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//
// $Id: G4Region.cc,v 1.26 2008/07/15 10:27:36 gcosmo Exp $
// GEANT4 tag $Name: geant4-09-02-ref-02 $
//
// 
// class G4Region Implementation
//
// --------------------------------------------------------------------

#include "G4Region.hh"
#include "G4RegionStore.hh"
#include "G4LogicalVolume.hh"
#include "G4VPhysicalVolume.hh"
#include "G4LogicalVolumeStore.hh"
#include "G4VNestedParameterisation.hh"
#include "G4VUserRegionInformation.hh"

// *******************************************************************
// Constructor:
//  - Adds self to region Store
// *******************************************************************
//
G4Region::G4Region(const G4String& pName)
  : fName(pName), fRegionMod(true), fCut(0), fUserInfo(0), fUserLimits(0),
    fFastSimulationManager(0), fWorldPhys(0), fRegionalSteppingAction(0)
{
  G4RegionStore* rStore = G4RegionStore::GetInstance();
  if (rStore->GetRegion(pName,false))
  {
    G4cerr << "WARNING - G4Region::G4Region()" << G4endl
           << "          Region " << pName << " already existing in store !"
           << G4endl;
    G4Exception("G4Region::G4Region()", "InvalidSetup", JustWarning,
                "The region has NOT been registered !");
  }
  else
  {
    rStore->Register(this);
  }
}

// ********************************************************************
// Fake default constructor - sets only member data and allocates memory
//                            for usage restricted to object persistency.
// ********************************************************************
//
G4Region::G4Region( __void__& )
  : fName(""), fRegionMod(true), fCut(0), fUserInfo(0), fUserLimits(0),
    fFastSimulationManager(0), fWorldPhys(0), fRegionalSteppingAction(0)
{
  // Register to store
  //
  G4RegionStore::GetInstance()->Register(this);
}

// *******************************************************************
// Destructor:
//  - Removes self from region Store
// *******************************************************************
//
G4Region::~G4Region()
{
  G4RegionStore::GetInstance()->DeRegister(this);
  if(fUserInfo) delete fUserInfo;
}

// *******************************************************************
// ScanVolumeTree:
//  - Scans recursively the 'lv' logical volume tree, retrieves
//    and places all materials in the list.
//  - The boolean flag 'region' identifies if the volume tree must
//    have region reset (false) or if the current region must be
//    associated to the logical volume 'lv' and its tree (true).
// *******************************************************************
//
void G4Region::ScanVolumeTree(G4LogicalVolume* lv, G4bool region)
{
  // If logical volume is going to become a region, add 
  // its material to the list if not already present
  //
  G4Region* currentRegion = 0;
  size_t noDaughters = lv->GetNoDaughters();
  G4Material* volMat = lv->GetMaterial();
  if(!volMat)
  {
    G4String errmsg = "Logical volume <";
    errmsg += lv->GetName();
    errmsg += "> does not have a valid material pointer.\n";
    errmsg += "A logical volume belonging to the (tracking) world volume ";
    errmsg += "must have a valid material.\nCheck your geometry construction.";
    G4Exception("G4Region::ScanVolumeTree()", "SetupError",
                FatalException, errmsg);
  }
  if (region)
  {
    currentRegion = this;
    AddMaterial(volMat);
  }

  // Set the LV region to be either the current region or NULL,
  // according to the boolean selector
  //
  lv->SetRegion(currentRegion);

  // Stop recursion here if no further daughters are involved
  //
  if(noDaughters==0) return;

  G4VPhysicalVolume* daughterPVol = lv->GetDaughter(0);
  if (daughterPVol->IsParameterised())
  {
    // Adopt special treatment in case of parameterised volumes,
    // where parameterisation involves a new material scan
    //
    G4VPVParameterisation* pParam = daughterPVol->GetParameterisation();

    if (pParam->GetMaterialScanner())
    {
      size_t matNo = pParam->GetMaterialScanner()->GetNumberOfMaterials();
      for (register size_t mat=0; mat<matNo; mat++)
      {
        volMat = pParam->GetMaterialScanner()->GetMaterial(mat);
        if(!volMat)
        {
          G4String errmsg = "The parameterisation for the physical volume <";
          errmsg += daughterPVol->GetName();
          errmsg += ">\n does not return a valid material pointer.\n";
          errmsg += "A volume belonging to the (tracking) world volume must ";
          errmsg += "have a valid material.\nCheck your parameterisation.";
          G4Exception("G4Region::ScanVolumeTree()",
                      "SetupError", FatalException, errmsg);
        }
        AddMaterial(volMat);
      }
    }
    else
    {
      size_t repNo = daughterPVol->GetMultiplicity();
      for (register size_t rep=0; rep<repNo; rep++)
      {
        volMat = pParam->ComputeMaterial(rep, daughterPVol);
        if(!volMat)
        {
          G4String errmsg = "The parameterisation for the physical volume <";
          errmsg += daughterPVol->GetName();
          errmsg += ">\n does not return a valid material pointer.\n";
          errmsg += "A volume belonging to the (tracking) world volume must ";
          errmsg += "have a valid material.\nCheck your parameterisation.";
          G4Exception("G4Region::ScanVolumeTree()",
                      "SetupError", FatalException, errmsg);
        }
        AddMaterial(volMat);
      }
    }
    G4LogicalVolume* daughterLVol = daughterPVol->GetLogicalVolume();
    ScanVolumeTree(daughterLVol, region);
  }
  else
  {
    for (register size_t i=0; i<noDaughters; i++)
    {
      G4LogicalVolume* daughterLVol = lv->GetDaughter(i)->GetLogicalVolume();
      if (!daughterLVol->IsRootRegion())
      {
        // Set daughter's LV to be a region and store materials in
        // the materials list, if the LV is not already a root region
        //
        ScanVolumeTree(daughterLVol, region);
      }
    }
  }
}

// *******************************************************************
// AddRootLogicalVolume:
//  - Adds a root logical volume and sets its daughters flags as
//    regions. It also recomputes the materials list for the region.
// *******************************************************************
//
void G4Region::AddRootLogicalVolume(G4LogicalVolume* lv)
{
  // Check the logical volume is not already in the list
  //
  G4RootLVList::iterator pos;
  pos = std::find(fRootVolumes.begin(),fRootVolumes.end(),lv);
  if (pos == fRootVolumes.end())
  {
    // Insert the root volume in the list and set it as root region
    //
    fRootVolumes.push_back(lv);
    lv->SetRegionRootFlag(true);
  }

  // Scan recursively the tree of daugther volumes and set regions
  //
  ScanVolumeTree(lv, true);

  // Set region as modified
  //
  fRegionMod = true;
}

// *******************************************************************
// RemoveRootLogicalVolume:
//  - Removes a root logical volume and resets its daughters flags as
//    regions. It also recomputes the materials list for the region.
// *******************************************************************
//
void G4Region::RemoveRootLogicalVolume(G4LogicalVolume* lv, G4bool scan)
{
  // Find and remove logical volume from the list
  //
  G4RootLVList::iterator pos;
  pos = std::find(fRootVolumes.begin(),fRootVolumes.end(),lv);
  if (pos != fRootVolumes.end())
  {
    if (fRootVolumes.size() != 1)  // Avoid resetting flag for world since
    {                              // volume may be already deleted !
      lv->SetRegionRootFlag(false);
    }
    fRootVolumes.erase(pos);
  }

  if (scan)  // Update the materials list
  {
    UpdateMaterialList();
  }

  // Set region as modified
  //
  fRegionMod = true;
}

// *******************************************************************
// ClearMaterialList:
//  - Clears the material list.
// *******************************************************************
//
void G4Region::ClearMaterialList()
{
  fMaterials.clear();
}

// *******************************************************************
// UpdateMaterialList:
//  - computes material list looping through
//    each root logical volume in the region.
// *******************************************************************
//
void G4Region::UpdateMaterialList()
{
  // Reset the materials list
  //
  ClearMaterialList();

  // Loop over the root logical volumes and rebuild the list
  // of materials from scratch
  //
  G4RootLVList::iterator pLV;
  for (pLV=fRootVolumes.begin(); pLV!=fRootVolumes.end(); pLV++)
  {
    ScanVolumeTree(*pLV, true);
  }
}

// *******************************************************************
// SetWorld:
//  - Set the world physical volume if this region belongs to this
//    world. If the given pointer is null, reset the pointer.
// *******************************************************************
//
void G4Region::SetWorld(G4VPhysicalVolume* wp)
{
  if(!wp)
  { fWorldPhys = 0; }
  else
  { if(BelongsTo(wp)) fWorldPhys = wp; }

  return;
}

// *******************************************************************
// BelongsTo:
//  - Returns whether this region belongs to the given physical volume
//    (recursively scanned to the bottom of the hierarchy)
// *******************************************************************
// 
G4bool G4Region::BelongsTo(G4VPhysicalVolume* thePhys) const
{
  G4LogicalVolume* currLog = thePhys->GetLogicalVolume();
  if (currLog->GetRegion()==this) {return true;}

  G4int nDaughters = currLog->GetNoDaughters();
  while (nDaughters--)
  {
    if (BelongsTo(currLog->GetDaughter(nDaughters))) {return true;}
  }

  return false;
}

// *******************************************************************
// ClearFastSimulationManager:
//  - Set G4FastSimulationManager pointer to the one for the parent region
//    if it exists. Otherwise set to null.
// *******************************************************************
//
void G4Region::ClearFastSimulationManager()
{
  G4bool isUnique;
  G4Region* parent = GetParentRegion(isUnique);
  if(parent)
  {
    if (isUnique)
    {
      fFastSimulationManager = parent->GetFastSimulationManager();
    }
    else
    {
      G4cout << "WARNING - G4Region::GetParentRegion()" << G4endl
             << "          Region <" << fName << "> belongs to more than"
             << " one parent region !" << G4endl;
      G4String message =
           "A region (" + fName + ") cannot belong to more than one \n"
         + "direct parent region, to have fast-simulation assigned.";
      G4Exception("G4Region::ClearFastSimulationManager()",
                  "InvalidSetup", JustWarning, message);
      fFastSimulationManager = 0;
    }
  }
  else
  {
    fFastSimulationManager = 0;
  }
}

// *******************************************************************
// GetParentRegion:
//  - Returns a region that contains this region.
//    Otherwise null is returned.
// *******************************************************************
// 
G4Region* G4Region::GetParentRegion(G4bool& unique) const
{
  G4Region* parent = 0; unique = true;
  G4LogicalVolumeStore* lvStore = G4LogicalVolumeStore::GetInstance();
  G4LogicalVolumeStore::iterator lvItr;

  // Loop over all logical volumes in the store
  //
  for(lvItr=lvStore->begin(); lvItr!=lvStore->end(); lvItr++)
  {
    G4int nD = (*lvItr)->GetNoDaughters();
    G4Region* aR = (*lvItr)->GetRegion();

    // Loop over all daughters of each logical volume
    //
    for(G4int iD=0; iD<nD; iD++)
    {
      if((*lvItr)->GetDaughter(iD)->GetLogicalVolume()->GetRegion()==this)
      { 
        if(parent)
        {
          if(parent!=aR) { unique = false; }
        }
        else  // Cache LV parent region which includes a daughter volume
              // with the same associated region as the current one
        {
          parent = aR;
        }
      }
    }
  }
  return parent;
}