Add FlatRegion interface and an associated iterator

src/main/java/com/sk89q/worldedit/regions/CuboidRegion.java

@@ -32,7 +32,7 @@
  *
  * @author sk89q
  */
-public class CuboidRegion extends AbstractRegion {
+public class CuboidRegion extends AbstractRegion implements FlatRegion {
     /**
      * Store the first point.
      */
@@ -371,6 +371,16 @@ public void remove() {
         };
     }
 
+    @Override
+    public Iterable<Vector2D> asFlatRegion() {
+        return new Iterable<Vector2D>() {
+            @Override
+            public Iterator<Vector2D> iterator() {
+                return new FlatRegionIterator(CuboidRegion.this);
+            }
+        };
+    }
+
     /**
      * Returns string representation in the format
      * "(minX, minY, minZ) - (maxX, maxY, maxZ)".

src/main/java/com/sk89q/worldedit/regions/CylinderRegion.java

@@ -20,6 +20,7 @@
 package com.sk89q.worldedit.regions;
 
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.Set;
 import com.sk89q.worldedit.LocalWorld;
 import com.sk89q.worldedit.Vector;
@@ -31,7 +32,7 @@
  *
  * @author yetanotherx
  */
-public class CylinderRegion extends AbstractRegion {
+public class CylinderRegion extends AbstractRegion implements FlatRegion {
     private Vector center;
     private Vector2D center2D;
     private Vector2D radius;
@@ -342,6 +343,16 @@ public boolean setY(int y) {
         return false;
     }
 
+    @Override
+    public Iterable<Vector2D> asFlatRegion() {
+        return new Iterable<Vector2D>() {
+            @Override
+            public Iterator<Vector2D> iterator() {
+                return new FlatRegionIterator(CylinderRegion.this);
+            }
+        };
+    }
+
     /**
      * Returns string representation in the format
      * "(centerX, centerY, centerZ) - (radiusX, radiusZ)"

src/main/java/com/sk89q/worldedit/regions/FlatRegion.java

@@ -0,0 +1,27 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com> and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.worldedit.regions;
+
+import com.sk89q.worldedit.Vector2D;
+
+public interface FlatRegion extends Region {
+
+    public Iterable<Vector2D> asFlatRegion();
+}

src/main/java/com/sk89q/worldedit/regions/FlatRegionIterator.java

@@ -0,0 +1,97 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com> and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.worldedit.regions;
+
+import java.util.Iterator;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.Vector2D;
+
+public class FlatRegionIterator implements Iterator<Vector2D>  {
+
+    private Region region;
+    private int y;
+    private int minX;
+    private int nextX;
+    private int nextZ;
+    private int maxX;
+    private int maxZ;
+
+    public FlatRegionIterator(Region region) {
+        this.region = region;
+
+        Vector min = region.getMinimumPoint();
+        Vector max = region.getMaximumPoint();
+
+        this.y = min.getBlockY();
+
+        this.minX = min.getBlockX();
+
+        this.nextX = minX;
+        this.nextZ = min.getBlockZ();
+
+        this.maxX = max.getBlockX();
+        this.maxZ = max.getBlockZ();
+
+        forward();
+    }
+
+    @Override
+    public boolean hasNext() {
+        return nextX != Integer.MIN_VALUE;
+    }
+
+    private void forward() {
+        while (hasNext() && !region.contains(new Vector(nextX, y, nextZ))) {
+            forwardOne();
+        }
+    }
+
+    @Override
+    public Vector2D next() {
+        if (!hasNext()) {
+            throw new java.util.NoSuchElementException();
+        }
+
+        Vector2D answer = new Vector2D(nextX, nextZ);
+
+        forwardOne();
+        forward();
+
+        return answer;
+    }
+
+    private void forwardOne() {
+        if (++nextX <= maxX) {
+            return;
+        }
+        nextX = minX;
+
+        if (++nextZ <= maxZ) {
+            return;
+        }
+        nextX = Integer.MIN_VALUE;
+    }
+
+    @Override
+    public void remove() {
+        throw new UnsupportedOperationException();
+    }
+}

src/main/java/com/sk89q/worldedit/regions/Polygonal2DRegion.java

@@ -37,7 +37,7 @@
  *
  * @author sk89q
  */
-public class Polygonal2DRegion extends AbstractRegion {
+public class Polygonal2DRegion extends AbstractRegion implements FlatRegion {
     private List<BlockVector2D> points;
     private BlockVector min;
     private BlockVector max;
@@ -469,6 +469,16 @@ public Iterator<BlockVector> iterator() {
         return new RegionIterator(this);
     }
 
+    @Override
+    public Iterable<Vector2D> asFlatRegion() {
+        return new Iterable<Vector2D>() {
+            @Override
+            public Iterator<Vector2D> iterator() {
+                return new FlatRegionIterator(Polygonal2DRegion.this);
+            }
+        };
+    }
+
     /**
      * Returns string representation in the format
      * "(x1, z1) - ... - (xN, zN) * (minY - maxY)"