Add a cylindrical region selector.

- Supports shift
- Supports expand/contract on the y axis
- getArea is slightly inaccurate, but more accuracy would mean more CPU usage.
- Displays as a cuboid in legacy mode.

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

@@ -0,0 +1,328 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * 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.HashSet;
+import java.util.Set;
+import com.sk89q.worldedit.LocalWorld;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.Vector2D;
+import com.sk89q.worldedit.data.ChunkStore;
+
+/**
+ * Represents a cylindrical region.
+ *
+ * @author yetanotherx
+ */
+public class CylinderRegion extends AbstractRegion {
+    private Vector center;
+    private Vector2D center2D;
+    private Vector2D radius;
+    private int minY;
+    private int maxY;
+    private boolean hasY = false;
+
+    /**
+     * Construct the region
+     */
+    public CylinderRegion() {
+        this((LocalWorld) null);
+    }
+
+    /**
+     * Construct the region.
+     * 
+     * @param world
+     */
+    public CylinderRegion(LocalWorld world) {
+        this(world, new Vector(), new Vector2D(), 0, 0);
+        hasY = false;
+    }
+
+    /**
+     * Construct the region.
+     * 
+     * @param world
+     * @param points
+     * @param minY
+     * @param maxY
+     */
+    public CylinderRegion(LocalWorld world, Vector center, Vector2D radius, int minY, int maxY) {
+        super(world);
+        this.center = center;
+        setRadius(radius);
+        this.minY = minY;
+        this.maxY = maxY;
+        hasY = true;
+    }
+
+    public CylinderRegion(CylinderRegion region) {
+        this(region.world, region.center, region.getRadius(), region.minY, region.maxY);
+        hasY = region.hasY;
+    }
+
+    /**
+     * Returns the main center point of the cylinder
+     * 
+     * @return 
+     */
+    public Vector getCenter() {
+        return center;
+    }
+
+    /**
+     * Sets the main center point of the region
+     * 
+     */
+    public void setCenter(Vector center) {
+        this.center = center;
+        this.center2D = center.toVector2D();
+    }
+
+    /**
+     * Returns the radius of the cylinder
+     * 
+     * @return 
+     */
+    public Vector2D getRadius() {
+        return radius.subtract(0.5, 0.5);
+    }
+
+    /**
+     * Sets the radius of the cylinder
+     * 
+     * @param radius 
+     */
+    public void setRadius(Vector2D radius) {
+        this.radius = radius.add(0.5, 0.5);
+    }
+
+    /**
+     * Extends the radius to be at least the given radius
+     * 
+     * @param minRadius
+     */
+    public void extendRadius(Vector2D minRadius) {
+        setRadius(Vector2D.getMaximum(minRadius, getRadius()));
+    }
+
+    /**
+     * Set the minimum Y.
+     * 
+     * @param y
+     */
+    public void setMinimumY(int y) {
+        hasY = true;
+        minY = y;
+    }
+
+    /**
+     * Se the maximum Y.
+     * 
+     * @param y
+     */
+    public void setMaximumY(int y) {
+        hasY = true;
+        maxY = y;
+    }
+
+    /**
+     * Get the lower point of a region.
+     * 
+     * @return min. point
+     */
+    public Vector getMinimumPoint() {
+        return center2D.subtract(getRadius()).toVector(minY);
+    }
+
+    /**
+     * Get the upper point of a region.
+     * 
+     * @return max. point
+     */
+    public Vector getMaximumPoint() {
+        return center2D.add(getRadius()).toVector(maxY);
+    }
+
+    /**
+     * Gets the maximum Y value
+     * @return 
+     */
+    public int getMaximumY() {
+        return maxY;
+    }
+
+    /**
+     * Gets the minimum Y value
+     * @return 
+     */
+    public int getMinimumY() {
+        return minY;
+    }
+
+    /**
+     * Get the number of blocks in the region.
+     * 
+     * @return number of blocks
+     */
+    public int getArea() {
+        return (int) Math.floor(radius.getX() * radius.getZ() * Math.PI * getHeight());
+    }
+
+    /**
+     * Get X-size.
+     *
+     * @return width
+     */
+    public int getWidth() {
+        return (int) (2 * radius.getX());
+    }
+
+    /**
+     * Get Y-size.
+     *
+     * @return height
+     */
+    public int getHeight() {
+        return maxY - minY + 1;
+    }
+
+    /**
+     * Get Z-size.
+     *
+     * @return length
+     */
+    public int getLength() {
+        return (int) (2 * radius.getZ());
+    }
+
+    /**
+     * Expand the region.
+     *
+     * @param change
+     */
+    public void expand(Vector change) throws RegionOperationException {
+        if (change.getBlockX() != 0 || change.getBlockZ() != 0) {
+            throw new RegionOperationException("Cylinders can only be expanded vertically.");
+        }
+
+        int changeY = change.getBlockY();
+        if (changeY > 0) {
+            maxY += changeY;
+        } else {
+            minY += changeY;
+        }
+    }
+
+    /**
+     * Contract the region.
+     *
+     * @param change
+     */
+    public void contract(Vector change) throws RegionOperationException {
+        if (change.getBlockX() != 0 || change.getBlockZ() != 0) {
+            throw new RegionOperationException("Cylinders can only be expanded vertically.");
+        }
+
+        int changeY = change.getBlockY();
+        if (changeY > 0) {
+            minY += changeY;
+        } else {
+            maxY += changeY;
+        }
+    }
+
+    @Override
+    public void shift(Vector change) throws RegionOperationException {
+        setCenter(getCenter().add(change));
+
+        int changeY = change.getBlockY();
+        maxY += changeY;
+        minY += changeY;
+    }
+
+    /**
+     * Checks to see if a point is inside this region.
+     */
+    public boolean contains(Vector pt) {
+        final int blockY = pt.getBlockY();
+        if (blockY < minY || blockY > maxY) {
+            return false;
+        }
+
+        return pt.toVector2D().subtract(center2D).divide(radius).lengthSq() <= 1;
+    }
+
+    /**
+     * Get a list of chunks.
+     * 
+     * @return
+     */
+    public Set<Vector2D> getChunks() {
+        Set<Vector2D> chunks = new HashSet<Vector2D>();
+
+        Vector min = getMinimumPoint();
+        Vector max = getMaximumPoint();
+
+        for (int x = min.getBlockX(); x <= max.getBlockX(); ++x) {
+            for (int z = min.getBlockZ(); z <= max.getBlockZ(); ++z) {
+                Vector pt = new Vector(x, minY, z);
+                if (contains(pt)) {
+                    chunks.add(ChunkStore.toChunk(pt));
+                }
+            }
+        }
+
+        return chunks;
+    }
+
+    /**
+     * Sets the height of the cylinder to fit the specified Y.
+     * 
+     * @param y 
+     * @return true if the area was expanded
+     */
+    public boolean setY(int y) {
+        if (!hasY) {
+            minY = y;
+            maxY = y;
+            hasY = true;
+            return true;
+        } else if (y < minY) {
+            minY = y;
+            return true;
+        } else if (y > maxY) {
+            maxY = y;
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns string representation in the format
+     * "(centerX, centerY, centerZ) - (radiusX, radiusZ)"
+     * 
+     * @return string
+     */
+    @Override
+    public String toString() {
+        return center + " - " + radius;
+    }
+}