mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-25 00:43:44 +00:00
125 lines
4.7 KiB
C++
125 lines
4.7 KiB
C++
/*=============================================================================
|
||
Copyright (c) 2011-2016 Bolero MURAKAMI
|
||
https://github.com/bolero-MURAKAMI/Sprout
|
||
|
||
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
||
=============================================================================*/
|
||
#ifndef SPROUT_MATH_ATAN2_HPP
|
||
#define SPROUT_MATH_ATAN2_HPP
|
||
|
||
#include <type_traits>
|
||
#include <sprout/config.hpp>
|
||
#include <sprout/limits.hpp>
|
||
#include <sprout/math/detail/config.hpp>
|
||
#include <sprout/math/detail/float_compute.hpp>
|
||
#include <sprout/math/constants.hpp>
|
||
#include <sprout/math/isnan.hpp>
|
||
#include <sprout/math/signbit.hpp>
|
||
#include <sprout/math/copysign.hpp>
|
||
#include <sprout/math/signbit.hpp>
|
||
#include <sprout/math/atan.hpp>
|
||
#include <sprout/type_traits/float_promote.hpp>
|
||
#include <sprout/type_traits/enabler_if.hpp>
|
||
|
||
namespace sprout {
|
||
namespace math {
|
||
namespace detail {
|
||
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
|
||
inline SPROUT_CONSTEXPR float
|
||
builtin_atan2(float y, float x) {
|
||
return __builtin_atan2f(y, x);
|
||
}
|
||
inline SPROUT_CONSTEXPR double
|
||
builtin_atan2(double y, double x) {
|
||
return __builtin_atan2(y, x);
|
||
}
|
||
inline SPROUT_CONSTEXPR long double
|
||
builtin_atan2(long double y, long double x) {
|
||
return __builtin_atan2l(y, x);
|
||
}
|
||
#endif
|
||
|
||
template<typename T>
|
||
inline SPROUT_CONSTEXPR T
|
||
atan2_impl(T y, T x) {
|
||
return x < 0 ? sprout::math::atan(y / x) + (
|
||
y < 0 ? -sprout::math::pi<T>()
|
||
: sprout::math::pi<T>()
|
||
)
|
||
: sprout::math::atan(y / x)
|
||
;
|
||
}
|
||
} // namespace detail
|
||
//
|
||
// atan2
|
||
//
|
||
// issue:
|
||
// [ !(SPROUT_USE_BUILTIN_CMATH_FUNCTION || SPROUT_USE_BUILTIN_COPYSIGN_FUNCTION) ]
|
||
// atan2(<28>}0, -0) returns <20>}ƒÎ .
|
||
// # returns <20>}0 . ( same as atan2(<28>}0, +0) )
|
||
// atan2(-0, x) returns -ƒÎ for x < 0.
|
||
// # returns +ƒÎ . ( same as atan2(+0, x) )
|
||
// atan2(-NaN, -NaN) returns -NaN .
|
||
// # returns +NaN . ( same as atan2(+NaN, +NaN) )
|
||
//
|
||
template<
|
||
typename FloatType,
|
||
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
|
||
>
|
||
inline SPROUT_CONSTEXPR FloatType
|
||
atan2(FloatType y, FloatType x) {
|
||
return sprout::math::isnan(y)
|
||
? sprout::math::isnan(x)
|
||
? sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
|
||
: sprout::numeric_limits<FloatType>::quiet_NaN()
|
||
: y
|
||
: sprout::math::isnan(x) ? x
|
||
: x == -sprout::numeric_limits<FloatType>::infinity()
|
||
? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::three_quarters_pi<FloatType>()
|
||
: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::three_quarters_pi<FloatType>()
|
||
: sprout::math::copysign(sprout::math::pi<FloatType>(), y)
|
||
: x == sprout::numeric_limits<FloatType>::infinity()
|
||
? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::quarter_pi<FloatType>()
|
||
: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::quarter_pi<FloatType>()
|
||
: FloatType(0) * y
|
||
: y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::half_pi<FloatType>()
|
||
: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::half_pi<FloatType>()
|
||
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
|
||
: sprout::math::detail::builtin_atan2(y, x)
|
||
#else
|
||
: y == 0
|
||
? x < 0 ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
|
||
: x > 0 ? FloatType(0) * y
|
||
: sprout::math::signbit(x) ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
|
||
: FloatType(0) * y
|
||
: x == 0
|
||
? y < 0 ? -sprout::math::half_pi<FloatType>()
|
||
: sprout::math::half_pi<FloatType>()
|
||
: static_cast<FloatType>(
|
||
sprout::math::detail::atan2_impl(
|
||
static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
|
||
static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)
|
||
)
|
||
)
|
||
#endif
|
||
;
|
||
}
|
||
template<
|
||
typename ArithmeticType1,
|
||
typename ArithmeticType2,
|
||
typename sprout::enabler_if<
|
||
std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
|
||
>::type = sprout::enabler
|
||
>
|
||
inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
|
||
atan2(ArithmeticType1 y, ArithmeticType2 x) {
|
||
typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
|
||
return sprout::math::atan2(static_cast<type>(y), static_cast<type>(x));
|
||
}
|
||
} // namespace math
|
||
|
||
using sprout::math::atan2;
|
||
} // namespace sprout
|
||
|
||
#endif // #ifndef SPROUT_MATH_ATAN2_HPP
|