) {}  //设置相机的视图矩阵
    virtual osg::Matrixd getMatrix() const;  //获取相机的姿态矩阵
    virtual osg::Matrixd getInverseMatrix() const;   //获取相机的视图矩阵 

    //所有操作在这里响应
    virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& us);

    // Attach a node to the manipulator.
    virtual void setNode(osg::Node*);
    virtual osg::Node* getNode();
    bool established();

    /**
    * Sets the camera position, optionally moving it there over time.
    */
    //virtual void setViewpoint(const osgEarth::Viewpoint& vp, double duration_s = 0.0);
    virtual void home(double /*unused*/);
    virtual void home(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& us);

    void addMouseEvent(const osgGA::GUIEventAdapter& ea);
    bool calcMovement(const osgGA::GUIEventAdapter& ea);
protected:
    osg::Vec3   _eye;               //视点位置
    osg::Quat    _rotate;            //旋转姿态
    osg::ref_ptr<osg::Node>  _root;

    osg::observer_ptr<osg::Node> _node;
    osg::observer_ptr<osgEarth::MapNode>   _mapNode;

    osg::ref_ptr<const osgEarth::SpatialReference> _srs;

    float        _speed;                //速度

    // Internal event stack comprising last two mouse events.
    osg::ref_ptr<const osgGA::GUIEventAdapter> _ga_t1;
    osg::ref_ptr<const osgGA::GUIEventAdapter> _ga_t0;

};

类实现：EarthWalkManipulator.cpp

//南水之源  20180101
#include "EarthWalkManipulator.h"
#include <osgViewer\Viewer>

#include <osgDB\ReadFile>
#include <osg\MatrixTransform>

using namespace osgEarth;

EarthWalkManipulator::EarthWalkManipulator()
{
    _eye = osg::Vec3d(, , );
    //_rotate = osg::Quat(-osg::PI_2, osg::X_AXIS);
    _speed = 1.0;
}

EarthWalkManipulator::~EarthWalkManipulator()
{
}

//获取相机的姿态矩阵
osg::Matrixd EarthWalkManipulator::getMatrix() const
{
    osg::Matrix mat;
    mat.setRotate(_rotate);//先旋转
    mat.postMultTranslate(_eye);//再平移
    return mat;
}

osg::Matrixd EarthWalkManipulator::getInverseMatrix() const
{
    osg::Matrix mat;
    mat.setRotate(-_rotate);
    mat.preMultTranslate(-_eye);
    return mat;
    //return osg::Matrixd::inverse(getMatrix());
}

void
EarthWalkManipulator::home(double unused)
{
    _eye = osg::Vec3d(, , );
    _speed = 1.0;
}

void
EarthWalkManipulator::home(const osgGA::GUIEventAdapter&, osgGA::GUIActionAdapter& us)
{
    home(0.0);
    us.requestRedraw();
}

void
EarthWalkManipulator::setNode(osg::Node* node)
{
    // you can only set the node if it has not already been set, OR if you are setting
    // it to NULL. (So to change it, you must first set it to NULL.) This is to prevent
    // OSG from overwriting the node after you have already set on manually.
    if (node == 0L || !_node.valid())
    {
        _root = node;
        _node = node;
        _mapNode = 0L;
        _srs = 0L;

        established();

        osg::Matrix matrixGood1;
        GeoPoint point1(_srs, , , 10000.0);
        point1.createLocalToWorld(matrixGood1);

        _eye = matrixGood1.getTrans();

        osg::Vec3d worldup;
        point1.createWorldUpVector(worldup);

        osg::Matrix mat;
        matrixGood1.getRotate().get(mat);
        osg::Vec3d eye, center, up;
        mat.getLookAt(eye, center, up);
        mat.makeLookAt(eye, -worldup, up);

        _rotate = mat.getRotate();

    }
}

osg::Node*
EarthWalkManipulator::getNode()
{
    return _node.get();
}

bool EarthWalkManipulator::handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& us)
{
    switch (ea.getEventType())
    {
    case(osgGA::GUIEventAdapter::FRAME):
    {
        if (calcMovement(ea))//根据鼠标在屏幕中的位置调整相机转向
            us.requestRedraw();
        return true;
    }break;
    case(osgGA::GUIEventAdapter::SCROLL):
    {
        osg::Quat qat;
        osg::Matrix mat;
        _rotate.get(mat);
        osg::Vec3d eye, center, up;
        mat.getLookAt(eye, center, up);

        osg::Vec3d dirction = center - eye;
        dirction.normalize();
        up.normalize();
        osg::Vec3d cross = dirction^up;
        cross.normalize();

        cross *= 0.01;
        switch (ea.getScrollingMotion())
        {
        case osgGA::GUIEventAdapter::ScrollingMotion::SCROLL_UP://逆时针旋转相机
        {
            mat = osg::Matrix::lookAt(eye, center, up + cross);
            _rotate = mat.getRotate();
        }break;
        case osgGA::GUIEventAdapter::ScrollingMotion::SCROLL_DOWN://顺时针旋转相机
        {
            mat = osg::Matrix::lookAt(eye, center, up - cross);
            _rotate = mat.getRotate();
        }break;
        }
        return true;
    }break;
    case (osgGA::GUIEventAdapter::KEYDOWN):
    {
        osg::Vec3   v3Direction;         //视点方向
        osg::Matrix mCameraQuat;
        osg::Vec3d  v3Eye, v3Center, v3Up;
        _rotate.get(mCameraQuat);
        mCameraQuat.getLookAt(v3Eye, v3Center, v3Up);//这里的v3Eye不是实际相机的位置，而是0，0，0
        v3Direction = v3Center - v3Eye;
        v3Direction.normalize();
        osg::Vec3d v3CrossVector = v3Up^v3Direction;
        v3CrossVector.normalize();
        if (ea.getKey() == 'w' || ea.getKey() == 'W' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Up)//前进
        {
            _eye += v3Direction * _speed;
        }
        if (ea.getKey() == 's' || ea.getKey() == 'S' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Down)//后退
        {
            _eye -= v3Direction * _speed;
        }
        if (ea.getKey() == 'a' || ea.getKey() == 'A' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Left)//左移
        {
            _eye += v3CrossVector * _speed;
        }
        if (ea.getKey() == 'd' || ea.getKey() == 'D' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Right)//右移
        {
            _eye -= v3CrossVector * _speed;
        }
        if (ea.getKey() == '-' || ea.getKey() == '_' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Control_L)//减10倍移动速度
        {
            _speed /= 10.0;
            if (_speed < 1.0)
            {
                _speed = 1.0;
            }
        }
        if (ea.getKey() == '=' || ea.getKey() == '+' || ea.getKey() == osgGA::GUIEventAdapter::KEY_Shift_L)//加10倍移动速度
        {
            _speed *= 10.0;
            if (_speed > 100000.0)
            {
                _speed = 100000.0;
            }
        }

        if (ea.getKey() == 'h' || ea.getKey() == 'H')//在当前经纬度，姿态回正：1.视点向地面 2.头部向正北
        {
            v3Eye = _eye;//使用相机实际位置
            osg::Vec3d v3EyeLonLat;
            _srs->transformFromWorld(v3Eye, v3EyeLonLat);
            //先获取当前位置的经纬度，再获取当前正上，正北
            osg::Matrix mRealAttitude;

            if (v3EyeLonLat.z() < )//v3EyeLonLat.z()是眼点实际海拔
                v3EyeLonLat.z() = ;//将海拔0以下的物体拉到海拔100米

            GeoPoint gEyeGeo(_srs, v3EyeLonLat.x(), v3EyeLonLat.y(), v3EyeLonLat.z());
            gEyeGeo.createLocalToWorld(mRealAttitude);

            osg::Vec3d v3HorizonUp;//指天向量
            gEyeGeo.createWorldUpVector(v3HorizonUp);

            _eye = mRealAttitude.getTrans();

            mRealAttitude.getLookAt(v3Eye, v3Center, v3Up);//获取新的位置和姿态

            osg::Matrix mDeviationAttitude;//向北位置偏移0.00001纬度，为了计算正北方向
            GeoPoint gDeviationEyeGeo(_srs, v3EyeLonLat.x(), v3EyeLonLat.y() + 0.00001, v3EyeLonLat.z());
            gDeviationEyeGeo.createLocalToWorld(mDeviationAttitude);
            osg::Vec3d v3DeviationNorthPoint = mDeviationAttitude.getTrans();
            osg::Vec3d v3NorthHeadUp = v3DeviationNorthPoint - v3Eye;
            v3NorthHeadUp.normalize();//指北向量

            //if (v3EyeLonLat.y() < 90.0 && v3EyeLonLat.y() > 0.0)//没研究出为什么北半球和南半球需要相反，但实际使用没问题
            //{
            //    mRealAttitude.makeLookAt(osg::Vec3d(0,0,0), -v3HorizonUp, -v3NorthHeadUp);
            //}
            if (v3EyeLonLat.y() < 89.99999  && v3EyeLonLat.y() > -90.0)
            {
                mRealAttitude.makeLookAt(osg::Vec3d(, , ), -v3HorizonUp, v3NorthHeadUp);
            }
            _rotate = mRealAttitude.getRotate();
        }
    }break;
    default:
        return false;
    }
}

bool
EarthWalkManipulator::established()
{
    if (_srs.valid() && _mapNode.valid() && _node.valid())
        return true;

    // lock down the observed node:
    osg::ref_ptr<osg::Node> safeNode;
    if (!_node.lock(safeNode))
        return false;

    // find a map node or fail:
    _mapNode = osgEarth::MapNode::findMapNode(safeNode.get());
    if (!_mapNode.valid())
        return false;

    // Cache the SRS.
    _srs = _mapNode->getMapSRS();
    return true;
}

void EarthWalkManipulator::addMouseEvent(const osgGA::GUIEventAdapter& ea)
{
    _ga_t1 = _ga_t0;
    _ga_t0 = &ea;
}

bool EarthWalkManipulator::calcMovement(const osgGA::GUIEventAdapter& ea)
{
    osg::Quat qat;
    osg::Matrix mat;
    _rotate.get(mat);
    osg::Vec3d eye, center, up;
    mat.getLookAt(eye, center, up);

    osg::Vec3d dirction = center - eye;
    dirction.normalize();
    up.normalize();
    osg::Vec3d cross = dirction^up;
    cross.normalize();

    double x1 = ea.getXnormalized();
    double y1 = ea.getYnormalized();

    osg::Vec3d deviation(, , );
    if (x1 > 0.1)
    {
        deviation += cross * 0.001;
    }
    else if (x1 < -0.1)
    {
        deviation -= cross * 0.001;
    }
    if (y1 > 0.1)
    {
        deviation += up * 0.001;
    }
    else if (y1 < -0.1)
    {
        deviation -= up * 0.001;
    }

    mat = osg::Matrix::lookAt(eye, deviation + center, up);
    _rotate = mat.getRotate();

    return true;
}

使用：main.cpp

#include <osg/Image>
#include <osgGA/StateSetManipulator>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgEarth/Map>
#include <osgEarth/MapNode>
#include <osgEarth/Registry>
#include <osgEarthSymbology/Geometry>
#include <osgEarthSymbology/GeometryRasterizer>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/AutoClipPlaneHandler>
#include <osgEarth/ImageToHeightFieldConverter>
#include <osgEarth/ImageUtils>
#include <osgEarth/FileUtils>
#include <osgEarth/Registry>
#include <osgEarth/MapFrame>
#include <osgDB/FileUtils>
#include <osgDB/FileNameUtils>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>

#include <osgEarthUtil/ExampleResources>
#include <math.h>

#include <osgGA/NodeTrackerManipulator>
#include <osgGA/AnimationPathManipulator>
#include <osgGA/KeySwitchMatrixManipulator>
#include "EarthWalkManipulator.h"

using namespace osgEarth;
using namespace osgEarth::Util;
using namespace osgEarth::Symbology;

int main(int argc, char** argv)
{
    //正常的.earth文件加载
    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer;
    MapNode* s_mapNode = 0L;
    osg::Node* earthFile = MapNodeHelper().load(arguments, &viewer);
    if (earthFile)
        s_mapNode = MapNode::get(earthFile);
    if (!s_mapNode)
    {
        OE_WARN << "Unable to load earth file." << std::endl;
        return -;
    }
    osg::Group* root = new osg::Group();
    root->addChild(earthFile);

    osg::Matrix matrixGood1;
    osg::Vec3d geopoint1, geopoint2, geopoint3;
    GeoPoint point1(s_mapNode->getMapSRS(), , , );
    point1.createLocalToWorld(matrixGood1);
    //matrixGood1.getLookAt(geopoint1, geopoint2, geopoint3);
    //osg::Vec3 _vector = geopoint1 - geopoint2;

    //添加一头牛，查看位置是否正确
    //osg::Node* cow = osgDB::readNodeFile("D:\\temp\\node\\cow.osg");
    //
    //osg::ref_ptr<osg::MatrixTransform> pat = new osg::MatrixTransform;
    //pat->addChild(cow);
    //pat->setMatrix(osg::Matrix::scale(200000, 200000, 200000));

    //osg::Matrix maaat2;
    //osg::ref_ptr<osg::MatrixTransform> pat2 = new osg::MatrixTransform;
    //pat2->setMatrix(osg::Matrix::rotate(matrixGood1.getRotate())*
    //    osg::Matrix::translate(matrixGood1.getTrans()));
    //pat2->addChild(pat);
    //root->addChild(pat2);

    viewer.setSceneData(root);

    //模型漫游器
    osgGA::NodeTrackerManipulator* nodeTrack = new osgGA::NodeTrackerManipulator();
    nodeTrack->setTrackNode(root);

    /*************************************动画漫游器**下*********************************/
    GeoPoint gPoint1(s_mapNode->getMap()->getSRS(), , , );
    osg::Matrix gMatrix1;
    gPoint1.createLocalToWorld(gMatrix1);//获取当前地球上的正确姿态
    //由于相机，自身向下看，所以在当前姿态基础上抬起60度，注意是前乘！
    gMatrix1.preMultRotate(osg::Quat(osg::DegreesToRadians(60.0), osg::X_AXIS));
    osg::Quat q1;    gMatrix1.get(q1);//获取当前矩阵姿态
    osg::Vec3d vPos1 = gMatrix1.getTrans();//获取当前矩阵位置

    GeoPoint gPoint2(s_mapNode->getMap()->getSRS(), 32.01, 118.01, );
    osg::Matrix gMatrix2;
    gPoint2.createLocalToWorld(gMatrix2);
    gMatrix2.preMultRotate(osg::Quat(osg::DegreesToRadians(60.0), osg::X_AXIS));
    osg::Quat q2;
    gMatrix2.get(q2);
    osg::Vec3d vPos2 = gMatrix2.getTrans();

    GeoPoint gPoint3(s_mapNode->getMap()->getSRS(), 32.02, 118.02, );
    osg::Matrix gMatrix3;
    gPoint3.createLocalToWorld(gMatrix3);
    osg::Quat q3;
    gMatrix3.get(q3);
    osg::Vec3d vPos3 = gMatrix3.getTrans();
    //获取相机之后再顺旋转,其实是错误的姿态
    osg::Quat qbuf(osg::DegreesToRadians(60.0), osg::X_AXIS);
    q3    *= qbuf;

    //使用动画漫游器
    osgGA::AnimationPathManipulator *animationPathMp = new osgGA::AnimationPathManipulator();
    //给动画漫游器添加关键帧
    osg::AnimationPath* _animationPath = new osg::AnimationPath;
    _animationPath->insert(0.0, osg::AnimationPath::ControlPoint(vPos1, q1));//姿态正确
    _animationPath->insert(3.0, osg::AnimationPath::ControlPoint(vPos2, q2));//姿态正确
    _animationPath->insert(6.0, osg::AnimationPath::ControlPoint(vPos3, q3));//姿态错误！
    _animationPath->setLoopMode(osg::AnimationPath::SWING);//设置路径是回摆的
    animationPathMp->setAnimationPath(_animationPath);
    /*************************************动画漫游器**上*********************************/

    //这里添加三个漫游器，使用一个控制漫游器选择，按键盘‘3’就切换到路径动画漫游器了
    osgGA::KeySwitchMatrixManipulator* keyPtr = new osgGA::KeySwitchMatrixManipulator();
    keyPtr->addMatrixManipulator('', "earthMan", new EarthManipulator());
    keyPtr->addMatrixManipulator('', "trakerMan", nodeTrack);
    keyPtr->addMatrixManipulator('', "animationPathMan", animationPathMp);
    keyPtr->addMatrixManipulator('', "earthWalkMan", new EarthWalkManipulator());
    viewer.setCameraManipulator(keyPtr);
    //viewer.setUpViewOnSingleScreen(0);

    {
        osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
        traits->x = ;
        traits->y = ;
        traits->width = ;
        traits->height = ;
        traits->windowDecoration = true;
        traits->doubleBuffer = true;
        traits->sharedContext = ;

        osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());

        osg::ref_ptr<osg::Camera> camera = new osg::Camera;
        camera->setGraphicsContext(gc.get());
        camera->setViewport(new osg::Viewport(, , traits->width, traits->height));
        GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
        camera->setDrawBuffer(buffer);
        camera->setReadBuffer(buffer);

        // add this slave camera to the viewer, with a shift left of the projection matrix
        viewer.addSlave(camera.get());
    }

    while(!viewer.done())
        viewer.frame();

    return ;
}

由于是初级版，所以有些操作还是比较反人类···

运行起来是用其他漫游器告诉你：能看到个地球

开始操作：

1.按‘4’切换到自定义的漫游器，现在你的视点在球心，啥也看不到

2.按‘s’或者‘下’，再按‘h’现在应该是在地球表面了（别问为什么会需要这么SB的操作···）

3.然后自己体验吧（不要晕了···）

后期会更新一个有良好操作的版本