/// <summary>
/// method to move the photon to its next location
/// </summary>
/// <param name="distance"></param>
/// <returns></returns>
public bool Move(double distance)
{
bool willHitBoundary = S >= distance;
if (willHitBoundary)
{
AdjustTrackLength(distance);
}
DP.Position.X += S * DP.Direction.Ux;
DP.Position.Y += S * DP.Direction.Uy;
DP.Position.Z += S * DP.Direction.Uz;
DP.TotalTime += DetectorBinning.GetTimeDelay(S, _tissue.Regions[CurrentRegionIndex].RegionOP.N);
CurrentTrackIndex++;
History.SubRegionInfoList[CurrentRegionIndex].PathLength += S;
// only increment number of collisions counter if NOT pseudo-collision
if (!willHitBoundary)
{
History.SubRegionInfoList[CurrentRegionIndex].NumberOfCollisions++;
}
History.AddDPToHistory(DP);
return(willHitBoundary);
}
/// <summary>
/// method to tally reflected photon by determining cumulative MT in each tissue subregion and binning in MT
/// </summary>
/// <param name="photon">Photon (includes HistoryData)</param>
public void Tally(Photon photon)
{
if (!IsWithinDetectorAperture(photon))
{
return;
}
// calculate the radial and time bin of reflected photon
var ir = DetectorBinning.WhichBin(DetectorBinning.GetRho(photon.DP.Position.X, photon.DP.Position.Y), Rho.Count - 1, Rho.Delta, Rho.Start);
for (int i = 0; i < NumSubregions; i++)
{
var timeInSubRegion = DetectorBinning.GetTimeDelay(photon.History.SubRegionInfoList[i].PathLength,
_tissue.Regions[i].RegionOP.N);
// make sure floating point round in Photon's update to S and subsequently to PathLength in SRIL doesn't get tallied
if (timeInSubRegion > 1e-14)
{
var it = DetectorBinning.WhichBin(timeInSubRegion, Time.Count - 1, Time.Delta, Time.Start);
// tally Continuous Absorption Weighting (CAW)
var tally = Math.Exp(-_tissue.Regions[i].RegionOP.Mua * photon.History.SubRegionInfoList[i].PathLength);
Mean[ir, i, it] += tally;
if (TallySecondMoment)
{
SecondMoment[ir, i, it] += tally * tally;
}
}
}
TallyCount++;
}