protected void SetNametableMirroring(MirroringMode mode)
{
switch (mode)
{
case MirroringMode.Horizontal:
// Horizontal mirroring: A A
// B B
this.MapNametableA(0x2000);
this.MirrorPpuRange(0x2000, 0x23FF, 0x2400, 0x27FF);
this.MapNametableB(0x2800);
this.MirrorPpuRange(0x2800, 0x2BFF, 0x2C00, 0x2FFF);
break;
case MirroringMode.Vertical:
// Vertical mirroring: A B
// A B
this.MapNametableA(0x2000);
this.MirrorPpuRange(0x2000, 0x23FF, 0x2800, 0x2BFF);
this.MapNametableB(0x2400);
this.MirrorPpuRange(0x2400, 0x27FF, 0x2C00, 0x2FFF);
break;
case MirroringMode.SingleScreenA:
// One screen, mapped to lower nametable: A A
// A A
this.MapNametableA(0x2000);
this.MapNametableB(-1);
this.MirrorPpuRange(0x2000, 0x23FF, 0x2400, 0x2FFF);
break;
case MirroringMode.SingleScreenB:
// One screen, mapped to upper nametable: B B
// B B
this.MapNametableA(-1);
this.MapNametableB(0x2400);
this.MirrorPpuRange(0x2400, 0x27FF, 0x2000, 0x23FF);
this.MirrorPpuRange(0x2400, 0x27FF, 0x2800, 0x2FFF);
break;
default:
throw new NotImplementedException(String.Format(CultureInfo.CurrentCulture, "Nametable mirroring mode '{0}' is not implemented!", mode));
}
}
private void LoadRom(string path)
{
byte[] rawROM = File.ReadAllBytes(path);
byte[] header = new ArraySegment <byte>(rawROM, 0, 16).ToArray();
byte[] signature = new ArraySegment <byte>(header, 0, 3).ToArray();
if (Encoding.ASCII.GetString(signature) != "NES")
{
throw new NotImplementedException("Only ROMS with iNES headers supported.");
}
PRGROM16K = header[4];
CHRROM8K = header[5];
PRGROM8K = header[8];
int flag6 = header[6];
int flag7 = header[7];
int flag9 = header[9];
int flag10 = header[10];
mirroringMode = (flag6 & 1) == 1 ? MirroringMode.Vertical : MirroringMode.Horizontal;
Trainer = (flag6 & 4) != 0;
NTSC = (flag10 & 1) == 0;
Mapper = flag6 >> 4 | (flag7 & 0xf0); //Lower nibble of flag6 | upper nibble of flag7
int prgFrom = 16;
if (Trainer)
{
prgFrom += 512;
}
int prgLength = 0x4000 * PRGROM16K;
PRGData = new ArraySegment <Byte>(rawROM, prgFrom, prgLength).ToArray();
int chrFrom = prgFrom + prgLength;
int chrLength = 0x2000 * CHRROM8K;
CHRData = new ArraySegment <Byte>(rawROM, chrFrom, chrLength).ToArray();
}
private void ReadHeader(ref SpanReader span)
{
if (span.ReadAsUnsignedInt() != _magicNumber)
{
throw new InvalidDataException("Invalid nes file.");
}
PrgRomSize = span.ReadAsByte() * 16u * 1024;
ChrRomSize = span.ReadAsByte() * 8u * 1024;
var flag6 = span.ReadAsByte();
MirroringMode = (MirroringMode)(flag6 & 0b1);
HasTrainer = (flag6 & 0b001) != 0;
var flag7 = span.ReadAsByte();
PrgRamSize = Math.Max((byte)1, span.ReadAsByte()) * 8u * 1024;
var flag9 = span.ReadAsByte();
var flag10 = span.ReadAsByte();
span.Advance(5);
}
public void SetMirroringMode(MirroringMode mirroringMode)
{
_mirroringMode = mirroringMode;
PlayerPrefs.SetInt("mirroringMode", (int)_mirroringMode);
if (_mirroringMode == MirroringMode.None)
{
_editor.MirroringString = "";
}
else if (_mirroringMode == MirroringMode.Horizontal)
{
_editor.MirroringString = "-MIRROR HORZ-";
}
else if (_mirroringMode == MirroringMode.Vertical)
{
_editor.MirroringString = "|MIRROR VERT|";
}
else if (_mirroringMode == MirroringMode.Both)
{
_editor.MirroringString = "/MIRROR BOTH/";
}
}
public void SetMirroringMode(MirroringMode mirroringMode)
{
_mirroringMode = mirroringMode;
PlayerPrefs.SetInt("mirroringMode", (int)_mirroringMode);
if(_mirroringMode == MirroringMode.None)
_editor.MirroringString = "";
else if(_mirroringMode == MirroringMode.Horizontal)
_editor.MirroringString = "-MIRROR HORZ-";
else if(_mirroringMode == MirroringMode.Vertical)
_editor.MirroringString = "|MIRROR VERT|";
else if(_mirroringMode == MirroringMode.Both)
_editor.MirroringString = "/MIRROR BOTH/";
}
public INESFile Parse(byte[] bytes)
{
this.Header = new ArraySegment <byte>(bytes, 0, 16);
// Expecting NES<eof> at the start of the file.
var fileIdentifier = BitConverter.ToUInt32(this.Header.Array, 0);
if (fileIdentifier != Constants.FileSignature)
{
throw new InvalidOperationException("File does not have expected header for iNES file.");
}
this.ProgramROMBankCount = this.Header.Get(4);
this.CharacterROMBankCount = this.Header.Get(5);
this.RAMBankCount = this.Header.Get(8);
if (this.RAMBankCount == 0)
{
this.RAMBankCount = 1;
}
this.RomControlByte1 = this.Header.Get(6);
this.RomControlByte2 = this.Header.Get(7);
this.MapperTypeLowerBits = (byte)(this.RomControlByte1 & 0xff0);
this.MapperTypeUpperBits = (byte)(this.RomControlByte2 & 0xff0);
// We pull the memory mapper id from the two separate bytes above and combine them here...
this.MemoryMapperId = (MemoryMapperIds)(this.MapperTypeUpperBits | this.MapperTypeLowerBits >> 4);
this.MirroringMode = this.RomControlByte1.GetBit(0)
? MirroringMode.Vertical
: MirroringMode.Horizontal;
// The mirroring mode can be overridden a couple bits later...
this.MirroringMode = this.RomControlByte1.GetBit(3)
? MirroringMode.FourScreen
: this.MirroringMode;
for (int i = 0; i < 7; i++)
{
this.Reserved[i] = this.Header.Get(9 + i);
}
if (this.HasTrainer)
{
this.Trainer = new ArraySegment <byte>(bytes, Constants.LocationOfTrainer, Constants.SizeOfTrainer).ToArray();
}
if (this.HasBatteryBackedRAM)
{
// TODO: We'll want to load in a file here at a later time
this.SRAM = new ArraySegment <byte>(bytes, Constants.LocationOfSRAM, Constants.SizeOfSRAM).ToArray();
}
else
{
this.SRAM = new byte[Constants.SizeOfSRAM];
}
int romBankOffset = this.HasTrainer
? Constants.SizeOfHeader + Constants.SizeOfTrainer
: Constants.SizeOfHeader;
for (int i = 0; i < this.ProgramROMBankCount; i++)
{
this.ROMBanks.Add(new ArraySegment <byte>(bytes, romBankOffset + (i * Constants.ROMBankSize), Constants.ROMBankSize).ToArray());
}
int chrBankOffset = romBankOffset + this.ROMBanks.Sum(bank => bank.Length);
for (int i = 0; i < this.CharacterROMBankCount; i++)
{
this.CharacterBanks.Add(new ArraySegment <byte>(bytes, chrBankOffset + (i * Constants.ChrBankSize), Constants.ChrBankSize).ToArray());
}
return(this);
}
