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// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "default.h"
namespace embree
{
/*! 1D probability distribution. The probability distribution
* function (PDF) can be initialized with arbitrary data and be
* sampled. */
class Distribution1D
{
public:
/*! Default construction. */
Distribution1D();
/*! Construction from distribution array f. */
Distribution1D(const float* f, const size_t size);
/*! Initialized the PDF and CDF arrays. */
void init(const float* f, const size_t size);
public:
/*! Draws a sample from the distribution. \param u is a random
* number to use for sampling */
float sample(const float u) const;
/*! Returns the probability density a sample would be drawn from location p. */
float pdf(const float p) const;
private:
size_t size; //!< Number of elements in the PDF
std::vector<float> PDF; //!< Probability distribution function
std::vector<float> CDF; //!< Cumulative distribution function (required for sampling)
};
}
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