1 files changed, 148 insertions, 0 deletions
diff --git a/src/Ryujinx.Input.SDL2/SDL2GamepadDriver.cs b/src/Ryujinx.Input.SDL2/SDL2GamepadDriver.cs
new file mode 100644
index 00000000..d4086a10
--- /dev/null
+++ b/src/Ryujinx.Input.SDL2/SDL2GamepadDriver.cs
@@ -0,0 +1,148 @@
+using Ryujinx.SDL2.Common;
+using System;
+using System.Collections.Generic;
+using static SDL2.SDL;
+
+namespace Ryujinx.Input.SDL2
+{
+    public class SDL2GamepadDriver : IGamepadDriver
+    {
+        private Dictionary<int, string> _gamepadsInstanceIdsMapping;
+        private List<string> _gamepadsIds;
+
+        public ReadOnlySpan<string> GamepadsIds => _gamepadsIds.ToArray();
+
+        public string DriverName => "SDL2";
+
+        public event Action<string> OnGamepadConnected;
+        public event Action<string> OnGamepadDisconnected;
+
+        public SDL2GamepadDriver()
+        {
+            _gamepadsInstanceIdsMapping = new Dictionary<int, string>();
+            _gamepadsIds = new List<string>();
+
+            SDL2Driver.Instance.Initialize();
+            SDL2Driver.Instance.OnJoyStickConnected += HandleJoyStickConnected;
+            SDL2Driver.Instance.OnJoystickDisconnected += HandleJoyStickDisconnected;
+
+            // Add already connected gamepads
+            int numJoysticks = SDL_NumJoysticks();
+
+            for (int joystickIndex = 0; joystickIndex < numJoysticks; joystickIndex++)
+            {
+                HandleJoyStickConnected(joystickIndex, SDL_JoystickGetDeviceInstanceID(joystickIndex));
+            }
+        }
+
+        private string GenerateGamepadId(int joystickIndex)
+        {
+            Guid guid = SDL_JoystickGetDeviceGUID(joystickIndex);
+
+            if (guid == Guid.Empty)
+            {
+                return null;
+            }
+
+            return joystickIndex + "-" + guid.ToString();
+        }
+
+        private int GetJoystickIndexByGamepadId(string id)
+        {
+            string[] data = id.Split("-");
+
+            if (data.Length != 6 || !int.TryParse(data[0], out int joystickIndex))
+            {
+                return -1;
+            }
+
+            return joystickIndex;
+        }
+
+        private void HandleJoyStickDisconnected(int joystickInstanceId)
+        {
+            if (_gamepadsInstanceIdsMapping.TryGetValue(joystickInstanceId, out string id))
+            {
+                _gamepadsInstanceIdsMapping.Remove(joystickInstanceId);
+                _gamepadsIds.Remove(id);
+
+                OnGamepadDisconnected?.Invoke(id);
+            }
+        }
+
+        private void HandleJoyStickConnected(int joystickDeviceId, int joystickInstanceId)
+        {
+            if (SDL_IsGameController(joystickDeviceId) == SDL_bool.SDL_TRUE)
+            {
+                string id = GenerateGamepadId(joystickDeviceId);
+
+                if (id == null)
+                {
+                    return;
+                }
+
+                // Sometimes a JoyStick connected event fires after the app starts even though it was connected before
+                // so it is rejected to avoid doubling the entries.
+                if (_gamepadsIds.Contains(id))
+                {
+                    return;
+                }
+
+                if (_gamepadsInstanceIdsMapping.TryAdd(joystickInstanceId, id))
+                {
+                    _gamepadsIds.Add(id);
+
+                    OnGamepadConnected?.Invoke(id);
+                }
+            }
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                SDL2Driver.Instance.OnJoyStickConnected -= HandleJoyStickConnected;
+                SDL2Driver.Instance.OnJoystickDisconnected -= HandleJoyStickDisconnected;
+
+                // Simulate a full disconnect when disposing
+                foreach (string id in _gamepadsIds)
+                {
+                    OnGamepadDisconnected?.Invoke(id);
+                }
+
+                _gamepadsIds.Clear();
+
+                SDL2Driver.Instance.Dispose();
+            }
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        public IGamepad GetGamepad(string id)
+        {
+            int joystickIndex = GetJoystickIndexByGamepadId(id);
+
+            if (joystickIndex == -1)
+            {
+                return null;
+            }
+
+            if (id != GenerateGamepadId(joystickIndex))
+            {
+                return null;
+            }
+
+            IntPtr gamepadHandle = SDL_GameControllerOpen(joystickIndex);
+
+            if (gamepadHandle == IntPtr.Zero)
+            {
+                return null;
+            }
+
+            return new SDL2Gamepad(gamepadHandle, id);
+        }
+    }
+}