source: GTP/trunk/Lib/Vis/Preprocessing/src/GlRenderer.cpp @ 931

#include "Mesh.h"
#include "GlRenderer.h"
#include "ViewCellsManager.h"
#include "SceneGraph.h"
#include "Pvs.h"
#include "Viewcell.h"
#include "Beam.h"
#include "KdTree.h"
#include "Environment.h"

//#define GL_GLEXT_PROTOTYPES
#include <GL/glext.h>
#include <Cg/cg.h>
#include <Cg/cgGL.h>

#include <QVBoxLayout>

namespace GtpVisibilityPreprocessor {

static CGcontext sCgContext = NULL;
static CGprogram sCgFragmentProgram = NULL;
static CGprofile sCgFragmentProfile;

GLuint frontDepthMap;
GLuint backDepthMap;

const int depthMapSize = 512;
static vector<int> sQueries;

GlRendererWidget *rendererWidget = NULL;
GlDebuggerWidget *debuggerWidget = NULL;


#ifdef _WIN32
PFNGLGENOCCLUSIONQUERIESNVPROC glGenOcclusionQueriesNV;
PFNGLBEGINOCCLUSIONQUERYNVPROC glBeginOcclusionQueryNV;
PFNGLENDOCCLUSIONQUERYNVPROC glEndOcclusionQueryNV;
PFNGLGETOCCLUSIONQUERYUIVNVPROC glGetOcclusionQueryuivNV;

//PFNGLGENQUERIESARBPROC glGenQueriesARB;
//PFNGLBEGINQUERYARBPROC glBeginQueryARB;
//PFNGLENDQUERYARBPROC glEndQueryARB;
//PFNGLGETQUERYUIVARBPROC glGetQueryuivARB;
#endif


GlRenderer::GlRenderer(SceneGraph *sceneGraph,
                                           ViewCellsManager *viewCellsManager,
                                           KdTree *tree):
  Renderer(sceneGraph, viewCellsManager),
  mKdTree(tree)
{
  mSceneGraph->CollectObjects(&mObjects);
  mViewPoint = mSceneGraph->GetBox().Center();
  mViewDirection = Vector3(0,0,1);

  mViewPoint = Vector3(991.7, 187.8, -271);
  mViewDirection = Vector3(0.9, 0, -0.4);

  //  timerId = startTimer(10);
  // debug coords for atlanta
  //  mViewPoint = Vector3(3473, 6.778, -1699);
  //  mViewDirection = Vector3(-0.2432, 0, 0.97);
  
  mFrame = 0;
  mWireFrame = false;
  environment->GetBoolValue("Preprocessor.detectEmptyViewSpace", mDetectEmptyViewSpace);
  mSnapErrorFrames = true;
  mSnapPrefix = "snap/";
  mUseForcedColors = false;

  mUseGlLists = true;
  
}

GlRenderer::~GlRenderer()
{
  cerr<<"gl renderer destructor..\n";
  if (sCgFragmentProgram)
        cgDestroyProgram(sCgFragmentProgram);
  if (sCgContext)
        cgDestroyContext(sCgContext);
  cerr<<"done."<<endl;
}


static void handleCgError() 
{
    Debug << "Cg error: " << cgGetErrorString(cgGetError()) << endl;
    exit(1);
}

void
GlRenderer::RenderIntersectable(Intersectable *object)
{

  glPushAttrib(GL_CURRENT_BIT);
  if (mUseFalseColors)
        SetupFalseColor(object->mId);
  

  switch (object->Type()) {
  case Intersectable::MESH_INSTANCE:
        RenderMeshInstance((MeshInstance *)object);
        break;
  case Intersectable::VIEW_CELL:
          RenderViewCell(dynamic_cast<ViewCell *>(object));
          break;
  default:
        cerr<<"Rendering this object not yet implemented\n";
        break;
  }

  glPopAttrib();
}


void
GlRenderer::RenderViewCell(ViewCell *vc)
{
  if (vc->GetMesh()) {

        if (!mUseFalseColors) {
          if (vc->GetValid()) 
                glColor3f(0,1,0);
          else
                glColor3f(0,0,1);
        }
        
        RenderMesh(vc->GetMesh());
  } else {
        // render viewcells in the subtree
        if (!vc->IsLeaf()) {
          ViewCellInterior *vci = (ViewCellInterior *) vc;

          ViewCellContainer::iterator it = vci->mChildren.begin();
          for (; it != vci->mChildren.end(); ++it) {
                RenderViewCell(*it);
          }
        } else {
          //      cerr<<"Empty viewcell mesh\n";
        }
  }
}


void
GlRenderer::RenderMeshInstance(MeshInstance *mi)
{
  RenderMesh(mi->GetMesh());
}

void
GlRenderer::SetupFalseColor(const int id)
{
  // swap bits of the color
  glColor3ub(id&255, (id>>8)&255, (id>>16)&255);
}


int GlRenderer::GetId(int r, int g, int b) const
{
        return r + (g << 8) + (b << 16);
}

void
GlRenderer::SetupMaterial(Material *m)
{
  if (m)
        glColor3fv(&(m->mDiffuseColor.r));
}

void
GlRenderer::RenderMesh(Mesh *mesh)
{
  int i = 0;

  if (!mUseFalseColors && !mUseForcedColors)
        SetupMaterial(mesh->mMaterial);
  
  for (i=0; i < mesh->mFaces.size(); i++) {
        if (mWireFrame)
          glBegin(GL_LINE_LOOP);
        else
          glBegin(GL_POLYGON);

        Face *face = mesh->mFaces[i];
        for (int j = 0; j < face->mVertexIndices.size(); j++) {
          glVertex3fv(&mesh->mVertices[face->mVertexIndices[j]].x);
        }
        glEnd();
  }
}
        
void
GlRenderer::InitGL()
{
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  glEnable(GL_CULL_FACE);
  glShadeModel(GL_FLAT);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_CULL_FACE);
  
  glGenOcclusionQueriesNV = (PFNGLGENOCCLUSIONQUERIESNVPROC)
        wglGetProcAddress("glGenOcclusionQueriesNV");
  glBeginOcclusionQueryNV = (PFNGLBEGINOCCLUSIONQUERYNVPROC)
        wglGetProcAddress("glBeginOcclusionQueryNV");
  glEndOcclusionQueryNV = (PFNGLENDOCCLUSIONQUERYNVPROC)
        wglGetProcAddress("glEndOcclusionQueryNV");
  glGetOcclusionQueryuivNV = (PFNGLGETOCCLUSIONQUERYUIVNVPROC)
        wglGetProcAddress("glGetOcclusionQueryuivNV");


#if 0
  glGenQueriesARB = (PFNGLGENDQUERIESARBPROC)
        wglGetProcAddress("glGenQueriesARB");
  glBeginQueryARB = (PFNGLBEGINQUERYARBPROC)
        wglGetProcAddress("glBeginQueryARB");
  glEndQueryARB = (PFNGLENDQUERYARBPROC)
        wglGetProcAddress("glEndQueryARB");
  glGetQueryuivARB = (PFNGLGETQUERYUIVARBPROC)
        wglGetProcAddress("glGetQueryuivARB");

#endif
  

#if 0
  GLfloat mat_ambient[]   = {  0.5, 0.5, 0.5, 1.0  };
  /*  mat_specular and mat_shininess are NOT default values     */
  GLfloat mat_diffuse[]   = {  1.0, 1.0, 1.0, 1.0  };
  GLfloat mat_specular[]  = {  0.3, 0.3, 0.3, 1.0  };
  GLfloat mat_shininess[] = {  1.0  };
  
  GLfloat light_ambient[]  = {  0.2, 0.2, 0.2, 1.0  };
  GLfloat light_diffuse[]  = {  0.4, 0.4, 0.4, 1.0  };
  GLfloat light_specular[] = {  0.3, 0.3, 0.3, 1.0  };
  
  GLfloat lmodel_ambient[] = {  0.3, 0.3, 0.3, 1.0  };
  
  
  // default Material
  glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
  glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);

  // a light
  glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  
  glLightfv(GL_LIGHT1, GL_AMBIENT, light_ambient);
  glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
  glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular);
  
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
  
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  
  
  // set position of the light
  GLfloat infinite_light[] = {  1.0, 0.8, 1.0, 0.0  };
  glLightfv (GL_LIGHT0, GL_POSITION, infinite_light);
  
  // set position of the light2
  GLfloat infinite_light2[] = {  -0.3, 1.5, 1.0, 0.0  };
  glLightfv (GL_LIGHT1, GL_POSITION, infinite_light2);
  
  glColorMaterial( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
  //   glColorMaterial( GL_FRONT_AND_BACK, GL_SPECULAR);
  glEnable(GL_COLOR_MATERIAL);
  
  glShadeModel( GL_FLAT );
  
  glDepthFunc( GL_LESS );
  glEnable( GL_DEPTH_TEST );
#endif

  glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );

  glEnable( GL_NORMALIZE );
  
  glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
}

void
GlRendererWidget::RenderInfo()
{
  QString s;
  int vc = 0;
  if (mViewCellsManager)
        vc = mViewCellsManager->GetViewCells().size();
  int filter = 0;
  if (mViewCellsManager)
        filter = mViewCellsManager->GetMaxFilterSize();

  s.sprintf("frame:%04d viewpoint:(%4.1f,%4.1f,%4.1f) dir:(%4.1f,%4.1f,%4.1f) viewcells:%04d filter:%04d pvs:%04d error:%5.5f\%",
                        mFrame,
                        mViewPoint.x,
                        mViewPoint.y,
                        mViewPoint.z,
                        mViewDirection.x,
                        mViewDirection.y,
                        mViewDirection.z,
                        vc,

                        filter,
                        mPvsSize,
                        mRenderError*100.0f
                        );
  
  glColor3f(0.0f,0.0f,0.0f);
  renderText(0,20,s);
  
  if (mShowRenderCost) {
        static vector<float> costFunction;
        static float maxCost = -1;
        if (costFunction.size()==0) {
          ViewCellsTree *tree = mViewCellsManager->GetViewCellsTree();
          if (tree) {
                tree->GetCostFunction(costFunction);
                maxCost = -1;
                for (int i=0;  i < costFunction.size(); i++) {
                  //              cout<<i<<":"<<costFunction[i]<<" ";
                  if (costFunction[i] > maxCost)
                        maxCost = costFunction[i];
                }
          }
        }

        
        int currentPos = mViewCellsManager->GetViewCells().size();
        float currentCost=-1;

        if (currentPos < costFunction.size())
          currentCost = costFunction[currentPos];
#if 0   
        cout<<"costFunction.size()="<<costFunction.size()<<endl;
        cout<<"CP="<<currentPos<<endl;
        cout<<"MC="<<maxCost<<endl;
        cout<<"CC="<<currentCost<<endl;
#endif
        if (costFunction.size()) {
          glDisable(GL_DEPTH_TEST);
          // init ortographic projection
          glMatrixMode(GL_PROJECTION);
          glPushMatrix();
          
          glLoadIdentity();
          gluOrtho2D(0, 1.0f, 0, 1.0f);
          
          glTranslatef(0.1f, 0.1f, 0.0f);
          glScalef(0.8f, 0.8f, 1.0f);
          glMatrixMode(GL_MODELVIEW);
          glLoadIdentity();
          
          glColor3f(1.0f,0,0);
          glBegin(GL_LINE_STRIP);
          //      glVertex3f(0,0,0);
          
          for (int i=0;  i < costFunction.size(); i++) {
                float x =  i/(float)costFunction.size();
                float y = costFunction[i]/(maxCost*0.5f);
                glVertex3f(x,y,0.0f);
          }
          glEnd();
          
          glColor3f(1.0f,0,0);
          glBegin(GL_LINES);
          float x =  currentPos/(float)costFunction.size();
          glVertex3f(x,0.0,0.0f);
          glVertex3f(x,1.0f,0.0f);
          glEnd();
          
          glColor3f(0.0f,0,0);
          // show a grid
          glBegin(GL_LINE_LOOP);
          glVertex3f(0,0,0.0f);
          glVertex3f(1,0,0.0f);
          glVertex3f(1,1,0.0f);
          glVertex3f(0,1,0.0f);
          glEnd();

          glBegin(GL_LINES);
          for (int i=0;  i < 50000 && i < costFunction.size(); i+=10000) {
                float x =  i/(float)costFunction.size();
                glVertex3f(x,0.0,0.0f);
                glVertex3f(x,1.0f,0.0f);
          }

          for (int i=0;  i < maxCost; i+=100) {
                float y = i/(maxCost*0.5f);
                glVertex3f(0,y,0.0f);
                glVertex3f(1,y,0.0f);
          }

          glEnd();

          
          // restore the projection matrix
          glMatrixMode(GL_PROJECTION);
          glPopMatrix();
          glMatrixMode(GL_MODELVIEW);
          glEnable(GL_DEPTH_TEST);

        }
  }
}


void
GlRenderer::SetupProjection(const int w, const int h, const float angle)
{
  glViewport(0, 0, w, h);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(angle, 1.0, 0.1, 2.0*Magnitude(mSceneGraph->GetBox().Diagonal()));
  glMatrixMode(GL_MODELVIEW);
}

void
GlRenderer::SetupCamera()
{
  Vector3 target = mViewPoint + mViewDirection;

  Vector3 up(0,1,0);
  
  if (abs(DotProd(mViewDirection, up)) > 0.99f)
        up = Vector3(1, 0, 0);
  
  glLoadIdentity();
  gluLookAt(mViewPoint.x, mViewPoint.y, mViewPoint.z,
                        target.x, target.y, target.z,
                        up.x, up.y, up.z);
}


void
GlRendererBuffer::EvalRenderCostSample(
                                                                           RenderCostSample &sample
                                                                           )
{
  mViewCellsManager->GetViewPoint(mViewPoint);
  cout<<mViewPoint<<endl;
  
  // take a render cost sample by rendering a cube
  Vector3 directions[6];
  directions[0] = Vector3(1,0,0);
  directions[1] = Vector3(0,1,0);
  directions[2] = Vector3(0,0,1);
  directions[3] = Vector3(-1,0,0);
  directions[4] = Vector3(0,-1,0);
  directions[5] = Vector3(0,0,-1);

  sample.mVisibleObjects = 0;

  int i, j;
  
  // reset object visibility
  for (i=0; i < mObjects.size(); i++) {
        mObjects[i]->mCounter = 0;
  }
  mFrame++;
  for (i=0; i < 6; i++) {
        mViewDirection = directions[i];
        SetupCamera();
        glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        
        glDepthFunc( GL_LESS );

        mUseFalseColors = true;

        RenderScene();

        if (1) {
          char filename[256];
          sprintf(filename, "snap/frame-%04d-%d.png", mFrame, i);
          QImage im = toImage();
          im.save(filename, "PNG");
        }
        
        bool useItemBuffer = false;
        
        if (useItemBuffer) {
          // read back the texture
          glReadPixels(0, 0,
                                   GetWidth(), GetHeight(),
                                   GL_RGBA,
                                   GL_UNSIGNED_BYTE,
                                   mPixelBuffer);
          
          int x, y;
          unsigned int *p = mPixelBuffer;
          for (y = 0; y < GetHeight(); y++)
                for (x = 0; x < GetWidth(); x++, p++) {
                  unsigned int id = (*p) & 0xFFFFFF;
                  if (id != 0xFFFFFF)
                        mObjects[id]->mCounter++;
                }
          
        } else {
        
          //      glDepthFunc( GL_LEQUAL );
          glDepthFunc( GL_LEQUAL );
          
          glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
          glDepthMask(GL_FALSE);
          
          // now issue queries for all objects
          for (j = 0; j < mObjects.size(); j++) {
                int q;
                for (q = 0; j + q < mObjects.size() && q < mOcclusionQueries.size(); q++) {
                  glBeginOcclusionQueryNV(mOcclusionQueries[q]);
                  RenderIntersectable(mObjects[j+q]);
                  glEndOcclusionQueryNV();
                }
                
                
                // collect results of the queries
                for (q = 0; j + q < mObjects.size() && q < mOcclusionQueries.size(); q++) {
                  unsigned int pixelCount;
                  // reenable other state

#if 1
                  do {
                        glGetOcclusionQueryuivNV(mOcclusionQueries[q],
                                                                         GL_PIXEL_COUNT_AVAILABLE_NV,
                                                                         &pixelCount);
                        if (!pixelCount)
                          cout<<"W";
                  } while(!pixelCount);
#endif

                  glGetOcclusionQueryuivNV(mOcclusionQueries[q],
                                                                   GL_PIXEL_COUNT_NV,
                                                                   &pixelCount);
                  //            if (pixelCount)
                  //              cout<<"q="<<mOcclusionQueries[q]<<" pc="<<pixelCount<<" ";
                  mObjects[j+q]->mCounter += pixelCount;
                }
                j += q;
          }
          
          glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
          glDepthMask(GL_TRUE);
        }
          
        
  }  
  // now evaluate the statistics over that sample
  // currently only the number of visible objects is taken into account
  sample.Reset();
  for (j = 0; j < mObjects.size(); j++) {
        if (mObjects[j]->mCounter) {
          sample.mVisibleObjects++;
          sample.mVisiblePixels += mObjects[j]->mCounter;
        }
  }
  cout<<"RS="<<sample.mVisibleObjects<<" ";
}

void
GlRendererBuffer::SampleRenderCost(
                                                                   const int n,
                                                                   vector<RenderCostSample> &samples
                                                                   )
{
  makeCurrent();

  if (mPixelBuffer == NULL)
        mPixelBuffer = new unsigned int[GetWidth()*GetHeight()];
  
  SetupProjection(GetHeight(), GetHeight(), 90.0f);

  samples.resize(n);
  halton.Reset();
  
  int i;
  int numQ = 500;
  
  if (mOcclusionQueries.size() < numQ) {
        cout<<"allocating occ queries..."<<endl;
        
        numQ;
        unsigned int *queries = new unsigned int[numQ];
        for (i=0; i < numQ; i++)
          queries[i] = 111;
        
        glGenOcclusionQueriesNV(numQ, queries);
        
        mOcclusionQueries.resize(numQ);
        
        for (i=0; i < numQ; i++)
          mOcclusionQueries[i] = queries[i];
        
        delete queries;
  }
  
  for (i=0; i < n; i++)
        EvalRenderCostSample(
                                                 samples[i]
                                                 );

  doneCurrent();

}
  

void
GlRendererBuffer::RandomViewPoint()
{
  
  
  // do not use this function since it could return different viewpoints for
  // different executions of the algorithm

  //mViewCellsManager->GetViewPoint(mViewPoint);

  while (1) {
        Vector3 pVector = Vector3(halton.GetNumber(1),
                                                          halton.GetNumber(2),
                                                          halton.GetNumber(3));
        
        mViewPoint =  mSceneGraph->GetBox().GetPoint(pVector);
        ViewCell *v = mViewCellsManager->GetViewCell(mViewPoint);
        if (v && v->GetValid())
          break;
        // generate a new vector
        halton.GenerateNext();
  }
  
  
  Vector3 dVector = Vector3(2*M_PI*halton.GetNumber(4),
                                                        M_PI*halton.GetNumber(5),
                                                        0.0f);
  
  mViewDirection = Normalize(Vector3(sin(dVector.x),
                                                                         //                                                                      cos(dVector.y),
                                                                         0.0f,
                                                                         cos(dVector.x)));
  halton.GenerateNext();
}


GlRendererBuffer::GlRendererBuffer(const int w,
                                                                   const int h,
                                                                   SceneGraph *sceneGraph,
                                                                   ViewCellsManager *viewcells,
                                                                   KdTree *tree):
QGLPixelBuffer(QSize(w, h)), GlRenderer(sceneGraph, viewcells, tree) {
 
  environment->GetIntValue("Preprocessor.pvsRenderErrorSamples", mPvsStatFrames);
  mPvsErrorBuffer.resize(mPvsStatFrames);
  ClearErrorBuffer();

  mPixelBuffer = NULL;
  
  makeCurrent();
  InitGL();
  doneCurrent();
  
}

float
GlRendererBuffer::GetPixelError(int &pvsSize)
{
  float pErrorPixels = -1.0f;
  
  glReadBuffer(GL_BACK);
  
  //  mUseFalseColors = true;
  
  mUseFalseColors = false;

  static int query = -1;
  unsigned int pixelCount;

  if (query == -1)
        glGenOcclusionQueriesNV(1, (unsigned int *)&query);

  if (mDetectEmptyViewSpace) {
        // now check whether any backfacing polygon would pass the depth test
        SetupCamera();
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glEnable( GL_CULL_FACE );
        
        RenderScene();
        
        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
        glDepthMask(GL_FALSE);
        glDisable( GL_CULL_FACE );
        
        glBeginOcclusionQueryNV(query);
        
        RenderScene();
        
        glEndOcclusionQueryNV();
        
        // at this point, if possible, go and do some other computation
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
        glDepthMask(GL_TRUE);
        glEnable( GL_CULL_FACE );
        
        // reenable other state
        glGetOcclusionQueryuivNV(query,
                                                         GL_PIXEL_COUNT_NV,
                                                         &pixelCount);
        
        if (pixelCount > 0)
          return -1.0f; // backfacing polygon found -> not a valid viewspace sample
  } else
        glDisable( GL_CULL_FACE );
        

  ViewCell *viewcell = NULL;
  
  PrVs prvs;
  //  mViewCellsManager->SetMaxFilterSize(1);
  mViewCellsManager->GetPrVS(mViewPoint, prvs, mViewCellsManager->GetFilterWidth());
  viewcell = prvs.mViewCell;
  
  //  ViewCell *viewcell = mViewCellsManager->GetViewCell(mViewPoint);
  pvsSize = 0;
  if (viewcell) {
        SetupCamera();
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glColorMask(GL_FALSE, GL_TRUE, GL_FALSE, GL_FALSE);
        
        // Render PVS
        std::map<Intersectable *,
          PvsData<Intersectable *>,
          LtSample<Intersectable *> >::const_iterator it = viewcell->GetPvs().mEntries.begin();

        pvsSize = viewcell->GetPvs().mEntries.size();
        
        for (; it != viewcell->GetPvs().mEntries.end(); ++ it) {
          Intersectable *object = (*it).first;
          RenderIntersectable(object);
        }

        //      glColorMask(GL_TRUE, GL_FALSE, GL_FALSE, GL_FALSE);
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
        mUseFalseColors = true;

        glBeginOcclusionQueryNV(query);

        SetupCamera();

        RenderScene();
        
        glEndOcclusionQueryNV();
        

        unsigned int pixelCount;
        // reenable other state
        glGetOcclusionQueryuivNV(query,
                                                         GL_PIXEL_COUNT_NV,
                                                         &pixelCount);
        
        pErrorPixels = ((float)pixelCount)/(GetWidth()*GetHeight());
        if (mSnapErrorFrames && pErrorPixels > 0.01) {
          
          char filename[256];
          sprintf(filename, "error-frame-%04d-%0.5f.png", mFrame, pErrorPixels);
          QImage im = toImage();
          im.save(mSnapPrefix + filename, "PNG");
          if (1) { //0 && mFrame == 1543) {
                int x,y;
                int lastIndex = -1;
                for (y=0; y < im.height(); y++)
                  for (x=0; x < im.width(); x++) {
                        QRgb p = im.pixel(x,y);
                        int index = qRed(p) + (qGreen(p)<<8) + (qBlue(p)<<16);
                        if (qGreen(p) != 255 && index!=0) {
                          if (index != lastIndex) {
                                Debug<<"ei="<<index<<" ";
                                lastIndex = index;
                          }
                        }
                  }
          }


          mUseFalseColors = false;
          glPushAttrib(GL_CURRENT_BIT);
          glColor3f(0,1,0);
          glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
          SetupCamera();
          glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
          
          // Render PVS
          std::map<Intersectable *,
                PvsData<Intersectable *>,
                LtSample<Intersectable *> >::const_iterator it = viewcell->GetPvs().mEntries.begin();
          
          for (; it != viewcell->GetPvs().mEntries.end(); ++ it) {
                Intersectable *object = (*it).first;
                RenderIntersectable(object);
          }

          im = toImage();
          sprintf(filename, "error-frame-%04d-%0.5f-pvs.png", mFrame, pErrorPixels);
          im.save(mSnapPrefix + filename, "PNG");
          glPopAttrib();
        }
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
  }

  if (viewcell)
        mViewCellsManager->DeleteLocalMergeTree(viewcell);
  
  return pErrorPixels;
}


void
GlRendererWidget::SetupProjection(const int w, const int h)
{
  if (!mTopView)
        GlRenderer::SetupProjection(w, h);
  else {
        glViewport(0, 0, w, h);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        gluPerspective(50.0, 1.0, 0.1, 20.0*Magnitude(mSceneGraph->GetBox().Diagonal()));
        glMatrixMode(GL_MODELVIEW);
  }
}

void
GlRendererWidget::RenderPvs()
{
  SetupCamera();
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
  ViewCell *viewcell = NULL;

  PrVs prvs;
  
  if (!mUseFilter) {
        viewcell = mViewCellsManager->GetViewCell(mViewPoint, true);
  } else {
        //  mViewCellsManager->SetMaxFilterSize(1);
        mViewCellsManager->GetPrVS(mViewPoint, prvs, mViewCellsManager->GetFilterWidth());
        viewcell = prvs.mViewCell;
  }
  
  if (viewcell) {
        // copy the pvs so that it can be filtered...
        ObjectPvs pvs = viewcell->GetPvs();

        if (mUseSpatialFilter) {
          mViewCellsManager->ApplySpatialFilter(mKdTree,
                                                                                        mSpatialFilterSize*
                                                                                        Magnitude(mViewCellsManager->GetViewSpaceBox().Size()),
                                                                                        pvs);
        }
        
        
        // read back the texture
        std::map<Intersectable *,
          PvsData<Intersectable *>,
          LtSample<Intersectable *> >::const_iterator it = pvs.mEntries.begin();

        mPvsSize = pvs.mEntries.size();
          
        for (; it != pvs.mEntries.end(); ++ it) {
          Intersectable *object = (*it).first;
          float visibility = log10((*it).second.mSumPdf + 1)/5.0f;
          glColor3f(visibility, 0.0f, 0.0f);
          mUseForcedColors = true;
          RenderIntersectable(object);
          mUseForcedColors = false;
        }

        if (mRenderFilter) {
          mWireFrame = true;
          RenderIntersectable(viewcell);
          mWireFrame = false;
        }
        
        if (mUseFilter)
          mViewCellsManager->DeleteLocalMergeTree(viewcell);
  } else {
        ObjectContainer::const_iterator oi = mObjects.begin();
        for (; oi != mObjects.end(); oi++)
          RenderIntersectable(*oi);
  }
}

float
GlRendererWidget::RenderErrors()
{
  float pErrorPixels = -1.0f;

  glReadBuffer(GL_BACK);
  
  mUseFalseColors = true;

  SetupCamera();
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
  double eq[4];
  eq[0] = mSceneCutPlane.mNormal.x;
  eq[1] = mSceneCutPlane.mNormal.y;
  eq[2] = mSceneCutPlane.mNormal.z;
  eq[3] = mSceneCutPlane.mD;
  
  if (mCutScene) {
        glClipPlane(GL_CLIP_PLANE0, eq);
    glEnable(GL_CLIP_PLANE0);
  }
  
  if (mDetectEmptyViewSpace) 
        glEnable( GL_CULL_FACE );
  else
        glDisable( GL_CULL_FACE );

  ObjectContainer::const_iterator oi = mObjects.begin();
  for (; oi != mObjects.end(); oi++)
        RenderIntersectable(*oi);

  ViewCell *viewcell = NULL;

  QImage im1, im2;
  QImage diff;
  
  if (viewcell) {
        // read back the texture
        im1 = grabFrameBuffer(true);
        
        RenderPvs();

        // read back the texture
        im2 = grabFrameBuffer(true);
        
        diff = im1;
        int x, y;
        int errorPixels = 0;
        
        for (y = 0; y < im1.height(); y++)
          for (x = 0; x < im1.width(); x++)
                if (im1.pixel(x, y) == im2.pixel(x, y))
                  diff.setPixel(x, y, qRgba(0,0,0,0));
                else {
                  diff.setPixel(x, y, qRgba(255,128,128,255));
                  errorPixels++;
                }
        pErrorPixels = ((float)errorPixels)/(im1.height()*im1.width());
  }

  // now render the pvs again
  SetupCamera();
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  mUseFalseColors = false;
  
  oi = mObjects.begin();
  for (; oi != mObjects.end(); oi++)
        RenderIntersectable(*oi);

  // now render im1
  if (viewcell) {
        if (0 && mTopView) {
          mWireFrame = true;
          RenderIntersectable(viewcell);
          mWireFrame = false;
        }
        
        // init ortographic projection
        glMatrixMode(GL_PROJECTION);
        glPushMatrix();
        
        glLoadIdentity();
        gluOrtho2D(0, 1.0f, 0, 1.0f);
        
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        
        bindTexture(diff);
        
        glPushAttrib(GL_ENABLE_BIT);
        glEnable( GL_ALPHA_TEST );
        glDisable( GL_CULL_FACE );
        glAlphaFunc( GL_GREATER, 0.5 );
        
        glEnable( GL_TEXTURE_2D );
        glBegin(GL_QUADS);
        
        glTexCoord2f(0,0);
        glVertex3f(0,0,0);
        
        glTexCoord2f(1,0);
        glVertex3f( 1, 0, 0);
        
        glTexCoord2f(1,1);
        glVertex3f( 1, 1, 0);
        
        glTexCoord2f(0,1);
        glVertex3f(0, 1, 0);
        glEnd();
        
        glPopAttrib();
        
        // restore the projection matrix
        glMatrixMode(GL_PROJECTION);
        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
  }

  glDisable(GL_CLIP_PLANE0);
  
  mRenderError = pErrorPixels;
  return pErrorPixels;
}

void
GlRenderer::_RenderScene()
{
  ObjectContainer::const_iterator oi = mObjects.begin();
  for (; oi != mObjects.end(); oi++)
        RenderIntersectable(*oi);
}

bool
GlRenderer::RenderScene()
{
  static int glList = -1;
  if (mUseGlLists) {
        if (glList == -1) {
          glList = glGenLists(1);
          glNewList(glList, GL_COMPILE);
          _RenderScene();
          glEndList();
        }
        glCallList(glList);
  } else
        _RenderScene();
        
  
  return true;
}


void
GlRendererBuffer::ClearErrorBuffer()
{
  for (int i=0; i < mPvsStatFrames; i++) {
        mPvsErrorBuffer[i].mError = 1.0f;
  }
}


void
GlRendererBuffer::EvalPvsStat()
{
  mPvsStat.Reset();
  halton.Reset();

  makeCurrent();
  SetupProjection(GetWidth(), GetHeight());
  
  for (int i=0; i < mPvsStatFrames; i++) {
        float err;
        // set frame id for saving the error buffer
        mFrame = i;
        RandomViewPoint();

        // atlanta problematic frames: 325 525 691 1543
#if 0
        if (mFrame != 325 &&
                mFrame != 525 &&
                mFrame != 691 &&
                mFrame != 1543)
          mPvsErrorBuffer[i] = -1;
        else {
          Debug<<"frame ="<<mFrame<<" vp="<<mViewPoint<<" vd="<<mViewDirection<<endl;
        }
#endif
        if (mPvsErrorBuffer[i].mError > 0.0f) {
          int pvsSize;
          float error = GetPixelError(pvsSize);
          mPvsErrorBuffer[i].mError = error;
          mPvsErrorBuffer[i].mPvsSize = pvsSize;

          emit UpdatePvsErrorItem(i,
                                                          mPvsErrorBuffer[i]);
          
          cout<<"("<<i<<","<<mPvsErrorBuffer[i].mError<<")";
          //      swapBuffers();
        }
        
        err = mPvsErrorBuffer[i].mError;
        
        if (err >= 0.0f) {
          if (err > mPvsStat.maxError)
                mPvsStat.maxError = err;
          mPvsStat.sumError += err;
          mPvsStat.sumPvsSize += mPvsErrorBuffer[i].mPvsSize;
          
          if (err == 0.0f)
                mPvsStat.errorFreeFrames++;
          mPvsStat.frames++;
        }
  }

  glFinish();
  doneCurrent();

  cout<<endl<<flush;
  //  mRenderingFinished.wakeAll();
}





void
GlRendererWidget::mousePressEvent(QMouseEvent *e)
{
  int x = e->pos().x();
  int y = e->pos().y();

  mousePoint.x = x;
  mousePoint.y = y;
  
}

void
GlRendererWidget::mouseMoveEvent(QMouseEvent *e)
{
  float MOVE_SENSITIVITY = Magnitude(mSceneGraph->GetBox().Diagonal())*1e-3;
  float TURN_SENSITIVITY=0.1f;
  float TILT_SENSITIVITY=32.0 ;
  float TURN_ANGLE= M_PI/36.0 ;

  int x = e->pos().x();
  int y = e->pos().y();
  
  if (e->modifiers() & Qt::ControlModifier) {
        mViewPoint.y += (y-mousePoint.y)*MOVE_SENSITIVITY/2.0;
        mViewPoint.x += (x-mousePoint.x)*MOVE_SENSITIVITY/2.0;
  } else {
        mViewPoint += mViewDirection*((mousePoint.y - y)*MOVE_SENSITIVITY);
        float adiff = TURN_ANGLE*(x - mousePoint.x)*-TURN_SENSITIVITY;
        float angle = atan2(mViewDirection.x, mViewDirection.z);
        mViewDirection.x = sin(angle+adiff);
        mViewDirection.z = cos(angle+adiff);
  }
  
  mousePoint.x = x;
  mousePoint.y = y;
  
  updateGL();
}

void
GlRendererWidget::mouseReleaseEvent(QMouseEvent *)
{


}

void
GlRendererWidget::resizeGL(int w, int h)
{
  SetupProjection(w, h);
  updateGL();
}

void
GlRendererWidget::paintGL()
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  
  if (!mRenderViewCells) {
        if (mRenderErrors)
          RenderErrors();
        else
          RenderPvs();
        RenderInfo();
  } else {
        RenderViewCells();
        
        mWireFrame = true;
        RenderScene();
        mWireFrame = false;
        
        RenderInfo();
  }

  mFrame++;
}


void
GlRendererWidget::SetupCamera()
{
  if (!mTopView)
        GlRenderer::SetupCamera();
  else {
        if (0) {
          float dist = Magnitude(mSceneGraph->GetBox().Diagonal())*0.05;
          Vector3 pos = mViewPoint - dist*Vector3(mViewDirection.x,
                                                                                          -1,
                                                                                          mViewDirection.y);
          
          Vector3 target = mViewPoint + dist*mViewDirection;
          Vector3 up(0,1,0);
          
          glLoadIdentity();
          gluLookAt(pos.x, pos.y, pos.z,
                                target.x, target.y, target.z,
                                up.x, up.y, up.z);
        } else {
          float dist = Magnitude(mSceneGraph->GetBox().Diagonal())*mTopDistance;
          Vector3 pos = mViewPoint  + dist*Vector3(0,
                                                                                           1,
                                                                                           0);
          
          Vector3 target = mViewPoint;
          Vector3 up(mViewDirection.x, 0, mViewDirection.z);
          
          glLoadIdentity();
          gluLookAt(pos.x, pos.y, pos.z,
                                target.x, target.y, target.z,
                                up.x, up.y, up.z);
          
        }
  }

}

void
GlRendererWidget::keyPressEvent ( QKeyEvent * e )
{
  switch (e->key()) {
  case Qt::Key_T:
        mTopView = !mTopView;
        SetupProjection(width(), height());
        updateGL();
        break;
  case Qt::Key_V:
        mRenderViewCells = !mRenderViewCells;
        updateGL();
        break;
  default:
        e->ignore();
        break;
  }
}

  
RendererControlWidget::RendererControlWidget(QWidget * parent, Qt::WFlags f):
  QWidget(parent, f)
{

  QVBoxLayout *vl = new QVBoxLayout;
  setLayout(vl);
  
  QWidget *vbox = new QGroupBox("ViewCells", this);
  layout()->addWidget(vbox);
  
  vl = new QVBoxLayout;
  vbox->setLayout(vl);

  QLabel *label = new QLabel("Granularity");
  vbox->layout()->addWidget(label);

  QSlider *slider = new QSlider(Qt::Horizontal, vbox);
  vl->addWidget(slider);
  slider->show();
  slider->setRange(1, 10000);
  slider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
  slider->setValue(200);

  connect(slider, SIGNAL(valueChanged(int)), SIGNAL(SetViewCellGranularity(int)));

  label = new QLabel("Filter size");
  vbox->layout()->addWidget(label);
  
  slider = new QSlider(Qt::Horizontal, vbox);
  vbox->layout()->addWidget(slider);
  slider->show();
  slider->setRange(1, 100);
  slider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
  slider->setValue(3);
  
  connect(slider, SIGNAL(valueChanged(int)), SIGNAL(SetVisibilityFilterSize(int)));


  label = new QLabel("Spatial Filter size");
  vbox->layout()->addWidget(label);
  
  slider = new QSlider(Qt::Horizontal, vbox);
  vbox->layout()->addWidget(slider);
  slider->show();
  slider->setRange(1, 100);
  slider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
  slider->setValue(10);
  
  connect(slider, SIGNAL(valueChanged(int)), SIGNAL(SetSpatialFilterSize(int)));



  QWidget *hbox = new QWidget(vbox);
  vl->addWidget(hbox);
  QHBoxLayout *hlayout = new QHBoxLayout;
  hbox->setLayout(hlayout);
  
  QCheckBox *cb = new QCheckBox("Show viewcells", hbox);
  hlayout->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetShowViewCells(bool)));

  cb = new QCheckBox("Show render cost", hbox);
  hlayout->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetShowRenderCost(bool)));

  cb = new QCheckBox("Show pvs sizes", hbox);
  hlayout->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetShowPvsSizes(bool)));

  vbox->resize(800,100);

  
  vbox = new QGroupBox("Rendering", this);
  layout()->addWidget(vbox);
  
  vl = new QVBoxLayout;
  vbox->setLayout(vl);



  slider = new QSlider(Qt::Horizontal, vbox);
  vbox->layout()->addWidget(slider);
  slider->show();
  slider->setRange(0, 1000);
  slider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
  slider->setValue(1000);

  connect(slider, SIGNAL(valueChanged(int)), SIGNAL(SetSceneCut(int)));

  cb = new QCheckBox("Render errors", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetRenderErrors(bool)));

  cb = new QCheckBox("Use filter", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(true);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetUseFilter(bool)));

  cb = new QCheckBox("Use spatial filter", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(true);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetUseSpatialFilter(bool)));

  cb = new QCheckBox("Render filter", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(true);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetRenderFilter(bool)));


  cb = new QCheckBox("Cut view cells", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetCutViewCells(bool)));

  cb = new QCheckBox("Cut scene", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetCutScene(bool)));

  
  slider = new QSlider(Qt::Horizontal, vbox);
  vbox->layout()->addWidget(slider);
  slider->show();
  slider->setRange(1, 1000);
  slider->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
  slider->setValue(500);
  
  connect(slider, SIGNAL(valueChanged(int)), SIGNAL(SetTopDistance(int)));
  
  cb = new QCheckBox("Top View", vbox);
  vbox->layout()->addWidget(cb);
  cb->setChecked(false);
  connect(cb, SIGNAL(toggled(bool)), SIGNAL(SetTopView(bool)));

  vbox = new QGroupBox("PVS Errors", this);
  layout()->addWidget(vbox);

  vl = new QVBoxLayout;
  vbox->setLayout(vl);

  mPvsErrorWidget = new QListWidget(vbox);
  vbox->layout()->addWidget(mPvsErrorWidget);
  
  connect(mPvsErrorWidget,
                  SIGNAL(doubleClicked(const QModelIndex &)),
                  this,
                  SLOT(PvsErrorClicked(const QModelIndex &)));
  
  QPushButton *button = new QPushButton("Next Error Frame", vbox);
  vbox->layout()->addWidget(button);
  connect(button, SIGNAL(clicked(void)), SLOT(FocusNextPvsErrorFrame(void)));

  setWindowTitle("Preprocessor Control Widget");
  adjustSize();
}



void
RendererControlWidget::FocusNextPvsErrorFrame(void)
{
  
  
}

void
RendererControlWidget::UpdatePvsErrorItem(int row,
                                                                                  GlRendererBuffer::PvsErrorEntry &pvsErrorEntry)
{

  QListWidgetItem *i = mPvsErrorWidget->item(row);
  QString s;
  s.sprintf("%5.5f", pvsErrorEntry.mError);
  if (i) {
        i->setText(s);
  } else {
        new QListWidgetItem(s, mPvsErrorWidget);
  }
  mPvsErrorWidget->update();
}

GlRendererWidget::GlRendererWidget(SceneGraph *sceneGraph,
                                                                   ViewCellsManager *viewcells,
                                                                   KdTree *tree,
                                                                   QWidget * parent,
                                                                   const QGLWidget * shareWidget,
                                                                   Qt::WFlags f
                                                                   )
  :
  GlRenderer(sceneGraph, viewcells, tree), QGLWidget(parent, shareWidget, f)
{
  mTopView = false;
  mRenderViewCells = false;
  mTopDistance = 1.0f;
  mCutViewCells = false;
  mCutScene = false;
  mRenderErrors = false;
  mRenderFilter = true;
  mUseFilter = true;
  mUseSpatialFilter = true;
  mShowRenderCost = false;
  mShowPvsSizes = false;
  mSpatialFilterSize = 0.01;
  mPvsSize = 0;
  mRenderError = 0.0f;
  mControlWidget = new RendererControlWidget(NULL);
  
  connect(mControlWidget, SIGNAL(SetViewCellGranularity(int)), this, SLOT(SetViewCellGranularity(int)));
  connect(mControlWidget, SIGNAL(SetSceneCut(int)), this, SLOT(SetSceneCut(int)));
  connect(mControlWidget, SIGNAL(SetTopDistance(int)), this, SLOT(SetTopDistance(int)));

  connect(mControlWidget, SIGNAL(SetVisibilityFilterSize(int)), this, SLOT(SetVisibilityFilterSize(int)));
  connect(mControlWidget, SIGNAL(SetSpatialFilterSize(int)), this, SLOT(SetSpatialFilterSize(int)));

  connect(mControlWidget, SIGNAL(SetShowViewCells(bool)), this, SLOT(SetShowViewCells(bool)));
  connect(mControlWidget, SIGNAL(SetShowRenderCost(bool)), this, SLOT(SetShowRenderCost(bool)));
  connect(mControlWidget, SIGNAL(SetShowPvsSizes(bool)), this, SLOT(SetShowPvsSizes(bool)));
  connect(mControlWidget, SIGNAL(SetTopView(bool)), this, SLOT(SetTopView(bool)));
  connect(mControlWidget, SIGNAL(SetCutViewCells(bool)), this, SLOT(SetCutViewCells(bool)));
  connect(mControlWidget, SIGNAL(SetCutScene(bool)), this, SLOT(SetCutScene(bool)));
  connect(mControlWidget, SIGNAL(SetRenderErrors(bool)), this, SLOT(SetRenderErrors(bool)));
  connect(mControlWidget, SIGNAL(SetRenderFilter(bool)), this, SLOT(SetRenderFilter(bool)));
  connect(mControlWidget, SIGNAL(SetUseFilter(bool)), this, SLOT(SetUseFilter(bool)));
  connect(mControlWidget, SIGNAL(SetUseSpatialFilter(bool)),
                  this, SLOT(SetUseSpatialFilter(bool)));

  
  mControlWidget->show();
}

void
GlRendererWidget::SetViewCellGranularity(int number)
{
  if (mViewCellsManager) 
        //      mViewCellsManager->SetMaxFilterSize(number);
    mViewCellsManager->CollectViewCells(number);

  updateGL();
}

void
GlRendererWidget::SetVisibilityFilterSize(int number)
{
  if (mViewCellsManager) 
        mViewCellsManager->SetMaxFilterSize(number);
  updateGL();
}

void
GlRendererWidget::SetSpatialFilterSize(int number)
{
  mSpatialFilterSize = 1e-3*number;
  updateGL();
}

void
GlRendererWidget::SetSceneCut(int number)
{
  // assume the cut plane can only be aligned with xz plane
  // shift it along y according to number, which is percentage of the bounding
  // box position
  if (mViewCellsManager) {
        AxisAlignedBox3 box = mViewCellsManager->GetViewSpaceBox();
        Vector3 p = box.Min() + (number/1000.0f)*box.Max();
        mSceneCutPlane.mNormal = Vector3(0,-1,0);
        mSceneCutPlane.mD = -DotProd(mSceneCutPlane.mNormal, p);
        updateGL();
  }
}

void
GlRendererWidget::SetTopDistance(int number)
{
  mTopDistance = number/1000.0f;
  updateGL();
}

void
GlRendererWidget::RenderViewCells()
{
  mUseFalseColors = true;

  SetupCamera();
  glEnable(GL_CULL_FACE);
  //glDisable(GL_CULL_FACE);
  glCullFace(GL_FRONT);
  double eq[4];
  eq[0] = mSceneCutPlane.mNormal.x;
  eq[1] = mSceneCutPlane.mNormal.y;
  eq[2] = mSceneCutPlane.mNormal.z;
  eq[3] = mSceneCutPlane.mD;

  if (mCutViewCells) {
        glClipPlane(GL_CLIP_PLANE0, eq);
        glEnable(GL_CLIP_PLANE0);
  }
  
  int i;
  ViewCellContainer &viewcells = mViewCellsManager->GetViewCells();
  int maxPvs = -1;
  for (i=0; i < viewcells.size(); i++) {
        ViewCell *vc = viewcells[i];
        int p = vc->GetPvs().GetSize();
        if (p > maxPvs)
          maxPvs = p;
  }


  for (i=0; i < viewcells.size(); i++) {
        ViewCell *vc = viewcells[i];
        //      Mesh *m = vc->GetMesh();


        RgbColor c;

        if (!mShowPvsSizes) 
          c = vc->GetColor();
        else {
          float importance = (float)vc->GetPvs().GetSize() / (float)maxPvs;
          c = RgbColor(importance, 1.0f - importance, 0.0f);
        }
        glColor3f(c.r, c.g, c.b);
        
        RenderViewCell(vc);
  }

  glDisable(GL_CLIP_PLANE0);

}

void GlRendererBuffer::SampleBeamContributions(Intersectable *sourceObject,
                                                                                           Beam &beam,
                                                                                           const int desiredSamples,
                                                                                           BeamSampleStatistics &stat)
{
        // TODO: should be moved out of here (not to be done every time)
        // only back faces are interesting for the depth pass
        glShadeModel(GL_FLAT);
        glDisable(GL_LIGHTING);

        // needed to kill the fragments for the front buffer
        glEnable(GL_ALPHA_TEST);
        glAlphaFunc(GL_GREATER, 0);

        // assumes that the beam is constructed and contains kd-tree nodes
        // and viewcells which it intersects
  
  
        // Get the number of viewpoints to be sampled
        // Now it is a sqrt but in general a wiser decision could be made.
        // The less viewpoints the better for rendering performance, since less passes
        // over the beam is needed.
        // The viewpoints could actually be generated outside of the bounding box which
        // would distribute the 'efective viewpoints' of the object surface and thus
        // with a few viewpoints better sample the viewpoint space....

        //TODO: comment in
        //int viewPointSamples = sqrt((float)desiredSamples);
        int viewPointSamples = max(desiredSamples / (GetWidth() * GetHeight()), 1);
        
        // the number of direction samples per pass is given by the number of viewpoints
        int directionalSamples = desiredSamples / viewPointSamples;
        
        Debug << "directional samples: " << directionalSamples << endl;
        for (int i = 0; i < viewPointSamples; ++ i) 
        {
                Vector3 viewPoint = beam.mBox.GetRandomPoint();
                
                // perhaps the viewpoint should be shifted back a little bit so that it always lies
                // inside the source object
                // 'ideally' the viewpoints would be distributed on the soureObject surface, but this
        // would require more complicated sampling (perhaps hierarchical rejection sampling of
                // the object surface is an option here - only the mesh faces which are inside the box
                // are considered as candidates) 
                
                SampleViewpointContributions(sourceObject,
                                                                         viewPoint,
                                                                         beam,
                                                                         directionalSamples,
                                                                         stat);
        }


        // note:
        // this routine would be called only if the number of desired samples is sufficiently
        // large - for other rss tree cells the cpu based sampling is perhaps more efficient
        // distributing the work between cpu and gpu would also allow us to place more sophisticated
        // sample distributions (silhouette ones) using the cpu and the jittered once on the GPU
        // in order that thios scheme is working well the gpu render buffer should run in a separate
        // thread than the cpu sampler, which would not be such a big problem....

        // disable alpha test again
        glDisable(GL_ALPHA_TEST);
}


void GlRendererBuffer::SampleViewpointContributions(Intersectable *sourceObject,
                                                                                                        const Vector3 viewPoint,
                                                                                                        Beam &beam,
                                                                                                        const int samples,
                                                    BeamSampleStatistics &stat)
{
    // 1. setup the view port to match the desired samples
        glViewport(0, 0, samples, samples);

        // 2. setup the projection matrix and view matrix to match the viewpoint + beam.mDirBox
        SetupProjectionForViewPoint(viewPoint, beam, sourceObject);


        // 3. reset z-buffer to 0 and render the source object for the beam
        //    with glCullFace(Enabled) and glFrontFace(GL_CW)
        //    save result to the front depth map
        //    the front depth map holds ray origins


        // front depth buffer must be initialised to 0
        float clearDepth;
        
        glGetFloatv(GL_DEPTH_CLEAR_VALUE, &clearDepth);
        glClearDepth(0.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);


        //glFrontFace(GL_CW);
        glEnable(GL_CULL_FACE);
        glCullFace(GL_FRONT);
        glColorMask(0, 0, 0, 0);
        

        // stencil is increased where the source object is located
        glEnable(GL_STENCIL_TEST);      
        glStencilFunc(GL_ALWAYS, 0x1, 0x1);
        glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);


#if 0
        static int glSourceObjList = -1;         
        if (glSourceObjList != -1) 
        {
                glSourceObjList = glGenLists(1);
                glNewList(glSourceObjList, GL_COMPILE);

                RenderIntersectable(sourceObject);
        
                glEndList();
        }
        glCallList(glSourceObjList);

#else
        RenderIntersectable(sourceObject);

#endif  

         // copy contents of the front depth buffer into depth texture
        glBindTexture(GL_TEXTURE_2D, frontDepthMap);    
        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, depthMapSize, depthMapSize);


        // reset clear function
        glClearDepth(clearDepth);

        
        
        // 4. set up the termination depth buffer (= standard depth buffer)
        //    only rays which have non-zero entry in the origin buffer are valid since
        //    they realy start on the object surface (this is tagged by setting a
        //    stencil buffer bit at step 3).
        
        glStencilFunc(GL_EQUAL, 0x1, 0x1);
        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glDepthMask(1);

        glEnable(GL_DEPTH_TEST);
                
        glEnable(GL_CULL_FACE);
        glCullFace(GL_BACK);

        // setup front depth buffer
        glEnable(GL_TEXTURE_2D);
        
        // bind pixel shader implementing the front depth buffer functionality
        cgGLBindProgram(sCgFragmentProgram);
        cgGLEnableProfile(sCgFragmentProfile);


        // 5. render all objects inside the beam 
        //    we can use id based false color to read them back for gaining the pvs

        glColorMask(1, 1, 1, 1);

        
        // if objects not stored in beam => extract objects
        if (beam.mFlags & !Beam::STORE_OBJECTS)
        {
                vector<KdNode *>::const_iterator it, it_end = beam.mKdNodes.end();

                Intersectable::NewMail();
                for (it = beam.mKdNodes.begin(); it != it_end; ++ it)
                {
                        mKdTree->CollectObjects(*it, beam.mObjects);
                }
        }


        //    (objects can be compiled to a gl list now so that subsequent rendering for
        //    this beam is fast - the same hold for step 3)
        //    Afterwards we have two depth buffers defining the ray origin and termination
        

#if 0
        static int glObjList = -1; 
        if (glObjList != -1) 
        {
                glObjList = glGenLists(1);
                glNewList(glObjList, GL_COMPILE);
        
                ObjectContainer::const_iterator it, it_end = beam.mObjects.end();
                for (it = beam.mObjects.begin(); it != it_end; ++ it)
                {
                        // render all objects except the source object
                        if (*it != sourceObject)
                                RenderIntersectable(*it);
                }
                
                glEndList();
        }

        glCallList(glObjList);
#else
        ObjectContainer::const_iterator it, it_end = beam.mObjects.end();
        for (it = beam.mObjects.begin(); it != it_end; ++ it)
        {       
                // render all objects except the source object
                if (*it != sourceObject)
                        RenderIntersectable(*it);
        }
#endif
        
   

        // 6. Use occlusion queries for all viewcell meshes associated with the beam ->
        //     a fragment passes if the corresponding stencil fragment is set and its depth is
        //     between origin and termination buffer

        // create new queries if necessary
        GenQueries((int)beam.mViewCells.size());

        // check whether any backfacing polygon would pass the depth test?
        // matt: should check both back /front facing because of dual depth buffer
        // and danger of cutting the near plane with front facing polys.
        
        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
        glDepthMask(GL_FALSE);
        glDisable(GL_CULL_FACE);

  
        ViewCellContainer::const_iterator vit, vit_end = beam.mViewCells.end();

        int queryIdx = 0;

        for (vit = beam.mViewCells.begin(); vit != vit_end; ++ vit)
        {
                glBeginOcclusionQueryNV(sQueries[queryIdx ++]);

                RenderIntersectable(*vit);
                
                glEndOcclusionQueryNV();
        }



        // at this point, if possible, go and do some other computation


        
        // 7. The number of visible pixels is the number of sample rays which see the source
        //    object from the corresponding viewcell -> remember these values for later update
        //   of the viewcell pvs - or update immediately?

        queryIdx = 0;
        unsigned int pixelCount;

        for (vit = beam.mViewCells.begin(); vit != vit_end; ++ vit)
        {
                // fetch queries
                glGetOcclusionQueryuivNV(sQueries[queryIdx ++],
                                                                 GL_PIXEL_COUNT_NV,
                                                                 &pixelCount);
                if (pixelCount)
                        Debug << "view cell " << (*vit)->GetId() << " visible pixels: " << pixelCount << endl;
        }
        

        // 8. Copmpute rendering statistics
        // In general it is not neccessary to remember to extract all the rays cast. I hope it
        // would be sufficient to gain only the intergral statistics about the new contributions
        // and so the rss tree would actually store no new rays (only the initial ones)
        // the subdivision of the tree would only be driven by the statistics (the glrender could
        // evaluate the contribution entropy for example)
        // However might be an option to extract/store only those the rays which made a contribution
        // (new viewcell has been discovered) or relative contribution greater than a threshold ... 

        ObjectContainer pvsObj;
        stat.pvsSize = ComputePvs(beam.mObjects, pvsObj);
        
        // to gain ray source and termination
        // copy contents of ray termination buffer into depth texture
        // and compare with ray source buffer
#if 0
        VssRayContainer rays;

        glBindTexture(GL_TEXTURE_2D, backDepthMap);     
        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, depthMapSize, depthMapSize);

        ComputeRays(Intersectable *sourceObj, rays);

#endif



        //-- cleanup


        // reset gl state
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
        glDepthMask(GL_TRUE);
        glEnable(GL_CULL_FACE);
        glDisable(GL_STENCIL_TEST);
        cgGLDisableProfile(sCgFragmentProfile);
        glDisable(GL_TEXTURE_2D);

        // remove objects from beam
        if (beam.mFlags & !Beam::STORE_OBJECTS)
                beam.mObjects.clear();
}


void GlRendererBuffer::GenQueries(const int numQueries)
{
        if ((int)sQueries.size() < numQueries)
        {
                const int n = numQueries - (int)sQueries.size();
                unsigned int *newQueries = new unsigned int[n];

                glGenOcclusionQueriesNV(n, (unsigned int *)newQueries);

                for (int i = 0; i < n; ++ i)
                {
                        sQueries.push_back(newQueries[i]);
                }

                delete [] newQueries;
        }
}


void GlRendererBuffer::SetupProjectionForViewPoint(const Vector3 &viewPoint, 
                                                                                                   const Beam &beam, 
                                                                                                   Intersectable *sourceObject)
{
        float left, right, bottom, top, znear, zfar;

        beam.ComputePerspectiveFrustum(left, right, bottom, top, znear, zfar,
                                                                   mSceneGraph->GetBox());

        //Debug << left << " " << right << " " << bottom << " " << top << " " << znear << " " << zfar << endl;
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glFrustum(left, right, bottom, top, znear, zfar);
        //glFrustum(-1, 1, -1, 1, 1, 20000);

    const Vector3 center = viewPoint + beam.GetMainDirection() * (zfar - znear) * 0.3f;
        const Vector3 up = 
                Normalize(CrossProd(beam.mPlanes[0].mNormal, beam.mPlanes[4].mNormal));

#ifdef _DEBUG
        Debug << "view point: " << viewPoint << endl;
        Debug << "eye: " << center << endl;
        Debug << "up: " << up << endl;
#endif

        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        gluLookAt(viewPoint.x, viewPoint.y, viewPoint.z, 
                          center.x, center.y, center.z,                   
                          up.x, up.y, up.z);
}               

  
void GlRendererBuffer::InitGL()
{
 makeCurrent(); 
 GlRenderer::InitGL();

#if 1
        // initialise dual depth buffer textures
        glGenTextures(1, &frontDepthMap);
        glBindTexture(GL_TEXTURE_2D, frontDepthMap);
        
        glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, depthMapSize, 
                depthMapSize, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

        glGenTextures(1, &backDepthMap);
        glBindTexture(GL_TEXTURE_2D, backDepthMap);
        
        glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, depthMapSize, 
                depthMapSize, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

        // cg initialization
        cgSetErrorCallback(handleCgError);
        sCgContext = cgCreateContext();
        
        if (cgGLIsProfileSupported(CG_PROFILE_ARBFP1))
                sCgFragmentProfile = CG_PROFILE_ARBFP1;
        else 
        {
          // try FP30
          if (cgGLIsProfileSupported(CG_PROFILE_FP30))
            sCgFragmentProfile = CG_PROFILE_FP30;
          else 
          {
                  Debug << "Neither arbfp1 or fp30 fragment profiles supported on this system" << endl;
                  exit(1);
          }
  }


 sCgFragmentProgram = cgCreateProgramFromFile(sCgContext,
                                                                                           CG_SOURCE, "../src/dual_depth.cg",
                                                                                           sCgFragmentProfile,
                                                                                           NULL, 
                                                                                           NULL);

  if (!cgIsProgramCompiled(sCgFragmentProgram))
          cgCompileProgram(sCgFragmentProgram);

  cgGLLoadProgram(sCgFragmentProgram);
  cgGLBindProgram(sCgFragmentProgram);

  Debug << "---- PROGRAM BEGIN ----\n" <<
          cgGetProgramString(sCgFragmentProgram, CG_COMPILED_PROGRAM) << "---- PROGRAM END ----\n";

#endif
  doneCurrent();
}


void GlRendererBuffer::ComputeRays(Intersectable *sourceObj, VssRayContainer &rays)
{
        for (int i = 0; i < depthMapSize * depthMapSize; ++ i)
        {
                //todo glGetTexImage()
        }
}



inline bool ilt(Intersectable *obj1, Intersectable *obj2)
{
        return obj1->mId < obj2->mId;
}


int GlRendererBuffer::ComputePvs(ObjectContainer &objects, 
                                                                 ObjectContainer &pvs) const
{
        int pvsSize = 0;
        QImage image = toImage();
        Intersectable::NewMail();

        std::stable_sort(objects.begin(), objects.end(), ilt);

        MeshInstance dummy(NULL);

        Intersectable *obj = NULL;
                        
        for (int x = 0; x < image.width(); ++ x)
        {
                for (int y = 0; y < image.height(); ++ y)
                {
                        QRgb pix = image.pixel(x, y);
                        const int id = GetId(qRed(pix), qGreen(pix), qBlue(pix));

                        dummy.SetId(id);

                        ObjectContainer::iterator oit =
                                lower_bound(objects.begin(), objects.end(), &dummy, ilt);
                        
                        
                        if (//(oit != oit.end()) && 
                                ((*oit)->GetId() == id) && 
                                !obj->Mailed())
                        {
                                obj = *oit;
                                obj->Mail();
                                ++ pvsSize;
                                pvs.push_back(obj);
                        }
                }
        }

        return pvsSize;
}

/***********************************************************************/
/*                     GlDebuggerWidget implementation                             */
/***********************************************************************/


GlDebuggerWidget::GlDebuggerWidget(GlRendererBuffer *buf, QWidget *parent)
      : QGLWidget(QGLFormat(QGL::SampleBuffers), parent), mRenderBuffer(buf)
{
        // create the pbuffer
    //pbuffer = new QGLPixelBuffer(QSize(512, 512), format(), this);
    timerId = startTimer(20);
    setWindowTitle(("OpenGL pbuffers"));
}


GlDebuggerWidget::~GlDebuggerWidget()
{
 mRenderBuffer->releaseFromDynamicTexture();
   glDeleteTextures(1, &dynamicTexture);
         
         DEL_PTR(mRenderBuffer);
}


void GlDebuggerWidget::initializeGL()
{
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();

        glFrustum(-1, 1, -1, 1, 10, 100);
        glTranslatef(-0.5f, -0.5f, -0.5f);
        glTranslatef(0.0f, 0.0f, -15.0f);
        glMatrixMode(GL_MODELVIEW);

        glEnable(GL_CULL_FACE);
        initCommon();
        initPbuffer();

}


void GlDebuggerWidget::resizeGL(int w, int h)
{
        glViewport(0, 0, w, h);
}


void GlDebuggerWidget::paintGL()
{
        // draw a spinning cube into the pbuffer..
        mRenderBuffer->makeCurrent();
        
        BeamSampleStatistics stats;
        mRenderBuffer->SampleBeamContributions(mSourceObject, mBeam, mSamples, stats);

        glFlush();

        // rendering directly to a texture is not supported on X11, unfortunately
    mRenderBuffer->updateDynamicTexture(dynamicTexture);
   
    // and use the pbuffer contents as a texture when rendering the
    // background and the bouncing cubes
    makeCurrent();
    glBindTexture(GL_TEXTURE_2D, dynamicTexture);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // draw the background
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();

        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();
}


void GlDebuggerWidget::initPbuffer()
{
        // set up the pbuffer context
    mRenderBuffer->makeCurrent();
        /*mRenderBuffer->InitGL();

        glViewport(0, 0, mRenderBuffer->size().width(), mRenderBuffer->size().height());
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-1, 1, -1, 1, -99, 99);
        glTranslatef(-0.5f, -0.5f, 0.0f);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);*/
        
        // generate a texture that has the same size/format as the pbuffer
    dynamicTexture = mRenderBuffer->generateDynamicTexture();

        // bind the dynamic texture to the pbuffer - this is a no-op under X11
        mRenderBuffer->bindToDynamicTexture(dynamicTexture);
        makeCurrent();
}

void GlDebuggerWidget::initCommon()
{
        glEnable(GL_TEXTURE_2D);
        glEnable(GL_DEPTH_TEST);

        glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
}

}