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.Game/SelectableExts.cs

@@ -0,0 +1,101 @@
+#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.Linq;
+using OpenRA.Primitives;
+
+namespace OpenRA.Traits
+{
+	public static class SelectableExts
+	{
+		public static int SelectionPriority(this ActorInfo a, Modifiers modifiers)
+		{
+			var selectableInfo = a.TraitInfoOrDefault<ISelectableInfo>();
+			return selectableInfo != null ? BaseSelectionPriority(selectableInfo, modifiers) : int.MinValue;
+		}
+
+		const int PriorityRange = 30;
+
+		public static int SelectionPriority(this Actor a, Modifiers modifiers)
+		{
+			var info = a.Info.TraitInfo<ISelectableInfo>();
+			var basePriority = BaseSelectionPriority(info, modifiers);
+
+			var viewer = (a.World.LocalPlayer == null || a.World.LocalPlayer.Spectating) ? a.World.RenderPlayer : a.World.LocalPlayer;
+
+			if (a.Owner == viewer || viewer == null)
+				return basePriority;
+
+			switch (viewer.RelationshipWith(a.Owner))
+			{
+				case PlayerRelationship.Ally: return basePriority - PriorityRange;
+				case PlayerRelationship.Neutral: return basePriority - 2 * PriorityRange;
+				case PlayerRelationship.Enemy: return basePriority - 3 * PriorityRange;
+
+				default:
+					throw new InvalidOperationException();
+			}
+		}
+
+		static int BaseSelectionPriority(ISelectableInfo info, Modifiers modifiers)
+		{
+			var priority = info.Priority;
+
+			if (modifiers.HasModifier(Modifiers.Ctrl) && !modifiers.HasModifier(Modifiers.Alt) && info.PriorityModifiers.HasFlag(SelectionPriorityModifiers.Ctrl))
+				priority = int.MaxValue;
+
+			if (modifiers.HasModifier(Modifiers.Alt) && !modifiers.HasModifier(Modifiers.Ctrl) && info.PriorityModifiers.HasFlag(SelectionPriorityModifiers.Alt))
+				priority = int.MaxValue;
+
+			return priority;
+		}
+
+		public static Actor WithHighestSelectionPriority(this IEnumerable<ActorBoundsPair> actors, int2 selectionPixel, Modifiers modifiers)
+		{
+			return actors.MaxByOrDefault(a => CalculateActorSelectionPriority(a.Actor.Info, a.Bounds, selectionPixel, modifiers)).Actor;
+		}
+
+		public static FrozenActor WithHighestSelectionPriority(this IEnumerable<FrozenActor> actors, int2 selectionPixel, Modifiers modifiers)
+		{
+			return actors.MaxByOrDefault(a => CalculateActorSelectionPriority(a.Info, a.MouseBounds, selectionPixel, modifiers));
+		}
+
+		static long CalculateActorSelectionPriority(ActorInfo info, in Polygon bounds, int2 selectionPixel, Modifiers modifiers)
+		{
+			if (bounds.IsEmpty)
+				return info.SelectionPriority(modifiers);
+
+			// Assume that the center of the polygon is the same as the center of the bounding box
+			// This isn't necessarily true for arbitrary polygons, but is fine for the hexagonal and diamond
+			// shapes that are currently implemented
+			var br = bounds.BoundingRect;
+			var centerPixel = new int2(
+				br.Left + br.Size.Width / 2,
+				br.Top + br.Size.Height / 2);
+
+			var pixelDistance = (centerPixel - selectionPixel).Length;
+			return info.SelectionPriority(modifiers) - (long)pixelDistance << 16;
+		}
+
+		static readonly Actor[] NoActors = [];
+
+		public static IEnumerable<Actor> SubsetWithHighestSelectionPriority(this IEnumerable<Actor> actors, Modifiers modifiers)
+		{
+			return actors.GroupBy(x => x.SelectionPriority(modifiers))
+				.OrderByDescending(g => g.Key)
+				.Select(g => g.AsEnumerable())
+				.DefaultIfEmpty(NoActors)
+				.FirstOrDefault();
+		}
+	}
+}