154 lines
3.7 KiB
C++
154 lines
3.7 KiB
C++
/*
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* This file is part of libgim.
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*
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* libgim is free software: you can redistribute it and/or modify it under the
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* terms of the GNU General Public License as published by the Free Software
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* Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with libgim. If not, see <http://www.gnu.org/licenses/>.
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*
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* Copyright 2010 Danny Robson <danny@nerdcruft.net>
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*/
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#include "maths.hpp"
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#include "float.hpp"
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#include <cmath>
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#include <type_traits>
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//-----------------------------------------------------------------------------
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template <typename T>
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bool
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is_pow2 (T value) {
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typedef typename std::enable_if<std::is_integral<T>::value, bool>::type return_type;
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return (return_type)(value && !(value & (value - 1)));
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}
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template bool is_pow2 (uint8_t);
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template bool is_pow2 (uint16_t);
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template bool is_pow2 (uint32_t);
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template bool is_pow2 (uint64_t);
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//-----------------------------------------------------------------------------
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template <typename T>
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double
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rootsquare (T a, T b)
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{ return sqrt (pow2 (a) + pow2 (b)); }
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template double rootsquare (double, double);
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template double rootsquare ( int, int);
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//-----------------------------------------------------------------------------
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template <typename T>
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bool
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is_integer (const T &value) {
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T integer;
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return exactly_equal (std::modf (value, &integer),
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static_cast<T> (0.0));
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}
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template bool is_integer (const double&);
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template bool is_integer (const float&);
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//-----------------------------------------------------------------------------
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template <>
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unsigned
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digits (const uint32_t &v) {
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return (v >= 1000000000) ? 10 :
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(v >= 100000000) ? 9 :
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(v >= 10000000) ? 8 :
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(v >= 1000000) ? 7 :
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(v >= 100000) ? 6 :
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(v >= 10000) ? 5 :
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(v >= 1000) ? 4 :
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(v >= 100) ? 3 :
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(v >= 10) ? 2 :
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1;
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}
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//-----------------------------------------------------------------------------
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template <>
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bool
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almost_equal (const float &a, const float &b)
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{ return ieee_single::almost_equal (a, b); }
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template <>
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bool
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almost_equal (const double &a, const double &b)
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{ return ieee_double::almost_equal (a, b); }
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//-----------------------------------------------------------------------------
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template <typename T>
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typename std::enable_if<std::is_integral<T>::value, T>::type
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round_up (T value, T align) {
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CHECK_HARD (align > 1);
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return (value + align - 1) / align;
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}
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//-----------------------------------------------------------------------------
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template <typename T>
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T
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round_pow2 (T value) {
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typedef typename std::enable_if<std::is_integral<T>::value, T>::type return_type;
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--value;
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for (unsigned i = 1; i < sizeof (T) * 8; i <<= 1) {
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value |= value >> i;
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}
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++value;
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return (return_type)value;
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}
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template uint8_t round_pow2 (uint8_t);
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template uint16_t round_pow2 (uint16_t);
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template uint32_t round_pow2 (uint32_t);
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template uint64_t round_pow2 (uint64_t);
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//-----------------------------------------------------------------------------
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template <typename T>
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int
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sign (T val) {
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return val >= 0 ? 1 : -1;
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}
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template <>
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int
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sign (float val) {
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return static_cast<int> (copysign (1.0f, val));
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}
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template <>
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int
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sign (double val) {
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return static_cast<int> (copysign (1.0, val));
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}
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template int sign (int);
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