From 4e0796814d377787d0391fc443b691c1437037e2 Mon Sep 17 00:00:00 2001
From: goyuken <goyuken@4bbf4f03-6f44-549e-7e59-35d4b0962838>
Date: Fri, 14 Dec 2012 15:17:14 +0000
Subject: [PATCH] VRC6 audio: restructure to send deltas directly to the NES
 apu, simplifying some things.  This would be pointless masturbation by
 itself, but this method will also lead to easier emulation of MMC5 audio.

---
 .../Consoles/Nintendo/NES/APU.cs              |  8 +++++
 .../Consoles/Nintendo/NES/Boards/VRC6.cs      | 15 ++++----
 BizHawk.Emulation/Sound/VRC6Alt.cs            | 35 ++++++++++++-------
 3 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
index a1ad3ae636..c67598fea6 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
@@ -1076,6 +1076,14 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 			public List<Delta> dlist = new List<Delta>();
 
+			/// <summary>only call in board.ClockCPU()</summary>
+			/// <param name="value"></param>
+			public void ExternalQueue(int value)
+			{
+				// sampleclock is incremented right before board.ClockCPU()
+				dlist.Add(new Delta(sampleclock - 1, value));
+			}
+
 			public uint sampleclock = 0;
 
 			int oldmix = 0;
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
index ccda43d7d2..9eedc8008d 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
@@ -30,8 +30,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			base.Dispose();
 			prg_banks_8k.Dispose();
 			chr_banks_1k.Dispose();
-			if (VRC6Sound != null)
-				VRC6Sound.Dispose();
+			//if (VRC6Sound != null)
+			//	VRC6Sound.Dispose();
 		}
 
 		public override void SyncState(Serializer ser)
@@ -96,7 +96,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			SyncPRG();
 			SetMirrorType(EMirrorType.Vertical);
 
-			VRC6Sound = new Sound.VRC6Alt((uint)NES.cpuclockrate);
+			if (NES.apu != null) // don't start up sound when in configurator
+				VRC6Sound = new Sound.VRC6Alt((uint)NES.cpuclockrate, NES.apu.ExternalQueue);
 
 			return true;
 		}
@@ -273,8 +274,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 		}
 
-		public override void ApplyCustomAudio(short[] samples)
-		{
+		//public override void ApplyCustomAudio(short[] samples)
+		//{
 			/*
 			short[] fmsamples = new short[samples.Length];
 			VRC6Sound.GetSamples(fmsamples);
@@ -284,8 +285,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				samples[i] = (short)((samples[i] >> 1) + (fmsamples[i] >> 1));
 			}
 			*/
-			VRC6Sound.ApplyCustomAudio(samples);
-		}
+		//	VRC6Sound.ApplyCustomAudio(samples);
+		//}
 
 	}
 }
\ No newline at end of file
diff --git a/BizHawk.Emulation/Sound/VRC6Alt.cs b/BizHawk.Emulation/Sound/VRC6Alt.cs
index 1a2e4e4124..86611408d6 100644
--- a/BizHawk.Emulation/Sound/VRC6Alt.cs
+++ b/BizHawk.Emulation/Sound/VRC6Alt.cs
@@ -5,19 +5,19 @@ using System.Text;
 
 namespace BizHawk.Emulation.Sound
 {
-	public class VRC6Alt : IDisposable
+	public class VRC6Alt// : IDisposable
 	{
 		// http://wiki.nesdev.com/w/index.php/VRC6_audio
 
 
 
-
-
+		/*
+		// the VRC6 now sends its blips back to the NES core, for simplicity
+		// (speed is the same)
+		
 		#region blip-buf interface
 
 		Sound.Utilities.BlipBuffer blip;
-		// yes, some of this is copy+pasted from the FDS, and more or less from the NES
-		// as soon as i decide that i like it and i use it a third time, i'll put it in a class
 
 		struct Delta
 		{
@@ -38,6 +38,7 @@ namespace BizHawk.Emulation.Sound
 
 		public void ApplyCustomAudio(short[] samples)
 		{
+			
 			int nsamp = samples.Length / 2;
 			if (nsamp > blipsize) // oh well.
 				nsamp = blipsize;
@@ -61,29 +62,35 @@ namespace BizHawk.Emulation.Sound
 				// nes audio is mono, so we can ignore the original value of samples[j+1]
 				samples[j + 1] = samples[j];
 			}
+			
 		}
-
 		#endregion
+		*/
 
 		Pulse pulse1, pulse2;
 		Saw saw;
 
+		Action<int> enqueuer;
+
 		/// <summary>
 		/// 
 		/// </summary>
 		/// <param name="freq">frequency of the M2 clock in hz</param>
-		public VRC6Alt(uint freq)
+		/// <param name="enqueuer">a place to dump deltas to</param>
+		public VRC6Alt(uint freq, Action<int> enqueuer)
 		{
+			this.enqueuer = enqueuer;
+			/*
 			if (freq > 0)
 			{
 				blip = new Utilities.BlipBuffer(blipsize);
 				blip.SetRates(freq, 44100);
-			}
+			}*/
 			pulse1 = new Pulse(PulseAddDiff);
 			pulse2 = new Pulse(PulseAddDiff);
 			saw = new Saw(SawAddDiff);
 		}
-
+		/*
 		public void Dispose()
 		{
 			if (blip != null)
@@ -91,18 +98,20 @@ namespace BizHawk.Emulation.Sound
 				blip.Dispose();
 				blip = null;
 			}
-		}
+		}*/
 
 		// the two pulse channels are about the same volume as 2a03 pulse channels.
 		// everything is flipped, though; but that's taken care of in the classes
 		void PulseAddDiff(int value)
 		{
-			dlist.Add(new Delta(sampleclock, value * 360));
+			//dlist.Add(new Delta(sampleclock, value * 360));
+			enqueuer(value * 360);
 		}
 		// saw ends up being not that loud because of differences in implementation
 		void SawAddDiff(int value)
 		{
-			dlist.Add(new Delta(sampleclock, value * 360));
+			//dlist.Add(new Delta(sampleclock, value * 360));
+			enqueuer(value * 360);
 		}
 
 		// state
@@ -151,7 +160,7 @@ namespace BizHawk.Emulation.Sound
 				pulse2.Clock();
 				saw.Clock();
 			}
-			sampleclock++;
+			//sampleclock++;
 		}
 
 		class Saw