osg hud and RTT

//////////////////////////////////////////////////////////////////////////
// hud and RTT
//////////////////////////////////////////////////////////////////////////

/*HUD 和 RTT 的结合*/
#include <osg/Group>
#include <osg/Camera>
#include <osgDB/ReadFile>
#include <osg/Geometry>
#include <osg/Image>
#include <osg/ShapeDrawable>
#include <osg/Texture2D>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osg/MatrixTransform>
#include <osgGA/DriveManipulator>
#include <iostream>
using namespace std;

class CameraUpdateCallBack :public osg::NodeCallback
{
public:
CameraUpdateCallBack(osg::MatrixTransform*mat) : _eye(0.0f, 0, 0)
{
_mat = mat;
}

virtual ~CameraUpdateCallBack(){

}
virtual void operator()(osg::Node*node, osg::NodeVisitor*nv){
osg::Camera*camera = dynamic_cast<osg::Camera*>(node);
if (camera){
// if(camera->getName().compare("MasterCamera")==0){
osg::Vec3 eye, center, up;
double left, right, bottom, top, znear, zfar;
camera->getViewMatrixAsLookAt(eye, center, up);
camera->getProjectionMatrixAsOrtho(left, right, bottom, top, znear, zfar);

_eye = eye;//记录相机坐标
//可以通过这种方法为烘培相机找到合适的视点
cout << "eye= " << eye.x() << " , " << eye.y() << " , " << eye.z() << endl;
cout << "up= " << up.x() << " , " << up.y() << " , " << up.z() << endl;
cout << "center= " << center.x() << " , " << center.y() << " , " << center.z() << endl;
cout << left << "," << right << " , " << bottom << " , " << top << " , " << znear << " , " << zfar << endl;

// }
}
// osg::MatrixTransform*mat=dynamic_cast<osg::MatrixTransform*>(node);
if (_mat){
osg::Matrix mm = _mat->getMatrix();
osg::Vec3 _eyeTmp = mm.getTrans();
mm.makeTranslate(_eyeTmp);
_mat->setMatrix(mm);
cout << "-------------------" << endl;
osg::Matrix m;
m.makeTranslate(_eye);
_mat->setMatrix(m);
}
traverse(node, nv);
}
private:
osg::Vec3 _eye;
osg::MatrixTransform *_mat;

};

osg::Node *createNode(osg::Texture2D*t2d){
osg::ref_ptr<osg::Geode>geode = new osg::Geode;
osg::StateSet *ss = geode->getOrCreateStateSet();
ss->setMode(GL_BLEND, osg::StateAttribute::ON);
ss->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
ss->setTextureAttributeAndModes(0, t2d, osg::StateAttribute::ON);

osg::ref_ptr<osg::ShapeDrawable>sd = new osg::ShapeDrawable(new osg::Box(osg::Vec3(200, 200, 0), 400, 400, 0.1));
sd->setColor(osg::Vec4(0.5, 0.5, 0.5, 0.8));
geode->addDrawable(sd);

return geode.release();
}
osg::Node *createRedPoint(){
osg::ref_ptr<osg::Geode>geode = new osg::Geode;
geode->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
osg::TessellationHints *hints = new osg::TessellationHints;
hints->setDetailRatio(1.0);
osg::ref_ptr<osg::ShapeDrawable>sd = new osg::ShapeDrawable(new osg::Cylinder(osg::Vec3(0, 0, 0), 10, 10), hints);
sd->setColor(osg::Vec4(1, 0, 0, 1));
geode->addDrawable(sd.get());
return geode.release();
}
//创建HUD
osg::Camera*createHUD(osg::Texture2D*t2d){
osg::ref_ptr<osg::Camera>camera = new osg::Camera;
camera->setViewMatrix(osg::Matrix::identity());
camera->setAllowEventFocus(false);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
//设置视口，就是相机投影到你显示器的哪个位置
camera->setViewport(00, 00, 1366, 768);
//投影变换就是定义一个可视空间，可视空间以外的物体不会被绘制到屏幕上
//setProjectionMatrixAsOrtho2主要用于二维图像到二维屏幕上的投影,它负责把三维空间的XY平面投射到屏幕上
camera->setProjectionMatrixAsOrtho2D(0, 1366, 0, 768);
camera->setClearMask(GL_DEPTH_BUFFER_BIT);
camera->setRenderOrder(osg::Camera::POST_RENDER);

camera->addChild(createNode(t2d));//设置HUD的内容
return camera.release();
}
//烘培纹理
void createRtt(osgViewer::Viewer*viewer){
osg::ref_ptr<osg::Group>gp = new osg::Group;
osg::ref_ptr<osg::Node>ceep = osgDB::readNodeFile("ceep.ive");
gp->addChild(ceep);

if (!viewer){
return;
}
osg::GraphicsContext::WindowingSystemInterface* wsi = osg::GraphicsContext::getWindowingSystemInterface();
if (!wsi){
cout << "wsi is NULL" << endl;
return;
}
unsigned int width, height;
wsi->getScreenResolution(osg::GraphicsContext::ScreenIdentifier(0), width, height);

osg::ref_ptr<osg::GraphicsContext::Traits>traits = new osg::GraphicsContext::Traits;
traits->x = 0;
traits->y = 0;
traits->width = width;
traits->height = height;
traits->windowDecoration = false;
traits->doubleBuffer = true;
traits->sharedContext = 0;

osg::ref_ptr<osg::GraphicsContext>gc = osg::GraphicsContext::createGraphicsContext(traits);
if (!gc.valid()){
return;
}
//创建主相机
osg::ref_ptr<osg::Camera>master = new osg::Camera;
master->setGraphicsContext(gc);
master->setViewport(00, 0, width, height);
master->setName("MasterCamera");
//找出合适的视点
// master->setUpdateCallback(new CameraUpdateCallBack);

viewer->addSlave(master);

//创建烘培相机
osg::ref_ptr<osg::Camera>rttCamera = new osg::Camera;
// rttCamera->setProjectionMatrixAsOrtho(4.45625e-310,4.27284e-311 , -1.41226e-44 , 7.897e-314 , -1.4067e-44 , 6.74853e-260);
rttCamera->setProjectionMatrixAsOrtho(-160, 160, -100, 100, 500, 500);

osg::Vec3 eye(-34.9553, 445.227, 1970.24);
osg::Vec3 center(-34.9516, 445, 1969.26);
osg::Vec3 up(0, 1, 0);
rttCamera->setViewMatrixAsLookAt(eye, center, up);
rttCamera->setRenderOrder(osg::Camera::PRE_RENDER);
rttCamera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
rttCamera->setAllowEventFocus(false);
rttCamera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);

rttCamera->addChild(ceep);//增加场景

osg::ref_ptr<osg::MatrixTransform>mat = new osg::MatrixTransform;
mat->addChild(createRedPoint());
rttCamera->addChild(mat.get());//增加红点(只有烘培相机需要红点)

//把红点传进去－－时时更新红点位置
master->setUpdateCallback(new CameraUpdateCallBack(mat.get()));

osg::Texture2D*t2d = new osg::Texture2D;
t2d->setInternalFormat(GL_RGBA);
rttCamera->attach(osg::Camera::COLOR_BUFFER, t2d);
// viewer->addSlave(rttCamera);
gp->addChild(rttCamera);
gp->addChild(createHUD(t2d));

viewer->setSceneData(gp);
return;
}

int main(int argc, char *argv[])
{
osg::ref_ptr<osgViewer::Viewer>viewer = new osgViewer::Viewer;
createRtt(viewer);
viewer->addEventHandler(new osgViewer::ScreenCaptureHandler);
//添加个漫游器
viewer->setCameraManipulator(new osgGA::DriveManipulator());
return viewer->run();
}