Add C64 color reduction palette

New feature

CHANGE-LOG.md

@@ -1,3 +1,6 @@
+## Version 1.0.5 (released 2021-11-11)
+- Add C64 color reduction palette 
+
 ## Version 1.0.4 (released 2021-11-11)
 - Nuget release also for .NET 6
 

ColorReductions.cs

@@ -46,6 +46,31 @@ public static void TrueColorBytesToCGABytes(in byte[] input, ref byte[] output)
 			output = FindNearestColor(input, fullCGAColors);
 		}
 
+		private static readonly List<byte[]> c64Colors = new List<byte[]>() 
+		{
+			new byte[] { 0x00, 0x00, 0x00 }, // black
+			new byte[] { 0xFF, 0xFF, 0xFF }, // white
+			new byte[] { 0x88, 0x00, 0x00 }, // red
+			new byte[] { 0xAA, 0xFF, 0xEE }, // cyan
+			new byte[] { 0xCC, 0x44, 0xCC }, // violet / purple
+			new byte[] { 0x00, 0xCC, 0x55 }, // green
+			new byte[] { 0x00, 0x00, 0xAA }, // blue
+			new byte[] { 0xEE, 0xEE, 0x77 }, // yellow
+			new byte[] { 0xDD, 0x88, 0x55 }, // orange
+			new byte[] { 0x66, 0x44, 0x00 }, // brown
+			new byte[] { 0xFF, 0x77, 0x77 }, // light red
+			new byte[] { 0x33, 0x33, 0x33 }, // dark grey
+			new byte[] { 0x77, 0x77, 0x77 }, // grey
+			new byte[] { 0xAA, 0xFF, 0x66 }, // light green
+			new byte[] { 0x00, 0x88, 0xFF }, // light blue
+			new byte[] { 0xBB, 0xBB, 0xBB }, // light grey     
+		};
+
+		public static void TrueColorBytesToC64Bytes(in byte[] input, ref byte[] output)
+		{
+			output = FindNearestColor(input, c64Colors);
+		}
+
 		private static byte[] FindNearestColor(byte[] actualColor, List<byte[]> allowedColors)
 		{
 			int index = 0;

Program.cs

@@ -26,7 +26,8 @@ public enum ColorReductionMethod
 		None,
 		TrueColorToWebSafe,
 		TrueColorToFullCGA,
-		TrueColorToFullEGA
+		TrueColorToFullEGA,
+		TrueColorToFullC64
 	}
 
 	public enum OutputFormat
@@ -68,6 +69,7 @@ method switch
 			ColorReductionMethod.TrueColorToWebSafe => ColorReductions.TrueColorBytesToWebSafeColorBytes,
 			ColorReductionMethod.TrueColorToFullCGA => ColorReductions.TrueColorBytesToCGABytes,
 			ColorReductionMethod.TrueColorToFullEGA => ColorReductions.TrueColorBytesToEGABytes,
+			ColorReductionMethod.TrueColorToFullC64 => ColorReductions.TrueColorBytesToC64Bytes,
 			_ => throw new ArgumentException(message: "invalid color reduction", paramName: method.ToString()),
 		};
 
@@ -90,6 +92,7 @@ method switch
 			{ ColorReductionMethod.TrueColorToWebSafe, "True colors to Web safe colors (216 different colors)" },
 			{ ColorReductionMethod.TrueColorToFullCGA, "True colors to full palette CGA colors (16 different colors)" },
 			{ ColorReductionMethod.TrueColorToFullEGA, "True colors to full palette EGA colors (64 different colors)" },
+			{ ColorReductionMethod.TrueColorToFullC64, "True colors to full palette C64 colors (16 different colors)" },
 		};
 
 		private static void PrintHelp()