YMF262.hh

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#ifndef YMF262_HH
#define YMF262_HH
 
#include "ResampledSoundDevice.hh"
#include "SimpleDebuggable.hh"
#include "EmuTimer.hh"
#include "EmuTime.hh"
#include "FixedPoint.hh"
#include "IRQHelper.hh"
#include "serialize_meta.hh"
#include <array>
#include <cstdint>
#include <memory>
#include <span>
#include <string>
 
namespace openmsx {
 
class DeviceConfig;
 
class YMF262 final : private ResampledSoundDevice, private EmuTimerCallback
{
public:
        // sin-wave entries
        static constexpr int SIN_BITS = 10;
        static constexpr int SIN_LEN  = 1 << SIN_BITS;
        static constexpr int SIN_MASK = SIN_LEN - 1;
 
public:
        YMF262(const std::string& name, const DeviceConfig& config,
               bool isYMF278);
        ~YMF262();
 
        void reset(EmuTime::param time);
        void writeReg   (unsigned r, uint8_t v, EmuTime::param time);
        void writeReg512(unsigned r, uint8_t v, EmuTime::param time);
        [[nodiscard]] uint8_t readReg(unsigned reg);
        [[nodiscard]] uint8_t peekReg(unsigned reg) const;
        [[nodiscard]] uint8_t readStatus();
        [[nodiscard]] uint8_t peekStatus() const;
 
        void setMixLevel(uint8_t x, EmuTime::param time);
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
public:
        using FreqIndex = FixedPoint<16>;
 
        enum EnvelopeState {
                EG_ATTACK, EG_DECAY, EG_SUSTAIN, EG_RELEASE, EG_OFF
        };
 
private:
        class Channel;
 
        class Slot {
        public:
                Slot();
                [[nodiscard]] inline int op_calc(unsigned phase, unsigned lfo_am) const;
                inline void FM_KEYON(uint8_t key_set);
                inline void FM_KEYOFF(uint8_t key_clr);
                inline void advanceEnvelopeGenerator(unsigned egCnt);
                inline void advancePhaseGenerator(Channel& ch, unsigned lfo_pm);
                void update_ar_dr();
                void update_rr();
                void calc_fc(const Channel& ch);
 
                void setFeedbackShift(uint8_t value) {
                        fb_shift = value ? 9 - value : 0;
                }
 
                template<typename Archive>
                void serialize(Archive& ar, unsigned version);
 
                // Phase Generator
                FreqIndex Cnt{0};  // frequency counter
                FreqIndex Incr{0}; // frequency counter step
                int* connect{nullptr}; // slot output pointer
                std::array<int, 2> op1_out{0, 0}; // slot1 output for feedback
 
                // Envelope Generator
                unsigned TL{0};  // total level: TL << 2
                unsigned TLL{0}; // adjusted now TL
                int volume{0};   // envelope counter
                int sl{0};       // sustain level: sl_tab[SL]
 
                std::span<const unsigned, SIN_LEN> waveTable; // waveform select
 
                EnvelopeState state{EG_OFF}; // EG: phase type
                unsigned eg_m_ar{0};  // (attack state)
                unsigned eg_m_dr{0};  // (decay state)
                unsigned eg_m_rr{0};  // (release state)
                uint8_t eg_sh_ar{0};  // (attack state)
                uint8_t eg_sel_ar{0}; // (attack state)
                uint8_t eg_sh_dr{0};  // (decay state)
                uint8_t eg_sel_dr{0}; // (decay state)
                uint8_t eg_sh_rr{0};  // (release state)
                uint8_t eg_sel_rr{0}; // (release state)
 
                uint8_t key{0}; // 0 = KEY OFF, >0 = KEY ON
 
                uint8_t fb_shift{0}; // PG: feedback shift value
                bool CON{false};     // PG: connection (algorithm) type
                bool eg_type{false}; // EG: percussive/non-percussive mode
 
                // LFO
                uint8_t AMmask{0}; // LFO Amplitude Modulation enable mask
                bool vib{false};   // LFO Phase Modulation enable flag (active high)
 
                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 ksr{0}; // key scale rate: kcode>>KSR
                uint8_t mul{0}; // multiple: mul_tab[ML]
        };
 
        class Channel {
        public:
                void chan_calc(unsigned lfo_am);
                void chan_calc_ext(unsigned lfo_am);
 
                template<typename Archive>
                void serialize(Archive& ar, unsigned version);
 
                std::array<Slot, 2> slot;
 
                int block_fnum{0};    // block+fnum
                FreqIndex fc{0};      // Freq. Increment base
                unsigned ksl_base{0}; // KeyScaleLevel Base step
                uint8_t kcode{0};     // key code (for key scaling)
 
                // there are 12 2-operator channels which can be combined in pairs
                // to form six 4-operator channel, they are:
                //  0 and 3,
                //  1 and 4,
                //  2 and 5,
                //  9 and 12,
                //  10 and 13,
                //  11 and 14
                bool extended{false}; // set if this channel forms up a 4op channel with
                                      // another channel (only used by first of pair of
                                      // channels, ie 0,1,2 and 9,10,11)
        };
 
        // SoundDevice
        [[nodiscard]] float getAmplificationFactorImpl() const override;
        void generateChannels(std::span<float*> bufs, unsigned num) override;
 
        void callback(uint8_t flag) override;
 
        void writeRegDirect(unsigned r, uint8_t v, EmuTime::param time);
        void init_tables();
        void setStatus(uint8_t flag);
        void resetStatus(uint8_t flag);
        void changeStatusMask(uint8_t flag);
        void advance();
 
        [[nodiscard]] inline unsigned genPhaseHighHat();
        [[nodiscard]] inline unsigned genPhaseSnare();
        [[nodiscard]] inline unsigned genPhaseCymbal();
 
        void chan_calc_rhythm(unsigned lfo_am);
        void set_mul(unsigned sl, uint8_t v);
        void set_ksl_tl(unsigned sl, uint8_t v);
        void set_ar_dr(unsigned sl, uint8_t v);
        void set_sl_rr(unsigned sl, uint8_t v);
        bool checkMuteHelper();
 
        [[nodiscard]] inline bool isExtended(unsigned ch) const;
        [[nodiscard]] inline Channel& getFirstOfPair(unsigned ch);
        [[nodiscard]] inline Channel& getSecondOfPair(unsigned ch);
 
        struct Debuggable final : SimpleDebuggable {
                Debuggable(MSXMotherBoard& motherBoard, const std::string& name);
                [[nodiscard]] uint8_t read(unsigned address) override;
                void write(unsigned address, uint8_t value, EmuTime::param time) override;
        } debuggable;
 
        // Bitmask for register 0x04
        static constexpr int R04_ST1       = 0x01; // Timer1 Start
        static constexpr int R04_ST2       = 0x02; // Timer2 Start
        static constexpr int R04_MASK_T2   = 0x20; // Mask Timer2 flag
        static constexpr int R04_MASK_T1   = 0x40; // Mask Timer1 flag
        static constexpr int R04_IRQ_RESET = 0x80; // IRQ RESET
 
        // Bitmask for status register
        static constexpr int STATUS_T2      = R04_MASK_T2;
        static constexpr int STATUS_T1      = R04_MASK_T1;
        // Timers (see EmuTimer class for details about timing)
        const std::unique_ptr<EmuTimer> timer1; //  80.8us OPL4  ( 80.5us OPL3)
        const std::unique_ptr<EmuTimer> timer2; // 323.1us OPL4  (321.8us OPL3)
 
        IRQHelper irq;
 
        std::array<int, 18> chanOut = {};      // 18 channels
 
        std::array<uint8_t, 512> reg = {};
        std::array<Channel, 18> channel;  // OPL3 chips have 18 channels
 
        std::array<int, 18 * 4> pan; // channels output masks 4 per channel
                                     //    0xffffffff = enable
        unsigned eg_cnt{0};          // global envelope generator counter
        unsigned noise_rng{1};       // 23 bit noise shift register
 
        // LFO
        using LFOAMIndex = FixedPoint< 6>;
        using LFOPMIndex = FixedPoint<10>;
        LFOAMIndex lfo_am_cnt{0};
        LFOPMIndex lfo_pm_cnt{0};
        bool lfo_am_depth{false};
        uint8_t lfo_pm_depth_range{0};
 
        uint8_t rhythm{0};              // Rhythm mode
        bool nts{false};                        // NTS (note select)
        bool OPL3_mode{false};          // OPL3 extension enable flag
 
        uint8_t status{0};              // status flag
        uint8_t status2{0};
        uint8_t statusMask{0};          // status mask
 
        bool alreadySignaledNEW2{false};
        const bool isYMF278;            // true iff this is actually a YMF278
                                        // ATM only used for NEW2 bit
};
SERIALIZE_CLASS_VERSION(YMF262, 2);
 
} // namespace openmsx
 
#endif