celeritas::GeantGeoTrackView Class Reference

Navigate through a Geant4 geometry on a single thread. More...

#include <GeantGeoTrackView.hh>

Classes
struct	DetailedInitializer
	Helper struct for initializing from an existing geometry state. More...

Public Types
Type aliases
using	Initializer_t = GeoTrackInitializer
using	ParamsRef = NativeCRef< GeantGeoParamsData >
using	StateRef = NativeRef< GeantGeoStateData >
using	real_type = double
using	Real3 = Array< real_type, 3 >

Public Member Functions
	GeantGeoTrackView (ParamsRef const &params, StateRef const &state, TrackSlotId tid)
	Construct from params and state data.
GeantGeoTrackView &	operator= (Initializer_t const &init)
	Construct the state.
GeantGeoTrackView &	operator= (DetailedInitializer const &init)
	Construct the state from a direction and a copy of the parent state. More...
VolumeId	volume_id () const
	Get the volume ID in the current cell.
VolumeInstanceId	volume_instance_id () const
	Get the physical volume ID in the current cell.
LevelId	level () const
	Get the depth in the geometry hierarchy.
void	volume_instance_id (Span< VolumeInstanceId > levels) const
	Get the volume instance ID at every level. More...
bool	is_outside () const
	Whether the track is outside the valid geometry region.
bool	is_on_boundary () const
	Whether the track is on the boundary of a volume.
CELER_FORCEINLINE bool	failed () const
	Whether the last operation resulted in an error.
Propagation	find_next_step ()
	Find the distance to the next geometric boundary.
Propagation	find_next_step (real_type max_step)
	Find the distance to the next geometric boundary. More...
real_type	find_safety ()
	Find the safety at the current position.
CELER_FUNCTION real_type	find_safety (real_type max_step)
	Find the safety at the current position. More...
void	move_to_boundary ()
	Move to the next boundary but don't cross yet.
void	move_internal (real_type step)
	Move within the current volume. More...
void	move_internal (Real3 const &pos)
	Move within the current volume to a nearby point. More...
void	cross_boundary ()
	Cross from one side of the current surface to the other. More...
void	set_dir (Real3 const &newdir)
	Change the track's direction. More...
CELER_FORCEINLINE Real3 const &	pos () const
CELER_FORCEINLINE Real3 const &	dir () const
SurfaceId	surface_id () const
SurfaceId	next_surface_id () const

Static Public Member Functions
static constexpr real_type	extra_push ()
	A tiny push to make sure tracks do not get stuck at boundaries.

Detailed Description

Navigate through a Geant4 geometry on a single thread.

This wraps a Geant4 geometry navigator and volume hierarchy state with the same Celeritas tracker interface. It's not going to be the most efficient code since the G4Navigator includes a lot of helper functions for managing safety distance, tracking through a field, etc. We also independently store a "celeritas" native position and direction, as well as duplicating the "geant4" position and direction that are also stored under the hood in the heavyweight navigator.

For a description of ordering requirements, see:

See also

OrangeTrackView .

Member Function Documentation

cross_boundary()

void celeritas::GeantGeoTrackView::cross_boundary ( )

inline

Cross from one side of the current surface to the other.

The position must be on the boundary following a move-to-boundary.

dir()

CELER_FORCEINLINE Real3 const& celeritas::GeantGeoTrackView::dir ( ) const

inline

State accessors

find_next_step()

Propagation celeritas::GeantGeoTrackView::find_next_step ( real_type  max_step )

inline

Find the distance to the next geometric boundary.

It seems that ComputeStep cannot be called twice in a row without an intermediate call to LocateGlobalPointWithinVolume: the safety will be set to zero.

find_safety()

auto celeritas::GeantGeoTrackView::find_safety ( real_type  max_step )

inline

Find the safety at the current position.

Warning

This can change the boundary state if the track was moved to or initialized a point on the boundary.

move_internal() [1/2]

void celeritas::GeantGeoTrackView::move_internal ( Real3 const &  pos )

inline

Move within the current volume to a nearby point.

See G4PathFinder::ReLocate from G4SafetyHelper::ReLocateWithinVolume from G4VMultipleScattering::AlongStepDoIt .

move_internal() [2/2]

void celeritas::GeantGeoTrackView::move_internal ( real_type  dist )

inline

Move within the current volume.

The straight-line distance must be less than the distance to the boundary.

next_surface_id()

SurfaceId celeritas::GeantGeoTrackView::next_surface_id ( ) const

inline

VecGeom states are never "on" a surface

operator=()

GeantGeoTrackView & celeritas::GeantGeoTrackView::operator= ( DetailedInitializer const &  init )

inline

Construct the state from a direction and a copy of the parent state.

G4Track::SetTouchableHandle from G4VEmProcess::PostStepDoIt

maybe see G4SteppingManager::Stepping

pos()

CELER_FORCEINLINE Real3 const& celeritas::GeantGeoTrackView::pos ( ) const

inline

State accessors

set_dir()

void celeritas::GeantGeoTrackView::set_dir ( Real3 const &  newdir )

inline

Change the track's direction.

This happens after a scattering event or movement inside a magnetic field. It resets the calculated distance-to-boundary.

surface_id()

SurfaceId celeritas::GeantGeoTrackView::surface_id ( ) const

inline

VecGeom states are never "on" a surface

volume_instance_id()

void celeritas::GeantGeoTrackView::volume_instance_id ( Span< VolumeInstanceId >  levels ) const

inline

Get the volume instance ID at every level.

The input span size must be equal to the value of "level" plus one. The top-most level ("world" or level zero) starts at index zero and moves downward. Note that Geant4 uses the reverse nomenclature.

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The documentation for this class was generated from the following file:

• GeantGeoTrackView.hh