зеркало из https://github.com/AvaloniaUI/angle.git
93 строки
2.3 KiB
C++
93 строки
2.3 KiB
C++
//
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// Copyright 2014 The ANGLE Project Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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//
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// random_utils:
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// Helper functions for random number generation.
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//
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#ifndef UTIL_RANDOM_UTILS_H
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#define UTIL_RANDOM_UTILS_H
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#include <random>
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#include <vector>
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#include "common/vector_utils.h"
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#include "util/util_export.h"
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namespace angle
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{
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class ANGLE_UTIL_EXPORT RNG
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{
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public:
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// Seed from clock
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RNG();
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// Seed from fixed number.
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RNG(unsigned int seed);
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~RNG();
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void reseed(unsigned int newSeed);
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bool randomBool(float probTrue = 0.5f);
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int randomInt();
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int randomIntBetween(int min, int max);
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unsigned int randomUInt();
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float randomFloat();
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float randomFloatBetween(float min, float max);
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float randomFloatNonnegative();
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float randomNegativeOneToOne();
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template <class T>
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T &randomSelect(std::vector<T> &elements)
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{
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return elements[randomIntBetween(0, static_cast<int>(elements.size()) - 1)];
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}
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template <class T>
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const T &randomSelect(const std::vector<T> &elements)
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{
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return elements.at(randomIntBetween(0, static_cast<int>(elements.size()) - 1));
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}
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private:
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std::default_random_engine mGenerator;
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};
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// Implemented inline to avoid cross-module allocation issues.
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inline void FillVectorWithRandomUBytes(RNG *rng, std::vector<uint8_t> *data)
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{
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for (size_t i = 0; i < data->size(); ++i)
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{
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(*data)[i] = static_cast<uint8_t>(rng->randomIntBetween(0, 255));
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}
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}
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inline void FillVectorWithRandomUBytes(std::vector<uint8_t> *data)
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{
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RNG rng;
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FillVectorWithRandomUBytes(&rng, data);
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}
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inline Vector3 RandomVec3(int seed, float minValue, float maxValue)
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{
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RNG rng(seed);
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srand(seed);
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return Vector3(rng.randomFloatBetween(minValue, maxValue),
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rng.randomFloatBetween(minValue, maxValue),
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rng.randomFloatBetween(minValue, maxValue));
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}
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inline Vector4 RandomVec4(int seed, float minValue, float maxValue)
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{
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RNG rng(seed);
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srand(seed);
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return Vector4(
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rng.randomFloatBetween(minValue, maxValue), rng.randomFloatBetween(minValue, maxValue),
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rng.randomFloatBetween(minValue, maxValue), rng.randomFloatBetween(minValue, maxValue));
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}
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} // namespace angle
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#endif // UTIL_RANDOM_UTILS_H
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