add TargetFrameLength to rewind settings

src/BizHawk.Client.Common/config/RewindConfig.cs

@@ -2,9 +2,26 @@
 {
 	public interface IRewindSettings
 	{
-		public bool UseCompression { get; }
+		/// <summary>
+		/// Gets a value indicating whether or not to enable rewinding
+		/// </summary>
 		public bool Enabled { get; }
+
+		/// <summary>
+		/// Gets a value indicating whether or not to compress savestates before storing them
+		/// </summary>
+		public bool UseCompression { get; }
+		
+
+		/// <summary>
+		/// Max amount of buffer space to use in MB
+		/// </summary>
 		public int BufferSize { get; }
+
+		/// <summary>
+		/// Desired frame length (number of emulated frames you can go back before running out of buffer)
+		/// </summary>
+		public int TargetFrameLength { get; }
 	}
 
 	public class RewindConfig : IRewindSettings
@@ -12,5 +29,6 @@
 		public bool UseCompression { get; set; }
 		public bool Enabled { get; set; } = true;
 		public int BufferSize { get; set; } = 512; // in mb
+		public int TargetFrameLength { get; set; } = 600;
 	}
 }

src/BizHawk.Client.Common/rewind/Zwinder.cs

@@ -19,22 +19,20 @@ namespace BizHawk.Client.Common
 			maintain a separate rewinder alongside this one that is customized for those cores.
 		*/
 
-		/// <param name="targetSize">size of rewinder backing store in bytes</param>
-		/// <param name="targetFrameLength">desired frame length (number of emulated frames you can go back before running out of buffer)</param>
-		public Zwinder(int targetFrameLength, IBinaryStateable stateSource, IRewindSettings settings)
+		public Zwinder(IBinaryStateable stateSource, IRewindSettings settings)
 		{
 			long targetSize = settings.BufferSize * 1024 * 1024;
 			if (targetSize < 65536)
 				throw new ArgumentOutOfRangeException(nameof(targetSize));
-			if (targetFrameLength < 1)
-				throw new ArgumentOutOfRangeException(nameof(targetFrameLength));
+			if (settings.TargetFrameLength < 1)
+				throw new ArgumentOutOfRangeException(nameof(settings.TargetFrameLength));
 
 			Size = 1L << (int)Math.Floor(Math.Log(targetSize, 2));
 			_sizeMask = Size - 1;
 			_buffer = new byte[Size];
 			Active = true;
 			_stateSource = stateSource;
-			_targetFrameLength = targetFrameLength;
+			_targetFrameLength = settings.TargetFrameLength;
 			_states = new StateInfo[STATEMASK + 1];
 			_kompress = settings.UseCompression;
 		}

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -866,7 +866,7 @@ namespace BizHawk.Client.EmuHawk
 		{
 			Rewinder?.Dispose();
 			Rewinder = Emulator.HasSavestates() && Config.Rewind.Enabled
-				? new Zwinder(600, Emulator.AsStatable(), Config.Rewind)
+				? new Zwinder(Emulator.AsStatable(), Config.Rewind)
 				: null;
 		}