looper/backends/playback/zsm/zsm_backend.hpp

#pragma once
#include "playback_backend.hpp"
#include <cstdint>
#include <stddef.h>
#include <stdint.h>
#include "file_backend.hpp"
enum ZsmCommandId {
    PsgWrite,
    ExtCmd,
    FmWrite,
    ZsmEOF,
    Delay
};
struct reg_pair {
    uint8_t reg;
    uint8_t val;
};
struct ZsmCommand {
    ZsmCommandId id;
    union {
        struct {
            uint8_t reg;
            uint8_t val;
        } psg_write;
        struct {
            uint8_t channel;
            uint8_t bytes;
            union {
                uint8_t *pcm;
                struct {
                    uint8_t chip_id;
                    uint8_t writes;
                    uint8_t *write_bytes;
                } expansion;
                uint8_t *sync;
                uint8_t *custom;
            };
        } extcmd;
        struct {
            uint8_t len;
            reg_pair *regs;
        } fm_write;
        uint8_t delay;
    };
    ~ZsmCommand();
};
class ZsmBackend : public PlaybackBackend {
    File *file;
    std::vector<uint8_t> audio_buf;
    uint32_t loop_point;
    uint32_t pcm_offset;
    uint8_t fm_mask;
    uint16_t psg_channel_mask;
    uint16_t tick_rate;
    size_t music_data_start;
    size_t music_data_len;
    double ticks;
    double delayTicks = 0.0;
    double position;
    void seek_internal(double position);
    ZsmCommand get_command();
    public:
    inline std::string get_id() override {
        return "zsm";
    }
    inline std::string get_name() override {
        return "ZSM player";
    }
    void seek(double position) override;
    void load(const char *filename) override;
    void switch_stream(int idx) override;
    void cleanup() override;
    int get_stream_idx() override;
    size_t render(void *buf, size_t maxlen) override;
    double get_position() override;
    inline ~ZsmBackend() override { }
};