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#pragma once
#include "../base/base.hpp"
#include "../base/assert.hpp"
#include "../std/cmath.hpp"
#include "../std/limits.hpp"
#include "../std/type_traits.hpp"
#include <boost/integer.hpp>
namespace my
{
template <typename T> inline T Abs(T x)
{
return (x < 0 ? -x : x);
}
// Compare floats or doubles for almost equality.
// maxULPs - number of closest floating point values that are considered equal.
// Infinity is treated as almost equal to the largest possible floating point values.
// NaN produces undefined result.
// See http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm for details.
template <typename FloatT> bool AlmostEqual(FloatT x, FloatT y, unsigned int maxULPs = 256)
{
STATIC_ASSERT(is_floating_point<FloatT>::value);
STATIC_ASSERT(numeric_limits<FloatT>::is_iec559);
STATIC_ASSERT(!numeric_limits<FloatT>::is_exact);
STATIC_ASSERT(!numeric_limits<FloatT>::is_integer);
// Make sure maxUlps is non-negative and small enough that the
// default NAN won't compare as equal to anything.
ASSERT_LESS(maxULPs, 4 * 1024 * 1024, ());
int const bits = 8 * sizeof(FloatT);
typedef typename boost::int_t<bits>::exact IntType;
typedef typename boost::uint_t<bits>::exact UIntType;
IntType xInt = *reinterpret_cast<IntType const *>(&x);
IntType yInt = *reinterpret_cast<IntType const *>(&y);
// Make xInt and yInt lexicographically ordered as a twos-complement int
IntType const highestBit = IntType(1) << (bits - 1);
if (xInt < 0)
xInt = highestBit - xInt;
if (yInt < 0)
yInt = highestBit - yInt;
UIntType const diff = Abs(xInt - yInt);
return (diff <= maxULPs);
}
template <typename TFloat> inline TFloat DegToRad(TFloat deg)
{
return deg * TFloat(math::pi) / TFloat(180);
}
template <typename TFloat> inline TFloat RadToDeg(TFloat rad)
{
return rad * TFloat(180) / TFloat(math::pi);
}
template <typename T> inline T id(T const & x)
{
return x;
}
template <typename T> inline T sq(T const & x)
{
return x * x;
}
template <typename T, typename TMin, typename TMax>
inline T clamp(T x, TMin xmin, TMax xmax)
{
if (x > xmax)
return xmax;
if (x < xmin)
return xmin;
return x;
}
template <typename T> inline bool between_s(T a, T b, T x)
{
return (a <= x && x <= b);
}
template <typename T> inline bool between_i(T a, T b, T x)
{
return (a < x && x < b);
}
inline int rounds(double x)
{
return (x > 0.0 ? int(x + 0.5) : int(x - 0.5));
}
inline size_t SizeAligned(size_t size, size_t align)
{
// static_cast .
return size + (static_cast<size_t>(-static_cast<ptrdiff_t>(size)) & (align - 1));
}
template <typename T>
bool IsIntersect(T const & x0, T const & x1, T const & x2, T const & x3)
{
return !((x1 < x2) || (x3 < x0));
}
// Computes x^n.
template <typename T> inline T PowUint(T x, uint64_t n)
{
T res = 1;
for (T t = x; n > 0; n >>= 1, t *= t)
if (n & 1)
res *= t;
return res;
}
template <typename T> inline T NextModN(T x, T n)
{
return x + 1 == n ? 0 : x + 1;
}
template <typename T> inline T PrevModN(T x, T n)
{
return x == 0 ? n - 1 : x - 1;
}
}
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