YM2413Burczynski.hh

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#ifndef YM2413BURCZYNSKI_HH
#define YM2413BURCZYNSKI_HH
 
#include "YM2413Core.hh"
 
#include "FixedPoint.hh"
#include "serialize_meta.hh"
 
#include <array>
#include <span>
 
namespace openmsx {
namespace YM2413Burczynski {
 
// sin wave entries
inline constexpr int SIN_BITS = 10;
inline constexpr size_t SIN_LEN  = 1 << SIN_BITS;
inline constexpr size_t SIN_MASK = SIN_LEN - 1;
 
class Channel;
 
using FreqIndex = FixedPoint<16>;
 
class Slot
{
public:
        Slot();
 
        void resetOperators();
 
        void updateGenerators(const Channel& channel);
 
        [[nodiscard]] int calcOutput(const Channel& channel, unsigned eg_cnt, bool carrier,
                                     unsigned lfo_am, int phase);
        [[nodiscard]] int calc_slot_mod(const Channel& channel, unsigned eg_cnt, bool carrier,
                                        unsigned lfo_pm, unsigned lfo_am);
        [[nodiscard]] int calc_envelope(const Channel& channel, unsigned eg_cnt, bool carrier);
        [[nodiscard]] int calc_phase(const Channel& channel, unsigned lfo_pm);
 
        enum class KeyPart : uint8_t { MAIN = 1, RHYTHM = 2 };
        void setKeyOn(KeyPart part);
        void setKeyOff(KeyPart part);
        void setKeyOnOff(KeyPart part, bool enabled);
 
        [[nodiscard]] bool isActive() const;
 
        void setFrequencyMultiplier(uint8_t value);
 
        void setKeyScaleRate(bool value);
 
        void setEnvelopeSustained(bool value);
 
        void setVibrato(bool value);
 
        void setAmplitudeModulation(bool value);
 
        void setTotalLevel(const Channel& channel, uint8_t value);
 
        void setKeyScaleLevel(const Channel& channel, uint8_t value);
 
        void setWaveform(uint8_t value);
 
        void setFeedbackShift(uint8_t value);
 
        void setAttackRate(const Channel& channel, uint8_t value);
 
        void setDecayRate(const Channel& channel, uint8_t value);
 
        void setReleaseRate(const Channel& channel, uint8_t value);
 
        void setSustainLevel(uint8_t value);
 
        void updateFrequency(const Channel& channel);
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
public: // public for serialization, otherwise could be private
        enum class EnvelopeState {
                DUMP, ATTACK, DECAY, SUSTAIN, RELEASE, OFF
        };
 
private:
        void setEnvelopeState(EnvelopeState state);
 
        void updateTotalLevel(const Channel& channel);
        void updateAttackRate(int kcodeScaled);
        void updateDecayRate(int kcodeScaled);
        void updateReleaseRate(int kcodeScaled);
 
        std::span<const unsigned, SIN_LEN> waveTable;   // waveform select
 
        // Phase Generator
        FreqIndex phase{0}; // frequency counter
        FreqIndex freq{0};  // frequency counter step
 
        // Envelope Generator
        int TL{0};      // total level: TL << 2
        int TLL{0};     // adjusted now TL
        int egOut{0};   // envelope counter
        int sl{0};      // sustain level: sl_tab[SL]
        EnvelopeState state;
 
        std::array<int, 2> op1_out = {0, 0}; // MOD output for feedback
        bool eg_sustain{false};  // percussive/non-percussive mode
        uint8_t fb_shift{0}; // feedback shift value
 
        uint8_t key{0}; // 0 = KEY OFF, >0 = KEY ON
 
        std::span<const uint8_t, 8> eg_sel_dp;
        std::span<const uint8_t, 8> eg_sel_ar;
        std::span<const uint8_t, 8> eg_sel_dr;
        std::span<const uint8_t, 8> eg_sel_rr;
        std::span<const uint8_t, 8> eg_sel_rs;
        unsigned eg_mask_dp{0}; // == (1 << eg_sh_dp) - 1
        unsigned eg_mask_ar{0}; // == (1 << eg_sh_ar) - 1
        unsigned eg_mask_dr{0}; // == (1 << eg_sh_dr) - 1
        unsigned eg_mask_rr{0}; // == (1 << eg_sh_rr) - 1
        unsigned eg_mask_rs{0}; // == (1 << eg_sh_rs) - 1
        uint8_t eg_sh_dp{0};    // (dump state)
        uint8_t eg_sh_ar{0};    // (attack state)
        uint8_t eg_sh_dr{0};    // (decay state)
        uint8_t eg_sh_rr{0};    // (release state for non-perc.)
        uint8_t eg_sh_rs{0};    // (release state for perc.mode)
 
        uint8_t ar{0};  // attack rate: AR<<2
        uint8_t dr{0};  // decay rate:  DR<<2
        uint8_t rr{0};  // release rate:RR<<2
        uint8_t KSR{0}; // key scale rate
        uint8_t ksl{0}; // key scale level
        uint8_t mul{0}; // multiple: mul_tab[ML]
 
        // LFO
        uint8_t AMmask{0}; // LFO Amplitude Modulation enable mask
        uint8_t vib{0};    // LFO Phase Modulation enable flag (active high)
};
 
class Channel
{
public:
        [[nodiscard]] int calcOutput(unsigned eg_cnt, unsigned lfo_pm, unsigned lfo_am, int fm);
 
        void setFrequency(int block_fnum);
 
        void setFrequencyLow(uint8_t value);
 
        void setFrequencyHigh(uint8_t value);
 
        void updateInstrumentPart(int part, uint8_t value);
 
        void updateInstrument(std::span<const uint8_t, 8> inst);
 
        [[nodiscard]] int getBlockFNum() const;
        [[nodiscard]] FreqIndex getFrequencyIncrement() const;
        [[nodiscard]] int getKeyScaleLevelBase() const;
        [[nodiscard]] uint8_t getKeyCode() const;
        [[nodiscard]] bool isSustained() const;
        void setSustain(bool sustained);
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
        Slot mod;
        Slot car;
 
private:
        // phase generator state
        int block_fnum{0}; // block+fnum
        FreqIndex fc{0};   // Freq. increment base
        int ksl_base{0};   // KeyScaleLevel Base step
        bool sus{false};   // sus on/off (release speed in percussive mode)
};
 
class YM2413 final : public YM2413Core
{
public:
        YM2413();
 
        // YM2413Core
        void reset() override;
        void writePort(bool port, uint8_t value, int offset) override;
        void pokeReg(uint8_t reg, uint8_t value) override;
        [[nodiscard]] uint8_t peekReg(uint8_t reg) const override;
        void generateChannels(std::span<float*, 9 + 5> bufs, unsigned num) override;
        [[nodiscard]] float getAmplificationFactor() const override;
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
private:
        void writeReg(uint8_t reg, uint8_t value);
 
        void resetOperators();
 
        [[nodiscard]] bool isRhythm() const;
 
        [[nodiscard]] Channel& getChannelForReg(uint8_t reg);
 
        void updateCustomInstrument(int part, uint8_t value);
 
        void setRhythmFlags(uint8_t old);
 
private:
        std::array<Channel, 9> channels;
 
        unsigned eg_cnt;
 
        int noise_rng;
 
        unsigned idleSamples;
 
        using LFOAMIndex = FixedPoint< 6>;
        using LFOPMIndex = FixedPoint<10>;
        LFOAMIndex lfo_am_cnt{0};
        LFOPMIndex lfo_pm_cnt{0};
 
        std::array<std::array<uint8_t, 8>, 19> inst_tab;
 
        std::array<uint8_t, 0x40> reg;
        uint8_t registerLatch;
};
 
} // namespace YM2413Burczynski
 
SERIALIZE_CLASS_VERSION(YM2413Burczynski::YM2413, 4);
SERIALIZE_CLASS_VERSION(YM2413Burczynski::Channel, 3);
SERIALIZE_CLASS_VERSION(YM2413Burczynski::Slot, 2);
 
} // namespace openmsx
 
#endif