/// <summary>
/// Method used to Run the Emulator Task
///
/// Task will run until the _powerOn value is set to false
/// </summary>
private void Run()
{
//Frame Timing Stopwatch
var sw = Stopwatch.StartNew();
//CPU startup state is always at 4 cycles
_cpu.Cycles = 4;
int cpuTicks;
while (_powerOn)
{
//If we're not idling (DMA), tick the CPU
if (_cpuIdleCycles == 0)
{
cpuTicks = _cpu.Tick();
}
else
{
//Otherwise, mark it as an idle cycle and carry on
_cpuIdleCycles--;
_cpu.Instruction.Cycles = 1;
_cpu.Cycles++;
cpuTicks = 1;
}
//Count how many cycles that instruction took and
//execute that number of instruction * 3 for the PPU
//We do ceiling since it's ok for the PPU to overshoot at this point
for (var i = 0; i < cpuTicks * 3; i++)
{
_ppu.Tick();
}
//If the PPU has signaled NMI, reset its status and signal the CPU
if (_ppu.NMI)
{
_ppu.NMI = false;
_cpu.NMI = true;
}
//Check to see if there's a frame in the PPU Frame Buffer
//If there is, let's render it
if (_ppu.FrameReady)
{
_processFrame(_ppu.FrameBuffer);
_ppu.FrameReady = false;
//Throttle our frame rate here to the desired rate (if required)
switch (_enumEmulatorSpeed)
{
case enumEmulatorSpeed.Turbo:
continue;
case enumEmulatorSpeed.Normal when sw.ElapsedMilliseconds < 17:
Thread.Sleep((int)(17 - sw.ElapsedMilliseconds));
break;
case enumEmulatorSpeed.Half when sw.ElapsedMilliseconds < 32:
Thread.Sleep((int)(32 - sw.ElapsedMilliseconds));
break;
}
sw.Restart();
}
}
}
