add --remap cmdlet to OpenRA Utility, remaps between ra/cnc/etc palettes.

OpenRA.FileFormats/PlayerColorRemap.cs

@@ -21,15 +21,26 @@ namespace OpenRA.FileFormats
 	{
 		Dictionary<int, Color> remapColors;
 
+		static readonly int[] CncRemapRamp = new[] { 0, 2, 4, 6, 8, 10, 13, 15, 1, 3, 5, 7, 9, 11, 12, 14 };
+		static readonly int[] NormalRemapRamp = new[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
+
+		public static int GetRemapBase(PaletteFormat fmt)
+		{
+			return (fmt == PaletteFormat.cnc) ? 0xb0 : (fmt == PaletteFormat.d2k) ? 240 : 80;
+		}
+
+		public static int[] GetRemapRamp(PaletteFormat fmt)
+		{
+			return (fmt == PaletteFormat.cnc) ? CncRemapRamp : NormalRemapRamp;
+		}
+
 		public PlayerColorRemap(PaletteFormat fmt, ColorRamp c)
 		{
 			var c1 = c.GetColor(0);
 			var c2 = c.GetColor(1); /* temptemp: this can be expressed better */
 
-			var baseIndex = (fmt == PaletteFormat.cnc) ? 0xb0 : (fmt == PaletteFormat.d2k) ? 240 : 80;
+			var baseIndex = GetRemapBase(fmt);
-			var ramp = (fmt == PaletteFormat.cnc)
+			var ramp = GetRemapRamp(fmt);
-				? new[] { 0, 2, 4, 6, 8, 10, 13, 15, 1, 3, 5, 7, 9, 11, 12, 14 }
-				: new[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
 
 			remapColors = ramp.Select((x, i) => Pair.New(baseIndex + i, ColorLerp(x / 16f, c1, c2)))
 				.ToDictionary(u => u.First, u => u.Second);

OpenRA.Utility/Command.cs

@@ -171,5 +171,51 @@ namespace OpenRA.Utility
 				File.WriteAllBytes( f, data );
 			}
 		}
+
+		static int ColorDistance(uint a, uint b)
+		{
+			var ca = Color.FromArgb((int)a);
+			var cb = Color.FromArgb((int)b);
+
+			return Math.Abs((int)ca.R - (int)cb.R) +
+				Math.Abs((int)ca.G - (int)cb.G) +
+				Math.Abs((int)ca.B - (int)cb.B);
+		}
+
+		public static void RemapShp(string[] args)
+		{
+			var remap = new Dictionary<int,int>();
+
+			/* the first 4 entries are fixed */
+			for( var i = 0; i < 4; i++ )
+				remap[i] = i;
+
+			var srcPaletteType = (PaletteFormat)Enum.Parse(typeof(PaletteFormat), args[1].Split(':')[0]);
+			var destPaletteType = (PaletteFormat)Enum.Parse(typeof(PaletteFormat), args[2].Split(':')[0]);
+
+			/* the remap range is always 16 entries, but their location and order changes */
+			for( var i = 0; i < 16; i++ )
+				remap[ PlayerColorRemap.GetRemapBase(srcPaletteType) + PlayerColorRemap.GetRemapRamp(srcPaletteType)[i] ]
+					= PlayerColorRemap.GetRemapBase(destPaletteType) + PlayerColorRemap.GetRemapRamp(destPaletteType)[i];
+
+			/* map everything else to the best match based on channel-wise distance */
+			var srcPalette = Palette.Load(args[1].Split(':')[1], false);
+			var destPalette = Palette.Load(args[2].Split(':')[1], false);
+
+			var fullIndexRange = OpenRA.Graphics.Util.MakeArray<int>(256, x => x);
+
+			for( var i = 0; i < 256; i++ )
+				if (!remap.ContainsKey(i))
+					remap[i] = fullIndexRange
+						.Where(a => !remap.ContainsValue(a))
+						.OrderBy(a => ColorDistance(destPalette.Values[a], srcPalette.Values[i]))
+						.First();
+
+			var srcImage = ShpReader.Load(args[3]);
+
+			using( var destStream = File.Create(args[4]) )
+				ShpWriter.Write(destStream, srcImage.Width, srcImage.Height,
+					srcImage.Select( im => im.Image.Select(px => (byte)remap[px]).ToArray() ));
+		}
 	}
 }

OpenRA.Utility/Program.cs

@@ -26,6 +26,7 @@ namespace OpenRA.Utility
 				{ "--fromd2", Command.ConvertFormat2ToFormat80 },
 				{ "--extract", Command.ExtractFiles },
 				{ "--tmp-png", Command.ConvertTmpToPng },
+				{ "--remap", Command.RemapShp },
 			};
 
 			if (args.Length == 0) { PrintUsage(); return; }
@@ -57,6 +58,7 @@ namespace OpenRA.Utility
 			Console.WriteLine("  --png SHPFILE PALETTE [--transparent] Convert a SHP to a PNG containing all of its frames, optionally setting up transparency");
 			Console.WriteLine("  --extract MOD[,MOD]* FILES		  Extract files from mod packages");
 			Console.WriteLine("  --tmp-png MOD[,MOD]* THEATER FILES        Extract terrain tiles to PNG");
+			Console.WriteLine("  --remap SRCMOD:PAL DESTMOD:PAL SRCSHP DESTSHP  Remap SHPs to another palette");
 		}
 
 		static string GetNamedArg(string[] args, string arg)