simulation_parameters.h

#pragma once

#include <cstdlib>
#include <tuple>

namespace wayverb {
namespace waveguide {

struct single_band_parameters final {
    double cutoff;

    double usable_portion;
};

constexpr auto to_tuple(const single_band_parameters& x) {
    return std::tie(x.cutoff, x.usable_portion);
}

constexpr bool operator==(const single_band_parameters& a,
                          const single_band_parameters& b) {
    return to_tuple(a) == to_tuple(b);
}

constexpr bool operator!=(const single_band_parameters& a,
                          const single_band_parameters& b) {
    return !(a == b);
}

struct multiple_band_constant_spacing_parameters final {
    size_t bands;

    double cutoff;

    double usable_portion;
};

constexpr auto to_tuple(const multiple_band_constant_spacing_parameters& x) {
    return std::tie(x.bands, x.cutoff, x.usable_portion);
}

constexpr bool operator==(const multiple_band_constant_spacing_parameters& a,
                          const multiple_band_constant_spacing_parameters& b) {
    return to_tuple(a) == to_tuple(b);
}

constexpr bool operator!=(const multiple_band_constant_spacing_parameters& a,
                          const multiple_band_constant_spacing_parameters& b) {
    return !(a == b);
}

constexpr auto compute_cutoff_frequency(double sample_rate,
                                        double usable_portion) {
    return sample_rate * 0.25 * usable_portion;
}

constexpr auto compute_sampling_frequency(double cutoff,
                                          double usable_portion) {
    return cutoff / (0.25 * usable_portion);
}

template <typename T>
constexpr auto compute_sampling_frequency(const T& t) {
    return compute_sampling_frequency(t.cutoff, t.usable_portion);
}

}  // namespace waveguide
}  // namespace wayverb