mpd/src/pcm/PcmUtils.hxx
2013-11-22 23:24:40 +01:00

79 lines
2.1 KiB
C++

/*
* Copyright (C) 2003-2013 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_PCM_UTILS_H
#define MPD_PCM_UTILS_H
#include "Compiler.h"
#include <limits>
#include <stdint.h>
/**
* Add a byte count to the specified pointer. This is a utility
* function to convert a source pointer and a byte count to an "end"
* pointer for use in loops.
*/
template<typename T>
static inline const T *
pcm_end_pointer(const T *p, size_t size)
{
return (const T *)((const uint8_t *)p + size);
}
/**
* Check if the value is within the range of the provided bit size,
* and caps it if necessary.
*/
template<typename T, typename U, unsigned bits>
gcc_const
static inline T
PcmClamp(U x)
{
constexpr U MIN_VALUE = -(U(1) << (bits - 1));
constexpr U MAX_VALUE = (U(1) << (bits - 1)) - 1;
typedef std::numeric_limits<T> limits;
static_assert(MIN_VALUE >= limits::min(), "out of range");
static_assert(MAX_VALUE <= limits::max(), "out of range");
if (gcc_unlikely(x < MIN_VALUE))
return T(MIN_VALUE);
if (gcc_unlikely(x > MAX_VALUE))
return T(MAX_VALUE);
return T(x);
}
/**
* Check if the values in this buffer are within the range of the
* provided bit size, and clamps them whenever necessary.
*/
template<typename T, typename U, unsigned bits>
static inline void
PcmClampN(T *dest, const U *src, unsigned n)
{
while (n-- > 0)
*dest++ = PcmClamp<T, U, bits>(*src++);
}
#endif