Files
ZXSpectrum48K/Desktop/BeeperDevice.cs
2026-04-30 14:35:12 +01:00

87 lines
2.8 KiB
C#

using NAudio.Wave;
using Core.Interfaces;
using System;
using System.Threading;
namespace Desktop
{
public class BeeperDevice : IAudioDevice
{
private WaveOutEvent _waveOut;
private BufferedWaveProvider _buffer;
// Audio Filtering
private float _lastSample = 0.0f;
private float _lastFiltered = 0.0f;
// AY-3-8912 Digital Oscillators (Phase Trackers)
private float _phaseA = 0f;
private float _phaseB = 0f;
private float _phaseC = 0f;
public BeeperDevice()
{
_waveOut = new WaveOutEvent();
_waveOut.DesiredLatency = 50;
// 44.1kHz, 1 channel (Mono), Float format
_buffer = new BufferedWaveProvider(WaveFormat.CreateIeeeFloatWaveFormat(44100, 1));
_buffer.BufferDuration = TimeSpan.FromSeconds(1);
_buffer.DiscardOnBufferOverflow = true;
_waveOut.Init(_buffer);
_waveOut.Play();
}
public void AddSample(bool isHigh, float freqA, float volA, float freqB, float volB, float freqC, float volC)
{
// Buffer overrun check
while (_buffer.BufferedDuration.TotalMilliseconds > 80)
{
Thread.Sleep(1);
}
// 1. The Beeper (Reduced base volume from 0.2 to 0.1 to make headroom for the AY)
float beeper = isHigh ? 0.1f : -0.1f;
// 2. Channel A Oscillator
float ayA = 0f;
if (freqA > 0)
{
_phaseA += freqA / 44100f;
if (_phaseA > 1f) _phaseA -= 1f; // Wrap around
ayA = (_phaseA < 0.5f ? 0.1f : -0.1f) * volA;
}
// 3. Channel B Oscillator
float ayB = 0f;
if (freqB > 0)
{
_phaseB += freqB / 44100f;
if (_phaseB > 1f) _phaseB -= 1f;
ayB = (_phaseB < 0.5f ? 0.1f : -0.1f) * volB;
}
// 4. Channel C Oscillator
float ayC = 0f;
if (freqC > 0)
{
_phaseC += freqC / 44100f;
if (_phaseC > 1f) _phaseC -= 1f;
ayC = (_phaseC < 0.5f ? 0.1f : -0.1f) * volC;
}
// Mix them all together!
float rawSample = beeper + ayA + ayB + ayC;
// Pass the mixed sound wave through your existing High-Pass filter to stop popping
float filteredSample = rawSample - _lastSample + 0.995f * _lastFiltered;
_lastSample = rawSample;
_lastFiltered = filteredSample;
// Convert to bytes and drop it in the pipe
byte[] bytes = BitConverter.GetBytes(filteredSample);
_buffer.AddSamples(bytes, 0, 4);
}
}
}