Added NonRisingVisitor.

src/main/java/com/sk89q/worldedit/function/visitor/NonRisingVisitor.java

@@ -0,0 +1,50 @@
+/*
+ * 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 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.function.visitor;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.function.RegionFunction;
+import com.sk89q.worldedit.function.mask.Mask;
+
+import java.util.Collection;
+
+/**
+ * A {@link RecursiveVisitor} that goes orthogonally to the side and down, but never up.
+ */
+public class NonRisingVisitor extends RecursiveVisitor {
+
+    /**
+     * Create a new recursive visitor.
+     *
+     * @param mask the mask
+     * @param function the function
+     */
+    public NonRisingVisitor(Mask mask, RegionFunction function) {
+        super(mask, function);
+        Collection<Vector> directions = getDirections();
+        directions.clear();
+        directions.add(new Vector(1, 0, 0));
+        directions.add(new Vector(-1, 0, 0));
+        directions.add(new Vector(0, 0, 1));
+        directions.add(new Vector(0, 0, -1));
+        directions.add(new Vector(0, -1, 0));
+    }
+
+}