Add ISaveRam implementation for AppleII, fix bug which caused DiskIIC…

…ontroller to not be correctly stated

ExternalCoreProjects/Virtu/Disk525.cs

@@ -4,21 +4,28 @@ namespace Jellyfish.Virtu
 {
 	internal abstract class Disk525
 	{
-		protected byte[] Data;
+		protected readonly byte[] Data;
+		private readonly byte[] Original;
 		public bool IsWriteProtected;
 
 		protected Disk525(byte[] data, bool isWriteProtected)
 		{
 			Data = data;
+			Original = (byte[])data.Clone();
 			IsWriteProtected = isWriteProtected;
 		}
 
 		public virtual void Sync(IComponentSerializer ser)
 		{
-			ser.Sync(nameof(Data), ref Data, false);
+			ser.SyncDelta("DataDelta", Original, Data);
 			ser.Sync(nameof(IsWriteProtected), ref IsWriteProtected);
 		}
 
+		public void DeltaUpdate(Action<byte[], byte[]> callback)
+		{
+			callback(Data, Original);
+		}
+
 		public static Disk525 CreateDisk(string name, byte[] data, bool isWriteProtected)
 		{
 			if (name == null)

ExternalCoreProjects/Virtu/DiskIIDrive.cs

@@ -1,4 +1,6 @@
-namespace Jellyfish.Virtu
+using System;
+
+namespace Jellyfish.Virtu
 {
 	public sealed class DiskIIDrive
 	{
@@ -29,8 +31,6 @@ public void Sync(IComponentSerializer ser)
 			ser.Sync(nameof(_trackNumber), ref _trackNumber);
 			ser.Sync(nameof(_trackOffset), ref _trackOffset);
 			ser.Sync(nameof(_trackData), ref _trackData, false);
-
-			// TODO: save the delta, this is saving the rom into save states
 			_disk?.Sync(ser);
 		}
 
@@ -120,5 +120,11 @@ internal void FlushTrack()
 
 		private const int TrackNumberMax = 0x44;
 		private const int PhaseCount = 4;
+
+		public void DeltaUpdate(Action<byte[], byte[]> callback)
+		{
+			FlushTrack();
+			_disk.DeltaUpdate(callback);
+		}
 	}
 }

ExternalCoreProjects/Virtu/IComponentSerializer.cs

@@ -13,5 +13,7 @@ public interface IComponentSerializer
 		void Sync(string name, ref byte[] val, bool useNull);
 		void Sync(string name, ref ushort[] val, bool useNull);
 		void Sync(string name, ref int[] val, bool useNull);
+
+		void SyncDelta<T>(string name, T[] original, T[] current) where T : unmanaged;
 	}
 }

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

@@ -198,7 +198,7 @@ public void ResolveWithDefaults()
 
 			CommonEntriesFor(VSystemID.Raw.AmstradCPC, basePath: Path.Combine(".", "AmstradCPC"), omitSaveRAM: true),
 
-			CommonEntriesFor(VSystemID.Raw.AppleII, basePath: Path.Combine(".", "Apple II"), omitSaveRAM: true),
+			CommonEntriesFor(VSystemID.Raw.AppleII, basePath: Path.Combine(".", "Apple II")),
 
 			CommonEntriesFor(VSystemID.Raw.Arcade, basePath: Path.Combine(".", "Arcade")),
 

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -26,6 +26,7 @@
 using BizHawk.Emulation.Cores;
 using BizHawk.Emulation.Cores.Arcades.MAME;
 using BizHawk.Emulation.Cores.Calculators.TI83;
+using BizHawk.Emulation.Cores.Computers.AppleII;
 using BizHawk.Emulation.Cores.Computers.Commodore64;
 using BizHawk.Emulation.Cores.Consoles.NEC.PCE;
 using BizHawk.Emulation.Cores.Consoles.Nintendo.Ares64;
@@ -1922,7 +1923,7 @@ private void LoadSaveRam()
 					byte[] sram;
 
 					// some cores might not know how big the saveram ought to be, so just send it the whole file
-					if (Emulator is C64 or MGBAHawk or NeoGeoPort or NES { BoardName: "FDS" })
+					if (Emulator is AppleII or C64 or MGBAHawk or NeoGeoPort or NES { BoardName: "FDS" })
 					{
 						sram = File.ReadAllBytes(saveRamPath);
 					}

src/BizHawk.Emulation.Common/Database/Database.cs

@@ -379,6 +379,7 @@ public static GameInfo GetGameInfo(byte[] romData, string fileName)
 
 				case ".PO":
 				case ".DO":
+				case ".NIB":
 					game.System = VSystemID.Raw.AppleII;
 					break;
 

src/BizHawk.Emulation.Cores/Computers/AppleII/AppleII.ISaveRam.cs

@@ -0,0 +1,78 @@
+using System;
+using System.IO;
+
+using BizHawk.Common;
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Computers.AppleII
+{
+	public partial class AppleII : ISaveRam
+	{
+		private byte[][] _diskDeltas;
+
+		private void InitSaveRam()
+		{
+			_diskDeltas = new byte[DiskCount][];
+		}
+
+		public bool SaveRamModified => true;
+
+		public byte[] CloneSaveRam()
+		{
+			using var ms = new MemoryStream();
+			using var bw = new BinaryWriter(ms);
+
+			SaveDelta();
+			bw.Write(DiskCount);
+			for (var i = 0; i < DiskCount; i++)
+			{
+				bw.WriteByteBuffer(_diskDeltas[i]);
+			}
+
+			return ms.ToArray();
+		}
+
+		public void StoreSaveRam(byte[] data)
+		{
+			using var ms = new MemoryStream(data, false);
+			using var br = new BinaryReader(ms);
+
+			var ndisks = br.ReadInt32();
+
+			if (ndisks != DiskCount)
+			{
+				throw new InvalidOperationException("Disk count mismatch!");
+			}
+
+			for (var i = 0; i < DiskCount; i++)
+			{
+				_diskDeltas[i] = br.ReadByteBuffer(returnNull: true);
+			}
+
+			LoadDelta(true);
+		}
+
+		private void SaveDelta()
+		{
+			_machine.DiskIIController.Drive1.DeltaUpdate((original, current) =>
+			{
+				_diskDeltas[CurrentDisk] = DeltaSerializer.GetDelta<byte>(original, current).ToArray();
+			});
+		}
+
+		private void LoadDelta(bool maybeDifferent)
+		{
+			_machine.DiskIIController.Drive1.DeltaUpdate((original, current) =>
+			{
+				if (_diskDeltas[CurrentDisk] is not null)
+				{
+					DeltaSerializer.ApplyDelta<byte>(original, current, _diskDeltas[CurrentDisk]);
+				}
+				else if (maybeDifferent)
+				{
+					original.AsSpan().CopyTo(current);
+				}
+			});
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Computers/AppleII/AppleII.IStatable.cs

@@ -30,6 +30,7 @@ public void LoadStateBinary(BinaryReader reader)
 		private void SyncState(AppleSerializer ser)
 		{
 			int version = 2;
+			var oldCurrentDisk = CurrentDisk;
 			ser.BeginSection(nameof(AppleII));
 			ser.Sync(nameof(version), ref version);
 			ser.Sync("Frame", ref _frame);
@@ -66,10 +67,27 @@ private void SyncState(AppleSerializer ser)
 			_machine.NoSlotClock.Sync(ser);
 			ser.EndSection();
 
+			// disk change, we need to swap disks so SyncDelta works later
+			if (CurrentDisk != oldCurrentDisk)
+			{
+				_machine.DiskIIController.Drive1.InsertDisk("junk" + _romSet[CurrentDisk].Extension, (byte[])_romSet[CurrentDisk].Data.Clone(), false);
+			}
+
 			ser.BeginSection("DiskIIController");
 			_machine.DiskIIController.Sync(ser);
 			ser.EndSection();
 
+			ser.BeginSection("InactiveDisks");
+			for (var i = 0; i < DiskCount; i++)
+			{
+				// the current disk is handled in DiskIIController
+				if (i != CurrentDisk)
+				{
+					ser.Sync($"DiskDelta{i}", ref _diskDeltas[i], useNull: true);
+				}
+			}
+			ser.EndSection();
+
 			ser.EndSection();
 		}
 

src/BizHawk.Emulation.Cores/Computers/AppleII/AppleII.cs

@@ -23,22 +23,30 @@ static AppleII()
 		[CoreConstructor(VSystemID.Raw.AppleII)]
 		public AppleII(CoreLoadParameters<Settings, SyncSettings> lp)
 		{
-			_romSet = lp.Roms.Select(r => r.RomData).ToList();
+			static (byte[], string) GetRomAndExt(IRomAsset romAssert)
+			{
+				var ext = romAssert.Extension.ToUpperInvariant();
+				return ext switch
+				{
+					".DSK" or ".PO" or ".DO" or ".NIB" => (romAssert.FileData, ext),
+					".2mg" => throw new NotSupportedException("Unsupported extension .2mg!"), // TODO: add a way to support this (we have hashes of this format in our db it seems?)
+					_ => (romAssert.FileData, ".DSK") // no idea, let's assume it's just a .DSK?
+				};
+			}
+
+			_romSet = lp.Roms.Select(GetRomAndExt).ToList();
 			var ser = new BasicServiceProvider(this);
 			ServiceProvider = ser;
 
 			const string TRACE_HEADER = "6502: PC, opcode, register (A, X, Y, P, SP, Cy), flags (NVTBDIZC)";
 			_tracer = new TraceBuffer(TRACE_HEADER);
 
-			_disk1 = _romSet[0];
-
 			_appleIIRom = lp.Comm.CoreFileProvider.GetFirmwareOrThrow(new(SystemId, "AppleIIe"), "The Apple IIe BIOS firmware is required");
 			_diskIIRom = lp.Comm.CoreFileProvider.GetFirmwareOrThrow(new(SystemId, "DiskII"), "The DiskII firmware is required");
 
 			_machine = new Components(_appleIIRom, _diskIIRom);
 
-			// make a writable memory stream cloned from the rom.
-			// for junk.dsk the .dsk is important because it determines the format from that
+			InitSaveRam();
 			InitDisk();
 
 			ser.Register<ITraceable>(_tracer);
@@ -55,11 +63,10 @@ public AppleII(CoreLoadParameters<Settings, SyncSettings> lp)
 
 		private static readonly ControllerDefinition AppleIIController;
 
-		private readonly List<byte[]> _romSet = new List<byte[]>();
+		private readonly List<(byte[] Data, string Extension)> _romSet;
 		private readonly ITraceable _tracer;
 
 		private readonly Components _machine;
-		private byte[] _disk1;
 		private readonly byte[] _appleIIRom;
 		private readonly byte[] _diskIIRom;
 
@@ -75,12 +82,14 @@ public int CurrentDisk
 
 		public void SetDisk(int discNum)
 		{
+			SaveDelta();
 			CurrentDisk = discNum;
 			InitDisk();
 		}
 
 		private void IncrementDisk()
 		{
+			SaveDelta();
 			CurrentDisk++;
 			if (CurrentDisk >= _romSet.Count)
 			{
@@ -92,6 +101,7 @@ private void IncrementDisk()
 
 		private void DecrementDisk()
 		{
+			SaveDelta();
 			CurrentDisk--;
 			if (CurrentDisk < 0)
 			{
@@ -103,11 +113,10 @@ private void DecrementDisk()
 
 		private void InitDisk()
 		{
-			_disk1 = _romSet[CurrentDisk];
-
 			// make a writable memory stream cloned from the rom.
-			// for junk.dsk the .dsk is important because it determines the format from that
-			_machine.Memory.DiskIIController.Drive1.InsertDisk("junk.dsk", (byte[])_disk1.Clone(), false);
+			// the extension is important here because it determines the format from that
+			_machine.DiskIIController.Drive1.InsertDisk("junk" + _romSet[CurrentDisk].Extension, (byte[])_romSet[CurrentDisk].Data.Clone(), false);
+			LoadDelta(false);
 		}
 
 		private static readonly List<string> RealButtons = new List<string>(Keyboard.GetKeyNames()
@@ -120,7 +129,7 @@ private void InitDisk()
 		};
 
 		public bool DriveLightEnabled => true;
-		public bool DriveLightOn => _machine.Memory.DiskIIController.DriveLight;
+		public bool DriveLightOn => _machine.DiskIIController.DriveLight;
 
 		private bool _nextPressed;
 		private bool _prevPressed;

src/BizHawk.Emulation.Cores/Computers/AppleII/Components.cs

@@ -32,7 +32,7 @@ public Components(byte[] appleIIe, byte[] diskIIRom)
 				emptySlot,
 				emptySlot,
 				emptySlot,
-				new DiskIIController(Video, diskIIRom),
+				DiskIIController,
 				emptySlot);
 
 			Cpu.Reset();