void PhotonQuery::push_back(Photon const &data,
Photon::vector_type const &vDistance) {
tgir::Real const rCosTheta =
-hi::dot(data.dir(), pathVertex_.vGeometricNormal);
if (rCosTheta <= 0) {
return;
}
tgir::Vector3 const vPoint =
vDistance + data.dir() * hi::dot(vDistance, pathVertex_.vGeometricNormal);
tgir::Real const rDistanceSquared = hi::length_squared(vPoint);
if (rDistanceSquared >= PhotonQuery::max_search_range()) {
return;
}
#if 0 // フィルタをかけるか
#if 1 // コーンフィルタか
static tgir::Real const k = 1.1; // 円錐フィルタのパラメータ
tgir::Real const w = 1 - std::sqrt(rDistanceSquared) / (k * PhotonQuery::max_distance());
#else
static tgir::Real const alpha = 0.918; // ガウスフィルタのパラメータ
static tgir::Real const beta = 1.953;
tgir::Real const u = 1 - std::exp(-beta * rDistanceSquared / (2 * PhotonQuery::max_search_range()));
tgir::Real const s = 1 - std::exp(-beta);
tgir::Real const w = alpha * (1 - u / s);
#endif
rPower_ += data.pow() * w;
#else
rPower_ += data.pow();
#endif
}
Photon::Photon(const Photon& o) :
Worldline(o), SmartPointee(o),
object_(NULL),
freq_obs_(o.freq_obs_), transmission_freqobs_(o.transmission_freqobs_),
spectro_(NULL), transmission_(NULL)
{
if (o.object_()) {
object_ = o.object_ -> clone();
object_ -> metric(metric_);
}
if (o.spectro_()) {
spectro_ = o.spectro_ -> clone();
_allocateTransmission();
if (size_t nsamples = spectro_->nSamples())
memcpy(transmission_, o.getTransmission(), nsamples*sizeof(double));
}
}
PhotonMap* PhotonMap::PrecomputeIrradiance(int increment, const int N, const float maxDistance)
{
std::cout << "Precomputing irradiance" << std::endl;
PhotonMap *precomputed = new PhotonMap(MAX_PHOTON_COUNT);
for(int i = 0; i < (int)m_photons.size(); i += increment)
{
Photon p = m_photons[i];
p.Power(GetRadianceEstimate(N, maxDistance, m_photons[i].Position(), m_photons[i].SurfNormal()));
precomputed->AddPhoton(p);
}
precomputed->BalanceAndConstruct();
return precomputed;
}
void PhotonMap::Map::PrecomputeIrradianceEstimates(
unsigned int numThreads,
unsigned int threadNum,
float searchRadius,
unsigned int searchCount
) {
assert(finalized);
if (numPhotons > 0) {
static boost::mutex progressMutex;
const unsigned int photonsPerThread = numPhotons / numThreads;
const unsigned int photonsRemaining = numPhotons % photonsPerThread;
const unsigned int photonIdxL = (photonsPerThread * threadNum) + 1;
const unsigned int photonIdxR =
(photonsPerThread * (threadNum + 1)) +
((threadNum == (numThreads - 1))? photonsRemaining: 0);
const float photonRange = photonIdxR - photonIdxL;
unsigned int prevProgress = 0;
unsigned int currProgress = 0;
for (unsigned int photonIdx = photonIdxL; photonIdx <= photonIdxR; photonIdx++) {
Photon* p = &photonArray[photonIdx];
p->SetIrr(GetIrradianceEstimate(p->GetPos(), p->GetNrm(), searchRadius, searchCount, true));
currProgress = ((photonIdx - photonIdxL) / photonRange) * 100;
if ((currProgress > prevProgress) && ((currProgress % 10) == 0)) {
prevProgress = currProgress;
boost::mutex::scoped_lock lock(progressMutex);
std::cout << "[PhotonMap::Map::PrecomputeIrradiance]";
std::cout << " thread: " << threadNum << ", progress: " << currProgress << "%";
std::cout << " (photon " << (photonIdx - photonIdxL) << " of " << (photonIdxR - photonIdxL + 1) << ")";
std::cout << std::endl;
}
}
}
}
void
unittest::LineOnEllipseIntersection(){
Point3D centre(13,5,0);
double a = 3;
double b = 2;
ellipse e(centre, a, b);
Point3D position(1,3.005,0);
Vector3D momentum(1,0,0);
Photon testphoton;
testphoton.SetPosition(position);
testphoton.SetMomentum(momentum);
e.LineOnEllipseIntersection(testphoton);
}
void
unittest::Ellipse_Points3D(){
Point3D centre(13,5,0);
double a = 3;
double b = 2;
ellipse e(centre, a, b);
Point3D position(2,2,0);
Vector3D momentum(11,3,-1);
Photon testphoton;
testphoton.SetPosition(position);
testphoton.SetMomentum(momentum);
e.points3D(testphoton);
Test reader;
reader.PrintPoint(e.GetStorage().GetPoint());
reader.PrintPoint(e.GetStorage().GetPoint2());
}
void PhotonMapProperty::operator()(Photon const &photon) {
++nPhotons_;
tgir::Real const rPower = photon.pow();
rPowerAvg_ += rPower;
rPowerVar_ += hi::square_of(rPower);
if (rPowerMin_ > rPower) {
rPowerMin_ = rPower;
}
if (rPowerMax_ < rPower) {
rPowerMax_ = rPower;
}
}
void Surface::stop_photon(Photon& p)
{
if (p.is_valid()==false)
return;
if(isinf(_dCurvature))
{
p.valid=false;
return;
}
// flat case (intersect with z=0)
if (p.dz==0.)
{
// TODO
p.valid=false;
return;
}
double tmin=-p.z/p.dz;
if(_bIsFlat && (tmin<0.) )
{
// in the past of the photon
p.valid=false;
return;
}
// TODO optimise in case of spherical
// stop the photon in z=0
p.x+=tmin*p.dx;
p.y+=tmin*p.dy;
p.z=0.;
if(_bIsFlat || _bIsPerfect)
{
p.valid=update_auto_diameter(p.x,p.y);
return;
}
//compute the coef of the 2nd degree eq in t:
//the equation is t^2A+tB+C=0
// use p.z=0.
double dA=_dCurvature*(sqr(p.dx)+sqr(p.dy)+(_dConic+1.)*sqr(p.dz));
double dB=2.*(_dCurvature*(p.x*p.dx+p.y*p.dy)-p.dz);
double dC=_dCurvature*(sqr(p.x)+sqr(p.y));
double tfinal;
if (dA==0.)
{
if (dB==0.)
{
p.valid=false;
return;
}
//the equation is now : t*dB+dC=0 so:
tfinal=-dC/dB;
}
else //dA!=0
{
//solve the equation
double dB2=dB*dB;
double delta=dB2-4.*dC*dA;
if (delta<0.)
{
p.valid=false;
return;
}
double t1,t2;
if (delta!=dB2) // TODO enhance test
{
double sqrtDelta=sqrt(delta);
t1=(2.*dC)/(+sqrtDelta-dB);
t2=(2.*dC)/(-sqrtDelta-dB);
}
else
{
// delta~=dB2
// use approximate solution:
if (dB!=0.)
{
t1=-dC/dB;
t2=10.*t1; // to choose t1
}
else
{
p.valid=false; // bug if we are here
return;
}
}
// select t that gives the lowest abs(z)
//t1ok=abs(z+t1.*dz)<abs(z+t2.*dz); //oct ver
if (t1*t1<t2*t2) // todo optimize
tfinal=t1;
else
tfinal=t2;
}
// check if intersection is in the futur of the photon
if ( tmin+tfinal<0 )
{
p.valid=false;
return;
}
p.x+=p.dx*tfinal;
p.y+=p.dy*tfinal;
p.z+=p.dz*tfinal;
assert(p.is_valid());
p.valid=update_auto_diameter(p.x,p.y);
if(!_bIsAspheric)
return;
//aspheric mode
//p.x,p.y,p.z is already a good approximation of the surface (as a conic), but make some newton step
double x=p.x;
double y=p.y;
// double z=p.z;
double dOldT=0;
for(int iLoop=0;iLoop<NB_ITER_STOP_NEWTON;iLoop++)
{
//reproject z on aspheric curve
double zproj;
compute_z(x,y,zproj);
//compute normal on aspheric surface
double nx,ny,nz;
compute_normal(x,y,zproj,nx,ny,nz);
//compute the d value to have the plane x*nx+y*ny+z*nz+d=0
double d=-(x*nx+y*ny+zproj*nz);
//compute the intersect of this plane and the line defined by p (one newton step)
double t=(-d-p.x*nx-p.y*ny-p.z*nz)/(p.dx*nx+p.dy*ny+p.dz*nz); //TODO tester !=0
double distSQ=sqr(t-dOldT)*(sqr(p.dx)+sqr(p.dy)+sqr(p.dz));
x=p.x+t*p.dx;
y=p.y+t*p.dy;
double z=p.z+t*p.dz;
if(distSQ<sqr(RESOLUTION_STOP_NEWTON))
{
p.x=x;
p.y=y;
p.z=z;
p.valid=update_auto_diameter(p.x,p.y);
return;
}
dOldT=t;
}
//too many iterations
p.valid=false;
return;
}
void Surface::reflect_photon(Photon &p)
{
if (!p.is_valid())
return;
stop_photon(p);
if (!p.is_valid())
return;
if(_bIsPerfect)
{
//TODO optimise and merge tests
if(p.dz==0.) //no intersection
{
p.valid=false;
return;
}
//compute AP
if( (_dCurvature<CURVATURE_FLAT) && (_dCurvature>-CURVATURE_FLAT))
{
p.dz=-p.dz;
return; //flat mirror
}
double dFocal=0.5/_dCurvature;
double t=dFocal/p.dz;
double ax=p.dx*t;
double ay=p.dy*t;
double az=p.dz*t;
//TODO optimise tests with sign(t)
if(_dCurvature>0.)
{
if(p.dz>0.)
{
p.dx=+ax+p.x;
p.dy=+ay+p.y;
p.dz=-az-p.z;
}
else
{
p.dx=-ax-p.x;
p.dy=-ay-p.y;
p.dz=+az-p.z;
}
}
else
{
if(p.dz>0.)
{
p.dx=-ax-p.x;
p.dy=-ay-p.y;
p.dz=+az-p.z;
}
else
{
p.dx=+ax+p.x;
p.dy=+ay+p.y;
p.dz=-az-p.z;
}
}
return;
}
double nx,ny,nz;
compute_normal(p.x,p.y,p.z,nx,ny,nz);
// compute with the normal (nx,ny,nz)
double dRayonSq=sqr(nx)+sqr(ny)+sqr(nz);
assert(dRayonSq>0.);
double u=2.*(nx*p.dx+ny*p.dy+nz*p.dz)/dRayonSq;
p.dx-=nx*u;
p.dy-=ny*u;
p.dz-=nz*u;
}
void Surface::transmit_photon(Photon& p)
{
if (!p.is_valid())
return;
stop_photon(p);
if (!p.is_valid())
return;
if(_bIsPerfect)
{
//TODO optimise and merge tests
if(p.dz==0.) //no intersection
{
p.valid=false;
return;
}
//compute AP
if( (_dCurvature<CURVATURE_FLAT) && (_dCurvature>-CURVATURE_FLAT))
return; //flat lens
double dFocal=0.5/_dCurvature;
double t=dFocal/p.dz;
if(p.dz<0.)
t=-t;
double ax=p.dx*t;
double ay=p.dy*t;
double az=p.dz*t;
p.dx=ax-p.x;
p.dy=ay-p.y;
p.dz=az-p.z;
if(dFocal<0.)
{
p.dx=-p.dx;
p.dy=-p.dy;
p.dz=-p.dz;
}
return;
}
assert(_pMaterialNext!=0);
assert(_pMaterialPrev!=0);
double nx,ny,nz;
//compute the normal in p (center distance : ro)
double dRadiusSq=sqr(p.x)+sqr(p.y);
if (dRadiusSq!=0.)
{
compute_normal(p.x,p.y,p.z,nx,ny,nz);
Vector3D::normalize(nx,ny,nz);
}
else // at surface center or flat surface
{
nx=0.;
ny=0.;
nz=1.;
}
double u=nx*p.dx+ny*p.dy+nz*p.dz;
// compute with the normal (dx,dy,dz)
// u is the projection of I on the normal
//calcule de C1=u/I
double dC12=u*u/(sqr(p.dx)+sqr(p.dy)+sqr(p.dz));
double dRatioN=_pMaterialNext->index(p.lambda())/_pMaterialPrev->index(p.lambda()); //TODO store index and reuse
double denom=sqr(dRatioN)+dC12-1.;
if (denom<=0.)
{ // total reflexion
p.valid=false;
return;
}
double dT2T1=sqrt(dC12/denom);
double k=(1.-dT2T1)*u;
p.dx=nx*k+dT2T1*p.dx;
p.dy=ny*k+dT2T1*p.dy;
p.dz=nz*k+dT2T1*p.dz;
}
void LaserSource::reaction(Photon& photon, std::vector<std::vector<Photon>>& lightPaths)
{
photon.setVelocity(0.0);
}
void preprocess(const Scene *scene) {
/* Create a sample generator for the preprocess step */
Sampler *sampler = static_cast<Sampler *>(
NoriObjectFactory::createInstance("independent", PropertyList()));
Emitter* distantsDisk = scene->getDistantEmitter();
if(distantsDisk != nullptr ) {
float lngstDir = scene->getBoundingBox().getLongestDirection();
distantsDisk->setMaxRadius(lngstDir);
}
/* Allocate memory for the photon map */
m_photonMap = std::unique_ptr<PhotonMap>(new PhotonMap());
m_photonMap->reserve(m_photonCount);
/* Estimate a default photon radius */
if (m_photonRadius == 0)
m_photonRadius = scene->getBoundingBox().getExtents().norm() / 500.0f;
int storedPhotons = 0;
const std::vector<Emitter *> lights = scene->getEmitters();
int nLights = lights.size();
Color3f tp(1.0f, 1.0f, 1.0f);
cout << "Starting to create "<< m_photonCount << " photons!" << endl;
int percentDone= 0;
int onePercent = int(floor(m_photonCount / 100.0));
// create the expected number of photons
while(storedPhotons < m_photonCount) {
//uniformly sample 1 light (assuming that we only have area lights)
int var = int(std::min(sampler->next1D()*nLights, float(nLights) - 1.0f));
const areaLight* curLight = static_cast<const areaLight *> (lights[var]);
//sample a photon
Photon curPhoton;
Vector3f unQuantDir(0.0f,0.0f,0.0f);
curLight->samplePhoton(sampler, curPhoton, 1, nLights, unQuantDir);
Color3f alpha = curPhoton.getPower();
Color3f tp(1.0f, 1.0f, 1.0f);
//trace the photon
Intersection its;
Ray3f photonRay(curPhoton.getPosition(), unQuantDir);
m_shootedRays++;
if (scene->rayIntersect(photonRay, its)) {
while(true) {
const BSDF* curBSDF = its.mesh->getBSDF();
if (curBSDF->isDiffuse()) {
//store the photon
m_photonMap->push_back(Photon(
its.p /* Position */,
-photonRay.d /* Direction*/,
tp * alpha /* Power */
));
storedPhotons++;
}
if(!(storedPhotons < m_photonCount)) break;
BSDFQueryRecord query = BSDFQueryRecord(its.toLocal(-photonRay.d), Vector3f(0.0f), EMeasure::ESolidAngle);
Color3f fi = curBSDF->sample(query, sampler->next2D());
if(fi.maxCoeff() == 0.0f) break;
tp *= fi;
Vector3f wo = its.toWorld(query.wo);
photonRay = Ray3f(its.p, wo);
//ray escapes the scene
if (!scene->rayIntersect(photonRay, its)) break;
//stop critirium russian roulette
float q = tp.maxCoeff();
if(q < sampler->next1D()) break;
tp /= q;
}
}
if(onePercent != 0) {
if(storedPhotons % onePercent == 0){
int percent = int(floor(storedPhotons / onePercent));
if(percent % 10 == 0 && percentDone != percent){
percentDone = percent;
cout << percent << "%" << endl;
}
}
}
}
/* Build the photon map */
m_photonMap->build();
}
vector<Photon> selectPhotonsCMG(const Event & ev) {
const SingleVariableContainer<int> * gn = dynamic_cast<const SingleVariableContainer<int> *>(ev.findVariable("gn"));
const ArrayVariableContainer<float> * gn_px = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_px"));
const ArrayVariableContainer<float> * gn_py = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_py"));
const ArrayVariableContainer<float> * gn_pz = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_pz"));
const ArrayVariableContainer<float> * gn_en = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_en"));
const ArrayVariableContainer<int> * gn_idbits = dynamic_cast<const ArrayVariableContainer<int> *>(ev.findVariable("gn_idbits"));
const ArrayVariableContainer<float> * gn_chIso03 = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_chIso03"));
const ArrayVariableContainer<float> * gn_nhIso03 = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_nhIso03"));
const ArrayVariableContainer<float> * gn_gIso03 = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("gn_gIso03"));
const ArrayVariableContainer<float> * egn_sceta = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("egn_sceta"));
const ArrayVariableContainer<bool> * egn_isConv = dynamic_cast<const ArrayVariableContainer<bool> *>(ev.findVariable("egn_isConv"));
const ArrayVariableContainer<float> * egn_hoe = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("egn_hoe"));
const ArrayVariableContainer<float> * egn_sihih = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("egn_sihih"));
const ArrayVariableContainer<float> * egn_r9 = dynamic_cast<const ArrayVariableContainer<float> *>(ev.findVariable("egn_r9"));
const ArrayVariableContainer<int> * pidC = dynamic_cast<const ArrayVariableContainer<int> *>(ev.findVariable("gn_pid"));
vector<Photon> photons;
for ( int i = 0; i < gn->getVal(); ++i ) {
Photon tmpPhoton;
tmpPhoton.addFloatVar( gn_px->getName(), gn_px->getVal(i) );
tmpPhoton.addFloatVar( gn_py->getName(), gn_py->getVal(i) );
tmpPhoton.addFloatVar( gn_pz->getName(), gn_pz->getVal(i) );
tmpPhoton.addFloatVar( gn_en->getName(), gn_en->getVal(i) );
tmpPhoton.addIntVar( gn_idbits->getName(), gn_idbits->getVal(i) );
tmpPhoton.addFloatVar( gn_chIso03->getName(), gn_chIso03->getVal(i) );
tmpPhoton.addFloatVar( gn_nhIso03->getName(), gn_nhIso03->getVal(i) );
tmpPhoton.addFloatVar( gn_gIso03->getName(), gn_gIso03->getVal(i) );
int pid = pidC->getVal(i);
tmpPhoton.addFloatVar( egn_sceta->getName(), egn_sceta->getVal(pid) );
tmpPhoton.addBoolVar( egn_isConv->getName(), egn_isConv->getVal(pid) );
tmpPhoton.addFloatVar( egn_hoe->getName(), egn_hoe->getVal(pid) );
tmpPhoton.addFloatVar( egn_sihih->getName(), egn_sihih->getVal(pid) );
tmpPhoton.addFloatVar( egn_r9->getName(), egn_r9->getVal(pid) );
photons.push_back(tmpPhoton);
}
return photons;
}
void GameScreen::calculatePath()
{
/*
std::map<int, std::shared_ptr<Equipment>>::iterator it_on_grid = tool_manager.equipments_on_grid_.begin();
for(; it_on_grid!=tool_manager.equipments_on_grid_.end(); it_on_grid ++)
{
(*it_on_grid).second->lightOff();
}
*/
for(int i = 0; i != GameScreen::tool_manager.my_targets_.size(); i++)
{
GameScreen::tool_manager.my_targets_[i]->lightOff();
}
GameScreen::tool_manager.my_targets_[0]->lightOff();
sf::FloatRect windowRect(MARGIN, MARGIN, GRID_WIDTH*(BLOCK_SIZE), GRID_HEIGHT*(BLOCK_SIZE));
if(lightPaths.size() == 0)
{
for(int i = 0; i != tool_manager.my_lasers_.size(); i++)
{
std::vector<Photon> lightPath;
lightPath.push_back(tool_manager.my_lasers_[i].getPhoton());
lightPaths.push_back(lightPath);
}
}
for(int i = 0; i != lightPaths.size(); i++)
{
Photon current = lightPaths[i].back();
while(current.getVelocity() != 0.0 && windowRect.contains(current.getPosition()))
{
Photon nextPhoton = current;
int idx = nextPhoton.getIndex();
if(tool_manager.equipments_on_grid_.count(idx) > 0)
{
tool_manager.equipments_on_grid_[idx]->reaction(nextPhoton, lightPaths);
lightPaths[i].push_back(nextPhoton);
}
else
{
nextPhoton.myMove();
lightPaths[i].push_back(nextPhoton);
}
current = nextPhoton;
}
}
bool isAllHit = true;
/*
it_on_grid = tool_manager.equipments_on_grid_.begin();
for(; it_on_grid!=tool_manager.equipments_on_grid_.end(); it_on_grid ++)
{
if(!(*it_on_grid).second->isHit())
{
isAllHit = false;
break;
}
}
*/
for(int i = 0; i != GameScreen::tool_manager.my_targets_.size(); i++)
{
if(!GameScreen::tool_manager.my_targets_[0]->isHit())
{
isAllHit = false;
break;
}
}
if(isAllHit)
{
std::cout<<"all hit"<<std::endl;
}
}
void MCMLModel::DoOneRun (long numPhotonsSet) {
Photon photon;
for (long i = 0; i < numPhotonsSet; i++) {
photon.RunOnePhoton(this);
}
}
// ======================================================================
// During ray tracing, when a diffuse (or partially diffuse) object is
// hit, gather the nearby photons to approximate indirect illumination
bool comparePhotons(const Photon& p1,const Photon& p2)
{
double dis1 = (p1.getPosition()-p1.getPoint()).Length();
double dis2 = (p2.getPosition()-p2.getPoint()).Length();
return dis1<dis2;
}
// combines "tauint" (used to find the location of the
// forced first scattering event) and "tauint2" (used
// to find subsequent scattering positions within the
// grid from RANDOM optical depths)
bool Grid::Integrate(Photon& p, cfloat tau, IntegrateMode im) const {
bool ret = true;
float taurun = 0.0f, taucell = 0.0f;
float dtmp = 0.0f, dpath = 0.0f, dcell = 0.0f;
// translate by half the grid's represented dimensions
// (so pcur corresponds to the photon cell indices)
vec3 pcur = p.pos + hsize;
int celli = p.xcell;
int cellj = p.ycell;
int cellk = p.zcell;
#ifdef DEBUG
assert(IndicesInBounds(celli, cellj, cellk));
#endif
cfloat dsx = GetMaxXDistance(p, pcur); float dx = 0.0f;
cfloat dsy = GetMaxYDistance(p, pcur); float dy = 0.0f;
cfloat dsz = GetMaxZDistance(p, pcur); float dz = 0.0f;
cfloat dmax = std::min(std::min(dsx, dsy), dsz);
if (dmax < .001f) {
return false;
}
// start the path integration
while (taurun < tau && dpath < dmax * 0.999f) {
if (p.dir.x > 0.0f) {
dx = (xfaces[celli + 1] - pcur.x) / p.dir.x;
if (dx < EPSILON) {
pcur.x = xfaces[celli + 1];
celli += 1;
dx = (xfaces[celli + 1] - pcur.x) / p.dir.x;
}
} else if (p.dir.x < 0.0f) {
dx = (xfaces[celli] - pcur.x) / p.dir.x;
if (dx < EPSILON) {
pcur.x = xfaces[celli];
dx = (xfaces[celli - 1] - pcur.x) / p.dir.x;
celli -= 1;
}
} else if (p.dir.x == 0.0f) {
dx = hsize.x * 10000.0f;
}
if (p.dir.y > 0.0f) {
dy = (yfaces[cellj + 1] - pcur.y) / p.dir.y;
if (dy < EPSILON) {
pcur.y = yfaces[cellj + 1];
cellj += 1;
dy = (yfaces[cellj + 1] - pcur.y) / p.dir.y;
}
} else if (p.dir.y < 0.0f) {
dy = (yfaces[cellj] - pcur.y) / p.dir.y;
if (dy < EPSILON) {
pcur.y = yfaces[cellj];
dy = (yfaces[cellj - 1] - pcur.y) / p.dir.y;
cellj -= 1;
}
} else if (p.dir.y == 0.0f) {
dy = hsize.y * 10000.0f;
}
if (p.dir.z > 0.0f) {
dz = (zfaces[cellk + 1] - pcur.z) / p.dir.z;
if (dz < EPSILON) {
pcur.z = zfaces[cellk + 1];
cellk += 1;
dz = (zfaces[cellk + 1] - pcur.z) / p.dir.z;
}
} else if (p.dir.z < 0.0f) {
dz = (zfaces[cellk] - pcur.z) / p.dir.z;
if (dz < EPSILON) {
pcur.z = zfaces[cellk];
dz = (zfaces[cellk - 1] - pcur.z) / p.dir.z;
cellk -= 1;
}
} else if (p.dir.z == 0.0f) {
dz = hsize.z * 10000.0f;
}
// distances can be zero if we
// are right on a cell boundary
if (dx == 0.0f || fabs(dx) < .001f) { dx = hsize.x * 10000.0f; }
if (dy == 0.0f || fabs(dy) < .001f) { dy = hsize.y * 10000.0f; }
if (dz == 0.0f || fabs(dz) < .001f) { dz = hsize.z * 10000.0f; }
// find distance to next cell wall
// (minimum value of dx, dy, and dz)
dcell = std::min(std::min(dx, dy), dz);
if (dx < 0.0f) { dcell = std::min(dy, dz); }
if (dy < 0.0f) { dcell = std::min(dx, dz); }
if (dz < 0.0f) { dcell = std::min(dx, dy); }
// if moving through a "thicker" region of the grid
// where the cells are denser, we reach tau quicker
taucell = dcell * rhokappa[celli][cellj][cellk];
// (if taurun + taucell > tau) then the photon's next
// interaction event will be at distance d + dtmp, so
// update photon position and cell indices; otherwise
// photon moves over a distance dcell to the next cell
// wall
if (taurun + taucell >= tau) {
dtmp = (tau - taurun) / rhokappa[celli][cellj][cellk];
dpath += dtmp;
taurun += taucell;
pcur += (p.dir * dtmp);
} else {
dpath += dcell;
taurun += taucell;
pcur += (p.dir * dcell);
}
if (!GPosInBounds(pcur)) {
// fight numerical inaccuracy
ClampGPos(pcur);
}
celli = GetXCellIdx(pcur.x - hsize.x); // GetXCellIdx() already adds hsize.x to x!
cellj = GetYCellIdx(pcur.y - hsize.y); // GetYCellIdx() already adds hsize.y to y!
cellk = GetZCellIdx(pcur.z - hsize.z); // GetZCellIdx() already adds hsize.z to z!
#ifdef DEBUG
assert(IndicesInBounds(celli, cellj, cellk));
#endif
}
switch (im) {
case IM_RANDOM: {
if (dpath >= dmax * 0.999f) {
// photon escapes grid
ret = false;
} else {
// photon stays inside, update
// its pos and cell indices to
// the next interaction coords
p.UpdatePos(dpath);
if (!RPosInBounds(p.pos)) {
// fight numerical inaccuracy
ClampRPos(p.pos);
}
p.UpdateCellIndices(*this);
}
} break;
case IM_FORCED: {
p.pos = pcur - hsize;
if (!RPosInBounds(p.pos)) {
// fight numerical inaccuracy
ClampRPos(p.pos);
}
p.UpdateCellIndices(*this);
} break;
}
return ret;
}