SN76489.hh

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#ifndef SN76489_HH
#define SN76489_HH
 
#include "ResampledSoundDevice.hh"
#include "SimpleDebuggable.hh"
#include <array>
 
namespace openmsx {
 
class SN76489 final : public ResampledSoundDevice
{
public:
        SN76489(const DeviceConfig& config);
        ~SN76489();
 
        // ResampledSoundDevice
        void generateChannels(std::span<float*> buffers, unsigned num) override;
 
        void reset(EmuTime::param time);
        void write(byte value, EmuTime::param time);
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
private:
        class NoiseShifter {
        public:
                inline void initState(unsigned pattern, unsigned period);
 
                [[nodiscard]] inline unsigned getOutput() const;
 
                inline void advance();
 
                inline void queueAdvance(unsigned steps);
 
                void catchUp();
 
                template<typename Archive>
                void serialize(Archive& ar, unsigned version);
 
        private:
                unsigned pattern;
                unsigned period;
                unsigned random;
                unsigned stepsBehind;
        };
 
        void initState();
 
        void initNoise();
 
        [[nodiscard]] word peekRegister(unsigned reg, EmuTime::param time) const;
        void writeRegister(unsigned reg, word value, EmuTime::param time);
        template<bool NOISE> void synthesizeChannel(
                float*& buffer, unsigned num, unsigned generator);
 
private:
        NoiseShifter noiseShifter;
 
        std::array<word, 8> regs;
 
        byte registerLatch;
 
        std::array<word, 4> counters;
 
        std::array<byte, 4> outputs;
 
        struct Debuggable final : SimpleDebuggable {
                Debuggable(MSXMotherBoard& motherBoard, const std::string& name);
                [[nodiscard]] byte read(unsigned address, EmuTime::param time) override;
                void write(unsigned address, byte value, EmuTime::param time) override;
        } debuggable;
};
 
} // namespace openmsx
 
#endif