halton.h

#ifdef _MSC_VER
#pragma once
#endif

#ifndef _SPICA_HALTON_H_
#define _SPICA_HALTON_H_

#include <memory>
#include "core/cobject.h"
#include "core/sampler.h"
#include "core/random.h"

namespace spica {

class SPICA_EXPORTS Halton : public Sampler {
public:
    explicit Halton(int ns = 200, bool isPermute = true,
                    uint32_t seed = 0u);
    explicit Halton(RenderParams &params);

    ~Halton();

    double get1D() override;

    bool startNextSample() override;

    std::unique_ptr<Sampler> clone(unsigned int seed = 0) const override;

private:
    double radicalInverse(int n, int base, const int* p) const;

    static const int nPrimes_ = 1000;
    int nSamples_;
    int sampleIndex_;
    int nUsedSamples_;
    bool isPermute_;
    Random rng_;
    const std::unique_ptr<int[]> bases_;
    const std::unique_ptr<int[]> permute_;
    const std::unique_ptr<double[]> samples_;

};

SPICA_EXPORT_PLUGIN(Halton, "Halton sampler");

}  // namespace spica

#endif  // _SPICA_HALTON_H_