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// $Id: G4TrajectoryDrawerUtils.cc 107920 2017-12-13 08:06:00Z gcosmo $
//
// Jane Tinslay, John Allison, Joseph Perl November 2005
//
#include "G4TrajectoryDrawerUtils.hh"
#include "G4Colour.hh"
#include "G4Polyline.hh"
#include "G4Polymarker.hh"
#include "G4VTrajectory.hh"
#include "G4VTrajectoryPoint.hh"
#include "G4VisAttributes.hh"
#include "G4VisTrajContext.hh"
#include "G4VVisManager.hh"
#include "G4UIcommand.hh"
#include "G4AttValue.hh"

namespace G4TrajectoryDrawerUtils {

  enum TimesValidity {InvalidTimes, ValidTimes};

  TimesValidity GetPointsAndTimes
  (const G4VTrajectory& traj,
   const G4VisTrajContext& context,
   G4Polyline& trajectoryLine,
   G4Polymarker& auxiliaryPoints,
   G4Polymarker& stepPoints,
   std::vector<G4double>& trajectoryLineTimes,
   std::vector<G4double>& auxiliaryPointTimes,
   std::vector<G4double>& stepPointTimes)
  {
    TimesValidity validity = InvalidTimes;
    if (context.GetTimeSliceInterval()) validity = ValidTimes;

    // Memory for last trajectory point position for auxiliary point
    // time interpolation algorithm.  There are no auxiliary points
    // for the first trajectory point, so its initial value is
    // immaterial.
    G4ThreeVector lastTrajectoryPointPosition;

    // Keep positions.  Don't store unless first or different.
    std::vector<G4ThreeVector> positions;

    for (G4int iPoint=0; iPoint<traj.GetPointEntries(); iPoint++) {

      G4VTrajectoryPoint* aTrajectoryPoint = traj.GetPoint(iPoint);
      const G4ThreeVector& trajectoryPointPosition =
	aTrajectoryPoint->GetPosition();

      // Only store if first or if different
      if (positions.size() == 0 ||
	  trajectoryPointPosition != positions[positions.size()-1]) {

	// Pre- and Post-Point times from the trajectory point...
	G4double trajectoryPointPreTime = -std::numeric_limits<double>::max();
	G4double trajectoryPointPostTime = std::numeric_limits<double>::max();

	if (context.GetTimeSliceInterval() && validity == ValidTimes) {

	  std::vector<G4AttValue>* trajectoryPointAttValues =
	    aTrajectoryPoint->CreateAttValues();
	  if (!trajectoryPointAttValues) {
	    static G4bool warnedNoAttValues = false;
	    if (!warnedNoAttValues) {
	      G4cout <<
  "*************************************************************************"
  "\n*  WARNING: G4TrajectoryDrawerUtils::GetPointsAndTimes: no att values."
  "\n*************************************************************************"
		     << G4endl;
	      warnedNoAttValues = true;
	    }
	    validity = InvalidTimes;
	  } else {
	    G4bool foundPreTime = false, foundPostTime = false;
	    for (std::vector<G4AttValue>::iterator i =
		   trajectoryPointAttValues->begin();
		 i != trajectoryPointAttValues->end(); ++i) {
	      if (i->GetName() == "PreT") {
		trajectoryPointPreTime =
		  G4UIcommand::ConvertToDimensionedDouble(i->GetValue());
		foundPreTime = true;
	      }
	      if (i->GetName() == "PostT") {
		trajectoryPointPostTime =
		  G4UIcommand::ConvertToDimensionedDouble(i->GetValue());
		foundPostTime = true;
	      }
	    }
	    if (!foundPreTime || !foundPostTime) {
	      static G4bool warnedTimesNotFound = false;
	      if (!warnedTimesNotFound) {
		G4cout <<
  "*************************************************************************"
  "\n*  WARNING: G4TrajectoryDrawerUtils::GetPointsAndTimes: times not found."
  "\n You need to specify \"/vis/scene/add/trajectories rich\""
  "\n*************************************************************************"
		       << G4endl;
		warnedTimesNotFound = true;
	      }
	      validity = InvalidTimes;
	    }
	  }
          delete trajectoryPointAttValues;  // (Must be deleted after use.)
	}

	const std::vector<G4ThreeVector>* auxiliaries
	  = aTrajectoryPoint->GetAuxiliaryPoints();
	if (0 != auxiliaries) {
	  for (size_t iAux=0; iAux<auxiliaries->size(); ++iAux) {
	    const G4ThreeVector& auxPointPosition = (*auxiliaries)[iAux];
	    if (positions.size() == 0 ||
		auxPointPosition != positions[positions.size()-1]) {
	      // Only store if first or if different
	      positions.push_back(trajectoryPointPosition);
	      trajectoryLine.push_back(auxPointPosition);
	      auxiliaryPoints.push_back(auxPointPosition);
	      if (validity == ValidTimes) {
		// Interpolate time for auxiliary points...
		G4double s1 =
		  (auxPointPosition - lastTrajectoryPointPosition).mag();
		G4double s2 =
		  (trajectoryPointPosition - auxPointPosition).mag();
		G4double t = trajectoryPointPreTime +
		  (trajectoryPointPostTime - trajectoryPointPreTime) *
		  (s1 / (s1 + s2));
		trajectoryLineTimes.push_back(t);
		auxiliaryPointTimes.push_back(t);
	      }
	    }
	  }
	}

	positions.push_back(trajectoryPointPosition);
	trajectoryLine.push_back(trajectoryPointPosition);
	stepPoints.push_back(trajectoryPointPosition);
	if (validity == ValidTimes) {
	  trajectoryLineTimes.push_back(trajectoryPointPostTime);
	  stepPointTimes.push_back(trajectoryPointPostTime);
	}
        lastTrajectoryPointPosition = trajectoryPointPosition;
      }
    }
    return validity;    
  }

  static void SliceLine(G4double timeIncrement,
			G4Polyline& trajectoryLine,
			std::vector<G4double>& trajectoryLineTimes)
  {
    // Assumes valid arguments from GetPoints and GetTimes.

    G4Polyline newTrajectoryLine;
    std::vector<G4double> newTrajectoryLineTimes;

    newTrajectoryLine.push_back(trajectoryLine[0]);
    newTrajectoryLineTimes.push_back(trajectoryLineTimes[0]);
    size_t lineSize = trajectoryLine.size();
    if (lineSize > 1) {
      for (size_t i = 1; i < trajectoryLine.size(); ++i) {
	G4double deltaT = trajectoryLineTimes[i] - trajectoryLineTimes[i - 1];
	if (deltaT > 0.) {
	  G4double practicalTimeIncrement = 
	    std::max(timeIncrement, deltaT / 100.);
	  for (G4double t =
		 (int(trajectoryLineTimes[i - 1]/practicalTimeIncrement) + 1) *
		 practicalTimeIncrement;
	       t <= trajectoryLineTimes[i];
	       t += practicalTimeIncrement) {
	    G4ThreeVector pos = trajectoryLine[i - 1] +
	      (trajectoryLine[i] - trajectoryLine[i - 1]) *
	      ((t - trajectoryLineTimes[i - 1]) / deltaT);
	    newTrajectoryLine.push_back(pos);
	    newTrajectoryLineTimes.push_back(t);
	  }
	}
	newTrajectoryLine.push_back(trajectoryLine[i]);
	newTrajectoryLineTimes.push_back(trajectoryLineTimes[i]);
      }
    }

    trajectoryLine = newTrajectoryLine;
    trajectoryLineTimes = newTrajectoryLineTimes;
  }

  static void DrawWithoutTime(const G4VisTrajContext& myContext,
			      G4Polyline& trajectoryLine,
			      G4Polymarker& auxiliaryPoints,
			      G4Polymarker& stepPoints)
  {
    // Draw without time slice information

    G4VVisManager* pVVisManager = G4VVisManager::GetConcreteInstance();
    if (0 == pVVisManager) return;
    
    if (myContext.GetDrawLine()) {
      G4VisAttributes trajectoryLineAttribs(myContext.GetLineColour());
      trajectoryLineAttribs.SetVisibility(myContext.GetLineVisible());
      trajectoryLine.SetVisAttributes(&trajectoryLineAttribs);

      pVVisManager->Draw(trajectoryLine);
    }
  
    if (myContext.GetDrawAuxPts() && (auxiliaryPoints.size() > 0)) {
      auxiliaryPoints.SetMarkerType(myContext.GetAuxPtsType());
      auxiliaryPoints.SetSize(myContext.GetAuxPtsSizeType(), myContext.GetAuxPtsSize());
      auxiliaryPoints.SetFillStyle(myContext.GetAuxPtsFillStyle());

      G4VisAttributes auxiliaryPointsAttribs(myContext.GetAuxPtsColour());  
      auxiliaryPointsAttribs.SetVisibility(myContext.GetAuxPtsVisible());
      auxiliaryPoints.SetVisAttributes(&auxiliaryPointsAttribs);

      pVVisManager->Draw(auxiliaryPoints);
    }
  
    if (myContext.GetDrawStepPts() && (stepPoints.size() > 0)) {
      stepPoints.SetMarkerType(myContext.GetStepPtsType());
      stepPoints.SetSize(myContext.GetStepPtsSizeType(), myContext.GetStepPtsSize());
      stepPoints.SetFillStyle(myContext.GetStepPtsFillStyle());

      G4VisAttributes stepPointsAttribs(myContext.GetStepPtsColour()); 
      stepPointsAttribs.SetVisibility(myContext.GetStepPtsVisible());
      stepPoints.SetVisAttributes(&stepPointsAttribs);

      pVVisManager->Draw(stepPoints);
    }
  }

  static void DrawWithTime(const G4VisTrajContext& myContext,
			   G4Polyline& trajectoryLine,
			   G4Polymarker& auxiliaryPoints,
			   G4Polymarker& stepPoints,
			   std::vector<G4double>& trajectoryLineTimes,
			   std::vector<G4double>& auxiliaryPointTimes,
			   std::vector<G4double>& stepPointTimes)
  {
    // Draw with time slice information

    G4VVisManager* pVVisManager = G4VVisManager::GetConcreteInstance();
    if (0 == pVVisManager) return;

    if (myContext.GetDrawLine()) {
      G4VisAttributes trajectoryLineAttribs(myContext.GetLineColour());
      trajectoryLineAttribs.SetVisibility(myContext.GetLineVisible());

      for (size_t i = 1; i < trajectoryLine.size(); ++i ) {
	G4Polyline slice;
	slice.push_back(trajectoryLine[i -1]);
	slice.push_back(trajectoryLine[i]);
	trajectoryLineAttribs.SetStartTime(trajectoryLineTimes[i - 1]);
	trajectoryLineAttribs.SetEndTime(trajectoryLineTimes[i]);
	slice.SetVisAttributes(&trajectoryLineAttribs);
	pVVisManager->Draw(slice);
      }
    }

    if (myContext.GetDrawAuxPts() && (auxiliaryPoints.size() > 0)) {
      G4VisAttributes auxiliaryPointsAttribs(myContext.GetAuxPtsColour());  
      auxiliaryPointsAttribs.SetVisibility(myContext.GetAuxPtsVisible());

      for (size_t i = 0; i < auxiliaryPoints.size(); ++i ) {
	G4Polymarker point;
	point.push_back(auxiliaryPoints[i]);
	point.SetMarkerType(myContext.GetAuxPtsType());
	point.SetSize(myContext.GetAuxPtsSizeType(), myContext.GetAuxPtsSize());
	point.SetFillStyle(myContext.GetAuxPtsFillStyle());
	auxiliaryPointsAttribs.SetStartTime(auxiliaryPointTimes[i]);
	auxiliaryPointsAttribs.SetEndTime(auxiliaryPointTimes[i]);
	point.SetVisAttributes(&auxiliaryPointsAttribs);
	pVVisManager->Draw(point);
      }
    }

    if (myContext.GetDrawStepPts() && (stepPoints.size() > 0)) {
      G4VisAttributes stepPointsAttribs(myContext.GetStepPtsColour()); 
      stepPointsAttribs.SetVisibility(myContext.GetStepPtsVisible());

      for (size_t i = 0; i < stepPoints.size(); ++i ) {
	G4Polymarker point;
	point.push_back(stepPoints[i]);
	point.SetMarkerType(myContext.GetStepPtsType());
	point.SetSize(myContext.GetStepPtsSizeType(), myContext.GetStepPtsSize());
	point.SetFillStyle(myContext.GetStepPtsFillStyle());
	stepPointsAttribs.SetStartTime(stepPointTimes[i]);
	stepPointsAttribs.SetEndTime(stepPointTimes[i]);
	point.SetVisAttributes(&stepPointsAttribs);
	pVVisManager->Draw(point);
      }
    }
  }

  void DrawLineAndPoints(const G4VTrajectory& traj, const G4VisTrajContext& context) 
  {
    // Return if don't need to do anything
    if (!context.GetDrawLine() && !context.GetDrawAuxPts() && !context.GetDrawStepPts()) return;
    
    // Get points and times (times are returned only if time-slicing
    // is requested).
    G4Polyline trajectoryLine;
    G4Polymarker stepPoints;
    G4Polymarker auxiliaryPoints;
    std::vector<G4double> trajectoryLineTimes;
    std::vector<G4double> stepPointTimes;
    std::vector<G4double> auxiliaryPointTimes;

    TimesValidity validity = GetPointsAndTimes
      (traj, context,
       trajectoryLine, auxiliaryPoints, stepPoints,
       trajectoryLineTimes, auxiliaryPointTimes, stepPointTimes);
    
    if (validity == ValidTimes) {

      SliceLine(context.GetTimeSliceInterval(),
		trajectoryLine, trajectoryLineTimes);

      DrawWithTime(context,
		   trajectoryLine, auxiliaryPoints, stepPoints,
		   trajectoryLineTimes, auxiliaryPointTimes, stepPointTimes);

    } else {

      DrawWithoutTime(context, trajectoryLine, auxiliaryPoints, stepPoints);

    }
  }
}