Scroom::Bitmap::SampleIterator< ConstBase > Class Template Reference

#include <bitmap-helpers.hh>

Inheritance diagram for Scroom::Bitmap::SampleIterator< ConstBase >:

Collaboration diagram for Scroom::Bitmap::SampleIterator< ConstBase >:

Public Types
using	Base = std::remove_const_t< ConstBase >

Public Member Functions
	SampleIterator (ConstBase *base, int offset=0, int bps_=1)
Base	get ()
void	set (ConstBase value)
SampleIterator &	operator++ ()
SampleIterator	operator++ (int)
SampleIterator &	operator+= (unsigned int x)
Base	operator* ()
bool	operator== (const SampleIterator< ConstBase > &other) const
bool	operator!= (const SampleIterator< ConstBase > &other) const

Public Attributes
const int	bps
const int	samplesPerBase
const int	pixelOffset
const ConstBase	pixelMask
ConstBase *	currentBase
int	currentOffset

Static Public Attributes
static const int	bitsPerBase {8 * sizeof(ConstBase) / sizeof(byte)}

Private Member Functions
	SampleIterator (div_t d, ConstBase *base, int bps_)

Static Private Member Functions
static Base	mask (int bps)

Detailed Description

template<typename ConstBase>
class Scroom::Bitmap::SampleIterator< ConstBase >

Iterate over samples (bits) within a larger type, for example a byte

Allows you to extract (or set) specific bits in a larger datatype, as well as iterate over samples within the larger datatype, or even continuing with the next, if you reach the end of the current one

Parameters

Base	the larger type that contains the samples. Typically uint8_t

Member Typedef Documentation

Base

template<typename ConstBase >

using Scroom::Bitmap::SampleIterator< ConstBase >::Base = std::remove_const_t<ConstBase>

Constructor & Destructor Documentation

SampleIterator() [1/2]

template<typename ConstBase >

Scroom::Bitmap::SampleIterator< ConstBase >::SampleIterator ( div_t  d, ConstBase *  base, int  bps_  )

inlineprivate

      : bps(bps_)
      , samplesPerBase(bitsPerBase / bps)
      , pixelOffset(bps)
      , pixelMask(mask(bps))
      , currentBase(base + d.quot)
      , currentOffset(samplesPerBase - 1 - d.rem)
    {
    }

SampleIterator() [2/2]

template<typename ConstBase >

Scroom::Bitmap::SampleIterator< ConstBase >::SampleIterator ( ConstBase *  base, int  offset = 0, int  bps_ = 1  )

inlineexplicit

Construct a new SampleIterator

Parameters

base	Pointer to the element that contains the current sample
offset	number of the sample within that element
bps	Number of bits per sample

      : SampleIterator(div(offset, /* samplesPerBase */ bitsPerBase / bps_), base, bps_)
    {
    }

Member Function Documentation

get()

template<typename ConstBase >

Base Scroom::Bitmap::SampleIterator< ConstBase >::get ( )

inline

Get the value of the current sample

{ return (*currentBase >> (currentOffset * pixelOffset)) & pixelMask; }

mask()

template<typename ConstBase >

static Base Scroom::Bitmap::SampleIterator< ConstBase >::mask ( int  bps )

inlinestaticprivate

{ return (((ConstBase(1) << (bps - 1)) - 1) << 1) | 1; }

operator!=()

template<typename ConstBase >

bool Scroom::Bitmap::SampleIterator< ConstBase >::operator!= ( const SampleIterator< ConstBase > &  other ) const

inline

{ return !(*this == other); }

operator*()

template<typename ConstBase >

Base Scroom::Bitmap::SampleIterator< ConstBase >::operator* ( )

inline

Get the value of the current sample

{ return (*currentBase >> (currentOffset * pixelOffset)) & pixelMask; }

operator++() [1/2]

template<typename ConstBase >

SampleIterator & Scroom::Bitmap::SampleIterator< ConstBase >::operator++ ( )

inline

Move to the next sample

    {
      // Prefix operator
      if(!(currentOffset--))
      {
        currentOffset = samplesPerBase - 1;
        ++currentBase;
      }
 
      return *this;
    }

operator++() [2/2]

template<typename ConstBase >

SampleIterator Scroom::Bitmap::SampleIterator< ConstBase >::operator++ ( int  )

inline

Move to the next sample

    {
      // Postfix operator
      SampleIterator<ConstBase> result = *this;
 
      if(!(currentOffset--))
      {
        currentOffset = samplesPerBase - 1;
        ++currentBase;
      }
 
      return result;
    }

operator+=()

template<typename ConstBase >

SampleIterator & Scroom::Bitmap::SampleIterator< ConstBase >::operator+= ( unsigned int  x )

inline

Move x samples further

    {
      const int offset = samplesPerBase - 1 - currentOffset + x;
      const div_t d = div(offset, samplesPerBase);
      currentBase += d.quot;
      currentOffset = samplesPerBase - 1 - d.rem;
 
      return *this;
    }

operator==()

template<typename ConstBase >

bool Scroom::Bitmap::SampleIterator< ConstBase >::operator== ( const SampleIterator< ConstBase > &  other ) const

inline

    {
      return currentBase == other.currentBase && currentOffset == other.currentOffset && bps == other.bps;
    }

set()

template<typename ConstBase >

void Scroom::Bitmap::SampleIterator< ConstBase >::set ( ConstBase  value )

inline

Set the value of the current sample

    {
      *currentBase = (*currentBase & ~(pixelMask << currentOffset * pixelOffset)) | (value << (currentOffset * pixelOffset));
    }

Referenced by Operations::reduce(), OperationsColormapped::reduce(), and Operations1bppClipped::reduce().

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Member Data Documentation

bitsPerBase

template<typename ConstBase >

const int Scroom::Bitmap::SampleIterator< ConstBase >::bitsPerBase {8 * sizeof(ConstBase) / sizeof(byte)}

static

{8 * sizeof(ConstBase) / sizeof(byte)};

bps

template<typename ConstBase >

const int Scroom::Bitmap::SampleIterator< ConstBase >::bps

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::mask(), and Scroom::Bitmap::SampleIterator< ConstBase >::operator==().

currentBase

template<typename ConstBase >

ConstBase* Scroom::Bitmap::SampleIterator< ConstBase >::currentBase

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::get(), Scroom::Bitmap::SampleIterator< ConstBase >::operator*(), Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), Scroom::Bitmap::SampleIterator< ConstBase >::operator+=(), Scroom::Bitmap::SampleIterator< ConstBase >::operator==(), and Scroom::Bitmap::SampleIterator< ConstBase >::set().

currentOffset

template<typename ConstBase >

int Scroom::Bitmap::SampleIterator< ConstBase >::currentOffset

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::get(), Scroom::Bitmap::SampleIterator< ConstBase >::operator*(), Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), Scroom::Bitmap::SampleIterator< ConstBase >::operator+=(), Scroom::Bitmap::SampleIterator< ConstBase >::operator==(), and Scroom::Bitmap::SampleIterator< ConstBase >::set().

pixelMask

template<typename ConstBase >

const ConstBase Scroom::Bitmap::SampleIterator< ConstBase >::pixelMask

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::get(), Scroom::Bitmap::SampleIterator< ConstBase >::operator*(), and Scroom::Bitmap::SampleIterator< ConstBase >::set().

pixelOffset

template<typename ConstBase >

const int Scroom::Bitmap::SampleIterator< ConstBase >::pixelOffset

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::get(), Scroom::Bitmap::SampleIterator< ConstBase >::operator*(), and Scroom::Bitmap::SampleIterator< ConstBase >::set().

samplesPerBase

template<typename ConstBase >

const int Scroom::Bitmap::SampleIterator< ConstBase >::samplesPerBase

Referenced by Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), Scroom::Bitmap::SampleIterator< ConstBase >::operator++(), and Scroom::Bitmap::SampleIterator< ConstBase >::operator+=().

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

• libs/scroom/inc/scroom/bitmap-helpers.hh