Added TransformRegion to transform another Region.

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

@@ -0,0 +1,190 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.regions;
+
+import com.sk89q.worldedit.BlockVector;
+import com.sk89q.worldedit.BlockVector2D;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.math.transform.Identity;
+import com.sk89q.worldedit.math.transform.Transform;
+import com.sk89q.worldedit.world.World;
+
+import javax.annotation.Nullable;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Transforms another region according to a provided vector {@code Transform}.
+ *
+ * @see Transform
+ */
+public class TransformRegion extends AbstractRegion {
+
+    private final Region region;
+    private Transform transform = new Identity();
+
+    /**
+     * Create a new instance.
+     *
+     * @param region the region
+     * @param transform the transform
+     */
+    public TransformRegion(Region region, Transform transform) {
+        this(null, region, transform);
+    }
+
+    /**
+     * Create a new instance.
+     *
+     * @param world the world, which may be null
+     * @param region the region
+     * @param transform the transform
+     */
+    public TransformRegion(@Nullable World world, Region region, Transform transform) {
+        super(world);
+        checkNotNull(region);
+        checkNotNull(transform);
+        this.region = region;
+        this.transform = transform;
+    }
+
+    /**
+     * Get the untransformed, base region.
+     *
+     * @return the base region
+     */
+    public Region getRegion() {
+        return region;
+    }
+
+    /**
+     * Get the transform that is applied.
+     *
+     * @return the transform
+     */
+    public Transform getTransform() {
+        return transform;
+    }
+
+    /**
+     * Set the transform that is applied.
+     *
+     * @param transform the transform
+     */
+    public void setTransform(Transform transform) {
+        checkNotNull(transform);
+        this.transform = transform;
+    }
+
+    @Override
+    public Vector getMinimumPoint() {
+        return transform.apply(region.getMinimumPoint());
+    }
+
+    @Override
+    public Vector getMaximumPoint() {
+        return transform.apply(region.getMaximumPoint());
+    }
+
+    @Override
+    public Vector getCenter() {
+        return transform.apply(region.getCenter());
+    }
+
+    @Override
+    public int getArea() {
+        return region.getArea(); // Cannot transform this
+    }
+
+    @Override
+    public int getWidth() {
+        return getMaximumPoint().subtract(getMinimumPoint()).getBlockX() + 1;
+    }
+
+    @Override
+    public int getHeight() {
+        return getMaximumPoint().subtract(getMinimumPoint()).getBlockY() + 1;
+    }
+
+    @Override
+    public int getLength() {
+        return getMaximumPoint().subtract(getMinimumPoint()).getBlockZ() + 1;
+    }
+
+    @Override
+    public void expand(Vector... changes) throws RegionOperationException {
+        throw new RegionOperationException("Can't expand a TransformedRegion");
+    }
+
+    @Override
+    public void contract(Vector... changes) throws RegionOperationException {
+        throw new RegionOperationException("Can't contract a TransformedRegion");
+    }
+
+    @Override
+    public void shift(Vector change) throws RegionOperationException {
+        throw new RegionOperationException("Can't change a TransformedRegion");
+    }
+
+    @Override
+    public boolean contains(Vector pt) {
+        return region.contains(transform.inverse().apply(pt));
+    }
+
+    @Override
+    public List<BlockVector2D> polygonize(int maxPoints) {
+        List<BlockVector2D> origPoints = region.polygonize(maxPoints);
+        List<BlockVector2D> transformedPoints = new ArrayList<BlockVector2D>();
+        for (BlockVector2D vector : origPoints) {
+            transformedPoints.add(transform.apply(vector.toVector(0)).toVector2D().toBlockVector2D());
+        }
+        return transformedPoints;
+    }
+
+    @Override
+    public Iterator<BlockVector> iterator() {
+        final Iterator<BlockVector> it = region.iterator();
+
+        return new Iterator<BlockVector>() {
+            @Override
+            public boolean hasNext() {
+                return it.hasNext();
+            }
+
+            @Override
+            public BlockVector next() {
+                BlockVector next = it.next();
+                if (next != null) {
+                    return transform.apply(next).toBlockVector();
+                } else {
+                    return null;
+                }
+            }
+
+            @Override
+            public void remove() {
+                it.remove();
+            }
+        };
+    }
+}