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tenmon/3rdparty/include/pcl/EndianConversions.h
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2022-04-12 08:17:18 +02:00

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// ____ ______ __
// / __ \ / ____// /
// / /_/ // / / /
// / ____// /___ / /___ PixInsight Class Library
// /_/ \____//_____/ PCL 2.4.23
// ----------------------------------------------------------------------------
// pcl/EndianConversions.h - Released 2022-03-12T18:59:29Z
// ----------------------------------------------------------------------------
// This file is part of the PixInsight Class Library (PCL).
// PCL is a multiplatform C++ framework for development of PixInsight modules.
//
// Copyright (c) 2003-2022 Pleiades Astrophoto S.L. All Rights Reserved.
//
// Redistribution and use in both source and binary forms, with or without
// modification, is permitted provided that the following conditions are met:
//
// 1. All redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. All redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the names "PixInsight" and "Pleiades Astrophoto", nor the names
// of their contributors, may be used to endorse or promote products derived
// from this software without specific prior written permission. For written
// permission, please contact info@pixinsight.com.
//
// 4. All products derived from this software, in any form whatsoever, must
// reproduce the following acknowledgment in the end-user documentation
// and/or other materials provided with the product:
//
// "This product is based on software from the PixInsight project, developed
// by Pleiades Astrophoto and its contributors (https://pixinsight.com/)."
//
// Alternatively, if that is where third-party acknowledgments normally
// appear, this acknowledgment must be reproduced in the product itself.
//
// THIS SOFTWARE IS PROVIDED BY PLEIADES ASTROPHOTO AND ITS CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL PLEIADES ASTROPHOTO OR ITS
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, BUSINESS
// INTERRUPTION; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; AND LOSS OF USE,
// DATA OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
// ----------------------------------------------------------------------------
#ifndef __PCL_EndianConversions_h
#define __PCL_EndianConversions_h
/// \file pcl/EndianConversions.h
#include <pcl/Defs.h>
#include <pcl/Math.h>
namespace pcl
{
// ----------------------------------------------------------------------------
/*!
* \defgroup endianness_conversion_and_detection Endianness Conversion and Detection Functions
*/
/*!
* Converts a 16-bit unsigned integer from big endian to little endian byte
* storage order.
*
* \ingroup endianness_conversion_and_detection
*/
inline uint16 BigToLittleEndian( uint16 x )
{
return (x << 8) | (x >> 8);
}
/*!
* Converts a 32-bit unsigned integer from big endian to little endian byte
* storage order.
*
* \ingroup endianness_conversion_and_detection
*/
inline uint32 BigToLittleEndian( uint32 x )
{
return (RotL( x, 8 ) & 0x00ff00ffu) | (RotR( x, 8 ) & 0xff00ff00u);
}
/*!
* Converts a 64-bit unsigned integer from big endian to little endian byte
* storage order.
*
* \ingroup endianness_conversion_and_detection
*/
inline uint64 BigToLittleEndian( uint64 x )
{
return (uint64( BigToLittleEndian( uint32( x ) ) ) << 32) | uint64( BigToLittleEndian( uint32( x >> 32 ) ) );
}
/*!
* A convenience synonym function for little-to-big endian conversions, which
* we define for the sake of code legibility. It is obviously equivalent to
* BigToLittleEndian( x ).
*
* \ingroup endianness_conversion_and_detection
*/
template <typename T> inline T LittleToBigEndian( T x )
{
return BigToLittleEndian( x );
}
// ----------------------------------------------------------------------------
union __pcl_endian_check__ { uint32 w; uint8 b[ sizeof( uint32 ) ]; };
constexpr __pcl_endian_check__ __pcl_endian_check_sample__ = { 0xdeadbeef };
#ifdef __clang__
inline bool IsLittleEndianMachine()
{
return __pcl_endian_check_sample__.b[0] == 0xef;
}
inline bool IsBigEndianMachine()
{
return __pcl_endian_check_sample__.b[0] == 0xde;
}
#else
// Clang fails here with "read of member 'b' of union with active member 'w' is
// not allowed in a constant expression".
/*!
* Returns true iff the caller is running on a little-endian architecture.
*
* \ingroup endianness_conversion_and_detection
*/
constexpr bool IsLittleEndianMachine()
{
return __pcl_endian_check_sample__.b[0] == 0xef;
}
/*!
* Returns true iff the caller is running on a big-endian architecture.
*
* \ingroup endianness_conversion_and_detection
*/
constexpr bool IsBigEndianMachine()
{
return __pcl_endian_check_sample__.b[0] == 0xde;
}
#endif // __clang__
// ----------------------------------------------------------------------------
} // pcl
#endif // __PCL_EndianConversions_h
// ----------------------------------------------------------------------------
// EOF pcl/EndianConversions.h - Released 2022-03-12T18:59:29Z