/// <summary>
/// Frame is completed
/// </summary>
public void EndFrame()
{
// store the last pulse information
if (LastPulseTState <= _tStatesPerFrame - 1)
{
Pulse p = new Pulse
{
State = LastPulse,
Length = _tStatesPerFrame - LastPulseTState
};
Pulses.Add(p);
}
// create the sample array
var firstSampleOffset = _frameStart % TStatesPerSample == 0 ? 0 : TStatesPerSample - (_frameStart + TStatesPerSample) % TStatesPerSample;
var samplesInFrame = (_tStatesPerFrame - firstSampleOffset - 1) / TStatesPerSample + 1;
var samples = new short[samplesInFrame];
// convert pulses to samples
var sampleIndex = 0;
var currentEnd = _frameStart;
foreach (var pulse in Pulses)
{
var firstSample = currentEnd % TStatesPerSample == 0
? currentEnd : currentEnd + TStatesPerSample - currentEnd % TStatesPerSample;
for (var i = firstSample; i < currentEnd + pulse.Length; i += TStatesPerSample)
{
samples[sampleIndex++] = pulse.State ? (short)(_volume) : (short)0;
}
currentEnd += pulse.Length;
}
// fill the _sampleBuffer for ISoundProvider
soundBufferContains = (int)samplesInFrame;
if (soundBuffer.Length != soundBufferContains)
{
soundBuffer = new short[soundBufferContains];
}
samples.CopyTo(soundBuffer, 0);
_frameStart += _tStatesPerFrame;
}
/// <summary>
/// When the pulse value changes it is processed here
/// </summary>
/// <param name="pulse"></param>
public void ProcessPulseValue(bool pulse)
{
if (!_machine._renderSound)
{
return;
}
if (pulse == LastPulse)
{
// no change detected
return;
}
// set the lastpulse
LastPulse = pulse;
// get where we are in the frame
var currentULACycle = _machine.CurrentFrameCycle;
var currentBuzzerCycle = currentULACycle <= _tStatesPerFrame ? currentULACycle : _tStatesPerFrame;
var length = currentBuzzerCycle - LastPulseTState;
if (length == 0)
{
// the first T-State has changed the pulse
// do not add it
}
else if (length > 0)
{
// add the pulse
Pulse p = new Pulse
{
State = !pulse,
Length = length
};
Pulses.Add(p);
}
// set the last pulse tstate
LastPulseTState = currentBuzzerCycle;
}
