source: GTP/trunk/Lib/Vis/Preprocessing/src/GvsPreprocessor.cpp @ 1492

#include "Environment.h"
#include "GvsPreprocessor.h"
#include "GlRenderer.h"
#include "VssRay.h"
#include "ViewCellsManager.h"
#include "Triangle3.h"
#include "IntersectableWrapper.h"


namespace GtpVisibilityPreprocessor
{
  

GvsPreprocessor::GvsPreprocessor(): Preprocessor(), mSamplingType(0)
{
        Environment::GetSingleton()->GetIntValue("GvsPreprocessor.totalSamples", mTotalSamples);
        Environment::GetSingleton()->GetIntValue("GvsPreprocessor.initialSamples", mInitialSamples);
        Environment::GetSingleton()->GetIntValue("GvsPreprocessor.samplesPerPass", mSamplesPerPass);
        Environment::GetSingleton()->GetFloatValue("GvsPreprocessor.epsilon", mEps);
                

        Debug << "Gvs preprocessor options" << endl;
        Debug << "number of total samples: " << mTotalSamples << endl;
        Debug << "number of initial samples: " << mInitialSamples << endl;
        Debug << "number of samples per pass: " << mSamplesPerPass << endl;

        mStats.open("gvspreprocessor.log");
}


const bool GvsPreprocessor::DiscontinuityFound(const VssRay &ray, 
                                                                                           const VssRay &oldRay) const
{
        //|predicted(x)-xp|-|hit(x)-xp| > ?,
    //const Plane3 plane = tri->GetPlane();
        return false;
}


int GvsPreprocessor::HandleRay(const GvsRayInfo &gvsRay)
{
        VssRay *ray = gvsRay.mRay;

        if (!mViewCellsManager->ComputeSampleContribution(*ray, true, false))
                return 1;

        if (gvsRay.mFoundDiscontinuity)
        {
                return ReverseSampling(*ray);
        }
        else
        {
                return AdaptiveBorderSampling(*ray);
        }
}

/** Hepler function for adaptive border sampling. It finds 
        new sample points around a triangle in a eps environment
*/
static void CreateNewRays(SimpleRayContainer &simpleRays, 
                                                  const Triangle3 &hitTriangle,
                                                  const VssRay &ray, 
                                                  const int index,
                                                  const float eps)
{
        const int indexU = (index + 1) % 3;
        const int indexL = (index == 0) ? 2 : index - 1;

        const Vector3 a = hitTriangle.mVertices[index] - ray.GetDir();
        const Vector3 b = hitTriangle.mVertices[indexU] - hitTriangle.mVertices[index];
        const Vector3 c = hitTriangle.mVertices[index] - hitTriangle.mVertices[indexL];
        
        const float len = Magnitude(a);

        const Vector3 dir1 = CrossProd(a, b); //N((pi-xp)×(pi+1- pi));
        const Vector3 dir2 = CrossProd(a, c); // N((pi-xp)×(pi- pi-1))
        const Vector3 dir3 = DotProd(dir1, dir2) > 0 ? 
                Normalize(dir2 + dir1) : Normalize(CrossProd(a, dir2) + CrossProd(dir1, a)); // N((pi-xp)×di,i-1+di,i+1×(pi-xp))

        // compute the new three hit points
        // pi, i + 1
        const Vector3 pt1 = hitTriangle.mVertices[index] + eps * len * dir1; //pi+ e·|pi-xp|·di, j
        // pi, i - 1
    const Vector3 pt2 = hitTriangle.mVertices[index] + eps * len * dir2; //pi+ e·|pi-xp|·di, j
        // pi, i
        const Vector3 pt3 = hitTriangle.mVertices[index] + eps * len * dir3; //pi+ e·|pi-xp|·di, j
        
        /// create simple rays and store them in container
        Vector3 rayDir;
        rayDir = Normalize(pt1 - ray.GetOrigin());
        simpleRays.push_back(SimpleRay(rayDir, ray.GetOrigin()));
        rayDir = Normalize(pt2 - ray.GetOrigin());
        simpleRays.push_back(SimpleRay(rayDir, ray.GetOrigin()));
        rayDir = Normalize(pt3 - ray.GetOrigin());
        simpleRays.push_back(SimpleRay(rayDir, ray.GetOrigin()));
}



int GvsPreprocessor::AdaptiveBorderSampling(const VssRay &prevRay)
{
        cout << "a";
        Intersectable *tObj = prevRay.mTerminationObject;
        Triangle3 hitTriangle;

        // other types not implemented yet
        if (tObj->Type() == Intersectable::TRIANGLE_INTERSECTABLE)
        {
                hitTriangle = dynamic_cast<TriangleIntersectable *>(tObj)->GetItem();
        }

        SimpleRayContainer simpleRays;
        simpleRays.reserve(9);

        CreateNewRays(simpleRays, hitTriangle, prevRay, 0, mEps);
        CreateNewRays(simpleRays, hitTriangle, prevRay, 1, mEps);
        CreateNewRays(simpleRays, hitTriangle, prevRay, 2, mEps);

        VssRayContainer vssRays;
        
        CastRays(simpleRays, vssRays);
        // add to ray queue
        EnqueueRays(vssRays);

        return (int)vssRays.size();
}


int GvsPreprocessor::ReverseSampling(const VssRay &oldRay)
{
        cout << "r" << endl;
        // TODO
        return 1;
}


int GvsPreprocessor::CastInitialSamples(const int numSamples, 
                                                                                const int sampleType)
{       
        const long startTime = GetTime();

        // generate simple rays
        SimpleRayContainer simpleRays;
        GenerateRays(numSamples, sampleType, simpleRays);
        
        // generate vss rays
        VssRayContainer samples;
        CastRays(simpleRays, samples);
        
        // add to ray queue
        EnqueueRays(samples);

        Debug << "generated " <<  numSamples << " samples in " << TimeDiff(startTime, GetTime()) * 1e-3 << " secs" << endl;

        return (int)samples.size();
}


void GvsPreprocessor::EnqueueRays(VssRayContainer &samples, VssRay *oldRay)
{
        // add samples to ray queue
        VssRayContainer::const_iterator vit, vit_end = samples.end();
        for (vit = samples.begin(); vit != vit_end; ++ vit)
        {
                /// if there is no old ray, no discontinuity
                const bool gap = oldRay ? DiscontinuityFound(*(*vit), *oldRay) : false;
                mRayQueue.push(GvsRayInfo(*vit, gap));
        }
}


int GvsPreprocessor::Pass()
{
        int castSamples = 0;
        const int mSampleType = 0;
        while (castSamples < mSamplesPerPass) 
        {
                // Ray queue empty => 
                // cast a number of uniform samples to fill ray Queue
                CastInitialSamples(mInitialSamples, mSampleType);

                const int gvsSamples = ProcessQueue();
                castSamples += gvsSamples;
                //cout << "\ncast " << castSamples << " of " << mSamplesPerPass << endl;
        }

        return castSamples;
}


int GvsPreprocessor::ProcessQueue()
{
        int castSamples = 0;

        while (!mRayQueue.empty()) 
        {
                // handle next ray
                GvsRayInfo rayInfo = mRayQueue.top();
                mRayQueue.pop();
                
                castSamples += HandleRay(rayInfo);
        }

        return castSamples;
}


bool GvsPreprocessor::ComputeVisibility()
{
        Randomize(0);
        const long startTime = GetTime();
        
        mViewSpaceBox = mKdTree->GetBox();
        cout << "Gvs Preprocessor started\n" << flush;
        
        if (!mLoadViewCells)
        {       /// construct the view cells from the scratch
                ConstructViewCells(mViewSpaceBox);
                cout << "view cells loaded" << endl;
        }

        int castSamples = 0;

        while (castSamples < mTotalSamples) 
        {
                const int passSamples = Pass();
                castSamples += passSamples;
                
                /////////////
                // -- stats
                cout << "+";
                cout << "\nsamples cast " << passSamples << " (=" << castSamples << " of " << mTotalSamples << ")" << endl;
                //mVssRays.PrintStatistics(mStats);
                mStats << "#Time\n" << TimeDiff(startTime, GetTime())*1e-3 << endl
                           << "#TotalSamples\n" << castSamples << endl;

                mViewCellsManager->PrintPvsStatistics(mStats);
                // ComputeRenderError();
        }

        return true;
}

}