Add rainbow brush.

Drawing/Brushes/Brush.cs

@@ -33,6 +33,7 @@ namespace MCGalaxy.Drawing.Brushes {
             { "normal", SolidBrush.Process },
             { "paste", PasteBrush.Process },
             { "checkered", CheckeredBrush.Process },
+            { "rainbow", RainbowBrush.Process },
         };
     }
     
@@ -46,20 +47,6 @@ namespace MCGalaxy.Drawing.Brushes {
         }
     }
     
-    public sealed class RainbowBrush : Brush {
-        byte curBlock = Block.red;
-        
-        public override byte NextBlock(DrawOp op) {
-            byte block = curBlock; 
-            curBlock++;
-            if (curBlock > Block.darkpink)
-                curBlock = Block.red;
-            return block;
-        }
-        
-        public override byte NextExtBlock(DrawOp op) { return 0; }
-    }
-    
     public sealed class RandomBrush : Brush {
         readonly Random rnd = new Random();
         readonly byte type, extType;
@@ -75,22 +62,4 @@ namespace MCGalaxy.Drawing.Brushes {
         
         public override byte NextExtBlock(DrawOp op) { return extType; }
     }
-    
-    public sealed class RandomRainbowBrush : Brush {
-        readonly Random rnd;
-        
-        public RandomRainbowBrush() {
-            rnd = new Random();
-        }
-        
-        public RandomRainbowBrush(int seed) {
-            rnd = new Random(seed);
-        }
-        
-        public override byte NextBlock(DrawOp op) {
-            return (byte)rnd.Next(Block.red, Block.darkgrey);
-        }
-        
-        public override byte NextExtBlock(DrawOp op) { return 0; }
-    }
 }

Drawing/Brushes/CheckeredBrush.cs

@@ -30,7 +30,7 @@ namespace MCGalaxy.Drawing.Brushes {
             this.type2 = type2; this.extType2 = extType2;
         }
         
-        public static CheckeredBrush Process(BrushArgs args) {
+        public static Brush Process(BrushArgs args) {
             if (args.Message == "")
                 return new CheckeredBrush(args.Type, args.ExtType, 0, 0);
             string[] parts = args.Message.Split(' ');

Drawing/Brushes/PasteBrush.cs

@@ -29,7 +29,7 @@ namespace MCGalaxy.Drawing.Brushes {
             this.state = state;
         }
         
-        public static PasteBrush Process(BrushArgs args) {
+        public static Brush Process(BrushArgs args) {
             if (args.Player.CopyBuffer == null) {
                 args.Player.SendMessage("You haven't copied anything yet.");
                 return null;

Drawing/Brushes/RainbowBrush.cs

@@ -0,0 +1,63 @@
+/*
+    Copyright 2015 MCGalaxy
+        
+    Dual-licensed under the Educational Community License, Version 2.0 and
+    the GNU General Public License, Version 3 (the "Licenses"); you may
+    not use this file except in compliance with the Licenses. You may
+    obtain a copy of the Licenses at
+    
+    http://www.opensource.org/licenses/ecl2.php
+    http://www.gnu.org/licenses/gpl-3.0.html
+    
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the Licenses are distributed on an "AS IS"
+    BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+    or implied. See the Licenses for the specific language governing
+    permissions and limitations under the Licenses.
+ */
+using System;
+using System.Collections.Generic;
+using MCGalaxy.Commands;
+using MCGalaxy.Drawing.Ops;
+
+namespace MCGalaxy.Drawing.Brushes {
+    
+    public sealed class RainbowBrush : Brush {
+        
+        public override byte NextBlock(DrawOp op) {
+            int dx = op.Coords.X - op.Min.X;
+            int dy = op.Coords.Y - op.Min.Y;
+            int dz = op.Coords.Z - op.Min.Z;
+            
+            int offset = (dx + dy + dz) % 13;
+            if (offset < 0) offset += 13;
+            return (byte)(Block.red + offset);
+        }
+        
+        public override byte NextExtBlock(DrawOp op) { return 0; }
+        
+        public static Brush Process(BrushArgs args) {
+            if (args.Message == "random")
+            	return new RandomRainbowBrush();
+            return new RainbowBrush(); // TODO: seed
+        }
+    }
+    
+    public sealed class RandomRainbowBrush : Brush {
+        readonly Random rnd;
+        
+        public RandomRainbowBrush() {
+            rnd = new Random();
+        }
+        
+        public RandomRainbowBrush(int seed) {
+            rnd = new Random(seed);
+        }
+        
+        public override byte NextBlock(DrawOp op) {
+            return (byte)rnd.Next(Block.red, Block.darkgrey);
+        }
+        
+        public override byte NextExtBlock(DrawOp op) { return 0; }
+    }
+}

Drawing/Brushes/SolidBrush.cs

@@ -30,7 +30,7 @@ namespace MCGalaxy.Drawing.Brushes {
             this.extType = extType;
         }
         
-        public static SolidBrush Process(BrushArgs args) {
+        public static Brush Process(BrushArgs args) {
             if (args.Message == "")
                 return new SolidBrush(args.Type, args.ExtType);
             byte extType;

MCGalaxy_.csproj

@@ -395,6 +395,7 @@
     <Compile Include="Drawing\Brushes\Brush.cs" />
     <Compile Include="Drawing\Brushes\CheckeredBrush.cs" />
     <Compile Include="Drawing\Brushes\PasteBrush.cs" />
+    <Compile Include="Drawing\Brushes\RainbowBrush.cs" />
     <Compile Include="Drawing\Brushes\SolidBrush.cs" />
     <Compile Include="Drawing\CopyState.cs" />
     <Compile Include="Drawing\DrawOps\CuboidDrawOp.cs" />