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

#include <ghit.h>

Public Member Functions
	GHit (std::shared_ptr< GTouchable > gt, HitBitSet hbs, 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< int >	getPids () const
	Get per-step particle PDG encodings (when enabled).

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

std::vector< double >	getEs () const
	Get per-step total energies (when enabled).

double	getE () const
	Convenience accessor for the first energy value.

size_t	nsteps () const
	Number of recorded steps for the optional-energy vector.

std::string	getProcessName () const
	Get the representative 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.

void	calculateInfosForBit (int bit)
	Compute and cache derived information for the requested bit.

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	addHitInfosForBitset (HitBitSet hbs, const G4Step *thisStep)
	Append per-step information from a `G4Step` according to a bitset.

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 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) plus optional quantities controlled by HitBitSet.
Aggregated quantities: totals/averages (e.g., total energy deposited, average time, average positions, representative process name) computed lazily from the per-step vectors.

The optional information is controlled by HitBitSet (see ghitConventions.h : bit meanings and expected future extensions).

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 42 of file ghit.h.

Constructor & Destructor Documentation

◆ GHit()

GHit::GHit	(	std::shared_ptr< GTouchable >	gt,
		HitBitSet	hbs,
		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 (both always-present data and any enabled optional data in hbs).

Parameters

gt	Pointer to the `GTouchable` describing the sensitive element producing the hit.
hbs	Bitset selecting which optional hit information is recorded in addition to the always-present fields.
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

◆ addHitInfosForBitset()

void GHit::addHitInfosForBitset	(	HitBitSet	hbs,
		const G4Step *	thisStep )

Always records:

global and local positions,
energy deposited,
global time.

Then iterates over each bit of hbs and conditionally records optional information via the internal bit handler.

Parameters

hbs	Bitset selecting optional information to record.
thisStep	Step to extract per-step values from (must not be null).

Definition at line 10 of file addHitInfos.cc.

◆ calculateInfosForBit()

void GHit::calculateInfosForBit ( int bit )

This is primarily used to compute bit-0 derived quantities (total energy, average time, average local/global positions, representative process name).

Parameters

bit	Bit index for which derived information should be computed.

Note: Bits beyond 0 are currently placeholders for future extensions (see ghitConventions.h : planned bits).

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.

◆ create()

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

inlinestatic

This uses GTouchable::create(gopts) to build a test touchable, constructs a hit with an empty HitBitSet, and then 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 455 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 65 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 84 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 105 of file calculations.cc.

◆ getAvgLocalPosition()

G4ThreeVector GHit::getAvgLocalPosition ( )

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

Definition at line 134 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 353 of file ghit.h.

◆ getE()

double GHit::getE ( ) const

inline

Returns: The first energy value.

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

Definition at line 313 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 267 of file ghit.h.

◆ getEs()

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

inline

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

Definition at line 305 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 345 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 279 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 337 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 285 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 299 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 291 of file ghit.h.

◆ getProcessName()

std::string GHit::getProcessName ( ) const

inline

Returns: The cached representative process name string.

Note: This value is typically populated when calculateInfosForBit() runs for bit 0, or when average/total getters trigger calculations.

Definition at line 331 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 273 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 72 of file calculations.cc.

◆ 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 53 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 46 of file ghit.cc.

◆ nsteps()

size_t GHit::nsteps ( ) const

inline

Returns: The size of the Es vector.

Note: Depending on the HitBitSet configuration, Es may remain empty even if always-present vectors have entries.

Definition at line 322 of file ghit.h.

◆ operator delete()

void GHit::operator delete ( void * hit )

inline

Definition at line 475 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 470 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 100 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

◆ addHitInfosForBitset()

◆ calculateInfosForBit()

◆ create()

◆ Draw()

◆ getAverageTime()

◆ getAvgGlobaPosition()

◆ getAvgLocalPosition()

◆ getDetectorDimensions()

◆ getE()

◆ getEdeps()

◆ getEs()

◆ getGID()

◆ getGlobalPositions()

◆ getGTouchable()

◆ getLocalPositions()

◆ getPid()

◆ getPids()

◆ getProcessName()

◆ getTimes()

◆ getTotalEnergyDeposited()

◆ getTTID()

◆ is_same_hit()

◆ nsteps()

◆ operator delete()

◆ operator new()

◆ randomizeHitForTesting()