/**************************************************************************** Copyright (c) 2010-2012 cocos2d-x.org Copyright (c) 2013-2016 Chukong Technologies Inc. Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd. https://axis-project.github.io/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ****************************************************************************/ #ifndef __ccRandom_H_ #define __ccRandom_H_ #include #include #include "platform/CCPlatformMacros.h" /** * @addtogroup base * @{ */ NS_AX_BEGIN /** * @class RandomHelper * @brief A helper class for creating random number. */ class CC_DLL RandomHelper { public: template static T random_real(T min, T max) { std::uniform_real_distribution dist(min, max); auto& mt = RandomHelper::getEngine(); return dist(mt); } template static T random_int(T min, T max) { std::uniform_int_distribution dist(min, max); auto& mt = RandomHelper::getEngine(); return dist(mt); } private: static std::mt19937& getEngine(); }; /** * Returns a random value between `min` and `max`. */ template inline T random(T min, T max) { return RandomHelper::random_int(min, max); } template <> inline float random(float min, float max) { return RandomHelper::random_real(min, max); } template <> inline long double random(long double min, long double max) { return RandomHelper::random_real(min, max); } template <> inline double random(double min, double max) { return RandomHelper::random_real(min, max); } /** * Returns a random int between 0 and RAND_MAX. */ inline int random() { return axis::random(0, RAND_MAX); }; /** * Returns a random float between -1 and 1. * It can be seeded using std::srand(seed); */ inline float rand_minus1_1() { // FIXME: using the new c++11 random engine generator // without a proper way to set a seed is not useful. // Resorting to the old random method since it can // be seeded using std::srand() return ((std::rand() / (float)RAND_MAX) * 2) - 1; // return axis::random(-1.f, 1.f); }; /** * Returns a random float between 0 and 1. * It can be seeded using std::srand(seed); */ inline float rand_0_1() { // FIXME: using the new c++11 random engine generator // without a proper way to set a seed is not useful. // Resorting to the old random method since it can // be seeded using std::srand() return std::rand() / (float)RAND_MAX; // return axis::random(0.f, 1.f); }; NS_AX_END // end group /// @} #endif //__ccRandom_H_