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.Common/Pathfinder/IPathGraph.cs

@@ -0,0 +1,109 @@
+#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;
+
+namespace OpenRA.Mods.Common.Pathfinder
+{
+	/// <summary>
+	/// Represents a pathfinding graph with nodes and edges.
+	/// Nodes are represented as cells, and pathfinding information
+	/// in the form of <see cref="CellInfo"/> is attached to each one.
+	/// </summary>
+	public interface IPathGraph : IDisposable
+	{
+		/// <summary>
+		/// Given a source node, returns connections to all reachable destination nodes with their cost.
+		/// </summary>
+		/// <remarks>PERF: Returns a <see cref="List{T}"/> rather than an <see cref="IEnumerable{T}"/> as enumerating
+		/// this efficiently is important for pathfinding performance. Callers should interact with this as an
+		/// <see cref="IEnumerable{T}"/> and not mutate the result.</remarks>
+		List<GraphConnection> GetConnections(CPos source, Func<CPos, bool> targetPredicate);
+
+		/// <summary>
+		/// Gets or sets the pathfinding information for a given node.
+		/// </summary>
+		CellInfo this[CPos node] { get; set; }
+	}
+
+	public static class PathGraph
+	{
+		public const int PathCostForInvalidPath = int.MaxValue;
+		public const short MovementCostForUnreachableCell = short.MaxValue;
+	}
+
+	/// <summary>
+	/// Represents a full edge in a graph, giving the cost to traverse between two nodes.
+	/// </summary>
+	public readonly struct GraphEdge
+	{
+		public readonly CPos Source;
+		public readonly CPos Destination;
+		public readonly int Cost;
+
+		public GraphEdge(CPos source, CPos destination, int cost)
+		{
+			if (source == destination)
+				throw new ArgumentException($"{nameof(source)} and {nameof(destination)} must refer to different cells");
+			if (cost < 0)
+				throw new ArgumentOutOfRangeException(nameof(cost), $"{nameof(cost)} cannot be negative");
+			if (cost == PathGraph.PathCostForInvalidPath)
+				throw new ArgumentOutOfRangeException(nameof(cost), $"{nameof(cost)} cannot be used for an unreachable path");
+
+			Source = source;
+			Destination = destination;
+			Cost = cost;
+		}
+
+		public GraphConnection ToConnection()
+		{
+			return new GraphConnection(Destination, Cost);
+		}
+
+		public override string ToString() => $"{Source} -> {Destination} = {Cost}";
+	}
+
+	/// <summary>
+	/// Represents part of an edge in a graph, giving the cost to traverse to a node.
+	/// </summary>
+	public readonly struct GraphConnection
+	{
+		public readonly struct CostComparer : IComparer<GraphConnection>
+		{
+			public int Compare(GraphConnection x, GraphConnection y)
+			{
+				return x.Cost.CompareTo(y.Cost);
+			}
+		}
+
+		public readonly CPos Destination;
+		public readonly int Cost;
+
+		public GraphConnection(CPos destination, int cost)
+		{
+			if (cost < 0)
+				throw new ArgumentOutOfRangeException(nameof(cost), $"{nameof(cost)} cannot be negative");
+			if (cost == PathGraph.PathCostForInvalidPath)
+				throw new ArgumentOutOfRangeException(nameof(cost), $"{nameof(cost)} cannot be used for an unreachable path");
+
+			Destination = destination;
+			Cost = cost;
+		}
+
+		public GraphEdge ToEdge(CPos source)
+		{
+			return new GraphEdge(source, Destination, Cost);
+		}
+
+		public override string ToString() => $"-> {Destination} = {Cost}";
+	}
+}