Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType > Class Template Reference
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Class for performing a radix sort (fast comparison-less sort based on byte value) on various standard STL containers. More...

`#include <OgreRadixSort.h>`

## Classes

struct | SortEntry

## Public Types

typedef TContainer::iterator | ContainerIter

## Public Member Functions

| RadixSort ()
| ~RadixSort ()
template<class TFunction >
void | sort (TContainer &container, TFunction func)
| Main sort function. More...

## Protected Types

typedef std::vector< SortEntry, STLAllocator< SortEntry, GeneralAllocPolicy > > | SortVector
| Temp sort storage. More...

## Protected Member Functions

template<typename T >
void | finalPass (int byteIndex, T val)
void | finalPass (int byteIndex, int val)
void | finalPass (int byteIndex, float val)
unsigned char | getByte (int byteIndex, TCompValueType val)
void | sortPass (int byteIndex)

## Protected Attributes

int | mCounters [4][256]
| Alpha-pass counters of values (histogram) 4 of them so we can radix sort a maximum of a 32bit value. More...
SortVector * | mDest
int | mNumPasses
| Number of passes for this type. More...
int | mOffsets [256]
| Beta-pass offsets. More...
SortVector | mSortArea1
SortVector | mSortArea2
int | mSortSize
| Sort area size. More...
SortVector * | mSrc
TContainer | mTmpContainer

## Detailed Description

### template<class TContainer, class TContainerValueType, typename TCompValueType>
class Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >

Class for performing a radix sort (fast comparison-less sort based on byte value) on various standard STL containers.

Remarks
  A radix sort is a very fast sort algorithm. It doesn't use comparisons and thus is able to break the theoretical minimum O(N*logN) complexity. Radix sort is complexity O(k*N), where k is a constant. Note that radix sorting is not in-place, it requires additional storage, so it trades memory for speed. The overhead of copying means that it is only faster for fairly large datasets, so you are advised to only use it for collections of at least a few hundred items.

  This is a template class to allow it to deal with a variety of containers, and a variety of value types to sort on. In addition to providing the container and value type on construction, you also need to supply a functor object which will retrieve the value to compare on for each item in the list. For example, if you had an std::vector of by-value instances of an object of class 'Bibble', and you wanted to sort on Bibble::getDoobrie(), you'd have to firstly create a functor like this:
  struct BibbleSortFunctor
  {
  float operator()(const Bibble& val) const
  {
  return val.getDoobrie();
  }
  }
  Then, you need to declare a RadixSort class which names the container type, the value type in the container, and the type of the value you want to sort by. You can then call the sort function. E.g.
  RadixSort<BibbleList, Bibble, float> radixSorter;
  BibbleSortFunctor functor;
  radixSorter.sort(myBibbleList, functor);
  You should try to reuse RadixSort instances, since repeated allocation of the internal storage is then avoided.

Note
  Radix sorting is often associated with just unsigned integer values. Our implementation can handle both unsigned and signed integers, as well as floats (which are often not supported by other radix sorters). doubles are not supported; you will need to implement your functor object to convert to float if you wish to use this sort routine.

Definition at line 88 of file OgreRadixSort.h.

## Member Typedef Documentation

## ContainerIter

template<class TContainer, class TContainerValueType, typename TCompValueType>

typedef TContainer::iterator Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::ContainerIter

Definition at line 91 of file OgreRadixSort.h.

## SortVector

template<class TContainer, class TContainerValueType, typename TCompValueType>

typedef std::vector<SortEntry, STLAllocator<SortEntry, GeneralAllocPolicy> > Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::SortVector

protected

Temp sort storage.

Definition at line 113 of file OgreRadixSort.h.

## Constructor & Destructor Documentation

## RadixSort()

template<class TContainer, class TContainerValueType, typename TCompValueType>

Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::RadixSort | ( |  | ) |

Definition at line 237 of file OgreRadixSort.h.

## ~RadixSort()

template<class TContainer, class TContainerValueType, typename TCompValueType>

Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::~RadixSort | ( |  | ) |

Definition at line 238 of file OgreRadixSort.h.

## Member Function Documentation

## finalPass() [1/3]

template<class TContainer, class TContainerValueType, typename TCompValueType>
template<typename T >

void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::finalPass | ( | int | byteIndex,
|  | T | val
| ) |  |

protected

Definition at line 140 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## finalPass() [2/3]

template<class TContainer, class TContainerValueType, typename TCompValueType>

void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::finalPass | ( | int | byteIndex,
|  | int | val
| ) |  |

protected

Definition at line 147 of file OgreRadixSort.h.

## finalPass() [3/3]

template<class TContainer, class TContainerValueType, typename TCompValueType>

void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::finalPass | ( | int | byteIndex,
|  | float | val
| ) |  |

protected

Definition at line 180 of file OgreRadixSort.h.

## getByte()

template<class TContainer, class TContainerValueType, typename TCompValueType>

unsigned char Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::getByte | ( | int | byteIndex,
|  | TCompValueType | val
| ) |  |

protected

Definition at line 226 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::finalPass(), Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort(), and Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sortPass().

## sort()

template<class TContainer, class TContainerValueType, typename TCompValueType>
template<class TFunction >

void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::sort | ( | TContainer & | container,
|  | TFunction | func
| ) |  |

Main sort function.

Parameters

  container | A container of the type you declared when declaring
  func | A functor which returns the value for comparison when given a container value

Definition at line 246 of file OgreRadixSort.h.

## sortPass()

template<class TContainer, class TContainerValueType, typename TCompValueType>

void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::sortPass | ( | int | byteIndex | ) |

protected

Definition at line 121 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::finalPass(), and Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## Member Data Documentation

## mCounters

template<class TContainer, class TContainerValueType, typename TCompValueType>

int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mCounters[4][256]

protected

Alpha-pass counters of values (histogram) 4 of them so we can radix sort a maximum of a 32bit value.

Definition at line 95 of file OgreRadixSort.h.

## mDest

template<class TContainer, class TContainerValueType, typename TCompValueType>

SortVector* Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mDest

protected

Definition at line 117 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## mNumPasses

template<class TContainer, class TContainerValueType, typename TCompValueType>

int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mNumPasses

protected

Number of passes for this type.

Definition at line 101 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## mOffsets

template<class TContainer, class TContainerValueType, typename TCompValueType>

int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mOffsets[256]

protected

Beta-pass offsets.

Definition at line 97 of file OgreRadixSort.h.

## mSortArea1

template<class TContainer, class TContainerValueType, typename TCompValueType>

SortVector Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortArea1

protected

Definition at line 114 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## mSortArea2

template<class TContainer, class TContainerValueType, typename TCompValueType>

SortVector Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortArea2

protected

Definition at line 115 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## mSortSize

template<class TContainer, class TContainerValueType, typename TCompValueType>

int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortSize

protected

Sort area size.

Definition at line 99 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::finalPass(), and Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sortPass().

## mSrc

template<class TContainer, class TContainerValueType, typename TCompValueType>

SortVector* Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSrc

protected

Definition at line 116 of file OgreRadixSort.h.

Referenced by Ogre::RadixSort< ActiveParticleList, Ogre::Particle *, float >::sort().

## mTmpContainer

template<class TContainer, class TContainerValueType, typename TCompValueType>

TContainer Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mTmpContainer

protected

Definition at line 118 of file OgreRadixSort.h.

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

- OgreRadixSort.h

Copyright © 2012 Torus Knot Software Ltd
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.