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= Byte Order and Byte Swapping =

'''Include File(s):'''  [[http://hg.libsdl.org/SDL/file/default/include/SDL_endian.h|SDL_endian.h]]

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== Introduction ==
This category contains functions for handling endian-specific values.

Simple data types like integers and floats consist of several bytes. A 32bit integer (Sint32), for example, uses four bytes (as each byte has 8 bits). Endianness describes how the system orders the bytes of this value in memory.

Endianness comes in two forms - big and little.
 * SDL_LIL_ENDIAN means byte order is 1234, where the least significant byte is stored first
 * SDL_BIG_ENDIAN means byte order is 4321, where the most significant byte is stored first


''Example:''  Imagine the 32bit integer number {{{16,909,060}}} in decimal.
 In hexadecimal that would be ~+{{{0x01020304}}}+~. <<BR>>
 {{{0x01}}} is the most significant byte (the one that increases the value the most.  {{{0x04}}} is the least significant byte (as it increases the value the least).<<BR>>

 When that is stored in memory on a little-endian system they are stored with the least significant byte first, producing the byte stream:
  {{{0x04 0x03 0x02 0x01}}}<<BR>>

 When that is stored in memory on a big-endian system they are stored with the most significant byte first, producing the byte stream:
  {{{0x01 0x02 0x03 0x04}}}<<BR>>

For further information about endianness read the [[https://en.wikipedia.org/wiki/Endianness|Wikipedia]] article on the subject.

SDL_BYTEORDER is a macro that corresponds to the byte order used by the processor type it was compiled for.
 * SDL_BYTEORDER is SDL_LIL_ENDIAN for x86, x64, and similar systems that use the little endian byte order.
 * SDL_BYTEORDER is SDL_BIG_ENDIAN for PowerPC and similar systems that use the big endian byte order.


== Functions ==
<<FullSearchCached(category:CategoryEndian -CategoryEnum -CategoryStruct -title:SGFunctions)>>

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