From 3ebcaa8af0e75838a1fc1c25ad854887bcbd9669 Mon Sep 17 00:00:00 2001
From: "J.D. Purcell" <jdpurcell@gmail.com>
Date: Sat, 29 Apr 2017 14:04:11 -0400
Subject: [PATCH] Rewind cleanup / tweaks.

---
 BizHawk.Client.Common/rewind/Rewinder.cs | 75 ++++++++++--------------
 BizHawk.Client.EmuHawk/MainForm.cs       | 14 +----
 2 files changed, 34 insertions(+), 55 deletions(-)

diff --git a/BizHawk.Client.Common/rewind/Rewinder.cs b/BizHawk.Client.Common/rewind/Rewinder.cs
index 49e1ed67b0..9c71160482 100644
--- a/BizHawk.Client.Common/rewind/Rewinder.cs
+++ b/BizHawk.Client.Common/rewind/Rewinder.cs
@@ -15,53 +15,31 @@ namespace BizHawk.Client.Common
 		private long _memoryLimit = MaxByteArraySize;
 		private RewindThreader _rewindThread;
 		private byte[] _lastState;
-		private int _rewindFrequency = 1;
 		private bool _rewindDeltaEnable;
 		private bool _lastRewindLoadedState;
 		private byte[] _deltaBuffer = new byte[0];
 
-		public Rewinder()
-		{
-			RewindActive = true;
-		}
-
 		public Action<string> MessageCallback { get; set; }
 
-		public bool RewindActive { get; set; }
+		public bool RewindActive => RewindEnabled && !SuspendRewind;
 
-		public float FullnessRatio
-		{
-			get { return _rewindBuffer?.FullnessRatio ?? 0; }
-		}
+		private bool RewindEnabled { get; set; }
 
-		public int Count
-		{
-			get { return _rewindBuffer?.Count ?? 0; }
-		}
+		public bool SuspendRewind { get; set; }
 
-		public long Size
-		{
-			get { return _rewindBuffer?.Size ?? 0; }
-		}
+		public float FullnessRatio => _rewindBuffer?.FullnessRatio ?? 0;
 
-		public bool HasBuffer
-		{
-			get { return _rewindBuffer != null; }
-		}
+		public int Count => _rewindBuffer?.Count ?? 0;
 
-		public int RewindFrequency
-		{
-			get { return _rewindFrequency; }
-		}
+		public long Size => _rewindBuffer?.Size ?? 0;
 
-		private bool IsRewindEnabledAtAll
-		{
-			get { return Global.Config.RewindEnabledLarge || Global.Config.RewindEnabledMedium || Global.Config.RewindEnabledSmall; }
-		}
+		public bool HasBuffer => _rewindBuffer != null;
+
+		public int RewindFrequency { get; private set; }
 
 		public void Initialize()
 		{
-			Clear();
+			Uninitialize();
 
 			if (Global.Emulator.HasSavestates())
 			{
@@ -97,8 +75,10 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public void Clear()
+		public void Uninitialize()
 		{
+			Clear();
+
 			if (_rewindThread != null)
 			{
 				_rewindThread.Dispose();
@@ -111,6 +91,17 @@ namespace BizHawk.Client.Common
 				_rewindBuffer = null;
 			}
 
+			RewindEnabled = false;
+			RewindFrequency = 0;
+		}
+
+		public void Clear()
+		{
+			if (_rewindBuffer != null)
+			{
+				_rewindBuffer.Clear();
+			}
+
 			_lastState = new byte[0];
 		}
 
@@ -121,18 +112,14 @@ namespace BizHawk.Client.Common
 
 		private void SetRewindParams(bool enabled, int frequency)
 		{
-			if (RewindActive != enabled)
-			{
-				DoMessage("Rewind " + (enabled ? "Enabled" : "Disabled"));
-			}
-
-			if (_rewindFrequency != frequency && enabled)
+			DoMessage("Rewind " + (enabled ? "enabled" : "disabled"));
+			if (enabled)
 			{
 				DoMessage("Rewind frequency set to " + frequency);
 			}
 
-			RewindActive = enabled;
-			_rewindFrequency = frequency;
+			RewindEnabled = enabled;
+			RewindFrequency = frequency;
 		}
 
 		private byte[] BufferManage(byte[] inbuf, ref long size, bool allocate)
@@ -172,7 +159,7 @@ namespace BizHawk.Client.Common
 
 		public void Capture()
 		{
-			if (!IsRewindEnabledAtAll || !Global.Emulator.HasSavestates())
+			if (!RewindActive)
 			{
 				return;
 			}
@@ -182,7 +169,7 @@ namespace BizHawk.Client.Common
 				Initialize();
 			}
 
-			if (_rewindThread == null || Global.Emulator.Frame % _rewindFrequency != 0)
+			if (_rewindThread == null || Global.Emulator.Frame % RewindFrequency != 0)
 			{
 				return;
 			}
@@ -315,7 +302,7 @@ namespace BizHawk.Client.Common
 
 		public bool Rewind(int frames)
 		{
-			if (!Global.Emulator.HasSavestates() || _rewindThread == null)
+			if (!RewindActive || _rewindThread == null)
 			{
 				return false;
 			}
diff --git a/BizHawk.Client.EmuHawk/MainForm.cs b/BizHawk.Client.EmuHawk/MainForm.cs
index 491c9bf474..9a5e27595a 100644
--- a/BizHawk.Client.EmuHawk/MainForm.cs
+++ b/BizHawk.Client.EmuHawk/MainForm.cs
@@ -3700,7 +3700,7 @@ namespace BizHawk.Client.EmuHawk
 
 				GlobalWin.Tools.Restart();
 				RewireSound();
-				Global.Rewinder.Clear();
+				Global.Rewinder.Uninitialize();
 				Text = "BizHawk" + (VersionInfo.DeveloperBuild ? " (interim) " : string.Empty);
 				HandlePlatformMenus();
 				_stateSlots.Clear();
@@ -3727,16 +3727,8 @@ namespace BizHawk.Client.EmuHawk
 
 		public void EnableRewind(bool enabled)
 		{
-			if (enabled)
-			{
-				Global.Rewinder.RewindActive = true;
-				GlobalWin.OSD.AddMessage("Rewind enabled");
-			}
-			else
-			{
-				Global.Rewinder.RewindActive = false;
-				GlobalWin.OSD.AddMessage("Rewind suspended");
-			}
+			Global.Rewinder.SuspendRewind = !enabled;
+			GlobalWin.OSD.AddMessage("Rewind " + (enabled ? "enabled" : "suspended"));
 		}
 
 		public void ClearRewindData()