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/Graphics/PlayerColorRemap.cs

@@ -0,0 +1,53 @@
+#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.Immutable;
+using OpenRA.Primitives;
+
+namespace OpenRA.Graphics
+{
+	public class PlayerColorRemap : IPaletteRemap
+	{
+		readonly ImmutableArray<int> remapIndices;
+		readonly float hue;
+		readonly float saturation;
+		readonly float value;
+
+		public PlayerColorRemap(ImmutableArray<int> remapIndices, Color color)
+		{
+			this.remapIndices = remapIndices;
+
+			var (r, g, b) = color.ToLinear();
+			(hue, saturation, value) = Color.RgbToHsv(r, g, b);
+		}
+
+		public Color GetRemappedColor(Color original, int index)
+		{
+			if (!remapIndices.Contains(index))
+				return original;
+
+			// Color remapping is applied in a linear color space, so start
+			// by undoing the pre-multiplied alpha and gamma corrections
+			var (r, g, b) = original.ToLinear();
+
+			// Calculate the brightness (i.e HSV value) of the original colour
+			// This inlines the single line of Color.RgbToHsv() that we need
+			var value = Math.Max(Math.Max(r, g), b);
+
+			// Construct the new RGB color
+			(r, g, b) = Color.HsvToRgb(hue, saturation, value * this.value);
+
+			// Convert linear back to SRGB and pre-multiply by the alpha
+			return Color.FromLinear(original.A, r, g, b);
+		}
+	}
+}