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Fuzzy comparison is implemented only on floating-point types with type-specific epsilon, on integral types classic operator== is used. TypeTraits class is now extension of Math::TypeTraits (where it makes sense).pull/279/head
Vladimír Vondruš
14 years ago
5 changed files with 232 additions and 17 deletions
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/*
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Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz> |
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This file is part of Magnum. |
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Magnum is free software: you can redistribute it and/or modify |
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it under the terms of the GNU Lesser General Public License version 3 |
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only, as published by the Free Software Foundation. |
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Magnum is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU Lesser General Public License version 3 for more details. |
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*/ |
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#include "TypeTraitsTest.h" |
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#include <QtTest/QTest> |
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#include "TypeTraits.h" |
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QTEST_APPLESS_MAIN(Magnum::Math::Test::TypeTraitsTest) |
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namespace Magnum { namespace Math { namespace Test { |
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void TypeTraitsTest::equalsIntegral() { |
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_equalsIntegral<unsigned char>(); |
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_equalsIntegral<char>(); |
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_equalsIntegral<unsigned short>(); |
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_equalsIntegral<short>(); |
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_equalsIntegral<unsigned int>(); |
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_equalsIntegral<int>(); |
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_equalsIntegral<unsigned long int>(); |
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_equalsIntegral<long int>(); |
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_equalsIntegral<unsigned long long>(); |
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_equalsIntegral<long long>(); |
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} |
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void TypeTraitsTest::equalsFloatingPoint() { |
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_equalsFloatingPoint<float>(); |
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_equalsFloatingPoint<double>(); |
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} |
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template<class T> void TypeTraitsTest::_equalsIntegral() { |
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QVERIFY(TypeTraits<T>::equals(1, 1+TypeTraits<T>::epsilon())); |
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QVERIFY(!TypeTraits<T>::equals(1, 2)); |
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} |
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template<class T> void TypeTraitsTest::_equalsFloatingPoint() { |
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QVERIFY(TypeTraits<T>::equals(1.0f+TypeTraits<T>::epsilon()/2, 1.0f)); |
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QVERIFY(!TypeTraits<T>::equals(1.0f+TypeTraits<T>::epsilon()*2, 1.0f)); |
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QEXPECT_FAIL(0, "Comparing to infinity is broken", Continue); |
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QVERIFY(TypeTraits<T>::equals(std::numeric_limits<T>::infinity(), |
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std::numeric_limits<T>::infinity())); |
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QVERIFY(!TypeTraits<T>::equals(std::numeric_limits<T>::quiet_NaN(), |
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std::numeric_limits<T>::quiet_NaN())); |
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} |
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}}} |
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#ifndef Magnum_Math_Test_TypeTraitsTest_h |
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#define Magnum_Math_Test_TypeTraitsTest_h |
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/*
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Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz> |
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This file is part of Magnum. |
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|
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Magnum is free software: you can redistribute it and/or modify |
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it under the terms of the GNU Lesser General Public License version 3 |
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only, as published by the Free Software Foundation. |
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|
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Magnum is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU Lesser General Public License version 3 for more details. |
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*/ |
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#include <QtCore/QObject> |
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namespace Magnum { namespace Math { namespace Test { |
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class TypeTraitsTest: public QObject { |
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Q_OBJECT |
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private slots: |
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void equalsFloatingPoint(); |
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void equalsIntegral(); |
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private: |
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template<class T> void _equalsFloatingPoint(); |
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template<class T> void _equalsIntegral(); |
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}; |
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}}} |
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#endif |
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#ifndef Magnum_Math_TypeTraits_h |
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#define Magnum_Math_TypeTraits_h |
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/*
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Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz> |
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This file is part of Magnum. |
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|
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Magnum is free software: you can redistribute it and/or modify |
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it under the terms of the GNU Lesser General Public License version 3 |
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only, as published by the Free Software Foundation. |
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|
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Magnum is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU Lesser General Public License version 3 for more details. |
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*/ |
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/** @file
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* @brief Class Magnum::Math::TypeTraits |
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*/ |
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#include <cmath> |
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namespace Magnum { namespace Math { |
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/**
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@brief Traits class for numeric types |
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Traits classes are usable for detecting type features at compile time without |
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the need for repeated code such as method overloading or template |
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specialization for given types. |
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This class and class methods are specialized only for types where it makes |
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sense, it has empty implementation for unknown types or types which don't |
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support given feature, thus forcing the compilation stop with an error. |
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*/ |
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template<class T> struct TypeTraits { |
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#ifdef DOXYGEN_GENERATING_OUTPUT |
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/* Development note: the following values are implemented as inline
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functions, not as static const variables, because the compiler will |
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inline the return values instead of referencing to static data and |
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unlike static const variables these functions can return floats. */ |
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/**
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* @brief Epsilon value for fuzzy compare |
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* |
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* Returns 0 for integer types and reasonably small value for |
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* floating-point types. |
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*/ |
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constexpr inline static T epsilon(); |
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/**
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* @brief Fuzzy compare |
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* |
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* Uses equality for integer types and fuzzy compare for floating-point |
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* types (using @ref epsilon value). |
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*/ |
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static bool equals(T a, T b); |
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#endif |
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}; |
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/** @bug Infinity comparison! */ |
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/**
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* @todo Implement better fuzzy comparison algorithm, like at |
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* http://floating-point-gui.de/errors/comparison/ or
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* http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
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*/ |
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#ifndef DOXYGEN_GENERATING_OUTPUT |
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template<class T> struct _TypeTraitsIntegral { |
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constexpr inline static T epsilon() { return 0; } |
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inline constexpr static bool equals(T a, T b) { |
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return a == b; |
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} |
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}; |
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template<> struct TypeTraits<unsigned char>: public _TypeTraitsIntegral<unsigned char> {}; |
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template<> struct TypeTraits<char>: public _TypeTraitsIntegral<char> {}; |
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template<> struct TypeTraits<unsigned short>: public _TypeTraitsIntegral<unsigned short> {}; |
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template<> struct TypeTraits<short>: public _TypeTraitsIntegral<short> {}; |
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template<> struct TypeTraits<unsigned int>: public _TypeTraitsIntegral<unsigned int> {}; |
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template<> struct TypeTraits<int>: public _TypeTraitsIntegral<int> {}; |
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/* long is 32 bits somewhere and 64 bits elsewhere, so it cannot be mapped to
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any of them */ |
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template<> struct TypeTraits<long unsigned int>: public _TypeTraitsIntegral<long unsigned int> {}; |
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template<> struct TypeTraits<long int>: public _TypeTraitsIntegral<long int> {}; |
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template<> struct TypeTraits<unsigned long long>: public _TypeTraitsIntegral<unsigned long long> {}; |
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template<> struct TypeTraits<long long>: public _TypeTraitsIntegral<long long> {}; |
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template<class T> struct _TypeTraitsFloatingPoint { |
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inline static bool equals(T a, T b) { |
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return std::abs(a - b) < TypeTraits<T>::epsilon(); |
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} |
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}; |
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template<> struct TypeTraits<float>: public _TypeTraitsFloatingPoint<float> { |
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constexpr inline static float epsilon() { return 1.0e-6f; } |
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}; |
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template<> struct TypeTraits<double>: public _TypeTraitsFloatingPoint<double> { |
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constexpr inline static double epsilon() { return 1.0e-12; } |
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}; |
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#endif |
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}} |
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#endif |
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