/// <summary>
/// Processes the change of the EAR bit value
/// </summary>
/// <param name="fromTape">
/// False: EAR bit comes from an OUT instruction,
/// True: EAR bit comes from tape
/// </param>
/// <param name="earBit">EAR bit value</param>
public void ProcessEarBitValue(bool fromTape, bool earBit)
{
if (!fromTape && _useTapeMode)
{
// --- The EAR bit comes from and OUT instruction, but now we're in tape mode
return;
}
if (earBit == LastEarBit)
{
// --- The earbit has not changed
return;
}
LastEarBit = earBit;
var currentHostTact = HostVm.CurrentFrameTact;
var currentTact = currentHostTact <= _frameTacts ? currentHostTact : _frameTacts;
var length = currentTact - LastPulseTact;
// --- If the first tact changes the pulse, we do
// --- not add it
if (length > 0)
{
Pulses.Add(new EarBitPulse
{
EarBit = !earBit,
Lenght = length
});
}
LastPulseTact = currentTact;
}
/// <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;
}
/// <summary>
/// Allow the device to react to the completion of a frame
/// </summary>
public void OnFrameCompleted()
{
if (LastPulseTact <= _frameTacts - 1)
{
// --- We have to store the last pulse information
Pulses.Add(new EarBitPulse
{
EarBit = LastEarBit,
Lenght = _frameTacts - LastPulseTact
});
}
// --- Create the array for the samples
var firstSampleOffset = _frameBegins % _tactsPerSample == 0
? 0
: _tactsPerSample - (_frameBegins + _tactsPerSample) % _tactsPerSample;
var samplesInFrame = (_frameTacts - firstSampleOffset - 1) / _tactsPerSample + 1;
var samples = new float[samplesInFrame];
// --- Convert pulses to samples
var sampleIndex = 0;
var currentEnd = _frameBegins;
foreach (var pulse in Pulses)
{
var firstSample = currentEnd % _tactsPerSample == 0
? currentEnd
: currentEnd + _tactsPerSample - currentEnd % _tactsPerSample;
for (var i = firstSample; i < currentEnd + pulse.Lenght; i += _tactsPerSample)
{
samples[sampleIndex++] = pulse.EarBit ? 1.0F : 0.0F;
}
currentEnd += pulse.Lenght;
}
_beeperProvider?.AddSoundFrame(samples);
_frameBegins += _frameTacts;
}