v4k-git-backup/demos/ports/doom/src/m_swap.c

54 lines
1.2 KiB
C

// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
// Endianess handling, swapping 16bit and 32bit.
//
//-----------------------------------------------------------------------------
#include "doom_config.h"
#include "m_swap.h"
// Not needed with big endian.
#ifdef __BIG_ENDIAN__
// Swap 16bit, that is, MSB and LSB byte.
unsigned short SwapSHORT(unsigned short x)
{
// No masking with 0xFF should be necessary.
return (x >> 8) | (x << 8);
}
// Swapping 32bit.
unsigned long SwapLONG(unsigned long x)
{
return
(x >> 24)
| ((x >> 8) & 0xff00)
| ((x << 8) & 0xff0000)
| (x << 24);
}
#endif