/// <summary>
/// Value of registers is unspecified, so we initialize offsets using the values below.
/// </summary>
/// <param name="cart"></param>
public MMC3(Cartridge cart) : base(cart)
{
this.cart = cart;
prgOffsets[0] = prgBankOffset(0);
prgOffsets[1] = prgBankOffset(1);
prgOffsets[2] = prgBankOffset(-2);
prgOffsets[3] = prgBankOffset(-1);
}
public void ReadFileThrowFileNotFoundException()
{
//Arrange
string FileName = @"C:\Users\panda\Downloads\Super Mario Bros. (USA).nes";
NESEmu.CartridgeReader cartReader = new CartridgeReader(FileName);
//Act
try
{
NESEmu.Cartridge cart = cartReader.readCart();
}
catch (FileNotFoundException exception)
{
//Assert
StringAssert.Equals(exception, new FileNotFoundException());
}
}
public void ReadFile_CheckThreeBytes()
{
//Arrange
string FileName = @"C:\Users\panda\Downloads\Super Mario Bros. 3 (USA).nes";
NESEmu.CartridgeReader cartReader = new CartridgeReader(FileName);
byte firstByte = (byte)'N';
byte secondByte = (byte)'E';
byte thirdByte = (byte)'S';
//Act
NESEmu.Cartridge cart = cartReader.readCart();
//Assert
Assert.AreEqual(cart.Header[0], firstByte);
Assert.AreEqual(cart.Header[1], secondByte);
Assert.AreEqual(cart.Header[2], thirdByte);
}
/// <summary>
/// Method for reading a Cartridge object. It will attempt to read in Binary
/// and read the first 16 bytes. It will throw an error if it can't read the file or if
/// the first byte headers are not 'N', 'E', 'S'. This sepcifies that we are reading an
/// official NES file. It will then attempt to read the rest of the file in
/// binary.
/// </summary>
/// <returns></returns>
public Cartridge readCart()
{
cart = new Cartridge();
try
{
using (BinaryReader reader = new BinaryReader(File.Open(_filePath, FileMode.Open)))
{
cart.Header = reader.ReadBytes(16);
}
}
catch (FileNotFoundException filenotfound)
{
throw filenotfound;
}
if (cart.Header == null || cart.Header[0] != 'N' || cart.Header[1] != 'E' ||
cart.Header[2] != 'S' || cart.Header[3] != 0x1A)
{
throw new Exception("Unable to open file due to incorrect format or corruption.");
}
//TODO: Fix reading offsets by including trainer and SRAM
cart.Prgrom = new byte[_prgromConst * cart.Header[4]];
try
{
using (BinaryReader reader = new BinaryReader(File.Open(_filePath, FileMode.Open)))
{
reader.BaseStream.Position = 16;
cart.Prgrom = reader.ReadBytes(cart.Prgrom.Length);
}
}
catch (FileNotFoundException filenotfound)
{
throw filenotfound;
}
cart.Chrrom = new byte[_chrromConst * cart.Header[5]];
try
{
using (BinaryReader reader = new BinaryReader(File.Open(_filePath, FileMode.Open)))
{
reader.BaseStream.Position = cart.Prgrom.Length + 16;
cart.Chrrom = reader.ReadBytes(cart.Chrrom.Length);
}
}
catch (FileNotFoundException filenotfound)
{
throw filenotfound;
}
flags6 = cart.Header[6];
byte mirroringByte1 = (byte)(flags6 & 1);
byte mirroringByte2 = (byte)((flags6 >> 3) & 1);
cart.Mirroring = (byte)(mirroringByte1 | mirroringByte2 << 1);
cart.Save_RAM = (flags6 & 2) == 2;
cart.Trainer_Present = (flags6 & 4) == 4;
cart.Four_Screen_Mirroring = (flags6 & 8) == 8;
cart.mapper = flags6 & _firstBits;
cart.mapper = cart.mapper >> 4;
this.flags7 = cart.Header[7];
cart.mapper |= flags7 & _firstBits;
if (cart.Trainer_Present)
{
cart.Trainer = new byte[_trainerConst];
}
//In order to implement the memory mapper, Save RAM has to be implemented regardless
//of what is stated in the header. This should be handled more gracefully.
//if (cart.Save_RAM)
//{
// cart.Sram = new byte[0x2000];
//}
cart.Sram = new byte[0x2000];
return(cart);
}
