219 lines
8.7 KiB
C++
219 lines
8.7 KiB
C++
///\file
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/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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https://www.etlcpp.com
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Copyright(c) 2014 John Wellbelove
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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#ifndef ETL_NUMERIC_INCLUDED
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#define ETL_NUMERIC_INCLUDED
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#include "platform.h"
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#include "type_traits.h"
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#include "limits.h"
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#include "iterator.h"
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#if ETL_USING_STL
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#include <iterator>
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#endif
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///\defgroup numeric numeric
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///\ingroup utilities
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namespace etl
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{
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//***************************************************************************
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/// iota
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/// Reverse engineered version of std::iota for non C++ 0x11 compilers.
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/// Fills a range of elements with sequentially increasing values starting with <b>value</b>.
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///\param first An iterator to the first position to fill.
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///\param last An iterator to the last + 1 position.
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///\ingroup numeric
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//***************************************************************************
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template <typename TIterator, typename T>
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ETL_CONSTEXPR14 void iota(TIterator first, TIterator last, T value)
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{
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while (first != last)
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{
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*first++ = value++;
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}
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}
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//***************************************************************************
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/// midpoint
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/// For floating point.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 typename etl::enable_if<!etl::is_pointer<T>::value &&
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!etl::is_integral<T>::value &&
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etl::is_floating_point<T>::value, T>::type
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midpoint(T a, T b) ETL_NOEXCEPT
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{
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T lo = etl::numeric_limits<T>::min() * T(2);
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T hi = etl::numeric_limits<T>::max() * T(2);
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return ((abs(a) <= hi) && (abs(b) <= hi)) ?
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(a + b) / T(2) :
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(abs(a) < lo) ?
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a + (b / T(2)) :
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(abs(b) < lo) ?
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((a / T(2)) + b) :
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(a / T(2)) + (b / T(2));
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}
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//***************************************************************************
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/// midpoint
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/// For unsigned integrals.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 typename etl::enable_if<!etl::is_pointer<T>::value &&
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etl::is_integral<T>::value &&
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!etl::is_floating_point<T>::value &&
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etl::is_unsigned<T>::value, T>::type
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midpoint(T a, T b) ETL_NOEXCEPT
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{
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if (a > b)
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{
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return a - ((a - b) >> 1);
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}
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else
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{
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return a + ((b - a) >> 1);
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}
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}
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//***************************************************************************
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/// midpoint
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/// For signed integrals.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 typename etl::enable_if<!etl::is_pointer<T>::value&&
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etl::is_integral<T>::value &&
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!etl::is_floating_point<T>::value&&
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etl::is_signed<T>::value, T>::type
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midpoint(T a, T b) ETL_NOEXCEPT
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{
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typedef typename etl::make_unsigned<T>::type utype;
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if (a > b)
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{
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return a - T(utype(utype(a) - utype(b)) >> 1);
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}
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else
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{
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return a + T((utype(b) - utype(a)) >> 1);
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}
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}
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//***************************************************************************
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/// midpoint
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/// For pointers.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 typename etl::enable_if<etl::is_pointer<T>::value&&
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!etl::is_integral<T>::value &&
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!etl::is_floating_point<T>::value, T>::type
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midpoint(T a, T b) ETL_NOEXCEPT
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{
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if (a > b)
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{
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return b + (etl::distance(b, a) / 2U);
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}
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else
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{
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return a + (etl::distance(a, b) / 2U);
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}
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}
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//***************************************************************************
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/// midpoint
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/// For ETL random access iterators.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 T midpoint(T a, T b, typename etl::enable_if<!etl::is_pointer<T>::value &&
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!etl::is_integral<T>::value &&
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!etl::is_floating_point<T>::value &&
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etl::is_same<typename etl::iterator_traits<T>::iterator_category, ETL_OR_STD::random_access_iterator_tag>::value , int>::type = 0)
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{
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if (a > b)
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{
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return b + (etl::distance(b, a) / 2U);
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}
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else
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{
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return a + (etl::distance(a, b) / 2U);
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}
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}
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//***************************************************************************
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/// midpoint
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/// For ETL forward and bidirectional iterators.
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/// Parameter 'a' must be before 'b', otherwise the result is undefined.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14 T midpoint(T a, T b, typename etl::enable_if<(!etl::is_pointer<T>::value &&
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!etl::is_integral<T>::value &&
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!etl::is_floating_point<T>::value &&
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(etl::is_same<typename etl::iterator_traits<T>::iterator_category, ETL_OR_STD::forward_iterator_tag>::value ||
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etl::is_same<typename etl::iterator_traits<T>::iterator_category, ETL_OR_STD::bidirectional_iterator_tag>::value)), int>::type = 0)
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{
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etl::advance(a, etl::distance(a, b) / 2U);
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return a;
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}
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//***************************************************************************
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/// Linear interpolation
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/// For floating point.
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR typename etl::enable_if<etl::is_floating_point<T>::value, T>::type
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lerp(T a, T b, T t) ETL_NOEXCEPT
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{
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return a + (t * (b - a));
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}
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//***************************************************************************
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/// Linear interpolation
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/// For when any parameter is not floating point.
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//***************************************************************************
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template <typename TArithmetic1, typename TArithmetic2, typename TArithmetic3>
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ETL_CONSTEXPR typename etl::enable_if<!etl::is_floating_point<TArithmetic1>::value ||
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!etl::is_floating_point<TArithmetic2>::value ||
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!etl::is_floating_point<TArithmetic3>::value, typename etl::conditional<etl::is_same<TArithmetic1, long double>::value ||
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etl::is_same<TArithmetic2, long double>::value ||
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etl::is_same<TArithmetic3, long double>::value, long double, double>::type>::type
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lerp(TArithmetic1 a, TArithmetic2 b, TArithmetic3 t) ETL_NOEXCEPT
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{
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typedef typename etl::conditional<etl::is_integral<TArithmetic1>::value, double, TArithmetic1>::type typecast_a;
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typedef typename etl::conditional<etl::is_integral<TArithmetic2>::value, double, TArithmetic2>::type typecast_b;
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typedef typename etl::conditional<etl::is_integral<TArithmetic3>::value, double, TArithmetic3>::type typecast_t;
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return typecast_a(a) + (typecast_t(t) * (typecast_b(b) - typecast_a(a)));
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}
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}
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#endif
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