RTT，渲染到贴图

// DyncDistort.cpp : 定义应用程序的入口点。
//




#include "stdafx.h"
#include "DyncDistort.h"
#include "MCvMainClass.h"



// test Pbuffer in osg. added by LSL 2011/05/07
#include <osg/Node>
#include <osg/Geode>
#include <osg/Geometry>
#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osg/Texture2D>
#include <osg/MatrixTransform>

#pragma comment(lib,"osgd.lib")
#pragma comment(lib,"osgViewerd.lib")
#pragma comment(lib,"osgGAd.lib")
#pragma comment(lib,"osgDBd.lib")
#pragma comment(lib,"osgFXd.lib")
#pragma comment(lib,"osgUtild.lib")
// end

struct Rect2D
{
    float left;
    float right;
    float top;
    float bottom;
    float depth;
};


osg::Node * createTex()
{
    osg::Group * parent = new osg::Group;
     osg::Texture* texture = 0;

     unsigned tex_width = 128;
     unsigned tex_height = 128;
     osg::Texture2D* texture2D = new osg::Texture2D;
     texture2D->setTextureSize(tex_width, tex_height);
     texture2D->setInternalFormat(GL_RGBA);
     texture2D->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
     texture2D->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
     texture = texture2D;

     
     osg::Node * cow = osgDB::readNodeFile("cow.osg");
     osg::MatrixTransform * subgraph = new osg::MatrixTransform;
     subgraph->addChild(cow);

     // then create the camera node to do the render to texture
         
    osg::Camera* camera = new osg::Camera;
         {

         // set up the background color and clear mask.
         camera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
         camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

         const osg::BoundingSphere& bs = subgraph->getBound();
         if (!bs.valid())
         {
             return subgraph;
         }

         float znear = 1.0f*bs.radius();
         float zfar  = 3.0f*bs.radius();

         // 2:1 aspect ratio as per flag geometry below.
         float proj_top   = 0.25f*znear;
         float proj_right = 0.5f*znear;

         znear *= 0.9f;
         zfar *= 1.1f;

         // set up projection.
         camera->setProjectionMatrixAsFrustum(-proj_right,proj_right,-proj_top,proj_top,znear,zfar);

         // set view
         camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
         camera->setViewMatrixAsLookAt(bs.center()-osg::Vec3(0.0f,2.0f,0.0f)*bs.radius(),bs.center(),osg::Vec3(0.0f,0.0f,1.0f));

         // set viewport
         camera->setViewport(0,0,tex_width,tex_height);

         // set the camera to render before the main camera.
         camera->setRenderOrder(osg::Camera::PRE_RENDER);

         // tell the camera to use OpenGL frame buffer object where supported.
         camera->setRenderTargetImplementation(osg::Camera::PIXEL_BUFFER);

         // attach the texture and use it as the color buffer.
         camera->attach(osg::Camera::COLOR_BUFFER, texture);
     }

     {

         osg::ref_ptr<osg::Geometry > geom = new osg::Geometry;

         // getScreenRectAtDepth(m_frustum, m_frustum.maxdepth+5);    
         Rect2D rect;
         rect.depth = 100;
         rect.left = 100;
         rect.right = 300;
         rect.bottom = 100;
         rect.top = 200;

         // vertex
         osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array;
         geom->setVertexArray(v);
         v->push_back(osg::Vec3(rect.left, rect.depth, rect.bottom));
         v->push_back(osg::Vec3(rect.right, rect.depth, rect.bottom));
         v->push_back(osg::Vec3(rect.right, rect.depth, rect.top));
         v->push_back(osg::Vec3(rect.left, rect.depth, rect.top));
         geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4));

         // color
         osg::ref_ptr<osg::Vec4Array> c = new osg::Vec4Array;
         geom->setColorArray(c);
         geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
         c->push_back(osg::Vec4(1.0,1.0,1.0,1.0));
         c->push_back(osg::Vec4(1.0,1.0,1.0,1.0));
         c->push_back(osg::Vec4(1.0,1.0,1.0,1.0));
         c->push_back(osg::Vec4(1.0,1.0,1.0,1.0));

         // normal
         osg::ref_ptr<osg::Vec3Array> n = new osg::Vec3Array ;
         geom->setNormalArray(n);
         geom->setNormalBinding(osg::Geometry::BIND_OVERALL);
         n->push_back(osg::Vec3(0.f,-1.f,0.f));

         // ---texuture----
         //osg::ref_ptr<osg::Texture2D> tex = new osg::Texture2D;    
         //tex->setDataVariance(osg::Object::DYNAMIC);
         //tex->setResizeNonPowerOfTwoHint(false);
         //tex->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
         //tex->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
         //tex->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
         //tex->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);

         osg::StateSet * ss = geom->getOrCreateStateSet();
         //    ss->setAttributeAndModes(new osg::BlendFunc,osg::StateAttribute::ON);
         //    ss->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
         ss->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);

         //osg::ref_ptr<osg::Image> img = osgDB::readImageFile(path);
         //tex->setImage(img);

         // tex coordinate
         osg::ref_ptr<osg::Vec2Array> texcoor= new osg::Vec2Array;
         geom->setTexCoordArray(0,texcoor.get());
         texcoor->push_back(osg::Vec2(1.,0.));
         texcoor->push_back(osg::Vec2(0.,0.));
         texcoor->push_back(osg::Vec2(0.,1.));
         texcoor->push_back(osg::Vec2(1.,1.));

         osg::Geode* geode = new osg::Geode();
         geode->addDrawable(geom);

         parent->addChild(geode);
     }

     camera->addChild(subgraph);
     parent->addChild(camera);
    return parent;
}


int APIENTRY _tWinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPTSTR    lpCmdLine,
                     int       nCmdShow)
{

    osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;
    osg::ref_ptr<osg::Group> root = new osg::Group;
    root->addChild(createTex());
    viewer->setSceneData(root.get());
    viewer->realize();
    viewer->run();


    //MCvMainClass l_app;
    //IAppData AppData;
    //
    //AppData.InitWin32(hInstance, hPrevInstance, lpCmdLine, nCmdShow, "videoShowWindow", 0, 0, 1280, 750);

    //MWinFrameWork g_app;

    //g_app.Initialize(&AppData, &l_app);
    //l_app.SetFramePointer(&AppData);
    //g_app.Run();

    



    return 0;
}