void Cartridge3E::bank()

in atari_py/ale_interface/src/emucore/Cart3E.cxx [209:273]

• 48 lines of code
• 7 McCabe index (conditional complexity)

void Cartridge3E::bank(uInt16 bank)
{ 
  if(bankLocked) return;

  if(bank < 256)
  {
    // Make sure the bank they're asking for is reasonable
    if((uInt32)bank * 2048 < mySize)
    {
      myCurrentBank = bank;
    }
    else
    {
      // Oops, the bank they're asking for isn't valid so let's wrap it
      // around to a valid bank number
      myCurrentBank = bank % (mySize / 2048);
    }
  
    uInt32 offset = myCurrentBank * 2048;
    uInt16 shift = mySystem->pageShift();
  
    // Setup the page access methods for the current bank
    System::PageAccess access;
    access.device = this;
    access.directPokeBase = 0;
  
    // Map ROM image into the system
    for(uInt32 address = 0x1000; address < 0x1800; address += (1 << shift))
    {
      access.directPeekBase = &myImage[offset + (address & 0x07FF)];
      mySystem->setPageAccess(address >> shift, access);
    }
  }
  else
  {
    bank -= 256;
    bank %= 32;
    myCurrentBank = bank + 256;

    uInt32 offset = bank * 1024;
    uInt16 shift = mySystem->pageShift();
    uInt32 address;
  
    // Setup the page access methods for the current bank
    System::PageAccess access;
    access.device = this;
    access.directPokeBase = 0;
  
    // Map read-port RAM image into the system
    for(address = 0x1000; address < 0x1400; address += (1 << shift))
    {
      access.directPeekBase = &myRam[offset + (address & 0x03FF)];
      mySystem->setPageAccess(address >> shift, access);
    }

    access.directPeekBase = 0;

    // Map write-port RAM image into the system
    for(address = 0x1400; address < 0x1800; address += (1 << shift))
    {
      access.directPokeBase = &myRam[offset + (address & 0x03FF)];
      mySystem->setPageAccess(address >> shift, access);
    }
  }
}