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/**
* @file llendianswizzle.h
* @brief Functions for in-place bit swizzling
*
* $LicenseInfo:firstyear=2002&license=viewergpl$
*
* Copyright (c) 2002-2008, Linden Research, Inc.
*
* Second Life Viewer Source Code
* The source code in this file ("Source Code") is provided by Linden Lab
* to you under the terms of the GNU General Public License, version 2.0
* ("GPL"), unless you have obtained a separate licensing agreement
* ("Other License"), formally executed by you and Linden Lab. Terms of
* the GPL can be found in doc/GPL-license.txt in this distribution, or
* online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution, or
* online at http://secondlifegrid.net/programs/open_source/licensing/flossexception
*
* By copying, modifying or distributing this software, you acknowledge
* that you have read and understood your obligations described above,
* and agree to abide by those obligations.
*
* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
* COMPLETENESS OR PERFORMANCE.
* $/LicenseInfo$
*/
#ifndef LL_LLENDIANSWIZZLE_H
#define LL_LLENDIANSWIZZLE_H
/* This function is intended to be used for in-place swizzling, particularly after fread() of
binary values from a file. Such as:
numRead = fread(scale.mV, sizeof(float), 3, fp);
llendianswizzle(scale.mV, sizeof(float), 3);
It assumes that the values in the file are LITTLE endian, so it's a no-op on a little endian machine.
It keys off of typesize to do the correct swizzle, so make sure that typesize is the size of the native type.
64-bit types are not yet handled.
*/
#ifdef LL_LITTLE_ENDIAN
// little endian is native for most things.
inline void llendianswizzle(void *,int,int)
{
// Nothing to do
}
#endif
#ifdef LL_BIG_ENDIAN
// big endian requires a bit of work.
inline void llendianswizzle(void *p,int typesize, int count)
{
int i;
switch(typesize)
{
case 2:
{
U16 temp;
for(i=count ;i!=0 ;i--)
{
temp = ((U16*)p)[0];
((U16*)p)[0] = ((temp >> 8) & 0x000000FF) | ((temp << 8) & 0x0000FF00);
p = (void*)(((U16*)p) + 1);
}
}
break;
case 4:
{
U32 temp;
for(i=count; i!=0; i--)
{
temp = ((U32*)p)[0];
((U32*)p)[0] =
((temp >> 24) & 0x000000FF) |
((temp >> 8) & 0x0000FF00) |
((temp << 8) & 0x00FF0000) |
((temp << 24) & 0xFF000000);
p = (void*)(((U32*)p) + 1);
}
}
break;
}
}
#endif
// Use this when working with a single integral value you want swizzled
#define llendianswizzleone(x) llendianswizzle(&(x), sizeof(x), 1)
#endif // LL_LLENDIANSWIZZLE_H
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