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# Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType > Class Template Reference

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

`#include <OgreRadixSort.h>`

List of all members.

## Public Types
typedef TContainer::iterator | ContainerIter
## Public Member Functions
| RadixSort ()
| ~RadixSort ()
template<class TFunction>
void | sort (TContainer &container, TFunction func)
| Main sort function.
## Protected Member Functions
void | sortPass (int byteIndex)
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)
## 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.
int | mOffsets [256]
| Beta-pass offsets.
int | mSortSize
| Sort area size.
int | mNumPasses
| Number of passes for this type.
std::vector< SortEntry > | mSortArea1
| Temp sort storage.
std::vector< SortEntry > | mSortArea2
std::vector< SortEntry > * | mSrc
std::vector< SortEntry > * | mDest
TContainer | mTmpContainer
## Classes
struct | SortEntry

## 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 83 of file OgreRadixSort.h.

## Member Typedef Documentation

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

| Definition at line 86 of file OgreRadixSort.h.

## Constructor & Destructor Documentation

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

| Definition at line 231 of file OgreRadixSort.h.

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

| Definition at line 232 of file OgreRadixSort.h.

## Member Function Documentation

template<class TContainer, class TContainerValueType, typename TCompValueType>
void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::finalPass | ( | int | byteIndex,
|  | float | val
| ) | `[protected]`

| Definition at line 174 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::finalPass | ( | int | byteIndex,
|  | int | val
| ) | `[protected]`

| Definition at line 141 of file OgreRadixSort.h.

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 134 of file OgreRadixSort.h. Referenced by Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::sort().

template<class TContainer, class TContainerValueType, typename TCompValueType>
unsigned char Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::getByte | ( | int | byteIndex,
|  | TCompValueType | val
| ) | `[protected]`

| Definition at line 220 of file OgreRadixSort.h. Referenced by Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::finalPass(), Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::sort(), and Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::sortPass().

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 240 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
void Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::sortPass | ( | int | byteIndex | ) | `[protected]`

| Definition at line 115 of file OgreRadixSort.h. Referenced by Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::finalPass(), and Ogre::RadixSort< RenderablePassList, RenderablePass, uint32 >::sort().

## Member Data Documentation

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 90 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
std::vector<SortEntry>* Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mDest`[protected]`

| Definition at line 111 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mNumPasses`[protected]`

| Number of passes for this type. Definition at line 96 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mOffsets[256]`[protected]`

| Beta-pass offsets. Definition at line 92 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
std::vector<SortEntry> Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortArea1`[protected]`

| Temp sort storage. Definition at line 108 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
std::vector<SortEntry> Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortArea2`[protected]`

| Definition at line 109 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
int Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSortSize`[protected]`

| Sort area size. Definition at line 94 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
std::vector<SortEntry>* Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mSrc`[protected]`

| Definition at line 110 of file OgreRadixSort.h.

template<class TContainer, class TContainerValueType, typename TCompValueType>
TContainer Ogre::RadixSort< TContainer, TContainerValueType, TCompValueType >::mTmpContainer`[protected]`

| Definition at line 112 of file OgreRadixSort.h.

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

- OgreRadixSort.h

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sun Sep 30 10:52:26 2007