public void Update()
{
if (mute || turbo)
{
for (int updateCycle = lastUpdateCycle; updateCycle < currentTime; updateCycle++)
{
sampleRateDivider--;
if (sampleRateDivider <= 0)
{
output[outputPtr] = 0;
outputPtr++;
sampleRateDivider += sampleDivider;
}
}
lastUpdateCycle = currentTime;
return;
}
for (int updateCycle = lastUpdateCycle; updateCycle < currentTime; updateCycle++)
{
byte square1Volume = square1.Cycle();
byte square2Volume = square2.Cycle();
byte triangleVolume = triangle.Cycle();
byte noiseVolume = noise.Cycle();
byte dmcVolume = dmc.buffer[dmcOutputPtr++];
byte externalVolume = external.Cycle();//treating external volume as 0-255
#if DEBUGGER
nes.debug.APUCycle(square1Volume, square2Volume, triangleVolume, noiseVolume, dmcVolume, externalVolume);
#endif
square1Volume = (byte)(square1Volume * volume.square1);
square2Volume = (byte)(square2Volume * volume.square2);
triangleVolume = (byte)(triangleVolume * volume.triangle);
noiseVolume = (byte)(noiseVolume * volume.noise);
dmcVolume = (byte)(dmcVolume * volume.dmc);
externalVolume = (byte)(externalVolume * volume.external);
sampleTotal += (short)((tndTableShort[(3 * triangleVolume) + (2 * noiseVolume) + dmcVolume] + pulseTableShort[square1Volume + square2Volume] + (externalVolume << 7)) ^ 0x8000);//just inserting external sound linearly.
sampleCount++;
sampleRateDivider--;
if (sampleRateDivider <= 0) //&& outputPtr < output.Length)
{
double sample = sampleTotal / (sampleCount * 1.0);
sampleRateDivider += sampleDivider;
rollingAveTotal += sample;
rollingAve.Enqueue(sample);
if (rollingAveCount == rollingAveWindow)
{
rollingAveTotal -= rollingAve.Dequeue();
}
else
{
rollingAveCount++;
}
aveSample = rollingAveTotal / (rollingAveCount * 1.0); //aveSample reduces clicks by keeping waveform centered around 0, size of window can be adjusted with rollingAveWindow.
output[outputPtr++] = (short)(Math.Max(Math.Min(sample - aveSample, short.MaxValue), short.MinValue)); //I can't imagine clamping the audio could possibly sound worse then an overflow so this is how I shall do things (even though this will rarely even have an effect).
sampleTotal = 0;
sampleCount = 0;
}
}
lastUpdateCycle = currentTime;
}
