endian.h

//-----------------------------------------------------------------------------
// Application Core Library
// Copyright (c) 2009-2012 DuJardin Consulting, LLC.
// Portions Copyright (c) 2009 GarageGames, Inc.
//-----------------------------------------------------------------------------

#ifndef _ENDIAN_H_
#define _ENDIAN_H_

#ifndef _ACL_TYPES_H_
#include "core/types.h"
#endif

//------------------------------------------------------------------------------
// Endian conversions

inline U8 endianSwap(const U8 in_swap)
{
   return in_swap;
}

inline S8 endianSwap(const S8 in_swap)
{
   return in_swap;
}

/**
Convert the byte ordering on the U16 to and from big/little endian format.
@param in_swap Any U16
@returns swapped U16.
*/

inline U16 endianSwap(const U16 in_swap)
{
   return U16(((in_swap >> 8) & 0x00ff) |
      ((in_swap << 8) & 0xff00));
}

inline S16 endianSwap(const S16 in_swap)
{
   return S16(endianSwap(U16(in_swap)));
}

/**
Convert the byte ordering on the U32 to and from big/little endian format.
@param in_swap Any U32
@returns swapped U32.
*/
inline U32 endianSwap(const U32 in_swap)
{
   return U32(((in_swap >> 24) & 0x000000ff) |
      ((in_swap >>  8) & 0x0000ff00) |
      ((in_swap <<  8) & 0x00ff0000) |
      ((in_swap << 24) & 0xff000000));
}

inline S32 endianSwap(const S32 in_swap)
{
   return S32(endianSwap(U32(in_swap)));
}

inline U64 endianSwap(const U64 in_swap)
{
   U32 *inp = (U32 *) &in_swap;
   U64 ret;
   U32 *outp = (U32 *) &ret;
   outp[0] = endianSwap(inp[1]);
   outp[1] = endianSwap(inp[0]);
   return ret;
}

inline S64 endianSwap(const S64 in_swap)
{
   return S64(endianSwap(U64(in_swap)));
}

inline F32 endianSwap(const F32 in_swap)
{
   U32 result = endianSwap(* ((U32 *) &in_swap) );
   return * ((F32 *) &result);
}

inline F64 endianSwap(const F64 in_swap)
{
   U64 result = endianSwap(* ((U64 *) &in_swap) );
   return * ((F64 *) &result);
}

//------------------------------------------------------------------------------
// Endian conversions

#ifdef ACL_LITTLE_ENDIAN

#define ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(type) \
   inline type convertHostToLEndian(type i) { return i; } \
   inline type convertLEndianToHost(type i) { return i; } \
   inline type convertHostToBEndian(type i) { return endianSwap(i); } \
   inline type convertBEndianToHost(type i) { return endianSwap(i); }

#elif defined(ACL_BIG_ENDIAN)

#define ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(type) \
   inline type convertHostToLEndian(type i) { return endianSwap(i); } \
   inline type convertLEndianToHost(type i) { return endianSwap(i); } \
   inline type convertHostToBEndian(type i) { return i; } \
   inline type convertBEndianToHost(type i) { return i; }

#else
#error "Endian define not set!"
#endif


ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(U8)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(S8)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(U16)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(S16)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(U32)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(S32)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(U64)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(S64)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(F32)
   ACL_DECLARE_TEMPLATIZED_ENDIAN_CONV(F64)

#endif