public PPU(CPU cpu)
{
this.cpu = cpu;
latch = 0;
frameCount = 0;
tReg = new LoopyRegister();
vReg = new LoopyRegister();
// Two adjacent 16 * 16 2D arrays of 8 * 8 tiles. Used only for testing
PatternMemory = new Color[2, (16 * 8), (16 * 8)];
#if LOGGING
//CSV log - file creation
csvLogs = new DirectoryInfo(@"/Users/alexwright/Documents/MSc Files/Project/csv_logs");
dateTime = DateTime.UtcNow;
cultInfo = CultureInfo.CreateSpecificCulture("en-UK");
csvFileName = $"project_nes_ppu_log_{dateTime.ToString("o", cultInfo)}.csv";
filePath = $"{csvLogs.FullName}/{csvFileName}";
using (File.Create(filePath)) { }
using (StreamWriter file = new StreamWriter(filePath, true))
file.WriteLine(
$"frameCount," +
$"scanLine," +
$"cycle," +
$"vReg.Address," +
$"read(address)," +
$"ppuData," +
$"patternShifterHi," +
$"patternShifterLo," +
$"attribShifterHi," +
$"attribShifterLo," +
$"tileID," +
$"tileAttrib," +
$"tileMSB," +
$"tileLSB"
);
#endif
}
public void WriteDataFromBus(uint address, byte data)
{
switch (address)
{
case 0x2000: // Control
registerControl = data;
registerT.NameTableX = HasControlFlag(Control.NameTableX) ? (byte)1 : (byte)0;
registerT.NameTableY = HasControlFlag(Control.NameTableY) ? (byte)1 : (byte)0;
spriteSize = HasControlFlag(Control.SpriteSize) ? (byte)16 : (byte)8;
return;
case 0x2001: // Mask
registerMask = data;
return;
case 0x2002: // Status (read-only)
return;
case 0x2003: // OAM Address
oamAddress = data;
return;
case 0x2004: // OAM Data
mainOAM[oamAddress++] = data;
return;
case 0x2005: // Scroll
if (!byteLatch)
{
fineX = (byte)(data & 0x07);
registerT.CoarseX = (byte)(data >> 3);
}
else
{
registerT.FineY = (byte)(data & 0x07);
registerT.CoarseY = (byte)(data >> 3);
}
byteLatch = !byteLatch;
return;
case 0x2006: // PPU Address
if (!byteLatch)
{
registerT.Reg = (ushort)((registerT.Reg & 0x00FF) | (data << 8));
}
else
{
registerT.Reg = (ushort)((registerT.Reg & 0xFF00) | data);
registerV = registerT;
}
byteLatch = !byteLatch;
return;
case 0x2007: // PPU Data
WritePPUData(registerV.Reg, data);
if (registerV.Reg >= 0x3F00 && registerV.Reg <= 0x3F03)
{
patternTableDisplay[0].DataChanged();
patternTableDisplay[1].DataChanged();
}
registerV.Reg += (ushort)(HasControlFlag(Control.IncrementMode) ? 32 : 1);
return;
}
}
public void CpuWrite(ushort address, byte data)
{
switch (address)
{
case 0x0000: // Control
_control.reg = data;
_tRamAddress.SetFlag(LoopyRegister.Flags.NameTableX, _control.GetFlag(Control.Flags.NameTableX));
_tRamAddress.SetFlag(LoopyRegister.Flags.NameTableY, _control.GetFlag(Control.Flags.NameTableY));
break;
case 0x0001: // Mask
_mask.reg = data;
break;
case 0x0002: // Status
break;
case 0x0003: // OAM Address
break;
case 0x0004: // OAM Data
break;
case 0x0005: // Scroll
if (_addressLatch == 0)
{
_fineX = (byte)(data & 0x07);
_tRamAddress.SetCoarseX((byte)(data >> 3));
_ppuAddress = (ushort)((_ppuAddress & 0xFF00) | data << 8);
_addressLatch = 1;
}
else
{
_tRamAddress.SetFineY((byte)(data & 0x07));
_tRamAddress.SetCoarseY((byte)(data >> 3));
_addressLatch = 0;
}
break;
case 0x0006: // PPU Address
if (_addressLatch == 0)
{
_tRamAddress.reg = (ushort)((data & 0x3F) << 8 | _tRamAddress.reg & 0x00FF);
_addressLatch = 1;
}
else
{
_tRamAddress.reg = (ushort)(_tRamAddress.reg & 0xFF00 | data);
_vRamAddress = _tRamAddress;
_addressLatch = 0;
}
break;
case 0x0007: // PPU Data
PpuWrite(_vRamAddress.reg, data);
var inclementModeFlagValue = _control.GetFlag(Control.Flags.IncrementMode);
if (inclementModeFlagValue)
{
_vRamAddress.reg += 1;
}
else
{
_vRamAddress.reg += 32;
}
break;
}
}
