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// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "distribution1d.h"
namespace embree
{
/*! 2D probability distribution. The probability distribution
* function (PDF) can be initialized with arbitrary data and be
* sampled. */
class Distribution2D
{
public:
/*! Default construction. */
Distribution2D();
/*! Construction from 2D distribution array f. */
Distribution2D(const float* f, const size_t width, const size_t height);
/*! Initialized the PDF and CDF arrays. */
void init(const float* f, const size_t width, const size_t height);
public:
/*! Draws a sample from the distribution. \param u is a pair of
* random numbers to use for sampling */
Vec2f sample(const Vec2f& u) const;
/*! Returns the probability density a sample would be drawn from
* location p. */
float pdf(const Vec2f& p) const;
size_t width; //!< Number of elements in x direction
size_t height; //!< Number of elements in y direction
private:
Distribution1D yDist; //!< Distribution to select between rows
std::vector<Distribution1D> xDists; //!< One 1D Distribution per row
};
}
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