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//
// G4NavigationHistory Inline implementation
//
// Author: Paul Kent (CERN), 25.07.1996 - Initial version.
// ----------------------------------------------------------------------

extern G4GEOM_DLL G4Allocator<G4NavigationHistory>*& aNavigHistoryAllocator();

// There is no provision that this class is subclassed.
// If it is subclassed & new data members are added then the
// following "new" & "delete" will fail and give errors. 
//
inline
void* G4NavigationHistory::operator new(std::size_t)
{
  if (aNavigHistoryAllocator() == nullptr)
  {
    aNavigHistoryAllocator() = new G4Allocator<G4NavigationHistory>;
  }
  return (void *) aNavigHistoryAllocator()->MallocSingle();
}

inline
void G4NavigationHistory::operator delete(void *aHistory)
{
  aNavigHistoryAllocator()->FreeSingle((G4NavigationHistory *) aHistory);
}

inline
G4NavigationHistory&
G4NavigationHistory::operator=(const G4NavigationHistory &h)
{
  if (&h == this)  { return *this; }

  // *fNavHistory=*(h.fNavHistory);   // This works, but is very slow.

  if( GetMaxDepth() != h.GetMaxDepth() )
  {
    fNavHistory->resize( h.GetMaxDepth() );
  }

  for ( auto  ilev=G4int(h.fStackDepth); ilev>=0; --ilev )
  { 
    (*fNavHistory)[ilev] = (*h.fNavHistory)[ilev];
  }
  fStackDepth = h.fStackDepth;

  return *this;
}

inline
void G4NavigationHistory::Reset()
{
  fStackDepth=0;
}

inline
void G4NavigationHistory::Clear()
{
  G4AffineTransform origin(G4ThreeVector(0.,0.,0.));
  G4NavigationLevel tmpNavLevel = G4NavigationLevel(nullptr, origin, kNormal, -1) ;

  Reset();
  for (auto  ilev=G4long(fNavHistory->size()-1); ilev>=0; --ilev)
  {
     (*fNavHistory)[ilev] = tmpNavLevel;
  }
}

inline
void G4NavigationHistory::SetFirstEntry(G4VPhysicalVolume* pVol)
{
  G4ThreeVector translation(0.,0.,0.);
  G4int copyNo = -1;

  // Protection needed in case pVol=null 
  // so that a touchable-history can signal OutOfWorld 
  //
  if( pVol != nullptr )
  {
    translation = pVol->GetTranslation();
    copyNo = pVol->GetCopyNo();
  }
  (*fNavHistory)[0] =
    G4NavigationLevel( pVol, G4AffineTransform(translation), kNormal, copyNo );
}

inline
const G4AffineTransform* G4NavigationHistory::GetPtrTopTransform() const
{
  return (*fNavHistory)[fStackDepth].GetPtrTransform();
}

inline
const G4AffineTransform& G4NavigationHistory::GetTopTransform() const
{
  return (*fNavHistory)[fStackDepth].GetTransform();
}

inline
G4int G4NavigationHistory::GetTopReplicaNo() const
{
  return (*fNavHistory)[fStackDepth].GetReplicaNo();
}

inline
EVolume G4NavigationHistory::GetTopVolumeType() const
{
  return (*fNavHistory)[fStackDepth].GetVolumeType();
}

inline
G4VPhysicalVolume* G4NavigationHistory::GetTopVolume() const
{
  return (*fNavHistory)[fStackDepth].GetPhysicalVolume();
}

inline
std::size_t G4NavigationHistory::GetDepth() const
{
  return fStackDepth;
}

inline
const G4AffineTransform&
G4NavigationHistory::GetTransform(G4int n) const
{
  return (*fNavHistory)[n].GetTransform();
}

inline
G4int G4NavigationHistory::GetReplicaNo(G4int n) const
{
  return (*fNavHistory)[n].GetReplicaNo();
}

inline
EVolume G4NavigationHistory::GetVolumeType(G4int n) const
{
  return (*fNavHistory)[n].GetVolumeType();
}

inline
G4VPhysicalVolume* G4NavigationHistory::GetVolume(G4int n) const
{
  return (*fNavHistory)[n].GetPhysicalVolume();
}

inline
std::size_t G4NavigationHistory::GetMaxDepth() const
{
  return fNavHistory->size();
}

inline
void G4NavigationHistory::BackLevel()
{
  assert( fStackDepth>0 );

  // Tell  the  level  that I am forgetting it
  // delete (*fNavHistory)[fStackDepth];
  //
  --fStackDepth;
}

inline
void G4NavigationHistory::BackLevel(G4int n)
{
  assert( n<=G4int(fStackDepth) );
  fStackDepth-=n;
}

inline
void G4NavigationHistory::EnlargeHistory()
{
  std::size_t len = fNavHistory->size();
  if ( len == fStackDepth )
  {
    // Note: Resize operation clears additional entries
    //
    std::size_t nlen = len+kHistoryStride;
    fNavHistory->resize(nlen);
  }  
}


inline
void G4NavigationHistory::NewLevel( G4VPhysicalVolume* pNewMother,
                                    EVolume vType,
                                    G4int nReplica )
{
  ++fStackDepth;
  EnlargeHistory();  // Enlarge if required
  (*fNavHistory)[fStackDepth] =
    G4NavigationLevel( pNewMother, 
                       (*fNavHistory)[fStackDepth-1].GetTransform(),
                       G4AffineTransform(pNewMother->GetRotation(),
                       pNewMother->GetTranslation()),
                       vType,
                       nReplica ); 
  // The constructor computes the new global->local transform
}