duckstation/src/common/cd_image.h

#pragma once
#include "bitfield.h"
#include "types.h"
#include <tuple>

class ByteStream;

class CDImage
{
public:
  CDImage();
  ~CDImage();

  enum : u32
  {
    RAW_SECTOR_SIZE = 2352,
    DATA_SECTOR_SIZE = 2048,
    SECTOR_SYNC_SIZE = 12,
    SECTOR_HEADER_SIZE = 4,
    FRAMES_PER_SECOND = 75, // "sectors"
    SECONDS_PER_MINUTE = 60,
    FRAMES_PER_MINUTE = FRAMES_PER_SECOND * SECONDS_PER_MINUTE
  };

  enum class ReadMode : u32
  {
    DataOnly,  // 2048 bytes per sector.
    RawSector, // 2352 bytes per sector.
    RawNoSync, // 2340 bytes per sector.
  };

  struct SectorHeader
  {
    u8 minute;
    u8 second;
    u8 frame;
    u8 sector_mode;
  };

  // Conversion helpers.
  static constexpr u64 MSFToLBA(u32 pregap_seconds, u32 minute, u32 second, u32 frame)
  {
    return ZeroExtend64(minute) * FRAMES_PER_MINUTE + ZeroExtend64(second) * FRAMES_PER_SECOND + ZeroExtend64(frame) -
           ZeroExtend64(pregap_seconds) * FRAMES_PER_SECOND;
  }
  static constexpr std::tuple<u32, u32, u32> LBAToMSF(u32 pregap_seconds, u64 lba)
  {
    const u64 offset = (lba + (pregap_seconds * FRAMES_PER_SECOND) % FRAMES_PER_MINUTE);
    const u32 minute = Truncate32(lba / FRAMES_PER_MINUTE);
    const u32 second = Truncate32(offset / FRAMES_PER_SECOND);
    const u32 frame = Truncate32(offset % FRAMES_PER_SECOND);
    return std::make_tuple(minute, second, frame);
  }

  // Accessors.
  const std::string& GetFileName() const { return m_filename; }
  u32 GetPregapSeconds() const { return m_pregap_seconds; }
  u64 GetCurrentLBA() const { return m_current_lba; }
  std::tuple<u32, u32, u32> GetPositionMSF() const { return LBAToMSF(m_pregap_seconds, m_current_lba); }
  u64 GetLBACount() const { return m_lba_count; }

  bool Open(const char* path);

  // Seek to data LBA.
  bool Seek(u64 lba);

  // Seek to audio timestamp (MSF).
  bool Seek(u32 minute, u32 second, u32 frame);

  // Seek and read at the same time.
  u32 Read(ReadMode read_mode, u64 lba, u32 sector_count, void* buffer);
  u32 Read(ReadMode read_mode, u32 minute, u32 second, u32 frame, u32 sector_count, void* buffer);

  // Read from the current LBA. Returns the number of sectors read.
  u32 Read(ReadMode read_mode, u32 sector_count, void* buffer);

private:
  std::string m_filename;

  // TODO: Multiple data files from cue sheet
  ByteStream* m_data_file = nullptr;

  // Pregap size.
  u32 m_pregap_seconds = 2;

  // Current LBA/total LBAs.
  u64 m_current_lba = 0;
  u64 m_lba_count = 0;
};