public void Run(Action <Bitmap> drawFrame)
{
var sw = new Stopwatch();
while (true)
{
sw.Start();
var cpuCyclesSpent = Cpu.Step();
// If we get null back, the program has ended/hit unknown opcode.
if (cpuCyclesSpent == null)
{
return;
}
// Step PPU 3x as many as CPU used.
for (var i = 0; i < 3 * cpuCyclesSpent.Value; i++)
{
if (Ppu.Step())
{
drawFrame?.Invoke(Screen);
}
}
// Sleep until it's time for the next cycle.
var timeToSleep = cpuCyclesSpent.Value * (CpuCycleDurationMilliseconds - sw.ElapsedMilliseconds);
if (timeToSleep > 0)
{
Thread.Sleep((int)timeToSleep);
}
}
}
public Nes()
{
PpuRam = new PpuMemoryMap();
Ppu = new Ppu(PpuRam, Screen);
Ram = new MemoryMap(Ppu);
Cpu = new Cpu(Ram, programCounter: InitialProgramCounter, stackPointer: InitialStackPointer);
var cpuSpeed = 21.477272 / 12;
CpuCycleDurationMilliseconds = 1.0f / cpuSpeed;
}
public MemoryMap(Ppu ppu)
{
this.ppu = ppu;
}