source: trunk/VUT/GtpVisibilityPreprocessor/src/RenderSimulator.cpp @ 414

#include "RenderSimulator.h"
#include "KdTree.h"
#include "ViewCellBsp.h"
#include "ViewCell.h"

void SimulationStatistics::Print(ostream &app) const
{
        app << "===== Simulation statistics ===============\n";

        app << setprecision(4);

        app << "#N_CTIME  ( Simulation time [s] )\n" << Time() << " \n";

        app << "#MAX_COST ( maximal cost of a view cell )\n" << maxCost << "\n";

        app << "#MIN_COST ( minimal cost of a view cell )\n" << minCost << "\n";

        app << "#AVG_RENDER_TIME ( average render time )\n" << avgRenderTime << "\n";

        app << "#AVG_RENDER_TIME_NO_OVERHEAD ( average render time without overhead )\n" << avgRtWithoutOverhead << "\n";
        
        app << "===== END OF Simulation statistics ==========\n";
}

RenderSimulator::RenderSimulator()
{}

RenderSimulator::RenderSimulator(float objRenderCost, float vcOverhead, float moveSpeed):
mObjRenderCost(objRenderCost), mVcOverhead(vcOverhead), mMoveSpeed(moveSpeed)
{
}

/*****************************************************
 *     class ViewCellRenderSimulator implementation  *
 *****************************************************/

BspViewCellRenderSimulator::BspViewCellRenderSimulator(float objRenderCost, 
                                                                                           float vcOverhead, 
                                                                                           float moveSpeed,
                                                                                           BspTree *bspTree):
RenderSimulator(objRenderCost, vcOverhead, moveSpeed), mBspTree(bspTree)
{
}

Real BspViewCellRenderSimulator::SimulateRendering()
{
        mStat.Reset();
        mStat.Start();

        Real renderTime = 0;
        
        // overhead for loading the PVS of the view cells
        float loadPvsOverhead = 0;
        // probability that view point lies in a view cell
        float pInVcTotal = 0;
        // total probability that a view cell border is crossed
        float pCrossVcTotal = 0;

        // collect all view cells
        ViewCellContainer viewCells;
        mBspTree->CollectViewCells(viewCells);

        ViewCellContainer::const_iterator it, it_end = viewCells.end();

        // surface area substitute for probability
        PolygonContainer geom;

        for (it = viewCells.begin(); it != it_end; ++ it)
        {
                // compute view cell area
                mBspTree->ConstructGeometry(dynamic_cast<BspViewCell *>(*it), geom);
                const float area = Polygon3::GetArea(geom);
                CLEAR_CONTAINER(geom);

                // area substitute for view point probability
                float pInVc = area;
                                
                // compute render time of PVS times probability that view point is in view cell
                float vcCost = pInVc * RenderPvs(*(*it), mObjRenderCost);
                
                renderTime += vcCost;

                if (vcCost > mStat.maxCost)
                        mStat.maxCost = vcCost;
                else if (vcCost < mStat.minCost)
                        mStat.minCost = vcCost;

                // probability that a view cell border is crossed
                float pCrossVc = area;

                // crossing the border of a view cell is also depending on the move speed
                loadPvsOverhead += pCrossVc * mVcOverhead * mMoveSpeed;

                pInVcTotal += pInVc;
                pCrossVcTotal += pCrossVc;
        }

        
        renderTime /= pInVcTotal;
        loadPvsOverhead /= pCrossVcTotal;

        mStat.avgRtWithoutOverhead = renderTime;
        mStat.avgRenderTime = renderTime + loadPvsOverhead;
        
        mStat.Stop();

        return renderTime + loadPvsOverhead;
}

Real BspViewCellRenderSimulator::RenderPvs(ViewCell &viewCell, 
                                                                           float objRenderTime) const
{
        return viewCell.GetPvs().GetSize() * objRenderTime;
}

/********************************************************
 *     class KdLeafRenderSimulator implementation       *
 *******************************************************/

KdViewCellRenderSimulator::KdViewCellRenderSimulator(float objRenderCost, 
                                                                                         float vcOverhead,
                                                                                         float moveSpeed,
                                                                                         KdTree *kdTree):
RenderSimulator(objRenderCost, vcOverhead, moveSpeed), mKdTree(kdTree)
{
}

Real KdViewCellRenderSimulator::SimulateRendering()
{
        //mKdTree->CollectLeavesPvs();
        mStat.Reset();
        mStat.Start();

        // total render time
        Real renderTime = 0;
        // overhead for loading a view cell
        float loadPvsOverhead = 0;

        // probability that view point lies in a view cell
        float pInVcTotal = 0;//mKdTree->GetBox().GetVolume();

        // total probability that a view cell border is crossed
        float pCrossVcTotal = 0;

        vector<KdLeaf *> leaves;
        mKdTree->CollectLeaves(leaves);
        
        AxisAlignedBox3 box;

        vector<KdLeaf *>::const_iterator it, it_end = leaves.end();
        
        for (it = leaves.begin(); it != it_end; ++ it)
        {
                box = mKdTree->GetBox(*it);
                        
                // volume substitute for view point probability
                float pInVc = 0;
                
                if (0)
                        pInVc = box.GetVolume(); 
                else
                        pInVc = box.SurfaceArea();
                
                // probability that a view cell border is crossed
                const float pCrossVc = box.SurfaceArea();

                float vcCost = pInVc * RenderPvs(*it, mObjRenderCost);
                renderTime += vcCost;

                if (vcCost > mStat.maxCost)
                        mStat.maxCost = vcCost;
                else if (vcCost < mStat.minCost)
                        mStat.minCost = vcCost;

                loadPvsOverhead += pCrossVc * mVcOverhead * mMoveSpeed;

                pInVcTotal += pInVc;
                pCrossVcTotal += pCrossVc;
        }

        Debug << "RT: " << renderTime << endl;
        Debug << "pvsOverhead: " << loadPvsOverhead << endl;


        renderTime /= pInVcTotal;
        loadPvsOverhead /= pCrossVcTotal;

    mStat.avgRtWithoutOverhead = renderTime;
        mStat.avgRenderTime = renderTime + loadPvsOverhead;
        
        mStat.Stop();

        return renderTime + loadPvsOverhead;
}

Real KdViewCellRenderSimulator::RenderPvs(KdLeaf *leaf, 
                                                                                   float objRenderTime) const
{
        return leaf->mKdPvs.GetSize() * objRenderTime;
}