Adding Stella as A2600 emulation core (#3911)

* Adding initial version of the core

* Adding base files

* Trying to load waterbox now

* Adding stella

* Adding bk class

* Compiling bk interface to stella core

* Now compiling against Stella + SDL2-based BK backend

* Progress

* More progress

* Frame advancing (no render)

* Calling video update but crashing on zero div

* Now rendering to screen with correct palette

* Now rendering appropriately and with correct palette based on region

* Now reading controls

* Trying to capture audio

* Now adding audio

* Now polling inputs

* Now polling inputs

* Now reporting memory regions

* Added memory regions

* Removing debug prints

* Fixing indent

* Adding stella core

* Updating readme and make all cores

* Recovering ending comma

* Using heap alloc for sound buffer

* Removing unnecessary files

* Update src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.IMemoryDomains.cs

Co-authored-by: James Groom <[email protected]>

* Update src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.IMemoryDomains.cs

Co-authored-by: James Groom <[email protected]>

* Fix

* Restoring vscode

* Removing warning

* Update waterbox readme

* Fix Stella's `[Core]` attr

* Increased sound buffer size to 1Mb, as some games need more than 4K

---------

Co-authored-by: James Groom <[email protected]>
Co-authored-by: Morilli <[email protected]>
Co-authored-by: YoshiRulz <[email protected]>

.github/workflows/make.yml

@@ -60,6 +60,7 @@ jobs:
            git submodule update --init gpgx/Genesis-Plus-GX;
            git submodule update --init ../submodules/sameboy/libsameboy;
            git submodule update --init uae/libretro-uae;
+           git submodule update --init stella/core;
     - name: Download compiled waterbox
       uses: actions/download-artifact@v4
       with:
@@ -100,6 +101,7 @@ jobs:
           Assets/dll/turbo.wbx.zst
           Assets/dll/uzem.wbx.zst
           Assets/dll/vb.wbx.zst
+          Assets/dll/stella.wbx.zst
           Assets/dll/virtualjaguar.wbx.zst
 
   build-mame:

.gitmodules

@@ -74,6 +74,10 @@
 	path = waterbox/gpgx/Genesis-Plus-GX
 	url = https://github.com/TASEmulators/Genesis-Plus-GX.git
 	branch = tasvideos-2.2
+[submodule "waterbox/stella/core"]
+	path = waterbox/stella/core
+	url = https://github.com/TASEmulators/stella.git
+	branch = tasvideos-1
 [submodule "waterbox/uae/libretro-uae"]
 	path = waterbox/uae/libretro-uae
 	url = https://github.com/TASEmulators/libretro-uae.git

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

@@ -25,6 +25,8 @@ public class Config
 		/// </remarks>
 		public static readonly IReadOnlyList<(string[] AppliesTo, string[] CoreNames)> CorePickerUIData = new List<(string[], string[])>
 		{
+			([ VSystemID.Raw.A26 ],
+				[ CoreNames.Stella, CoreNames.Atari2600Hawk ]),
 			([ VSystemID.Raw.Satellaview ],
 				[ CoreNames.Bsnes115, CoreNames.SubBsnes115 ]),
 			([ VSystemID.Raw.GB, VSystemID.Raw.GBC ],
@@ -49,6 +51,7 @@ public class Config
 				[ CoreNames.Snes9X, CoreNames.Bsnes115, CoreNames.SubBsnes115, CoreNames.Faust, CoreNames.Bsnes ]),
 			([ VSystemID.Raw.TI83 ],
 				[ CoreNames.Emu83, CoreNames.TI83Hawk ]),
+
 		};
 
 		public static Dictionary<string, string> GenDefaultCorePreferences()

src/BizHawk.Emulation.Common/Enums.cs

@@ -7,7 +7,8 @@ public enum DisplayType
 	{
 		NTSC,
 		PAL,
-		Dendy
+		Dendy,
+		SECAM
 	}
 
 	/// <summary>

src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/LibStella.cs

@@ -0,0 +1,80 @@
+using System.Runtime.InteropServices;
+
+using BizHawk.BizInvoke;
+
+namespace BizHawk.Emulation.Cores.Consoles.Atari.Stella
+{
+	public abstract class CInterface
+	{
+
+		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+		public delegate int load_archive_cb(string filename, IntPtr buffer, int maxsize);
+
+		[StructLayout(LayoutKind.Sequential)]
+		public class InitSettings
+		{
+			public uint dummy;
+		}
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_get_audio(ref int n, ref IntPtr buffer);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract int stella_get_region();
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract bool stella_init(
+			string fileName,
+			load_archive_cb feload_archive_cb,
+			[In]InitSettings settings);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_frame_advance(int port1, int port2, bool reset, bool power, bool leftDiffToggled, bool rightDiffToggled);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_get_video(out int w, out int h, out int pitch, ref IntPtr buffer);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_get_frame_rate(out int fps);
+
+		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+		public delegate void input_cb();
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_set_input_callback(input_cb cb);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract byte stella_peek_tia(uint addr);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_poke_tia(uint addr, byte value);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract byte stella_peek_m6532(uint addr);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_poke_m6532(uint addr, byte value);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract byte stella_peek_systembus(uint addr);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_poke_systembus(uint addr, byte value);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract uint stella_get_cartram_size();
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract byte stella_peek_cartram(uint addr);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_poke_cartram(uint addr, byte value);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void stella_get_mainram_ptr(ref IntPtr addr);
+
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract IntPtr stella_get_cart_type();
+
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.Core.cs

@@ -0,0 +1,99 @@
+using BizHawk.Emulation.Cores.Components.M6502;
+using System.Runtime.CompilerServices;
+
+namespace BizHawk.Emulation.Cores.Atari.Stella
+{
+	public partial class Stella
+	{
+		internal struct CpuLink : IMOS6502XLink
+		{
+			public byte DummyReadMemory(ushort address) { return 0; }
+
+			public void OnExecFetch(ushort address) { }
+
+			public byte PeekMemory(ushort address) { return 0; }
+
+			public byte ReadMemory(ushort address) { return 0; }
+
+			public void WriteMemory(ushort address, byte value) { }
+		}
+
+		internal byte BaseReadMemory(ushort addr)
+		{
+			return 0;
+		}
+
+		internal byte BasePeekMemory(ushort addr)
+		{
+
+			return 0;
+		}
+
+		internal void BaseWriteMemory(ushort addr, byte value)
+		{
+		}
+
+		internal void BasePokeMemory(ushort addr, byte value)
+		{
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private byte ReadMemory(ushort addr)
+		{
+			return 0;
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private void WriteMemory(ushort addr, byte value)
+		{
+		}
+
+		internal void PokeMemory(ushort addr, byte value)
+		{
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private void ExecFetch(ushort addr)
+		{
+		}
+
+		private void RebootCore()
+		{
+		}
+
+		private void HardReset()
+		{
+		}
+
+		private void Cycle()
+		{
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		internal byte ReadControls1(bool peek)
+		{
+			return 0;
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		internal byte ReadControls2(bool peek)
+		{
+			return 0;
+		}
+
+		internal int ReadPot1(int pot)
+		{
+			return 0;
+		}
+
+		internal int ReadPot2(int pot)
+		{
+			return 0;
+		}
+
+		internal byte ReadConsoleSwitches(bool peek)
+		{
+			return 0;
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.IEmulator.cs

@@ -0,0 +1,65 @@
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Atari.Stella
+{
+	public partial class Stella : IEmulator
+	{
+		public IEmulatorServiceProvider ServiceProvider { get; }
+
+		public ControllerDefinition ControllerDefinition => _controllerDeck.Definition;
+
+        private bool _leftDifficultyToggled = false;
+		private bool _rightDifficultyToggled = false;
+
+		public bool FrameAdvance(IController controller, bool render, bool renderSound)
+		{
+
+			int port1 = _controllerDeck.ReadPort1(controller);
+			int port2 = _controllerDeck.ReadPort2(controller);
+
+			// Handle all the console controls here
+			bool powerPressed = false;
+			bool resetPressed = false;
+			if (controller.IsPressed("Power")) powerPressed = true;
+			if (controller.IsPressed("Reset")) resetPressed = true;
+			if (controller.IsPressed("Toggle Left Difficulty"))	_leftDifficultyToggled = !_leftDifficultyToggled;
+			if (controller.IsPressed("Toggle Right Difficulty")) _rightDifficultyToggled = !_rightDifficultyToggled;
+
+			IsLagFrame = true;
+
+			Core.stella_frame_advance(port1, port2, resetPressed, powerPressed, _leftDifficultyToggled, _rightDifficultyToggled);
+
+			if (IsLagFrame)
+				LagCount++;
+
+			if (render)
+				UpdateVideo();
+
+			if (renderSound)
+				update_audio();
+
+			_frame++;
+
+			return true;
+		}
+
+		public int _frame;
+
+		public int Frame => _frame;
+
+		public string SystemId => VSystemID.Raw.A26;
+
+		public bool DeterministicEmulation => true;
+
+		public void ResetCounters()
+		{
+			_frame = 0;
+			LagCount = 0;
+			IsLagFrame = false;
+		}
+
+		public void Dispose()
+		{
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.IInputPollable.cs

@@ -0,0 +1,24 @@
+using BizHawk.Emulation.Common;
+using BizHawk.Emulation.Cores.Consoles.Atari.Stella;
+
+namespace BizHawk.Emulation.Cores.Atari.Stella
+{
+	public partial class Stella : IInputPollable
+	{
+		public int LagCount { get; set; }
+
+		public bool IsLagFrame { get; set; }
+
+		public IInputCallbackSystem InputCallbacks => _inputCallbacks;
+
+		private readonly CInterface.input_cb _inputCallback;
+
+		private readonly InputCallbackSystem _inputCallbacks = new InputCallbackSystem();
+
+		private void input_callback()
+		{
+			InputCallbacks.Call();
+			IsLagFrame = false;
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/Atari/Stella/Stella.IMemoryDomains.cs

@@ -0,0 +1,64 @@
+using System.Collections.Generic;
+
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Atari.Stella
+{
+	public partial class Stella
+	{
+		internal IMemoryDomains MemoryDomains;
+		private uint _cartMemSize;
+
+		private void SetupMemoryDomains()
+		{
+			_cartMemSize = Core.stella_get_cartram_size();
+			var mainRamAddress = IntPtr.Zero;
+			var cartDPCRamAddress = IntPtr.Zero;
+			Core.stella_get_mainram_ptr(ref mainRamAddress);
+
+			var domains = new List<MemoryDomain>
+			{
+				new MemoryDomainDelegate(
+					"TIA",
+					16,
+					MemoryDomain.Endian.Little,
+					addr => Core.stella_peek_tia((uint)addr),
+					(addr, value) => Core.stella_poke_tia((uint)addr, value),
+					1),
+
+				new MemoryDomainDelegate(
+					"PIA",
+					1024,
+					MemoryDomain.Endian.Little,
+					addr => Core.stella_peek_m6532((uint)addr),
+					(addr, value) => Core.stella_poke_m6532((uint)addr, value),
+					1),
+
+				new MemoryDomainDelegate(
+					"System Bus",
+					65536,
+					MemoryDomain.Endian.Little,
+					addr => Core.stella_peek_systembus((uint) addr),
+					(addr, value) => Core.stella_poke_systembus((uint) addr, value),
+					1)
+			};
+
+			if (_cartMemSize > 0)
+			{
+				domains.Add(new MemoryDomainDelegate(
+					"Cart Ram",
+					_cartMemSize,
+					MemoryDomain.Endian.Little,
+					addr => Core.stella_peek_cartram((uint)addr),
+					(addr, value) => Core.stella_poke_cartram((uint)addr, value),
+					1));
+			}
+
+			MemoryDomainIntPtrMonitor mainRAM = new("Main RAM", MemoryDomain.Endian.Little, mainRamAddress, 128, true, 1, _elf);
+			domains.Add(mainRAM);
+
+			MemoryDomains = new MemoryDomainList(domains) { MainMemory = mainRAM };
+			((BasicServiceProvider)ServiceProvider).Register(MemoryDomains);
+		}
+	}
+}