add ColorRamp type; change everything to use it; maps not yet upgraded

OpenRA.FileFormats/ColorHSLR.cs

@@ -0,0 +1,64 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2010 The OpenRA Developers (see AUTHORS)
+ * 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. For more information,
+ * see LICENSE.
+ */
+#endregion
+
+using System.Drawing;
+
+namespace OpenRA.FileFormats
+{
+    public struct ColorRamp
+    {
+        public byte H,S,L,R;
+
+        public ColorRamp(byte h, byte s, byte l, byte r)
+        {
+            H = h; S = s; L = l; R = r;
+        }
+
+        /* returns a color along the Lum ramp */
+        public Color GetColor( float t )
+        {
+            return ColorFromHSL( H / 255f, S / 255f, float2.Lerp( L, R, t ) / 255f );
+        }
+
+        public override string ToString()
+        {
+            return "{0},{1},{2},{3}".F(H, S, L, R);
+        }
+
+        // hk is hue in the range [0,1] instead of [0,360]
+		public static Color ColorFromHSL(float hk, float s, float l)
+		{
+			// Convert from HSL to RGB
+			var q = (l < 0.5f) ? l * (1 + s) : l + s - (l * s);
+			var p = 2 * l - q;
+
+			float[] trgb = { hk + 1 / 3.0f,
+							  hk,
+							  hk - 1/3.0f };
+			float[] rgb = { 0, 0, 0 };
+
+			for (int k = 0; k < 3; k++)
+			{
+				while (trgb[k] < 0) trgb[k] += 1.0f;
+				while (trgb[k] > 1) trgb[k] -= 1.0f;
+			}
+
+			for (int k = 0; k < 3; k++)
+			{
+				if (trgb[k] < 1 / 6.0f) { rgb[k] = (p + ((q - p) * 6 * trgb[k])); }
+				else if (trgb[k] >= 1 / 6.0f && trgb[k] < 0.5) { rgb[k] = q; }
+				else if (trgb[k] >= 0.5f && trgb[k] < 2.0f / 3) { rgb[k] = (p + ((q - p) * 6 * (2.0f / 3 - trgb[k]))); }
+				else { rgb[k] = p; }
+			}
+
+			return Color.FromArgb((int)(rgb[0] * 255), (int)(rgb[1] * 255), (int)(rgb[2] * 255));
+		}
+    }
+}