ADD: CylinderSelection for worldguard to be able to create regions

MOD: moved polygonize method of CylinderRegion to RegionUtil so it can be
reused later on

src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java

@@ -47,9 +47,11 @@ import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.WorldEditOperation;
 import com.sk89q.worldedit.bags.BlockBag;
 import com.sk89q.worldedit.bukkit.selections.CuboidSelection;
+import com.sk89q.worldedit.bukkit.selections.CylinderSelection;
 import com.sk89q.worldedit.bukkit.selections.Polygonal2DSelection;
 import com.sk89q.worldedit.bukkit.selections.Selection;
 import com.sk89q.worldedit.regions.CuboidRegion;
+import com.sk89q.worldedit.regions.CylinderRegion;
 import com.sk89q.worldedit.regions.Polygonal2DRegion;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.regions.RegionSelector;
@@ -397,6 +399,8 @@ public class WorldEditPlugin extends JavaPlugin {
                 return new CuboidSelection(world, selector, (CuboidRegion) region);
             } else if (region instanceof Polygonal2DRegion) {
                 return new Polygonal2DSelection(world, selector, (Polygonal2DRegion) region);
+            } else if (region instanceof CylinderRegion) {
+                return new CylinderSelection(world, selector, (CylinderRegion) region);
             } else {
                 return null;
             }

src/main/java/com/sk89q/worldedit/bukkit/selections/CylinderSelection.java

@@ -0,0 +1,61 @@
+package com.sk89q.worldedit.bukkit.selections;
+
+import org.bukkit.World;
+
+import com.sk89q.worldedit.BlockVector2D;
+import com.sk89q.worldedit.LocalWorld;
+import com.sk89q.worldedit.bukkit.BukkitUtil;
+import com.sk89q.worldedit.regions.CylinderRegion;
+import com.sk89q.worldedit.regions.CylinderRegionSelector;
+import com.sk89q.worldedit.regions.RegionSelector;
+
+/**
+ * A selection representing a {@link CylinderRegion}
+ */
+public class CylinderSelection extends RegionSelection {
+
+    private CylinderRegion cylRegion;
+
+    public CylinderSelection(World world, RegionSelector selector, CylinderRegion region) {
+        super(world, selector, region);
+        this.cylRegion = region;
+    }
+    
+    public CylinderSelection(World world, BlockVector2D center, BlockVector2D radius, int minY, int maxY) {
+        super(world);
+        LocalWorld lWorld = BukkitUtil.getLocalWorld(world);
+
+        // Validate input
+        minY = Math.min(Math.max(0, minY), world.getMaxHeight());
+        maxY = Math.min(Math.max(0, maxY), world.getMaxHeight());
+
+        // Create and set up new selector
+        CylinderRegionSelector sel = new CylinderRegionSelector(lWorld, center, radius, minY, maxY);
+
+        // set up selection
+        cylRegion = sel.getIncompleteRegion();
+
+        // set up RegionSelection
+        setRegionSelector(sel);
+        setRegion(cylRegion);
+    }
+
+    /**
+     * Returns the center vector of the cylinder
+     * 
+     * @return the center
+     */
+    public BlockVector2D getCenter() {
+        return cylRegion.getCenter().toVector2D().toBlockVector2D();
+    }
+
+    /**
+     * Returns the radius vector of the cylinder
+     * 
+     * @return the radius
+     */
+    public BlockVector2D getRadius() {
+        return cylRegion.getRadius().toBlockVector2D();
+    }
+
+}

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

@@ -22,11 +22,13 @@ package com.sk89q.worldedit.regions;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+
 import com.sk89q.worldedit.BlockVector;
 import com.sk89q.worldedit.BlockVector2D;
 import com.sk89q.worldedit.LocalWorld;
 import com.sk89q.worldedit.Vector;
 import com.sk89q.worldedit.Vector2D;
+import com.sk89q.worldedit.util.RegionUtil;
 
 /**
  * Represents a cylindrical region.
@@ -366,22 +368,6 @@ public class CylinderRegion extends AbstractRegion implements FlatRegion {
 
     @Override
     public List<BlockVector2D> polygonize(int maxPoints) {
-        final Vector2D radius = getRadius();
-        int nPoints = (int) Math.ceil(Math.PI*radius.length());
-
-        // These strange semantics for maxPoints are copied from the selectSecondary method.
-        if (maxPoints >= 0 && nPoints >= maxPoints) {
-            nPoints = maxPoints - 1;
-        }
-
-        final List<BlockVector2D> points = new ArrayList<BlockVector2D>(nPoints);
-        for (int i = 0; i < nPoints; ++i) {
-            double angle = i * (2.0 * Math.PI) / nPoints;
-            final Vector2D pos = new Vector2D(Math.cos(angle), Math.sin(angle));
-            final BlockVector2D blockVector2D = pos.multiply(radius).add(center).toBlockVector2D();
-            points.add(blockVector2D);
-        }
-
-        return points;
+        return RegionUtil.polygonizeCylinder(center, radius, maxPoints);
     }
 }

src/main/java/com/sk89q/worldedit/util/RegionUtil.java

@@ -0,0 +1,45 @@
+package com.sk89q.worldedit.util;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.sk89q.worldedit.BlockVector2D;
+import com.sk89q.worldedit.Vector2D;
+
+/**
+ * Helper method for anything related to region calculations.
+ */
+public class RegionUtil {
+
+    private RegionUtil() {
+        
+    }
+
+    /**
+     * Calculates the polygon shape of a cylinder which can then be used for e.g. intersection detection.
+     * 
+     * @param center the center point of the cylinder
+     * @param radius the radius of the cylinder
+     * @param maxPoints max points to be used for the calculation
+     * @return a list of {@link BlockVector2D} which resemble the shape as a polygon
+     */
+    public static List<BlockVector2D> polygonizeCylinder(Vector2D center, Vector2D radius, int maxPoints) {
+        int nPoints = (int) Math.ceil(Math.PI*radius.length());
+
+        // These strange semantics for maxPoints are copied from the selectSecondary method.
+        if (maxPoints >= 0 && nPoints >= maxPoints) {
+            nPoints = maxPoints - 1;
+        }
+
+        final List<BlockVector2D> points = new ArrayList<BlockVector2D>(nPoints);
+        for (int i = 0; i < nPoints; ++i) {
+            double angle = i * (2.0 * Math.PI) / nPoints;
+            final Vector2D pos = new Vector2D(Math.cos(angle), Math.sin(angle));
+            final BlockVector2D blockVector2D = pos.multiply(radius).add(center).toBlockVector2D();
+            points.add(blockVector2D);
+        }
+
+        return points;
+    }
+    
+}