Stores step-by-step and aggregated information for a detector hit. More...

#include <ghit.h>

Public Member Functions
	GHit (std::shared_ptr< GTouchable > gt, const G4Step *thisStep=nullptr, const std::string &cScheme="default")
	Construct a hit container and optionally seed it from a step.

	~GHit () override=default
	Destructor.

void *	operator new (size_t)
	Allocate a `GHit` via the `G4Allocator` associated with this type.

void	operator delete (void *)
	Deallocate a `GHit` via the `G4Allocator` associated with this type.

void	Draw () override
	Visualize the hit using `Geant4` visualization primitives.

bool	is_same_hit (const GHit *hit) const
	Compare this hit against another hit by sensitive-element identity.

std::vector< double >	getEdeps () const
	Get per-step energy depositions.

std::vector< double >	getTimes () const
	Get per-step global times.

std::vector< G4ThreeVector >	getGlobalPositions () const
	Get per-step global positions.

std::vector< G4ThreeVector >	getLocalPositions () const
	Get per-step local positions.

std::vector< G4ThreeVector >	getTrackVertexPositions () const
	Get per-step current-track vertex positions.

G4ThreeVector	getTrackVertexPosition () const
	Convenience accessor for the first current-track vertex position.

std::vector< G4ThreeVector >	getMotherTrackVertexPositions () const
	Get per-step mother-track vertex positions.

G4ThreeVector	getMotherTrackVertexPosition () const
	Convenience accessor for the first mother-track vertex position.

std::vector< int >	getPids () const
	Get per-step particle PDG encodings (when enabled).

int	getPid () const
	Convenience accessor for the first particle ID.

std::vector< int >	getTids () const
	Get per-step particle track id (when enabled).

int	getTid () const
	Convenience accessor for the first track ID.

std::vector< int >	getMotherTids () const
	Get per-step mother track IDs.

int	getMotherTid () const
	Convenience accessor for the first mother track ID.

double	getE () const
	Convenience accessor for the first step track total energy.

size_t	nsteps () const
	Number of recorded steps.

size_t	getStepCount () const
	Number of recorded steps (same as nsteps()).

std::vector< G4ThreeVector >	getMomenta () const
	Get per-step track 3-momenta (always present).

G4ThreeVector	getMomentum () const
	Convenience accessor for the first step 3-momentum.

std::vector< double >	getTrackEs () const
	Get per-step track total energies (always present).

double	getTrackE () const
	Convenience accessor for the first step track total energy.

std::vector< int >	getMotherPids () const
	Get per-step mother particle PDG encodings (always present).

int	getMpid () const
	Convenience accessor for the first step mother particle PDG encoding.

std::string	getProcID () const
	Get the representative creator process name for this hit.

std::string	getProcessName () const
	Get the representative creator process name for the hit.

std::shared_ptr< GTouchable >	getGTouchable () const
	Get the associated sensitive-element descriptor.

std::vector< GIdentifier >	getGID () const
	Get the detector element identity.

std::vector< double >	getDetectorDimensions () const
	Get the sensitive-element dimensions.

double	getMass () const
	Get the sensitive element mass.

void	calculateInfos ()
	Compute and cache derived hit quantities.

double	getTotalEnergyDeposited ()
	Get the total deposited energy across all recorded steps.

double	getAverageTime ()
	Get the average time associated with the hit.

G4ThreeVector	getAvgLocalPosition ()
	Get the average local position of the hit.

G4ThreeVector	getAvgGlobaPosition ()
	Get the average global position of the hit.

void	addHitInfos (const G4Step *thisStep)
	Append per-step information from a `G4Step`.

void	randomizeHitForTesting (int nsteps)
	Randomize internal vectors for test-only usage.

std::vector< int >	getTTID () const
	Get the touchable identity values as integers.

Static Public Member Functions
static void	clearTrackVertexCache ()
	Clear the per-thread track vertex cache.

static GHit *	create (const std::shared_ptr< GOptions > &gopts)
	Create a fake hit for testing, using the current options.

Detailed Description

A GHit is a G4VHit that accumulates per-step quantities while a track traverses a sensitive detector element and deposits energy.

Conceptually, this class has two layers of information:

Per-step vectors: always-collected quantities (energy deposition, time, local/global positions, track identity, momentum, and creator process).
Aggregated quantities: totals/averages (e.g., total energy deposited, average time, average positions, representative process name) computed lazily from the per-step vectors.

Note: This class does not own the sensitive-element description. The associated GTouchable is stored as a std::shared_ptr so that the hit can be compared against other hits and can query identity/dimensions.

Definition at line 37 of file ghit.h.

Constructor & Destructor Documentation

◆ GHit()

GHit::GHit	(	std::shared_ptr< GTouchable >	gt,
		const G4Step *	thisStep = nullptr,
		const std::string &	cScheme = "default" )

This constructor initializes the hit bookkeeping and, if thisStep is not null, immediately records per-step information for that step.

Parameters

gt	Pointer to the `GTouchable` describing the sensitive element producing the hit.
thisStep	Optional `G4Step` used to seed the hit with an initial step record (default: null).
cScheme	Visualization color scheme name (default: "default"). The current implementation uses a simple hard-coded scheme but keeps this field for future expansion.

Definition at line 26 of file ghit.cc.

◆ ~GHit()

GHit::~GHit ( )

overridedefault

Member Function Documentation

◆ addHitInfos()

void GHit::addHitInfos ( const G4Step * thisStep )

Records global and local positions, energy deposited, time, track identity, momentum, total energy, mother-particle PDG, and creator process name.

Parameters

thisStep Step to extract per-step values from (must not be null).

Definition at line 12 of file addHitInfos.cc.

◆ calculateInfos()

void GHit::calculateInfos ( )

Calculates total deposited energy, average time, average local/global positions, and the representative creator process name from the per-step vectors.

Implementation notes (non-Doxygen):

Derived quantities use a lazy-cache model (computed on first access).
Energy-weighted averages are used when total deposited energy is non-zero.
When total energy is zero, fall back to simple arithmetic averaging.

Definition at line 16 of file calculations.cc.

◆ clearTrackVertexCache()

void GHit::clearTrackVertexCache ( )

static

Called at the beginning of each sensitive-detector event.

Definition at line 98 of file ghit.cc.

◆ create()

static GHit * GHit::create ( const std::shared_ptr< GOptions > & gopts )

inlinestatic

Builds a test touchable via GTouchable::create(gopts), constructs a hit with no initial step, and randomizes its contents using randomizeHitForTesting().

Parameters

gopts Options object used to create the test GTouchable.

Returns: Newly allocated GHit pointer. Ownership is transferred to the caller.

Warning: The returned pointer must be deleted by the caller.

Definition at line 596 of file ghit.h.

◆ Draw()

void GHit::Draw ( )

override

This draws a circle at the first recorded global position and selects visual attributes based on the total energy deposited.

Note: If no visualization manager is available, or if the hit has no recorded positions, the method returns without performing any drawing.

Definition at line 63 of file ghit.cc.

◆ getAverageTime()

double GHit::getAverageTime ( )

Returns: The energy-weighted average of the time if total deposited energy is non-zero, otherwise a simple arithmetic average.

Note: The internal cache uses an "uninitialized" sentinel; computation happens on first access.

Definition at line 66 of file calculations.cc.

◆ getAvgGlobaPosition()

G4ThreeVector GHit::getAvgGlobaPosition ( )

Returns: The averaged global position energy-weighted if possible.

Note: The function name is getAvgGlobaPosition() (missing 'l' in "Global") for historical reasons.

Definition at line 85 of file calculations.cc.

◆ getAvgLocalPosition()

G4ThreeVector GHit::getAvgLocalPosition ( )

Returns: The averaged local position, energy-weighted if possible.

Definition at line 112 of file calculations.cc.

◆ getDetectorDimensions()

std::vector< double > GHit::getDetectorDimensions ( ) const

inline

Returns: A vector of doubles representing the element dimensions.

Note: This forwards to GTouchable::getDetectorDimensions().

Definition at line 491 of file ghit.h.

◆ getE()

double GHit::getE ( ) const

inline

Alias for getTrackE() kept for API compatibility with existing digitization plugins.

Returns: The first recorded track total energy (MeV).

Warning: This assumes the internal trackEs vector is non-empty.

Definition at line 401 of file ghit.h.

◆ getEdeps()

std::vector< double > GHit::getEdeps ( ) const

inline

Returns: A copy of the vector of per-step deposited energies.

Definition at line 299 of file ghit.h.

◆ getGID()

std::vector< GIdentifier > GHit::getGID ( ) const

inline

Returns: A vector of GIdentifier describing the sensitive-element identity.

Note: This forwards to GTouchable::getIdentity().

Definition at line 483 of file ghit.h.

◆ getGlobalPositions()

std::vector< G4ThreeVector > GHit::getGlobalPositions ( ) const

inline

Returns: A copy of the vector of per-step global positions.

Definition at line 311 of file ghit.h.

◆ getGTouchable()

std::shared_ptr< GTouchable > GHit::getGTouchable ( ) const

inline

Returns: A copy of the std::shared_ptr managing the GTouchable.

Definition at line 475 of file ghit.h.

◆ getLocalPositions()

std::vector< G4ThreeVector > GHit::getLocalPositions ( ) const

inline

Returns: A copy of the vector of per-step local positions.

Definition at line 317 of file ghit.h.

◆ getMass()

double GHit::getMass ( ) const

inline

Returns: A double with the mass value

Definition at line 499 of file ghit.h.

◆ getMomenta()

std::vector< G4ThreeVector > GHit::getMomenta ( ) const

inline

Returns: A copy of the vector of per-step momenta.

Definition at line 419 of file ghit.h.

◆ getMomentum()

G4ThreeVector GHit::getMomentum ( ) const

inline

Returns: The first recorded track momentum.

Warning: This assumes the internal momenta vector is non-empty.

Definition at line 427 of file ghit.h.

◆ getMotherPids()

std::vector< int > GHit::getMotherPids ( ) const

inline

Returns: A copy of the vector of per-step mother PDG codes.

Definition at line 447 of file ghit.h.

◆ getMotherTid()

int GHit::getMotherTid ( ) const

inline

Returns: The first mother track ID.

Warning: This assumes the internal motherTids vector is non-empty.

Definition at line 391 of file ghit.h.

◆ getMotherTids()

std::vector< int > GHit::getMotherTids ( ) const

inline

Returns: A copy of the vector of mother track IDs.

Definition at line 383 of file ghit.h.

◆ getMotherTrackVertexPosition()

G4ThreeVector GHit::getMotherTrackVertexPosition ( ) const

inline

Returns: The first mother-track vertex position.

Warning: This assumes the internal motherTrackVertexPositions vector is non-empty.

Definition at line 347 of file ghit.h.

◆ getMotherTrackVertexPositions()

std::vector< G4ThreeVector > GHit::getMotherTrackVertexPositions ( ) const

inline

Returns: A copy of the vector of mother-track vertex positions.

Definition at line 337 of file ghit.h.

◆ getMpid()

int GHit::getMpid ( ) const

inline

Returns: The first recorded mother PDG code (sentinel when parent not yet seen).

Warning: This assumes the internal motherPids vector is non-empty.

Definition at line 455 of file ghit.h.

◆ getPid()

int GHit::getPid ( ) const

inline

Returns: The first particle ID.

Warning: This assumes the internal pids vector is non-empty.

Definition at line 363 of file ghit.h.

◆ getPids()

std::vector< int > GHit::getPids ( ) const

inline

Returns: A copy of the vector of per-step particle IDs.

Definition at line 355 of file ghit.h.

◆ getProcessName()

std::string GHit::getProcessName ( ) const

inline

Returns: The cached representative process name string, set by calculateInfos().

Definition at line 469 of file ghit.h.

◆ getProcID()

std::string GHit::getProcID ( ) const

inline

Alias for getProcessName() following G4 naming conventions.

Returns: The cached representative process name.

Definition at line 463 of file ghit.h.

◆ getStepCount()

size_t GHit::getStepCount ( ) const

inline

Returns: The size of the edeps vector.

Definition at line 413 of file ghit.h.

◆ getTid()

int GHit::getTid ( ) const

inline

Returns: The first particle ID.

Warning: This assumes the internal track vector is non-empty.

Definition at line 377 of file ghit.h.

◆ getTids()

std::vector< int > GHit::getTids ( ) const

inline

Returns: A copy of the vector of per-step track IDs.

Definition at line 369 of file ghit.h.

◆ getTimes()

std::vector< double > GHit::getTimes ( ) const

inline

Returns: A copy of the vector of per-step times.

Definition at line 305 of file ghit.h.

◆ getTotalEnergyDeposited()

double GHit::getTotalEnergyDeposited ( )

Returns: The summed energy deposition.

This method caches the result the first time it is called.

Definition at line 54 of file calculations.cc.

◆ getTrackE()

double GHit::getTrackE ( ) const

inline

Returns: The first recorded track total energy (MeV).

Warning: This assumes the internal trackEs vector is non-empty.

Definition at line 441 of file ghit.h.

◆ getTrackEs()

std::vector< double > GHit::getTrackEs ( ) const

inline

Returns: A copy of the vector of per-step track total energies (MeV).

Definition at line 433 of file ghit.h.

◆ getTrackVertexPosition()

G4ThreeVector GHit::getTrackVertexPosition ( ) const

inline

Returns: The first track vertex position.

Warning: This assumes the internal trackVertexPositions vector is non-empty.

Definition at line 331 of file ghit.h.

◆ getTrackVertexPositions()

std::vector< G4ThreeVector > GHit::getTrackVertexPositions ( ) const

inline

Returns: A copy of the vector of track vertex positions.

Definition at line 323 of file ghit.h.

◆ getTTID()

vector< int > GHit::getTTID ( ) const

Converts each GIdentifier returned by getGID() into its integer value.

Returns: Vector of integer identity values (one per identifier component).

Definition at line 51 of file ghit.cc.

◆ is_same_hit()

bool GHit::is_same_hit ( const GHit * hit ) const

Two hits are considered the "same" if their associated GTouchable objects compare equal (i.e. they refer to the same detector element identity according to GTouchable equality).

Parameters

hit	Pointer to the candidate hit to compare against (may be null).

Returns: True if hit is not null and the associated GTouchable matches.

Definition at line 44 of file ghit.cc.

◆ nsteps()

size_t GHit::nsteps ( ) const

inline

Returns: The size of the edeps vector, which is always populated.

Definition at line 407 of file ghit.h.

◆ operator delete()

void GHit::operator delete ( void * hit )

inline

Definition at line 615 of file ghit.h.

◆ operator new()

void * GHit::operator new ( size_t )

inline

Returns: Pointer to the allocated storage.

Note: The allocator is thread-local (see GHitAllocator below).

Definition at line 610 of file ghit.h.

◆ randomizeHitForTesting()

void GHit::randomizeHitForTesting ( int nsteps )

Fills vectors with pseudo-random positions, times, energies, and particle IDs.

Parameters

nsteps Number of pseudo-random steps to generate.

Warning: This is intended only for unit tests / examples. Do not use in production.

Definition at line 103 of file ghit.cc.

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

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ GHit()

◆ ~GHit()

Member Function Documentation

◆ addHitInfos()

◆ calculateInfos()

◆ clearTrackVertexCache()

◆ create()

◆ Draw()

◆ getAverageTime()

◆ getAvgGlobaPosition()

◆ getAvgLocalPosition()

◆ getDetectorDimensions()

◆ getE()

◆ getEdeps()

◆ getGID()

◆ getGlobalPositions()

◆ getGTouchable()

◆ getLocalPositions()

◆ getMass()

◆ getMomenta()

◆ getMomentum()

◆ getMotherPids()

◆ getMotherTid()

◆ getMotherTids()

◆ getMotherTrackVertexPosition()

◆ getMotherTrackVertexPositions()

◆ getMpid()

◆ getPid()

◆ getPids()

◆ getProcessName()

◆ getProcID()

◆ getStepCount()

◆ getTid()

◆ getTids()

◆ getTimes()

◆ getTotalEnergyDeposited()

◆ getTrackE()

◆ getTrackEs()

◆ getTrackVertexPosition()

◆ getTrackVertexPositions()

◆ getTTID()

◆ is_same_hit()

◆ nsteps()

◆ operator delete()

◆ operator new()

◆ randomizeHitForTesting()