src/rcrt/gi/PhotonKDTree.cpp

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#include "PhotonKDTree.h"
#include <algorithm>
#include <boost/bind.hpp>

using namespace std;

namespace rcrt
{


PhotonKDTree::PhotonKDTree(const float& maxRad):
        photons(0), maxSqrRadius(maxRad), root(0), empty(true)
{
}

PhotonKDTree::~PhotonKDTree()
{
        if(root) delete root;
}

bool PhotonKDTree::splitPlaneCompare(PKDSplitPlane* a, PKDSplitPlane* b)
{
        return a->p->getPos()[a->axis] <= b->p->getPos()[b->axis];
}

void PhotonKDTree::buildTree(vector<Photon*>* phots)
{
        if(phots->size() > 0)
                empty = false;
        else
                return;
        photons = phots;
        std::list<PKDSplitPlane*>* splitPlanes = new std::list<PKDSplitPlane*>();
        //calculate BoundingBox and generate list of potential splits
        Point3D minP(numeric_limits<float>::infinity());
        Point3D maxP(-numeric_limits<float>::infinity());
        unsigned int i = 0; 
        if(photons->size() % 2 != 0){
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), X_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), Y_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), Z_AXIS));
                minP = photons->at(i)->getPos();
                maxP = photons->at(i)->getPos();
                i++;
        }
        for(; i < photons->size(); i += 2){
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), X_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), Y_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i), Z_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i+1), X_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i+1), Y_AXIS));
                splitPlanes->push_back(new PKDSplitPlane(photons->at(i+1), Z_AXIS));
                Point3D tmpMin(photons->at(i)->getPos());
                Point3D tmpMax(photons->at(i+1)->getPos());
                for(int k = 0; k < 3; k++){
                        if(tmpMin[k] > tmpMax[k]){
                                std::swap(tmpMin[k], tmpMax[k]);
                        }
                        if(tmpMin[k] < minP[k])
                                minP[k] = tmpMin[k];
                        if(tmpMax[k] > maxP[k])
                                maxP[k] = tmpMax[k];
                }
        }
        AABB bbox(minP, maxP);
        //sort list of potential splitting planes
        splitPlanes->sort(splitPlaneCompare);
        root = new PKDNode(splitPlanes, maxSqrRadius, bbox);
        cout << "built tree" << endl;
}


void PhotonKDTree::getKNearest(std::vector<PKDSearchP>* result, const unsigned int& k,
                        const Point3D& pos, const Vec3D& normal, const float& radiusSqr,
                        const float& flat) const
{
        if(empty)
                return;
        root->getKNearest(result, k, pos, normal, radiusSqr, flat);
}

}

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