Initial commit: OpenRA game engine

Fork from OpenRA/OpenRA with one-click launch script (start-ra.cmd)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

OpenRA.Mods.Cnc/FileSystem/Pak.cs

@@ -0,0 +1,103 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using OpenRA.FileSystem;
+using OpenRA.Primitives;
+using FS = OpenRA.FileSystem.FileSystem;
+
+namespace OpenRA.Mods.Cnc.FileSystem
+{
+	public class PakFileLoader : IPackageLoader
+	{
+		struct Entry
+		{
+			public uint Offset;
+			public uint Length;
+			public string Filename;
+		}
+
+		sealed class PakFile : IReadOnlyPackage
+		{
+			public string Name { get; }
+			public IEnumerable<string> Contents => index.Keys;
+
+			readonly Dictionary<string, Entry> index = [];
+			readonly Stream stream;
+
+			public PakFile(Stream stream, string filename)
+			{
+				Name = filename;
+				this.stream = stream;
+
+				try
+				{
+					var offset = stream.ReadUInt32();
+					while (offset != 0)
+					{
+						var file = stream.ReadASCIIZ();
+						var next = stream.ReadUInt32();
+						var length = (next == 0 ? (uint)stream.Length : next) - offset;
+
+						// Ignore duplicate files
+						if (index.TryAdd(file, new Entry { Offset = offset, Length = length, Filename = file }))
+							offset = next;
+					}
+
+					index.TrimExcess();
+				}
+				catch
+				{
+					Dispose();
+					throw;
+				}
+			}
+
+			public Stream GetStream(string filename)
+			{
+				if (!index.TryGetValue(filename, out var entry))
+					return null;
+
+				return SegmentStream.CreateWithoutOwningStream(stream, entry.Offset, (int)entry.Length);
+			}
+
+			public bool Contains(string filename)
+			{
+				return index.ContainsKey(filename);
+			}
+
+			public IReadOnlyPackage OpenPackage(string filename, FS context)
+			{
+				// Not implemented
+				return null;
+			}
+
+			public void Dispose()
+			{
+				stream.Dispose();
+			}
+		}
+
+		bool IPackageLoader.TryParsePackage(Stream s, string filename, FS context, out IReadOnlyPackage package)
+		{
+			if (!filename.EndsWith(".pak", StringComparison.InvariantCultureIgnoreCase))
+			{
+				package = null;
+				return false;
+			}
+
+			package = new PakFile(s, filename);
+			return true;
+		}
+	}
+}