inline void CartridgeDPC::updateMusicModeDataFetchers()

in atari_py/ale_interface/src/emucore/CartDPC.cxx [150:201]

• 41 lines of code
• 8 McCabe index (conditional complexity)

inline void CartridgeDPC::updateMusicModeDataFetchers()
{
  // Calculate the number of cycles since the last update
  Int32 cycles = mySystem->cycles() - mySystemCycles;
  mySystemCycles = mySystem->cycles();

  // Calculate the number of DPC OSC clocks since the last update
  double clocks = ((15750.0 * cycles) / 1193191.66666667) + myFractionalClocks;
  Int32 wholeClocks = (Int32)clocks;
  myFractionalClocks = clocks - (double)wholeClocks;

  if(wholeClocks <= 0)
  {
    return;
  }

  // Let's update counters and flags of the music mode data fetchers
  for(int x = 5; x <= 7; ++x)
  {
    // Update only if the data fetcher is in music mode
    if(myMusicMode[x - 5])
    {
      Int32 top = myTops[x] + 1;
      Int32 newLow = (Int32)(myCounters[x] & 0x00ff);

      if(myTops[x] != 0)
      {
        newLow -= (wholeClocks % top);
        if(newLow < 0)
        {
          newLow += top;
        }
      }
      else
      {
        newLow = 0;
      }

      // Update flag register for this data fetcher
      if(newLow <= myBottoms[x])
      {
        myFlags[x] = 0x00;
      }
      else if(newLow <= myTops[x])
      {
        myFlags[x] = 0xff;
      }

      myCounters[x] = (myCounters[x] & 0x0700) | (uInt16)newLow;
    }
  }
}