tuning.hpp

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#pragma once
 
#include <pulp/timeline/assets.hpp>
 
#include <compare>
#include <cstdint>
#include <optional>
 
namespace pulp::timeline {


enum class TuningSystem : std::uint8_t {
    EqualTemperament,
    MtsEsp,
    Scala,
};

inline constexpr std::uint32_t kDefaultReferencePitchMillihertz = 440'000;
inline constexpr std::uint32_t kMinReferencePitchMillihertz = 20'000;
inline constexpr std::uint32_t kMaxReferencePitchMillihertz = 20'000'000;

struct TuningReference {
    TuningSystem system = TuningSystem::EqualTemperament;
    std::uint32_t reference_pitch_millihertz = kDefaultReferencePitchMillihertz;
    std::optional<ContentHash> scale_content;
    std::optional<ContentHash> keyboard_map_content;
 
    constexpr auto operator<=>(const TuningReference&) const = default;
};

constexpr bool valid_tuning_reference(const TuningReference& tuning) noexcept {
    if (tuning.reference_pitch_millihertz < kMinReferencePitchMillihertz ||
        tuning.reference_pitch_millihertz > kMaxReferencePitchMillihertz)
        return false;
    switch (tuning.system) {
    case TuningSystem::EqualTemperament:
    case TuningSystem::MtsEsp:
        return !tuning.scale_content && !tuning.keyboard_map_content;
    case TuningSystem::Scala:
        return tuning.scale_content && tuning.scale_content->valid() &&
               (!tuning.keyboard_map_content || tuning.keyboard_map_content->valid());
    }
    return false;
}

 
} // namespace pulp::timeline