source: GTP/trunk/Lib/Vis/OnlineCullingCHC/OGRE/src/OgreOcclusionCullingSceneManager.cpp @ 865

#include "OgreOcclusionCullingSceneManager.h"
#include "OgreVisibilityOptionsManager.h"
#include "OgreTypeConverter.h"
#include <OgreMath.h>
#include <OgreIteratorWrappers.h>
#include <OgreRenderSystem.h>
#include <OgreCamera.h>
#include <OgreLogManager.h>
#include <OgreStringConverter.h>
#include <OgreEntity.h>
#include <OgreSubEntity.h>
#include <OgreIteratorWrappers.h>
#include "VspBspTree.h"
#include "Containers.h"
#include "ViewCellsManager.h"

namespace Ogre {

//-----------------------------------------------------------------------
OcclusionCullingSceneManager::OcclusionCullingSceneManager(
                                                        GtpVisibility::VisibilityManager *visManager): 
mVisibilityManager(visManager), 
mShowVisualization(false),
mRenderNodesForViz(false),
mRenderNodesContentForViz(false),
mVisualizeCulledNodes(false),
mLeavePassesInQueue(0),
mDelayRenderTransparents(true),
mUseDepthPass(false),
mIsDepthPassPhase(false),
mUseItemBuffer(false),
//mUseItemBuffer(true),
mIsItemBufferPhase(false),
mCurrentEntityId(1),
mEnableDepthWrite(true),
mSkipTransparents(false),
mRenderTransparentsForItemBuffer(true),
mExecuteVertexProgramForAllPasses(true),
mIsHierarchicalCulling(false)
{
        mHierarchyInterface = new OctreeHierarchyInterface(this, mDestRenderSystem);
        
#if 0
        mDisplayNodes = true;
        mShowBoundingBoxes = true;
        mShowBoxes = true;
#endif
        // TODO: set maxdepth to reasonable value
        mMaxDepth = 50;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::InitDepthPass()
{
        MaterialPtr depthMat = MaterialManager::getSingleton().getByName("Visibility/DepthPass");

        if (depthMat.isNull())
    {
                depthMat = MaterialManager::getSingleton().create(
                "Visibility/DepthPass",
                ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

        mDepthPass = depthMat->getTechnique(0)->getPass(0);
                mDepthPass->setColourWriteEnabled(false);
                mDepthPass->setDepthWriteEnabled(true);
                mDepthPass->setLightingEnabled(false);
        }
        else
        {
                mDepthPass = depthMat->getTechnique(0)->getPass(0);
        }
}
//-----------------------------------------------------------------------
OcclusionCullingSceneManager::~OcclusionCullingSceneManager()
{
        OGRE_DELETE(mHierarchyInterface);
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::InitItemBufferPass()
{
        MaterialPtr itemBufferMat = MaterialManager::getSingleton().
                getByName("Visibility/ItemBufferPass");

        if (itemBufferMat.isNull())
    {
                // Init
                itemBufferMat = MaterialManager::getSingleton().create("Visibility/ItemBufferPass",
                ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

                mItemBufferPass = itemBufferMat->getTechnique(0)->getPass(0);
                mItemBufferPass->setColourWriteEnabled(true);
                mItemBufferPass->setDepthWriteEnabled(true);
                mItemBufferPass->setLightingEnabled(true);
                //mItemBufferPass->setLightingEnabled(false);
        }
        else
        {
                mItemBufferPass = itemBufferMat->getTechnique(0)->getPass(0);
        }
        //mItemBufferPass->setAmbient(1, 1, 0);
}
//-------------------------------------------------------------------------
void OcclusionCullingSceneManager::setWorldGeometry( const String& filename )
{
    // Clear out any existing world resources (if not default)
    if (ResourceGroupManager::getSingleton().getWorldResourceGroupName() != 
        ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME)
    {
        ResourceGroupManager::getSingleton().clearResourceGroup(
            ResourceGroupManager::getSingleton().getWorldResourceGroupName());
    }
    mTerrainPages.clear();
    // Load the configuration
    loadConfig(filename);

    // Resize the octree, allow for 1 page for now
    float max_x = mOptions.scale.x * mOptions.pageSize;
    float max_y = mOptions.scale.y;
    float max_z = mOptions.scale.z * mOptions.pageSize;

        float maxAxis = std::max(max_x, max_y);
        maxAxis = std::max(maxAxis, max_z);
        resize( AxisAlignedBox( 0, 0, 0, maxAxis, maxAxis, maxAxis ) );
    
    setupTerrainMaterial();

    setupTerrainPages();

 }

//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::PrepareVisualization(Camera *cam)
{
        // add player camera for visualization purpose
        try 
        {
                Camera *c;
                if ((c = getCamera("PlayerCam")) != NULL)
                {
                        getRenderQueue()->addRenderable(c);
                }   
    }
    catch (...)
    {
        // ignore
    }
        for (BoxList::iterator it = mBoxes.begin(); it != mBoxes.end(); ++it)
        {
                getRenderQueue()->addRenderable(*it);
        }
        if (mRenderNodesForViz || mRenderNodesContentForViz)
        {
                // HACK: change node material so it is better suited for visualization
                MaterialPtr nodeMat = MaterialManager::getSingleton().getByName("Core/NodeMaterial");
                nodeMat->setAmbient(1, 1, 0);
                nodeMat->setLightingEnabled(true);
                nodeMat->getTechnique(0)->getPass(0)->removeAllTextureUnitStates();

                for (NodeList::iterator it = mVisible.begin(); it != mVisible.end(); ++it)
                {
                        if (mRenderNodesForViz)
                        {
                                // render the leaf nodes
                                if (((*it)->numAttachedObjects() > 0) && ((*it)->numChildren() == 0) && 
                                         (*it)->getAttachedObject(0)->getMovableType() == "Entity")
                                {
                                        getRenderQueue()->addRenderable((*it));
                                }

                                // addbounding boxes instead of node itself
                                //(*it)->_addBoundingBoxToQueue(getRenderQueue());
                        }
                        if (mRenderNodesContentForViz) 
                        {
                                (*it)->_addToRenderQueue(cam, getRenderQueue(), false);
                        }
                }
        }       
}
//-----------------------------------------------------------------------
Pass *OcclusionCullingSceneManager::setPass(Pass* pass)
{
        // TODO: setting vertex program is not efficient
        //Pass *usedPass = ((mIsDepthPassPhase && !pass->hasVertexProgram()) ? mDepthPass : pass); 
        
        // set depth fill pass if we currently do not make an aabb occlusion query
        Pass *usedPass = (mIsDepthPassPhase && !mHierarchyInterface->IsBoundingBoxQuery() ? 
                                          mDepthPass : pass);
                
        IlluminationRenderStage savedStage = mIlluminationStage; 
        
        // set illumination stage to NONE so no shadow material is used 
        // for depth pass or for occlusion query
        if (mIsDepthPassPhase || mHierarchyInterface->IsBoundingBoxQuery())
        {
                mIlluminationStage = IRS_NONE;
        }
        
        // --- set vertex program of current pass in order to set correct depth
        if (mExecuteVertexProgramForAllPasses && mIsDepthPassPhase && pass->hasVertexProgram())
        {
                // add vertex program of current pass to depth pass
                mDepthPass->setVertexProgram(pass->getVertexProgramName());

                if (mDepthPass->hasVertexProgram())
                {
                        const GpuProgramPtr& prg = mDepthPass->getVertexProgram();
                        // Load this program if not done already
                        if (!prg->isLoaded())
                                prg->load();
                        // Copy params
                        mDepthPass->setVertexProgramParameters(pass->getVertexProgramParameters());
                }
        }
        else if (mDepthPass->hasVertexProgram())
        {
                mDepthPass->setVertexProgram("");
        }
        

        bool IsDepthWrite = usedPass->getDepthWriteEnabled();

        // global option which enables / disables depth writes
        if (!mEnableDepthWrite)
        {
                usedPass->setDepthWriteEnabled(false);
        }
        //else if (mIsItemBufferPass) {usedPass = mItemBufferPass;}
        
        Pass *result = SceneManager::setPass(usedPass);

        // reset depth write
        if (!mEnableDepthWrite)
        {
                usedPass->setDepthWriteEnabled(IsDepthWrite);
        }

        // reset illumination stage
        mIlluminationStage = savedStage;

        return result;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::_findVisibleObjects(Camera* cam,
                                                                                                                bool onlyShadowCasters)
{
        //-- show visible scene nodes and octree bounding boxes from last frame
        if (mShowVisualization)
    {
                PrepareVisualization(cam);
        }
        else 
        {       
                // for hierarchical culling, we interleave identification 
                // and rendering of objects in _renderVisibibleObjects

                // for the shadow pass we use only standard rendering
                // because of low occlusion
                if (mShadowTechnique == SHADOWTYPE_TEXTURE_MODULATIVE && 
                        mIlluminationStage == IRS_RENDER_TO_TEXTURE)
                {
                        TerrainSceneManager::_findVisibleObjects(cam, onlyShadowCasters);
                }
                // only shadow casters will be rendered in shadow texture pass
                // mHierarchyInterface->SetOnlyShadowCasters(onlyShadowCasters);
        }
        
        
        // -- delete lists stored for visualization
        mVisible.clear();
        mBoxes.clear();
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::_renderVisibleObjects()
{

        InitDepthPass();          // create material for depth pass
        InitItemBufferPass(); // create material for item buffer pass

        // save ambient light to reset later
        ColourValue savedAmbient = mAmbientLight;

        //-- apply standard rendering for some modes (e.g., visualization, shadow pass)

        if (mShowVisualization ||
           (mShadowTechnique == SHADOWTYPE_TEXTURE_MODULATIVE && 
            mIlluminationStage == IRS_RENDER_TO_TEXTURE))
        {       
                IlluminationRenderStage savedStage = mIlluminationStage; 
        
                if (mShowVisualization) 
                        // disable illumination stage to prevent rendering shadows
                        mIlluminationStage = IRS_NONE;

                // standard rendering for shadow maps because of performance
                TerrainSceneManager::_renderVisibleObjects();

                mIlluminationStage = savedStage;
        }
        else //-- the hierarchical culling algorithm
        {
                // don't render backgrounds for item buffer
                if (mUseItemBuffer)
                {
                        clearSpecialCaseRenderQueues();
                        getRenderQueue()->clear();
                }

                //-- hierarchical culling
                // the objects of different layers (e.g., background, scene, 
                // overlay) must be identified and rendered one after another

                //-- render all early skies
                clearSpecialCaseRenderQueues();
                addSpecialCaseRenderQueue(RENDER_QUEUE_BACKGROUND);
                addSpecialCaseRenderQueue(RENDER_QUEUE_SKIES_EARLY);
                setSpecialCaseRenderQueueMode(SceneManager::SCRQM_INCLUDE);

                TerrainSceneManager::_renderVisibleObjects();

#ifdef GTP_VISIBILITY_MODIFIED_OGRE
                // delete previously rendered content
                _deleteRenderedQueueGroups();
#endif

                //-- prepare queue for visible objects (i.e., all but overlay and skies late)
                clearSpecialCaseRenderQueues();
                addSpecialCaseRenderQueue(RENDER_QUEUE_SKIES_LATE);
                addSpecialCaseRenderQueue(RENDER_QUEUE_OVERLAY);
        
                // exclude this queues from hierarchical rendering
                setSpecialCaseRenderQueueMode(SceneManager::SCRQM_EXCLUDE);

                // set all necessary parameters for 
                // hierarchical visibility culling and rendering
                InitVisibilityCulling(mCameraInProgress);

        
                /** 
                * the hierarchical culling algorithm
                * for depth pass: we just find objects and update depth buffer
                * for "delayed" rendering: we render some passes afterwards
                * e.g., transparents, because they need front-to-back sorting
                **/
                
                mVisibilityManager->ApplyVisibilityCulling();

                // delete remaining renderables from queue (all not in mLeavePassesInQueue)
#ifdef GTP_VISIBILITY_MODIFIED_OGRE
                _deleteRenderedQueueGroups(mLeavePassesInQueue);
#endif

                //-- reset parameters
                mIsDepthPassPhase = false;
                mIsItemBufferPhase = false;
                mSkipTransparents = false;
                mLeavePassesInQueue = 0;
                

                // add visible nodes found by the visibility culling algorithm
                if (mUseDepthPass)
                {
                        for (NodeList::iterator it = mVisible.begin(); it != mVisible.end(); ++ it)
                        {
                                (*it)->_addToRenderQueue(mCameraInProgress, getRenderQueue(), false);
                        }
                }
                
                //-- now we can render all remaining queue objects
                // used for depth pass, transparents, overlay 
                clearSpecialCaseRenderQueues();

                TerrainSceneManager::_renderVisibleObjects();
        }
                
        // HACK: set the new render level index, important to avoid cracks
        // in terrain caused by LOD
        TerrainRenderable::NextRenderLevelIndex();
        
        // reset ambient light
        setAmbientLight(savedAmbient);

        getRenderQueue()->clear(); // finally clear render queue
        OGRE_DELETE(mRenderQueue); // HACK: should be cleared before ...
        WriteLog(); // write out stats

}

//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::_updateSceneGraph(Camera* cam)
{
        mVisibilityManager->GetCullingManager()->SetHierarchyInterface(mHierarchyInterface);
        mHierarchyInterface->SetRenderSystem(mDestRenderSystem);

        TerrainSceneManager::_updateSceneGraph(cam);
}
//-----------------------------------------------------------------------
bool OcclusionCullingSceneManager::setOption(const String & key, const void * val)
{
        if (key == "UseDepthPass")
        {
                mUseDepthPass = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "PrepareVisualization")
        {
                mShowVisualization = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "RenderNodesForViz")
        {
                mRenderNodesForViz = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "RenderNodesContentForViz")
        {
                mRenderNodesContentForViz = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "SkyBoxEnabled")
        {
                mSkyBoxEnabled = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "SkyPlaneEnabled")
        {
                mSkyPlaneEnabled = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "SkyDomeEnabled")
        {
                mSkyDomeEnabled = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "VisualizeCulledNodes")
        {
                mVisualizeCulledNodes = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "DelayRenderTransparents")
        {
                mDelayRenderTransparents = (*static_cast<const bool *>(val));
                return true;
        }

        if (key == "DepthWrite")
        {
                mEnableDepthWrite = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "UseItemBuffer")
        {
                mUseItemBuffer = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "ExecuteVertexProgramForAllPasses")
        { 
                mExecuteVertexProgramForAllPasses  = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "RenderTransparentsForItemBuffer")
        { 
                mRenderTransparentsForItemBuffer  = (*static_cast<const bool *>(val));
                return true;
        }
        if (key == "NodeVizScale")
        { 
                OctreeNode::setVizScale(*static_cast<const float *>(val));
                return true;
        }

        if (key == "UseArbQueries")
        {
                bool useArbQueries = (*static_cast<const bool *>(val));

                if (useArbQueries)
                {
                        mHierarchyInterface->DeleteQueries();
                        mDestRenderSystem->setConfigOption("ArbQueries", "Yes");
                }
                else
                {
                        mHierarchyInterface->DeleteQueries();
                        mDestRenderSystem->setConfigOption("ArbQueries", "No");
                }
        }
        return VisibilityOptionsManager(mVisibilityManager, mHierarchyInterface).
                setOption(key, val) || TerrainSceneManager::setOption(key, val);
}
//-----------------------------------------------------------------------
bool OcclusionCullingSceneManager::getOption(const String & key, void *val)
{
        if (key == "NumHierarchyNodes")
        {
                * static_cast<unsigned int *>(val) = (unsigned int)mNumOctants;
                return true;
        }
        
        return VisibilityOptionsManager(mVisibilityManager, mHierarchyInterface).
                getOption(key, val) && TerrainSceneManager::getOption(key, val);
}
//-----------------------------------------------------------------------
bool OcclusionCullingSceneManager::getOptionValues(const String & key, 
                                                                                                        StringVector &refValueList)
{
        return TerrainSceneManager::getOptionValues( key, refValueList);
}
//-----------------------------------------------------------------------
bool OcclusionCullingSceneManager::getOptionKeys(StringVector & refKeys)
{
        return VisibilityOptionsManager(mVisibilityManager, mHierarchyInterface).
                getOptionKeys(refKeys) || TerrainSceneManager::getOptionKeys(refKeys);
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::setVisibilityManager(GtpVisibility::
                                                                                                                 VisibilityManager *visManager)
{
        mVisibilityManager = visManager;
}
//-----------------------------------------------------------------------
GtpVisibility::VisibilityManager *OcclusionCullingSceneManager::getVisibilityManager( void )
{
        return mVisibilityManager;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::WriteLog()
{
        std::stringstream d;

        d << "Depth pass: " << StringConverter::toString(mUseDepthPass) << ", "
          << "Delay transparents: " << StringConverter::toString(mDelayRenderTransparents) << ", "
          << "Use optimization: " << StringConverter::toString(mHierarchyInterface->GetTestGeometryForVisibleLeaves()) << ", "
          << "Algorithm type: " << mVisibilityManager->GetCullingManagerType() << ", "
          << "Hierarchy nodes: " << mNumOctants << ", " 
          << "Traversed nodes: " << mHierarchyInterface->GetNumTraversedNodes() << ", "
          << "Rendered nodes: " << mHierarchyInterface->GetNumRenderedNodes() << ", "
          << "Query culled nodes: " << mVisibilityManager->GetCullingManager()->GetNumQueryCulledNodes() << ", "
          << "Frustum culled nodes: " << mVisibilityManager->GetCullingManager()->GetNumFrustumCulledNodes() << ", "
      << "Queries issued: " << mVisibilityManager->GetCullingManager()->GetNumQueriesIssued() << "\n";

        LogManager::getSingleton().logMessage(d.str());
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::renderObjects(
        const RenderPriorityGroup::TransparentRenderablePassList& objs, 
    bool doLightIteration, const LightList* manualLightList)
{
        // for correct rendering, transparents must be rendered after hierarchical culling
        if (!mSkipTransparents)
        {
                OctreeSceneManager::renderObjects(objs, doLightIteration, manualLightList);
        }
}
//-----------------------------------------------------------------------
bool OcclusionCullingSceneManager::validatePassForRendering(Pass* pass)
{
        // skip all but first pass if we are doing the depth pass
        if ((mIsDepthPassPhase || mIsItemBufferPhase) && pass->getIndex() > 0)
        {
                return false;
        }

        return SceneManager::validatePassForRendering(pass);
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::renderQueueGroupObjects(RenderQueueGroup* pGroup)
{
        if (!mIsItemBufferPhase)
        {
                TerrainSceneManager::renderQueueGroupObjects(pGroup);
                return;
        }

        //-- item buffer

    // Iterate through priorities
    RenderQueueGroup::PriorityMapIterator groupIt = pGroup->getIterator();

        while (groupIt.hasMoreElements())
    {
                RenderItemBuffer(groupIt.getNext());
        }
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::RenderItemBuffer(RenderPriorityGroup* pGroup)
{
        // Do solids
        RenderPriorityGroup::SolidRenderablePassMap solidObjs = pGroup->_getSolidPasses();

        // ----- SOLIDS LOOP -----
        RenderPriorityGroup::SolidRenderablePassMap::const_iterator ipass, ipassend;
        ipassend = solidObjs.end();

        for (ipass = solidObjs.begin(); ipass != ipassend; ++ipass)
        {
                // Fast bypass if this group is now empty
                if (ipass->second->empty()) 
                        continue;

                // Render only first pass
                if (ipass->first->getIndex() > 0)
                        continue;

                RenderPriorityGroup::RenderableList* rendList = ipass->second;
                
                RenderPriorityGroup::RenderableList::const_iterator irend, irendend;
                irendend = rendList->end();
                        
                for (irend = rendList->begin(); irend != irendend; ++irend)
                {
                        //std::stringstream d; d << "itembuffer, pass name: " << 
                        //      ipass->first->getParent()->getParent()->getName();
                        //      LogManager::getSingleton().logMessage(d.str());
                        
                        RenderSingleObjectForItemBuffer(*irend, ipass->first);
                }
        }

        // -- TRANSPARENT LOOP: must be handled differently 

        // transparents are treated either as solids or completely discarded
        if (mRenderTransparentsForItemBuffer)
        {
                RenderPriorityGroup::TransparentRenderablePassList transpObjs = 
                        pGroup->_getTransparentPasses();
                RenderPriorityGroup::TransparentRenderablePassList::const_iterator 
                        itrans, itransend;

                itransend = transpObjs.end();
                for (itrans = transpObjs.begin(); itrans != itransend; ++itrans)
                {
                        // like for solids, render only first pass
                        if (itrans->pass->getIndex() == 0)
                        {       
                                RenderSingleObjectForItemBuffer(itrans->renderable, itrans->pass);
                        }
                }
        }
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::RenderSingleObjectForItemBuffer(Renderable *rend, Pass *pass)
{
        static LightList nullLightList;
        
        int col[4];
        
        // -- create color code out of object id
        col[0] = (rend->getId() >> 16) & 255;
        col[1] = (rend->getId() >> 8) & 255;
        col[2] = rend->getId() & 255;
//      col[3] = 255;

        //mDestRenderSystem->setColour(col[0], col[1], col[2], col[3]);
    
        mItemBufferPass->setAmbient(ColourValue(col[0] / 255.0f,
                                                                                    col[1] / 255.0f, 
                                                                                        col[2] / 255.0f, 1));

        // set vertex program of current pass
        if (mExecuteVertexProgramForAllPasses && pass->hasVertexProgram())
        {
                mItemBufferPass->setVertexProgram(pass->getVertexProgramName());

                if (mItemBufferPass->hasVertexProgram())
                {
                        const GpuProgramPtr& prg = mItemBufferPass->getVertexProgram();
                        // Load this program if not done already
                        if (!prg->isLoaded())
                                prg->load();
                        // Copy params
                        mItemBufferPass->setVertexProgramParameters(pass->getVertexProgramParameters());
                }
        }
        else if (mItemBufferPass->hasVertexProgram())
        {
                mItemBufferPass->setVertexProgram("");
        }

        Pass *usedPass = setPass(mItemBufferPass); 


        // Render a single object, this will set up auto params if required
        renderSingleObject(rend, usedPass, false, &nullLightList);
}
//-----------------------------------------------------------------------
GtpVisibility::VisibilityManager *OcclusionCullingSceneManager::GetVisibilityManager()
{
        return mVisibilityManager;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::InitVisibilityCulling(Camera *cam)
{
        // reset culling manager stats
        mVisibilityManager->GetCullingManager()->InitFrame(mVisualizeCulledNodes);

        // set depth pass flag before rendering
        mIsDepthPassPhase = mUseDepthPass;

        // item buffer needs full ambient lighting to use item colors as unique id
        if (mUseItemBuffer) 
        {
                mIsItemBufferPhase = true;
                setAmbientLight(ColourValue(1,1,1,1));
        }


        // set passes which are stored in render queue 
        // for rendering AFTER hierarchical culling, i.e., passes which need 
        // a special rendering order
        mLeavePassesInQueue = 0;

        // if we have the depth pass or use an item buffer, no passes are left in the queue
        if (0 && !mUseDepthPass && !mUseItemBuffer)
        {
                if (mShadowTechnique == SHADOWTYPE_STENCIL_ADDITIVE)
                {
                        // TODO: remove this pass because it should be processed during hierarchical culling
                        //mLeavePassesInQueue |= RenderPriorityGroup::SOLID_PASSES_NOSHADOW;

                        mLeavePassesInQueue |= RenderPriorityGroup::SOLID_PASSES_DECAL;
                        mLeavePassesInQueue |= RenderPriorityGroup::SOLID_PASSES_DIFFUSE_SPECULAR;
                        mLeavePassesInQueue |= RenderPriorityGroup::TRANSPARENT_PASSES;

                        // just render ambient stuff
                        mIlluminationStage = IRS_AMBIENT;
                }
        
                if (mShadowTechnique == SHADOWTYPE_STENCIL_MODULATIVE)
                {
                        mLeavePassesInQueue |= RenderPriorityGroup::SOLID_PASSES_NOSHADOW;
                        mLeavePassesInQueue |= RenderPriorityGroup::TRANSPARENT_PASSES;
                }
        
                // transparents should be rendered after hierarchical culling to 
                // provide front-to-back ordering
                if (mDelayRenderTransparents)
                {
                        mLeavePassesInQueue |= RenderPriorityGroup::TRANSPARENT_PASSES;
                }
        }

        // skip rendering transparents in the hierarchical culling
        // (because they will be rendered afterwards)
        mSkipTransparents = mUseDepthPass || 
                (mLeavePassesInQueue & RenderPriorityGroup::TRANSPARENT_PASSES);

        // -- initialise interface for rendering traversal of the hierarchy
        mHierarchyInterface->SetHierarchyRoot(mOctree);
        
        // possible two cameras (one for culling, one for rendering)
        mHierarchyInterface->InitTraversal(mCameraInProgress, 
                                                                           mCullCamera ? getCamera("CullCamera") : NULL,
                                                                           mLeavePassesInQueue);
                
}
//-----------------------------------------------------------------------
OctreeHierarchyInterface *OcclusionCullingSceneManager::GetHierarchyInterface()
{
        return mHierarchyInterface;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::endFrame()
{
        TerrainRenderable::ResetRenderLevelIndex();
}
//-----------------------------------------------------------------------
Entity* OcclusionCullingSceneManager::createEntity(const String& entityName, 
                                                                                                        const String& meshName)
{
        Entity *ent = SceneManager::createEntity(entityName, meshName);

        for (int i = 0; i < (int)ent->getNumSubEntities(); ++i)
        {
                ent->getSubEntity(i)->setId(mCurrentEntityId);
        }

        // increase counter of entity id values
        ++ mCurrentEntityId;

        return ent;
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::renderAdditiveStencilShadowedQueueGroupObjects(RenderQueueGroup* pGroup)
{
        // only render solid passes during hierarchical culling
        if (mIsHierarchicalCulling)
        {
                RenderQueueGroup::PriorityMapIterator groupIt = pGroup->getIterator();
            LightList lightList;

                while (groupIt.hasMoreElements())
                {
                        RenderPriorityGroup* pPriorityGrp = groupIt.getNext();

                        // Sort the queue first
                        pPriorityGrp->sort(mCameraInProgress);

                        // Clear light list
                        lightList.clear();

                        // Render all the ambient passes first, no light iteration, no lights
                        mIlluminationStage = IRS_AMBIENT;

                        OctreeSceneManager::renderObjects(pPriorityGrp->_getSolidPasses(), false, &lightList);
                        // Also render any objects which have receive shadows disabled
                        OctreeSceneManager::renderObjects(pPriorityGrp->_getSolidPassesNoShadow(), true);
                }
        }
        else
        {
                OctreeSceneManager::renderAdditiveStencilShadowedQueueGroupObjects(pGroup);
        }
}
//-----------------------------------------------------------------------
void OcclusionCullingSceneManager::renderModulativeStencilShadowedQueueGroupObjects(RenderQueueGroup* pGroup)
{
   if (mIsHierarchicalCulling)
   {
           // Iterate through priorities
           RenderQueueGroup::PriorityMapIterator groupIt = pGroup->getIterator();

           while (groupIt.hasMoreElements())
           {
                   RenderPriorityGroup* pPriorityGrp = groupIt.getNext();

                   // Sort the queue first
                   pPriorityGrp->sort(mCameraInProgress);

                   // Do (shadowable) solids
                   OctreeSceneManager::renderObjects(pPriorityGrp->_getSolidPasses(), true);
           }
   }
   else
   {
           SceneManager::renderModulativeStencilShadowedQueueGroupObjects(pGroup);
   }
}


MovableObject *OcclusionCullingSceneManager::FindCorrespondingObject(const AxisAlignedBox &box)
{
        list<SceneNode *> sceneNodeList;

        findNodesIn(box, sceneNodeList, NULL);

        list<SceneNode *>::const_iterator sit, sit_end = sceneNodeList.end();

        bool overlap = false;

        MovableObject *bestFittingObj = NULL;
        float bestFit = 0.0;
        
        // find the bbox which is closest to the current bbox
        for (sit = sceneNodeList.begin(); sit != sceneNodeList.end(), !overlap; ++ sit)
        {
                SceneNode *sn = *sit;
                SceneNode::ObjectIterator oit = sn->getAttachedObjectIterator();

        while (oit.hasMoreElements())
                {
                         MovableObject *mo = oit.getNext();
                         const AxisAlignedBox bbox = mo->getWorldBoundingBox();
                         
                         const float overlap = GtpVisibilityPreprocessor::FactorOfOverlap(
                                 OgreTypeConverter::ConvertFromOgre(bbox), 
                                 OgreTypeConverter::ConvertFromOgre(box));

                         if (overlap > bestFit)
                         {
                                 bestFit = overlap;
                                 bestFittingObj = mo;

                                 // perfect fit => object found
                                 if (overlap > (1.0 - GtpVisibilityPreprocessor::Limits::Small))
                                        break;
                         }
                }
        }

        return bestFittingObj;
}


void OcclusionCullingSceneManager::LoadViewCells(string filename)
{
        GtpVisibilityPreprocessor::ObjectContainer objects;
        // identify the corresponding Ogre meshes using the bounding boxes
        IdentifyObjects(objects);

        // load the view cells assigning the found objects to the pvss
        mViewCellsManager->LoadViewCells(filename, &objects);
}


void OcclusionCullingSceneManager::IdentifyObjects(GtpVisibilityPreprocessor::ObjectContainer &objects)
{
        const string bboxesFilename = "boxes.out";

        GtpVisibilityPreprocessor::IndexedBoundingBoxContainer iboxes;
        mViewCellsManager->LoadBoundingBoxes(bboxesFilename, iboxes);

        GtpVisibilityPreprocessor::IndexedBoundingBoxContainer::
                const_iterator iit, iit_end = iboxes.end();

        for (iit = iboxes.begin(); iit != iit_end; ++ iit)
        {
                  const GtpVisibilityPreprocessor::AxisAlignedBox3 box = (*iit).second;
                  const AxisAlignedBox currentBox = OgreTypeConverter::ConvertToOgre(box);
                  
                  MovableObject *mo = FindCorrespondingObject(currentBox);

                  //objects.push_back(mi);
        }
}

} // namespace Ogre