Fix region intersection tests involving polygons.

Fixes WORLDGUARD-3216.

src/main/java/com/sk89q/worldguard/protection/regions/GlobalProtectedRegion.java

@@ -23,8 +23,10 @@
 import com.sk89q.worldedit.BlockVector2D;
 import com.sk89q.worldedit.Vector;
 
+import java.awt.geom.Area;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -47,6 +49,11 @@ public GlobalProtectedRegion(String id) {
         max = new BlockVector(0, 0, 0);
     }
 
+    @Override
+    public boolean isPhysicalArea() {
+        return false;
+    }
+
     @Override
     public List<BlockVector2D> getPoints() {
         // This doesn't make sense
@@ -74,7 +81,12 @@ public RegionType getType() {
     @Override
     public List<ProtectedRegion> getIntersectingRegions(Collection<ProtectedRegion> regions) {
         // Global regions are handled separately so it must not contain any positions
-        return new ArrayList<ProtectedRegion>();
+        return Collections.emptyList();
+    }
+
+    @Override
+    Area toArea() {
+        return null;
     }
 
 }

src/main/java/com/sk89q/worldguard/protection/regions/ProtectedCuboidRegion.java

@@ -24,8 +24,9 @@
 import com.sk89q.worldedit.Vector;
 import com.sk89q.worldguard.util.MathUtils;
 
+import java.awt.*;
+import java.awt.geom.Area;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -83,6 +84,11 @@ public void setMaximumPoint(BlockVector position) {
         setMinMaxPoints(min, position);
     }
 
+    @Override
+    public boolean isPhysicalArea() {
+        return true;
+    }
+
     @Override
     public List<BlockVector2D> getPoints() {
         List<BlockVector2D> pts = new ArrayList<BlockVector2D>();
@@ -115,30 +121,21 @@ public RegionType getType() {
     }
 
     @Override
-    public List<ProtectedRegion> getIntersectingRegions(Collection<ProtectedRegion> regions) {
+    Area toArea() {
-        checkNotNull(regions);
+        int x = getMinimumPoint().getBlockX();
+        int z = getMinimumPoint().getBlockZ();
+        int width = getMaximumPoint().getBlockX() - x;
+        int height = getMaximumPoint().getBlockZ() - z;
+        return new Area(new Rectangle(x, z, width, height));
+    }
 
-        List<ProtectedRegion> intersectingRegions = new ArrayList<ProtectedRegion>();
+    @Override
-
+    protected boolean intersects(ProtectedRegion region, Area thisArea) {
-        for (ProtectedRegion region : regions) {
+        if (region instanceof ProtectedCuboidRegion) {
-            if (!intersectsBoundingBox(region)) continue;
+            return intersectsBoundingBox(region);
-
+        } else {
-            // If both regions are Cuboids and their bounding boxes intersect, they intersect
+            return super.intersects(region, thisArea);
-            if (region instanceof ProtectedCuboidRegion) {
-                intersectingRegions.add(region);
-            } else if (region instanceof ProtectedPolygonalRegion) {
-                // If either region contains the points of the other,
-                // or if any edges intersect, the regions intersect
-                if (containsAny(region.getPoints()) || region.containsAny(getPoints()) || intersectsEdges(region)) {
-                    intersectingRegions.add(region);
-                }
-            } else if (region instanceof GlobalProtectedRegion) {
-                // Never intersects
-            } else {
-                throw new IllegalArgumentException("Not supported yet.");
-            }
         }
-        return intersectingRegions;
     }
 
     @Override

src/main/java/com/sk89q/worldguard/protection/regions/ProtectedPolygonalRegion.java

@@ -22,8 +22,10 @@
 import com.sk89q.worldedit.BlockVector2D;
 import com.sk89q.worldedit.Vector;
 
+import java.awt.*;
+import java.awt.geom.Area;
 import java.util.ArrayList;
-import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -37,7 +39,7 @@ public class ProtectedPolygonalRegion extends ProtectedRegion {
     public ProtectedPolygonalRegion(String id, List<BlockVector2D> points, int minY, int maxY) {
         super(id);
         setMinMaxPoints(points, minY, maxY);
-        this.points = points;
+        this.points = Collections.unmodifiableList(points);
         this.minY = min.getBlockY();
         this.maxY = max.getBlockY();
     }
@@ -61,6 +63,11 @@ private void setMinMaxPoints(List<BlockVector2D> points2D, int minY, int maxY) {
         setMinMaxPoints(points);
     }
 
+    @Override
+    public boolean isPhysicalArea() {
+        return true;
+    }
+
     @Override
     public List<BlockVector2D> getPoints() {
         return points;
@@ -133,27 +140,21 @@ public RegionType getType() {
     }
 
     @Override
-    public List<ProtectedRegion> getIntersectingRegions(Collection<ProtectedRegion> regions) {
+    Area toArea() {
-        checkNotNull(regions);
+        List<BlockVector2D> points = getPoints();
+        int numPoints = points.size();
+        int[] xCoords = new int[numPoints];
+        int[] yCoords = new int[numPoints];
 
-        List<ProtectedRegion> intersectingRegions = new ArrayList<ProtectedRegion>();
+        int i = 0;
-
+        for (BlockVector2D point : points) {
-        for (ProtectedRegion region : regions) {
+            xCoords[i] = point.getBlockX();
-            if (!intersectsBoundingBox(region)) continue;
+            yCoords[i] = point.getBlockZ();
-
+            i++;
-            if (region instanceof ProtectedPolygonalRegion || region instanceof ProtectedCuboidRegion) {
-                // If either region contains the points of the other,
-                // or if any edges intersect, the regions intersect
-                if (containsAny(region.getPoints()) || region.containsAny(getPoints()) || intersectsEdges(region)) {
-                    intersectingRegions.add(region);
-                }
-            } else if (region instanceof GlobalProtectedRegion) {
-                // Never intersects
-            } else {
-                throw new IllegalArgumentException("Not supported yet.");
-            }
         }
-        return intersectingRegions;
+
+        Polygon polygon = new Polygon(xCoords, yCoords, numPoints);
+        return new Area(polygon);
     }
 
     @Override

src/main/java/com/sk89q/worldguard/protection/regions/ProtectedRegion.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldguard.protection.regions;
 
+import com.google.common.collect.Lists;
 import com.sk89q.worldedit.BlockVector;
 import com.sk89q.worldedit.BlockVector2D;
 import com.sk89q.worldedit.Vector;
@@ -29,6 +30,7 @@
 import com.sk89q.worldguard.util.Normal;
 
 import javax.annotation.Nullable;
+import java.awt.geom.Area;
 import java.awt.geom.Line2D;
 import java.util.Collection;
 import java.util.List;
@@ -118,6 +120,13 @@ public String getId() {
         return id;
     }
 
+    /**
+     * Return whether this type of region encompasses physical area.
+     *
+     * @return Whether physical area is encompassed
+     */
+    public abstract boolean isPhysicalArea();
+
     /**
      * Get a vector containing the smallest X, Y, and Z components for the
      * corner of the axis-aligned bounding box that contains this region.
@@ -570,7 +579,39 @@ public final String getTypeName() {
      * @param regions a list of regions to source from
      * @return the elements of {@code regions} that intersect with this region
      */
-    public abstract List<ProtectedRegion> getIntersectingRegions(Collection<ProtectedRegion> regions);
+    public List<ProtectedRegion> getIntersectingRegions(Collection<ProtectedRegion> regions) {
+        checkNotNull(regions, "regions");
+
+        List<ProtectedRegion> intersecting = Lists.newArrayList();
+        Area thisArea = toArea();
+
+        for (ProtectedRegion region : regions) {
+            if (!region.isPhysicalArea()) continue;
+
+            if (intersects(region, thisArea)) {
+                intersecting.add(region);
+            }
+        }
+
+        return intersecting;
+    }
+
+    /**
+     * Test whether the given region intersects with this area.
+     *
+     * @param region the region to test
+     * @param thisArea an area object for this region
+     * @return true if the two regions intersect
+     */
+    protected boolean intersects(ProtectedRegion region, Area thisArea) {
+        if (intersectsBoundingBox(region)) {
+            Area testArea = region.toArea();
+            testArea.intersect(thisArea);
+            return !testArea.isEmpty();
+        } else {
+            return false;
+        }
+    }
 
     /**
      * Checks if the bounding box of a region intersects with with the bounding
@@ -631,6 +672,14 @@ protected boolean intersectsEdges(ProtectedRegion region) {
         return false;
     }
 
+    /**
+     * Return the AWT area, otherwise null if
+     * {@link #isPhysicalArea()} if false.
+     *
+     * @return The shape version
+     */
+    abstract Area toArea();
+
     @Override
     public boolean isDirty() {
         return dirty || owners.isDirty() || members.isDirty();