/// <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 check for absorption according to analog random walk process
/// </summary>
public void AbsorbAnalog()
{
if (_rng.NextDouble() > _tissue.Regions[CurrentRegionIndex].RegionOP.Mus /
(_tissue.Regions[CurrentRegionIndex].RegionOP.Mus +
_tissue.Regions[CurrentRegionIndex].RegionOP.Mua))
{
DP.StateFlag = DP.StateFlag.Add(PhotonStateType.Absorbed);
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
History.AddDPToHistory(DP);
}
}
/// <summary>
/// Method to test for death of the photon
/// </summary>
public void TestDeath()
{
TestWeightAndDistance();
// if VB crossing flagged
if (DP.StateFlag.HasFlag(PhotonStateType.PseudoDiffuseReflectanceVirtualBoundary) ||
DP.StateFlag.HasFlag(PhotonStateType.PseudoDiffuseTransmittanceVirtualBoundary) ||
DP.StateFlag.HasFlag(PhotonStateType.PseudoSpecularReflectanceVirtualBoundary))
{
//todo: revisit performance of the bitwise operations
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
History.AddDPToHistory(DP);
}
}
/// <summary>
/// Method that kills photon due to Russian Roulette, maximum path length, etc.
/// </summary>
public void TestWeightAndDistance()
{
// kill by RR if weight < user-input WEIGHT_LIMIT (=0.0 then no RR)
if (DP.Weight < _russianRouletteWeightThreshold)
{
if (DP.Weight == 0.0)
{
DP.StateFlag = DP.StateFlag.Add(PhotonStateType.KilledRussianRoulette);
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
}
else if (_rng.NextDouble() < CHANCE)
{
DP.Weight = DP.Weight / CHANCE;
}
else
{
DP.StateFlag = DP.StateFlag.Add(PhotonStateType.KilledRussianRoulette);
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
}
if (DP.StateFlag.HasFlag(PhotonStateType.KilledRussianRoulette))
{
History.AddDPToHistory(DP);
}
}
else
{
// kill photon if it has had too many collisions
if (History.HistoryData.Count >= MAX_HISTORY_PTS)
{
DP.StateFlag = DP.StateFlag.Add(PhotonStateType.KilledOverMaximumCollisions);
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
History.AddDPToHistory(DP);
}
// kill photon if it has gone too far
if (DP.TotalTime >= MAX_PHOTON_TIME)
{
DP.StateFlag = DP.StateFlag.Add(PhotonStateType.KilledOverMaximumPathLength);
DP.StateFlag = DP.StateFlag.Remove(PhotonStateType.Alive);
History.AddDPToHistory(DP);
}
}
}
