fix: Fix TTS COM exception in IL2CPP

Assets/Plugins/Windows/Interop.SpeechLib/EnumeratorToEnumVariantMarshaler.cs

@@ -0,0 +1,102 @@
+using System;
+using System.Collections;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace SpeechLib {
+	/// <summary>Marshals the COM <see langword="IEnumVARIANT" /> interface to the .NET Framework <see cref="T:System.Collections.IEnumerator" /> interface, and vice versa.</summary>
+	public class EnumeratorToEnumVariantMarshaler : ICustomMarshaler {
+		[ComImport]
+		[Guid("00020404-0000-0000-C000-000000000046")]
+		[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+		private interface IEnumVARIANT {
+			[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
+			void Next(int celt, [MarshalAs(UnmanagedType.Struct)] out object rgvar, out uint pceltFetched);
+
+			[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
+			void Skip(uint celt);
+
+			[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
+			void Reset();
+
+			[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
+			[return: MarshalAs(UnmanagedType.Interface)]
+			IEnumVARIANT Clone();
+		}
+
+		private class VARIANTEnumerator : IEnumerator {
+			private IEnumVARIANT com_enum;
+
+			private object current;
+
+			public object Current => current;
+
+			public VARIANTEnumerator(IEnumVARIANT com_enum) {
+				this.com_enum = com_enum;
+			}
+
+			public bool MoveNext() {
+				uint pceltFetched = 0u;
+				com_enum.Next(1, out var rgvar, out pceltFetched);
+				if (pceltFetched == 0) {
+					return false;
+				}
+				current = rgvar;
+				return true;
+			}
+
+			public void Reset() {
+				com_enum.Reset();
+			}
+		}
+
+		private static EnumeratorToEnumVariantMarshaler instance;
+
+		/// <summary>Performs necessary cleanup of the managed data when it is no longer needed.</summary>
+		/// <param name="pManagedObj">The managed object to be destroyed.</param>
+		public void CleanUpManagedData(object pManagedObj) {
+			throw new NotImplementedException();
+		}
+
+		/// <summary>Performs necessary cleanup of the unmanaged data when it is no longer needed.</summary>
+		/// <param name="pNativeData">A pointer to the unmanaged data to be destroyed.</param>
+		public void CleanUpNativeData(IntPtr pNativeData) {
+			Marshal.Release(pNativeData);
+		}
+
+		/// <summary>Returns an instance of the custom marshaler.</summary>
+		/// <param name="pstrCookie">String "cookie" parameter that can be used by the custom marshaler.</param>
+		/// <returns>An instance of the custom marshaler.</returns>
+		public static ICustomMarshaler GetInstance(string pstrCookie) {
+			if (instance == null) {
+				instance = new EnumeratorToEnumVariantMarshaler();
+			}
+			return instance;
+		}
+
+		/// <summary>Returns the size in bytes of the unmanaged data to be marshaled.</summary>
+		/// <returns>-1 to indicate the type this marshaler handles is not a value type.</returns>
+		public int GetNativeDataSize() {
+			throw new NotImplementedException();
+		}
+
+		/// <summary>Marshals an object from managed code to unmanaged code.</summary>
+		/// <param name="pManagedObj">The managed object to be converted.</param>
+		/// <returns>A pointer to the unmanaged object.</returns>
+		/// <exception cref="T:System.ArgumentNullException">
+		///   <paramref name="pManagedObj" /> is <see langword="null" />.</exception>
+		public IntPtr MarshalManagedToNative(object pManagedObj) {
+			throw new NotImplementedException();
+		}
+
+		/// <summary>Marshals an object from unmanaged code to managed code.</summary>
+		/// <param name="pNativeData">A pointer to the unmanaged object to be converted.</param>
+		/// <returns>A managed object.</returns>
+		/// <exception cref="T:System.ArgumentNullException">
+		///   <paramref name="pNativeData" /> is <see langword="null" />.</exception>
+		/// <exception cref="T:System.InvalidCastException">The unmanaged object that <paramref name="pNativeData" /> points to could not be converted.</exception>
+		public object MarshalNativeToManaged(IntPtr pNativeData) {
+			return new VARIANTEnumerator((IEnumVARIANT)Marshal.GetObjectForIUnknown(pNativeData));
+		}
+	}
+}