From e07919476c43777fc156d0b331ddd0d1406846e3 Mon Sep 17 00:00:00 2001
From: saxxonpike <saxxonpike@gmail.com>
Date: Mon, 12 Nov 2012 23:54:46 +0000
Subject: [PATCH] commodore64: basic sound support, still no envelope generator
 so sounds will sometimes carry

---
 .../Computers/Commodore64/C64.core.cs         |  2 +-
 .../Computers/Commodore64/C64.cs              |  2 +-
 .../Computers/Commodore64/Sid.cs              | 37 ++++++++++++++-----
 .../Computers/Commodore64/SidSoundProvider.cs | 33 ++++++++++++-----
 .../Computers/Commodore64/VicII.cs            |  4 ++
 5 files changed, 56 insertions(+), 22 deletions(-)

diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.core.cs b/BizHawk.Emulation/Computers/Commodore64/C64.core.cs
index 959f1f55f4..a0dd357529 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.core.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.core.cs
@@ -54,7 +54,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			vic = new VicII(signal, Region.NTSC);
 
 			// initialize sid
-			sid = new Sid(Region.NTSC, 88200);
+			sid = new Sid(Region.NTSC, 44100); // we'll assume 44.1k for now until there's a better way
 
 			// initialize memory (this must be done AFTER all other chips are initialized)
 			string romPath = CoreInputComm.C64_FirmwaresPath;
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.cs b/BizHawk.Emulation/Computers/Commodore64/C64.cs
index b1c83681fa..07d87e0842 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.cs
@@ -78,7 +78,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			_frame++;
 			_islag = true;
 
-			const int cyclesPerFrame = (14318181 / 14 / 60);
+			int cyclesPerFrame = vic.cyclesPerFrame;
 
 			foreach (IMedia media in mediaAttached)
 			{
diff --git a/BizHawk.Emulation/Computers/Commodore64/Sid.cs b/BizHawk.Emulation/Computers/Commodore64/Sid.cs
index 1d4f87ed9a..d9fb3b77dc 100644
--- a/BizHawk.Emulation/Computers/Commodore64/Sid.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/Sid.cs
@@ -179,15 +179,15 @@ namespace BizHawk.Emulation.Computers.Commodore64
 					case 0x09:
 					case 0x10:
 						index = addr / 7;
-						PW[index] &= 0x0700;
+						PW[index] &= 0x0F00;
 						PW[index] |= val;
 						break;
 					case 0x03:
 					case 0x0A:
 					case 0x11:
 						index = addr / 7;
-						F[index] &= 0xFF;
-						F[index] |= (val & 0x07) << 8;
+						PW[index] &= 0xFF;
+						PW[index] |= (val & 0x0F) << 8;
 						break;
 					case 0x04:
 					case 0x0B:
@@ -389,7 +389,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			int sawOutput;
 			int squOutput;
 			int noiseOutput;
-			int finalOutput = 0xFFF;
+			int finalOutput = 0x00000FFF;
 			bool outputEnabled = false;
 
 			// triangle waveform
@@ -425,10 +425,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 				}
 				else
 				{
-					if (regs.PW[index] >= ((waveClock[index] >> 12) & 0xFFF))
-						squOutput = 0xFFF;
-					else
-						squOutput = 0x000;
+					squOutput = (waveClock[index] >> 12) >= regs.PW[index] ? 0xFFF : 0x000;
 				}
 				finalOutput &= squOutput;
 				outputEnabled = true;
@@ -437,6 +434,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			// noise waveform
 			if (regs.NOISE[index])
 			{
+				// shift register information is from reSID
 				int sr = regs.SR[index];
 				noiseOutput = sr & 0x100000 >> 9;
 				noiseOutput |= sr & 0x040000 >> 8;
@@ -455,20 +453,25 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			{
 				waveClock[index] = 0x000000;
 				outputEnabled = false;
+				regs.SR[index] = 0x7FFFFF;
 			}
 			else
 			{
 				// shift register for generating noise
-				if ((waveClock[index] & 0x7FFFF) == 0x00000)
+				if ((waveClock[index] & 0x100000) != 0)
 					ProcessShiftRegister(index);
 
 				// increment wave clock
-				waveClock[index] = (waveClock[index] + regs.F[index]) & 0xFFFFFF;
+				waveClock[index] = (waveClock[index] + regs.F[index]) & 0x00FFFFFF;
 			}
 
 			// process the envelope generator
 			//ProcessEnvelope(index);
 
+			// a little hack until we fix the envelope generator
+			outputEnabled = regs.GATE[index];
+
+
 			// write to internal reg
 			if (outputEnabled)
 				regs.OSC[index] = finalOutput;
@@ -524,5 +527,19 @@ namespace BizHawk.Emulation.Computers.Commodore64
 					break;
 			}
 		}
+
+		private void WriteShiftRegister(int index, int sample)
+		{
+			regs.SR[index] &=
+				~((1 << 20) | (1 << 18) | (1 << 14) | (1 << 11) | (1 << 9) | (1 << 5) | (1 << 2) | (1 << 0)) |
+				((sample & 0x800) << 9) |
+				((sample & 0x400) << 8) |
+				((sample & 0x200) << 5) |
+				((sample & 0x100) << 3) |
+				((sample & 0x080) << 2) |
+				((sample & 0x040) >> 1) |
+				((sample & 0x020) >> 3) |
+				((sample & 0x010) >> 4);
+		}
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/SidSoundProvider.cs b/BizHawk.Emulation/Computers/Commodore64/SidSoundProvider.cs
index c7d33510a1..72571b8143 100644
--- a/BizHawk.Emulation/Computers/Commodore64/SidSoundProvider.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/SidSoundProvider.cs
@@ -25,6 +25,9 @@ namespace BizHawk.Emulation.Computers.Commodore64
 				if (sampleBufferReadIndex == sampleBufferCapacity)
 					sampleBufferReadIndex = 0;
 			}
+
+			// catch the buffer up
+			sampleBufferReadIndex = sampleBufferIndex;
 		}
 
 		private void InitSound(int initSampleRate)
@@ -36,8 +39,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		public void DiscardSamples()
 		{
 			sampleBuffer = new short[sampleBufferCapacity];
-			sampleBufferReadIndex = 0;
-			sampleBufferIndex = 0;
+			ResetBuffer();
 		}
 
 		public int MaxVolume
@@ -51,6 +53,12 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			}
 		}
 
+		private void ResetBuffer()
+		{
+			sampleBufferReadIndex = 0;
+			sampleBufferIndex = 0;
+		}
+
 		private void SubmitSample()
 		{
 			if (sampleCounter == 0)
@@ -58,16 +66,21 @@ namespace BizHawk.Emulation.Computers.Commodore64
 				short output;
 				output = Mix(regs.OSC[0], 0);
 				output = Mix(regs.OSC[1], output);
-				if (!regs.D3 && !regs.FILT[2])
+				
+				// voice 3 can be disabled with a specific register, but
+				// when the filter is enabled, it still plays
+				if (!regs.D3 || regs.FILT[2])
 					output = Mix(regs.OSC[2], output);
 
-				// disable sound for now...
-				output = 0;
-				sampleCounter = cyclesPerSample;
-				sampleBuffer[sampleBufferIndex] = output;
-				sampleBufferIndex++;
-				if (sampleBufferIndex == sampleBufferCapacity)
-					sampleBufferIndex = 0;
+				// 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;
+				}
 			}
 			sampleCounter--;
 		}
diff --git a/BizHawk.Emulation/Computers/Commodore64/VicII.cs b/BizHawk.Emulation/Computers/Commodore64/VicII.cs
index 6b03d3721b..febbc175d5 100644
--- a/BizHawk.Emulation/Computers/Commodore64/VicII.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/VicII.cs
@@ -484,6 +484,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		public byte[] colorMemory;
 		public int cycle;
 		public int cycleLeft;
+		public int cyclesPerFrame;
 		public bool dataForeground;
 		public bool displayEnabled;
 		public bool hBlank;
@@ -655,6 +656,9 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			// initialize screen
 			UpdateBorder();
 			UpdatePlotter();
+
+			// some helpful values
+			cyclesPerFrame = totalCycles * rasterTotalLines;
 		}
 
 		public byte Peek(int addr)