saturate.hpp
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// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
//
// Copyright (C) 2018 Intel Corporation
#ifndef OPENCV_GAPI_OWN_SATURATE_HPP
#define OPENCV_GAPI_OWN_SATURATE_HPP
#include <math.h>
#include <limits>
#include <type_traits>
#include <opencv2/gapi/own/assert.hpp>
namespace cv { namespace gapi { namespace own {
//-----------------------------
//
// Numeric cast with saturation
//
//-----------------------------
template<typename DST, typename SRC>
static inline DST saturate(SRC x)
{
// only integral types please!
GAPI_DbgAssert(std::is_integral<DST>::value &&
std::is_integral<SRC>::value);
if (std::is_same<DST, SRC>::value)
return static_cast<DST>(x);
if (sizeof(DST) > sizeof(SRC))
return static_cast<DST>(x);
// compiler must recognize this saturation,
// so compile saturate<s16>(a + b) with adds
// instruction (e.g.: _mm_adds_epi16 if x86)
return x < std::numeric_limits<DST>::min()?
std::numeric_limits<DST>::min():
x > std::numeric_limits<DST>::max()?
std::numeric_limits<DST>::max():
static_cast<DST>(x);
}
// Note, that OpenCV rounds differently:
// - like std::round() for add, subtract
// - like std::rint() for multiply, divide
template<typename DST, typename SRC, typename R>
static inline DST saturate(SRC x, R round)
{
if (std::is_floating_point<DST>::value)
{
return static_cast<DST>(x);
}
else if (std::is_integral<SRC>::value)
{
GAPI_DbgAssert(std::is_integral<DST>::value &&
std::is_integral<SRC>::value);
return saturate<DST>(x);
}
else
{
GAPI_DbgAssert(std::is_integral<DST>::value &&
std::is_floating_point<SRC>::value);
#ifdef _WIN32
// Suppress warning about converting x to floating-point
// Note that x is already floating-point at this point
#pragma warning(disable: 4244)
#endif
int ix = static_cast<int>(round(x));
#ifdef _WIN32
#pragma warning(default: 4244)
#endif
return saturate<DST>(ix);
}
}
// explicit suffix 'd' for double type
inline double ceild(double x) { return ceil(x); }
inline double floord(double x) { return floor(x); }
inline double roundd(double x) { return round(x); }
inline double rintd(double x) { return rint(x); }
} //namespace own
} //namespace gapi
} //namespace cv
#endif /* OPENCV_GAPI_OWN_SATURATE_HPP */