InDetDD::SiCellId Class Reference

Identifier for the strip or pixel cell. More...

#include <SiCellId.h>

Inheritance diagram for InDetDD::SiCellId:

Collaboration diagram for InDetDD::SiCellId:

Public Member Functions
	SiCellId ()
	Constructor. Set in invalid state.
	SiCellId (int strip)
	Construct with strip number.
	SiCellId (int phiIndex, int etaIndex)
	Construct with phi, eta index.
int	etaIndex () const
	Get eta index.
int	phiIndex () const
	Get phi index. Equivalent to strip().
int	strip () const
	Get strip number. Equivalent to phiIndex().
bool	isValid () const
	Test if its in a valid state.
bool	operator== (const SiCellId &other) const
	Test equality.
bool	operator!= (const SiCellId &other) const
	Test inequality.
bool	operator< (const SiCellId &other) const
	Operator for sorting.
unsigned int	word () const

Private Types
enum	MaskAndShiftConstants {   PHI_MASK = 0x0000ffff , PHI_NEG = 0x00008000 , ETA_MASK = 0x00007fff , ETA_SHIFT = 16 ,   ETA_NEG = 0x40000000 , VALID = 0x80000000 }

Private Attributes
unsigned int	m_word

Detailed Description

Identifier for the strip or pixel cell.

Just the strip number for SCT or phi_index, eta_index for pixel. Packs the numbers in an int. Supports negative indices and is initialized in an invalid state when using the default constructor.

Author

Grant Gorfine

Definition at line 29 of file SiCellId.h.

Member Enumeration Documentation

MaskAndShiftConstants

enum InDetDD::SiCellId::MaskAndShiftConstants

private

Enumerator
PHI_MASK
PHI_NEG
ETA_MASK
ETA_SHIFT
ETA_NEG
VALID

Definition at line 76 of file SiCellId.h.

                             {
    PHI_MASK  = 0x0000ffff,
    PHI_NEG   = 0x00008000, //  (PHI_MASK >> 1 + 1)
    ETA_MASK  = 0x00007fff,
    ETA_SHIFT = 16,
    ETA_NEG   = 0x40000000, // ((ETA_MASK >> 1 + 1) << ETA_SHIFT) 
    VALID     = 0x80000000
  };

Constructor & Destructor Documentation

SiCellId() [1/3]

InDetDD::SiCellId::SiCellId ( )

inline

Constructor. Set in invalid state.

Definition at line 92 of file SiCellId.h.

{
  // set in invalid state
  // This sets the invalid bit plus set phi and eta index to their most negative value
  m_word = VALID | ETA_NEG | PHI_NEG ;
}

SiCellId() [2/3]

InDetDD::SiCellId::SiCellId ( int strip )

inline

Construct with strip number.

Definition at line 108 of file SiCellId.h.

{
  if (strip < 0) strip = PHI_MASK + strip + 1;
  m_word = strip & PHI_MASK;
}

SiCellId() [3/3]

InDetDD::SiCellId::SiCellId ( int phiIndex, int etaIndex )

inline

Construct with phi, eta index.

Definition at line 99 of file SiCellId.h.

{
  // The negative check is not really necessary if negative numbers are represented as twos complement but
  // I don't think that assumption is guaranteed to be portable.
  if (phiIndex < 0) phiIndex = PHI_MASK + phiIndex + 1; // For negative number store as two's complement
  if (etaIndex < 0) etaIndex = ETA_MASK + etaIndex + 1;
  m_word = (phiIndex  & PHI_MASK) | ((etaIndex & ETA_MASK) << ETA_SHIFT);
}

Member Function Documentation

etaIndex()

int InDetDD::SiCellId::etaIndex ( ) const

inline

Get eta index.

Definition at line 114 of file SiCellId.h.

{
  if (m_word & ETA_NEG) { // Negative index
    return ((m_word >> ETA_SHIFT) & ETA_MASK) - ETA_MASK - 1;
  } 
  return (m_word >> ETA_SHIFT) & ETA_MASK;
}

isValid()

bool InDetDD::SiCellId::isValid ( ) const

inline

Test if its in a valid state.

Definition at line 136 of file SiCellId.h.

{
  return !(m_word & VALID);
}

operator!=()

bool InDetDD::SiCellId::operator!= ( const SiCellId & other ) const

inline

Test inequality.

Definition at line 146 of file SiCellId.h.

{
  return (m_word != other.m_word);
} 

operator<()

bool InDetDD::SiCellId::operator< ( const SiCellId & other ) const

inline

Operator for sorting.

Definition at line 151 of file SiCellId.h.

{
  return (m_word < other.m_word);
} 

operator==()

bool InDetDD::SiCellId::operator== ( const SiCellId & other ) const

inline

Test equality.

Definition at line 141 of file SiCellId.h.

{
  return (m_word == other.m_word);
} 

phiIndex()

int InDetDD::SiCellId::phiIndex ( ) const

inline

Get phi index. Equivalent to strip().

Definition at line 122 of file SiCellId.h.

{
  if (m_word & PHI_NEG) { // Negative index
    return (m_word & PHI_MASK) - PHI_MASK - 1;
  } 
  return (m_word & PHI_MASK);
 
}

strip()

int InDetDD::SiCellId::strip ( ) const

inline

Get strip number. Equivalent to phiIndex().

Definition at line 131 of file SiCellId.h.

{
  return phiIndex();
}

word()

unsigned int InDetDD::SiCellId::word ( ) const

inline

Definition at line 67 of file SiCellId.h.

{ return m_word; } 

Member Data Documentation

m_word

unsigned int InDetDD::SiCellId::m_word

private

Definition at line 70 of file SiCellId.h.

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

• SiCellId.h