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.Dd December 21, 2022
.Dt AG_BYTESWAP 3
.Os Agar 1.7
.Sh NAME
.Nm AG_ByteSwap
.Nd agar byte swapping macros
.Sh SYNOPSIS
.Bd -literal
#include <agar/core/byteswap.h>
.Ed
.Sh DESCRIPTION
These macros swap the order of bytes in integers and floating-point types.
They are useful when reading or writing data of a specific endianness.
.Pp
.nr nS 1
.Ft "Uint16"
.Fn AG_Swap16 "Uint16 value"
.Pp
.Ft "Uint32"
.Fn AG_Swap32 "Uint32 value"
.Pp
.Ft "Uint64"
.Fn AG_Swap64 "Uint64 value"
.Pp
.Ft "Uint16"
.Fn AG_SwapLE16 "Uint16 value"
.Pp
.Ft "Uint32"
.Fn AG_SwapLE32 "Uint32 value"
.Pp
.Ft "Uint64"
.Fn AG_SwapLE64 "Uint64 value"
.Pp
.Ft "Uint16"
.Fn AG_SwapBE16 "Uint16 value"
.Pp
.Ft "Uint32"
.Fn AG_SwapBE32 "Uint32 value"
.Pp
.Ft "Uint64"
.Fn AG_SwapBE64 "Uint64 value"
.Pp
.nr nS 0
The
.Fn AG_Swap16 ,
.Fn AG_Swap32
and
.Fn AG_Swap64
functions return the parameter's value with the byte order reversed.
.Pp
.Fn AG_SwapLE16 ,
.Fn AG_SwapLE32 ,
and
.Fn AG_SwapLE64
return the given value with the byte order reversed if the current
architecture is big-endian.
On little-endian machines, these functions return the value unchanged.
.Pp
.Fn AG_SwapBE16 ,
.Fn AG_SwapBE32
and
.Fn AG_SwapBE64
return the given value with the byte order reversed if the current
architecture is little-endian.
On big-endian machines, these functions return the value unchanged.
.Pp
If 64-bit types are not supported (!AG_HAVE_64BIT), then
.Fn AG_Swap64 ,
.Fn AG_SwapLE64
and
.Fn AG_SwapBE64
are undefined.
.Sh EXAMPLES
The following code reverses the byte order of an array of 32-bit values:
.Pp
.Bd -literal -offset indent
.\" SYNTAX(c)
void
SwapData32(Uint32 *data, int len)
{
	int i;

	for (i = 0; i < len; i++)
		data[i] = AG_Swap32(data[i]);
}
.Ed
.Sh SEE ALSO
.Xr AG_DataSource 3 ,
.Xr AG_Intro 3
.Sh HISTORY
The
.Nm
macros first appeared in Agar 1.3.4.