Add SDL_messagebox.h

Makefile

@@ -9,6 +9,7 @@ DEPS = \
 
 # Source Lists
 SDL2 = \
+	src/LPUtf8StrMarshaler.cs \
 	src/SDL2.cs \
 	src/SDL2_image.cs \
 	src/SDL2_mixer.cs \

src/SDL2.cs

@@ -365,6 +365,28 @@ namespace SDL2
 		
 		#endregion
 		
+		#region SDL_messagebox.h
+		
+		public enum SDL_MessageBoxFlags : uint
+		{
+			SDL_MESSAGEBOX_ERROR		= 0x00000010,
+			SDL_MESSAGEBOX_WARNING		= 0x00000020,
+			SDL_MESSAGEBOX_INFORMATION	= 0x00000040
+		}
+		
+		/* window refers to an SDL_Window* */
+		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
+		public static extern int SDL_ShowSimpleMessageBox(
+			UInt32 flags,
+			[In()] [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(LPUtf8StrMarshaler))]
+				string title,
+			[In()] [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(LPUtf8StrMarshaler))]
+				string message,
+			IntPtr window
+		);
+		
+		#endregion
+		
 		#region SDL_version.h, SDL_revision.h
 		
 		/* Similar to the headers, this is the version we're expecting to be