Sprout/sprout/numeric/dft/detail/triangle.hpp
2019-01-07 17:47:17 +09:00

34 lines
1.3 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 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_NUMERIC_DFT_DETAIL_TRINAGLE_HPP
#define SPROUT_NUMERIC_DFT_DETAIL_TRINAGLE_HPP
#include <sprout/config.hpp>
#include <sprout/math/constants.hpp>
#include <sprout/math/sin.hpp>
#include <sprout/math/asin.hpp>
namespace sprout {
namespace detail {
template<typename T>
inline SPROUT_CONSTEXPR T
triangle_value_impl(T const& t) {
typedef double elem_type;
using sprout::sin;
using sprout::asin;
return T(sprout::math::two_div_pi<elem_type>()) * asin(sin(T(sprout::math::two_pi<elem_type>()) * t));
}
template<typename T, typename Index>
inline SPROUT_CONSTEXPR T
triangle_value(T const& frequency, T const& amplitude, T const& phase, Index i) {
return amplitude * sprout::detail::triangle_value_impl(frequency * T(i) + phase);
}
} // namespace detail
} // namespace sprout
#endif // #ifndef SPROUT_NUMERIC_DFT_DETAIL_TRINAGLE_HPP