BizHawk/BizHawk.Emulation.Cores/Sound/HuC6280PSG.cs

263 lines
7.9 KiB
C#

using System;
using System.Collections.Generic;
using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
using BizHawk.Emulation.Common;
namespace BizHawk.Emulation.Cores.Components
{
// Emulates PSG audio unit of a PC Engine / Turbografx-16 / SuperGrafx.
// It is embedded on the CPU and doesn't have its own part number. None the less, it is emulated separately from the 6280 CPU.
public sealed class HuC6280PSG : ISoundProvider
{
public class PSGChannel
{
public ushort Frequency;
public byte Panning;
public byte Volume;
public bool Enabled;
public bool NoiseChannel;
public bool DDA;
public ushort NoiseFreq;
public short DDAValue;
public short[] Wave = new short[32];
public float SampleOffset;
}
public PSGChannel[] Channels = new PSGChannel[8];
public bool[] UserMute = new bool[8];
public byte VoiceLatch;
private byte WaveTableWriteOffset;
private readonly Queue<QueuedCommand> commands = new Queue<QueuedCommand>(256);
private long frameStartTime, frameStopTime;
const int SampleRate = 44100;
const int PsgBase = 3580000;
static readonly byte[] LogScale = { 0, 0, 10, 10, 13, 13, 16, 16, 20, 20, 26, 26, 32, 32, 40, 40, 51, 51, 64, 64, 81, 81, 102, 102, 128, 128, 161, 161, 203, 203, 255, 255 };
static readonly byte[] VolumeReductionTable = { 0x1F, 0x1D, 0x1B, 0x19, 0x17, 0x15, 0x13, 0x10, 0x0F, 0x0D, 0x0B, 0x09, 0x07, 0x05, 0x03, 0x00 };
public byte MainVolumeLeft;
public byte MainVolumeRight;
public int MaxVolume { get; set; }
public HuC6280PSG()
{
MaxVolume = short.MaxValue;
Waves.InitWaves();
for (int i = 0; i < 8; i++)
{
Channels[i] = new PSGChannel();
}
}
public void BeginFrame(long cycles)
{
while (commands.Count > 0)
{
var cmd = commands.Dequeue();
WritePSGImmediate(cmd.Register, cmd.Value);
}
frameStartTime = cycles;
}
public void EndFrame(long cycles)
{
frameStopTime = cycles;
}
public void WritePSG(byte register, byte value, long cycles)
{
commands.Enqueue(new QueuedCommand { Register = register, Value = value, Time = cycles - frameStartTime });
}
public void WritePSGImmediate(int register, byte value)
{
register &= 0x0F;
switch (register)
{
case 0: // Set Voice Latch
VoiceLatch = (byte)(value & 7);
break;
case 1: // Global Volume select;
MainVolumeLeft = (byte)((value >> 4) & 0x0F);
MainVolumeRight = (byte)(value & 0x0F);
break;
case 2: // Frequency LSB
Channels[VoiceLatch].Frequency &= 0xFF00;
Channels[VoiceLatch].Frequency |= value;
break;
case 3: // Frequency MSB
Channels[VoiceLatch].Frequency &= 0x00FF;
Channels[VoiceLatch].Frequency |= (ushort)(value << 8);
Channels[VoiceLatch].Frequency &= 0x0FFF;
break;
case 4: // Voice Volume
Channels[VoiceLatch].Volume = (byte)(value & 0x1F);
Channels[VoiceLatch].Enabled = (value & 0x80) != 0;
Channels[VoiceLatch].DDA = (value & 0x40) != 0;
if (Channels[VoiceLatch].Enabled == false && Channels[VoiceLatch].DDA)
{
//for the soudn debugger, this might be a useful indication that a new note has begun.. but not for sure
WaveTableWriteOffset = 0;
}
break;
case 5: // Panning
Channels[VoiceLatch].Panning = value;
break;
case 6: // Wave data
if (Channels[VoiceLatch].DDA == false)
{
Channels[VoiceLatch].Wave[WaveTableWriteOffset++] = (short)((value * 2047) - 32767);
WaveTableWriteOffset &= 31;
}
else
{
Channels[VoiceLatch].DDAValue = (short)((value * 2047) - 32767);
}
break;
case 7: // Noise
Channels[VoiceLatch].NoiseChannel = ((value & 0x80) != 0) && VoiceLatch >= 4;
if ((value & 0x1F) == 0x1F)
value &= 0xFE;
Channels[VoiceLatch].NoiseFreq = (ushort)(PsgBase / (64 * (0x1F - (value & 0x1F))));
break;
case 8: // LFO
// TODO: implement LFO
break;
case 9: // LFO Control
if ((value & 0x80) == 0 && (value & 3) != 0)
{
Console.WriteLine("**************** LFO ON !!!!!!!!!! *****************");
Channels[1].Enabled = false;
}
else
{
Channels[1].Enabled = true;
}
break;
}
}
public void DiscardSamples() { }
public void GetSamples(short[] samples)
{
int elapsedCycles = (int)(frameStopTime - frameStartTime);
int start = 0;
while (commands.Count > 0)
{
var cmd = commands.Dequeue();
int pos = (int)((cmd.Time * samples.Length) / elapsedCycles) & ~1;
MixSamples(samples, start, pos - start);
start = pos;
WritePSGImmediate(cmd.Register, cmd.Value);
}
MixSamples(samples, start, samples.Length - start);
}
void MixSamples(short[] samples, int start, int len)
{
for (int i = 0; i < 6; i++)
{
if (UserMute[i]) continue;
MixChannel(samples, start, len, Channels[i]);
}
}
void MixChannel(short[] samples, int start, int len, PSGChannel channel)
{
if (channel.Enabled == false) return;
if (channel.DDA == false && channel.Volume == 0) return;
short[] wave = channel.Wave;
int freq;
if (channel.NoiseChannel)
{
wave = Waves.NoiseWave;
freq = channel.NoiseFreq;
}
else if (channel.DDA)
{
freq = 0;
}
else
{
if (channel.Frequency <= 1) return;
freq = PsgBase / (32 * ((int)channel.Frequency));
}
int globalPanFactorLeft = VolumeReductionTable[MainVolumeLeft];
int globalPanFactorRight = VolumeReductionTable[MainVolumeRight];
int channelPanFactorLeft = VolumeReductionTable[channel.Panning >> 4];
int channelPanFactorRight = VolumeReductionTable[channel.Panning & 0xF];
int channelVolumeFactor = 0x1f - channel.Volume;
int volumeLeft = 0x1F - globalPanFactorLeft - channelPanFactorLeft - channelVolumeFactor;
if (volumeLeft < 0)
volumeLeft = 0;
int volumeRight = 0x1F - globalPanFactorRight - channelPanFactorRight - channelVolumeFactor;
if (volumeRight < 0)
volumeRight = 0;
float adjustedWaveLengthInSamples = SampleRate / (channel.NoiseChannel ? freq / (float)(channel.Wave.Length * 128) : freq);
float moveThroughWaveRate = wave.Length / adjustedWaveLengthInSamples;
int end = start + len;
for (int i = start; i < end; )
{
channel.SampleOffset %= wave.Length;
short value = channel.DDA ? channel.DDAValue : wave[(int)channel.SampleOffset];
samples[i++] += (short)(value * LogScale[volumeLeft] / 255f / 6f * MaxVolume / short.MaxValue);
samples[i++] += (short)(value * LogScale[volumeRight] / 255f / 6f * MaxVolume / short.MaxValue);
channel.SampleOffset += moveThroughWaveRate;
channel.SampleOffset %= wave.Length;
}
}
public void SyncState(Serializer ser)
{
ser.BeginSection("PSG");
ser.Sync("MainVolumeLeft", ref MainVolumeLeft);
ser.Sync("MainVolumeRight", ref MainVolumeRight);
ser.Sync("VoiceLatch", ref VoiceLatch);
ser.Sync("WaveTableWriteOffset", ref WaveTableWriteOffset);
for (int i = 0; i < 6; i++)
{
ser.BeginSection("Channel"+i);
ser.Sync("Frequency", ref Channels[i].Frequency);
ser.Sync("Panning", ref Channels[i].Panning);
ser.Sync("Volume", ref Channels[i].Volume);
ser.Sync("Enabled", ref Channels[i].Enabled);
if (i.In(4, 5))
{
ser.Sync("NoiseChannel", ref Channels[i].NoiseChannel);
ser.Sync("NoiseFreq", ref Channels[i].NoiseFreq);
}
ser.Sync("DDA", ref Channels[i].DDA);
ser.Sync("DDAValue", ref Channels[i].DDAValue);
ser.Sync("SampleOffset", ref Channels[i].SampleOffset);
ser.Sync("Wave", ref Channels[i].Wave, false);
ser.EndSection();
}
ser.EndSection();
}
class QueuedCommand
{
public byte Register;
public byte Value;
public long Time;
}
}
}