ShuriZma
/
BizHawk
mirror of https://github.com/TASEmulators/BizHawk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

commodore64: envelope generator added, sound should be somewhat decent now

This commit is contained in:
saxxonpike 2012-11-13 18:59:16 +00:00
parent c6ab71b5ed
commit b7334679c6
3 changed files with 160 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
BizHawk.Emulation/Computers/Commodore64/C64.core.cs
View File

@ -53,6 +53,10 @@ namespace BizHawk.Emulation.Computers.Commodore64
signal = new ChipSignals();
vic = new VicII(signal, Region.NTSC);
// assume NTSC for now
CoreOutputComm.VsyncDen = vic.cyclesPerFrame;
CoreOutputComm.VsyncNum = (14318181 / 14);
// initialize sid
sid = new Sid(Region.NTSC, 44100); // we'll assume 44.1k for now until there's a better way

167
BizHawk.Emulation/Computers/Commodore64/Sid.cs
View File

@ -274,8 +274,14 @@ namespace BizHawk.Emulation.Computers.Commodore64
392, 977, 1954, 3126,
3907, 11720, 19532, 31251
};
private int[] sustainLevels = {
0x00, 0x11, 0x22, 0x33,
0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xAA, 0xBB,
0xCC, 0xDD, 0xEE, 0xFF
};
private int[] syncIndex = { 2, 0, 1 };
private VoiceRegs[] voices;
public Func<int> ReadPotX;
@ -284,11 +290,12 @@ namespace BizHawk.Emulation.Computers.Commodore64
public int clock;
public int cyclesPerSample;
public bool[] envEnable = new bool[3];
public int[] envExp = new int[3];
public int[] envExpCounter = new int[3];
public int[] envRate = new int[3];
public int[] envRateCounter = new int[3];
public SidEnvelopeState[] envState = new SidEnvelopeState[3];
public bool[] gateLastCycle = new bool[3];
public bool[] lastGate = new bool[3];
public int output;
public SidRegs regs;
public int[] waveClock = new int[3];
@ -321,10 +328,19 @@ namespace BizHawk.Emulation.Computers.Commodore64
voices = regs.Voices;
}
private short Mix(int input, short mixSource)
private short Mix(int input, int volume, short mixSource)
{
// logarithmic volume (probably inaccurate)
int logVolume = volume * 256;
logVolume = (int)Math.Sqrt(logVolume);
// combine the volumes together 1:1
volume = (volume + logVolume) >> 1;
input &= 0xFFF;
input -= 0x800;
input *= volume;
input /= 255;
input += mixSource;
if (input > 32767)
input = 32767;
@ -359,6 +375,11 @@ namespace BizHawk.Emulation.Computers.Commodore64
if (voices[0].SYNC)
ProcessVoice(2);
// process each envelope
ProcessEnvelope(0);
ProcessEnvelope(1);
ProcessEnvelope(2);
// submit sample to soundprovider
SubmitSample();
@ -398,29 +419,81 @@ namespace BizHawk.Emulation.Computers.Commodore64
private void ProcessEnvelope(int index)
{
// envelope counter is 15 bits
envRateCounter[index] &= 0x7FFF;
if (!gateLastCycle[index] && voices[index].GATE)
{
envState[index] = SidEnvelopeState.Attack;
envEnable[index] = true;
}
else if (gateLastCycle[index] && !voices[index].GATE)
{
envState[index] = SidEnvelopeState.Release;
}
envRateCounter[index] = (envRateCounter[index] + 1) & 0xFFFF;
if (envRateCounter[index] == envRate[index])
{
envExpCounter[index] = 0;
if (envEnable[index])
envRateCounter[index] = 0;
if (envState[index] != SidEnvelopeState.Disabled)
{
envExpCounter[index] = (envExpCounter[index] + 1) & 0xFF;
if (envExpCounter[index] == 0)
envState[index] = SidEnvelopeState.Disabled;
if (envExpCounter[index] == envExp[index])
{
switch (envState[index])
{
case SidEnvelopeState.Attack:
if (voices[index].ENV < 0xFF)
voices[index].ENV++;
if (voices[index].ENV == 0xFF)
{
envState[index] = SidEnvelopeState.Decay;
UpdateEnvelopeRateCounter(index);
}
break;
case SidEnvelopeState.Decay:
if (voices[index].ENV > sustainLevels[voices[index].STN] && voices[index].ENV > 0)
voices[index].ENV--;
break;
case SidEnvelopeState.Release:
if (voices[index].ENV > 0)
voices[index].ENV--;
if (voices[index].ENV == 0)
{
envState[index] = SidEnvelopeState.Disabled;
UpdateEnvelopeRateCounter(index);
}
break;
}
envExpCounter[index] = 0;
ProcessEnvelopeExpCounter(index);
}
else if (envState[index] == SidEnvelopeState.Attack)
{
ProcessEnvelopeExpCounter(index);
}
}
}
gateLastCycle[index] = voices[index].GATE;
}
private void ProcessEnvelopeExpCounter(int index)
{
switch (voices[index].ENV)
{
case 0xFF:
envExp[index] = 1;
break;
case 0x5D:
envExp[index] = 2;
break;
case 0x36:
envExp[index] = 4;
break;
case 0x1A:
envExp[index] = 8;
break;
case 0x0E:
envExp[index] = 16;
break;
case 0x06:
envExp[index] = 30;
break;
case 0x00:
envExp[index] = 1;
break;
}
}
private void ProcessShiftRegister(int index)
@ -492,14 +565,12 @@ namespace BizHawk.Emulation.Computers.Commodore64
noiseOutput |= sr & 0x000001 << 4;
finalOutput &= noiseOutput;
outputEnabled = true;
// other waveforms write into the shift register
if (voices[index].SQU || voices[index].TRI || voices[index].SAW)
WriteShiftRegister(index, finalOutput);
}
// process the envelope generator
//ProcessEnvelope(index);
// a little hack until we fix the envelope generator
outputEnabled = voices[index].GATE;
// write to internal reg
if (outputEnabled)
voices[index].OSC = finalOutput;
@ -528,7 +599,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
switch (envState[index])
{
case SidEnvelopeState.Attack:
envRate[index] = envRateIndex[voices[index].ATK];
envRate[index] = envRateIndex[voices[index].ATK] / 3;
break;
case SidEnvelopeState.Decay:
envRate[index] = envRateIndex[voices[index].DCY];
@ -537,13 +608,57 @@ namespace BizHawk.Emulation.Computers.Commodore64
envRate[index] = envRateIndex[voices[index].RLS];
break;
}
ProcessEnvelopeExpCounter(index);
}
public void Write(ushort addr, byte val)
{
int index;
bool gate;
addr &= 0x1F;
switch (addr)
{
case 0x04:
case 0x0B:
case 0x12:
// set control
index = addr / 7;
gate = lastGate[index];
regs[addr] = val;
lastGate[index] = voices[index].GATE;
if (!gate && lastGate[index])
{
envExpCounter[index] = 0;
envState[index] = SidEnvelopeState.Attack;
voices[index].ENV = 0;
envRateCounter[index] = 0;
UpdateEnvelopeRateCounter(index);
ProcessEnvelopeExpCounter(index);
}
else if (gate && !lastGate[index])
{
envExpCounter[index] = 0;
envState[index] = SidEnvelopeState.Release;
UpdateEnvelopeRateCounter(index);
}
break;
case 0x05:
case 0x0C:
case 0x13:
// set attack/decay
index = addr / 7;
regs[addr] = val;
UpdateEnvelopeRateCounter(index);
break;
case 0x06:
case 0x0D:
case 0x14:
// set sustain/release
index = addr / 7;
regs[addr] = val;
UpdateEnvelopeRateCounter(index);
break;
case 0x19:
case 0x1A:
case 0x1B:

28
BizHawk.Emulation/Computers/Commodore64/SidSoundProvider.cs
View File

@ -13,20 +13,28 @@ namespace BizHawk.Emulation.Computers.Commodore64
private int sampleBufferReadIndex;
private int sampleCounter;
public void DiscardSamples()
{
sampleBuffer = new short[sampleBufferCapacity];
ResetBuffer();
}
public void GetSamples(short[] samples)
{
int count = samples.Length;
int copied = 0;
while ((sampleBufferIndex != sampleBufferReadIndex) && (copied < count))
while (copied < count)
{
samples[copied] = sampleBuffer[sampleBufferReadIndex++];
samples[copied] = sampleBuffer[sampleBufferReadIndex];
if (sampleBufferIndex != sampleBufferReadIndex)
sampleBufferReadIndex++;
copied++;
if (sampleBufferReadIndex == sampleBufferCapacity)
sampleBufferReadIndex = 0;
}
// catch the buffer up
// catch buffer up
sampleBufferReadIndex = sampleBufferIndex;
}
@ -36,12 +44,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
DiscardSamples();
}
public void DiscardSamples()
{
sampleBuffer = new short[sampleBufferCapacity];
ResetBuffer();
}
public int MaxVolume
{
get
@ -64,22 +66,22 @@ namespace BizHawk.Emulation.Computers.Commodore64
if (sampleCounter == 0)
{
short output;
output = Mix(voices[0].OSC, 0);
output = Mix(voices[1].OSC, output);
output = Mix(voices[0].OSC, voices[0].ENV, 0);
output = Mix(voices[1].OSC, voices[1].ENV, output);
// voice 3 can be disabled with a specific register, but
// when the filter is enabled, it still plays
if (!regs.D3 || voices[2].FILT)
output = Mix(voices[2].OSC, output);
output = Mix(voices[2].OSC, voices[2].ENV, output);
// run twice since the buffer expects stereo sound (I THINK)
for (int i = 0; i < 2; i++)
{
sampleCounter = cyclesPerSample;
sampleBuffer[sampleBufferIndex] = output;
sampleBufferIndex++;
if (sampleBufferIndex == sampleBufferCapacity)
sampleBufferIndex = 0;
sampleBuffer[sampleBufferIndex] = output;
}
}
sampleCounter--;