Changed how ground finding operations were implemented.

src/main/java/com/sk89q/worldedit/regions/search/AbstractGroundSearch.java

@@ -0,0 +1,76 @@
+/*
+ * 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.regions.search;
+
+import com.sk89q.worldedit.Vector;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static net.minecraft.util.com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Utility class for finding the first ground block starting from a certain
+ * position and traversing down.
+ */
+public abstract class AbstractGroundSearch implements GroundSearch {
+
+    /**
+     * Returns whether the given block should be "passed through" when
+     * conducting the ground search.
+     *
+     * @param position return whether the given block is the ground
+     * @return true if the search should stop
+     */
+    protected abstract boolean isGround(Vector position);
+
+    /**
+     * Find the ground block starting from the given position and traversing
+     * downward until reaching minY (inclusive).
+     * </p>
+     * The highest ground block that may be returned is at the location of
+     * the origin location. The lowest ground block that may be returned is
+     * in the same column as the origin but with y = minY.
+     * </p>
+     * It is possible for no ground block to be found if the given origin
+     * block is underground to begin with.
+     *
+     * @param origin the origin
+     * @param minY the minimum Y to end the search at
+     * @return the location of a ground block, or null if none was found
+     */
+    public Vector findGround(Vector origin, int minY) {
+        checkNotNull(origin);
+        checkArgument(minY <= origin.getBlockY(), "minY <= origin Y");
+
+        // Don't want to be in the ground
+        if (isGround(origin.add(0, 1, 0))) {
+            return null;
+        }
+
+        for (int y = origin.getBlockY() + 1; y >= minY; --y) {
+            Vector test = origin.setY(y);
+            if (isGround(test)) {
+                return test;
+            }
+        }
+
+        return null;
+    }
+
+}

src/main/java/com/sk89q/worldedit/regions/search/GroundSearch.java

@@ -0,0 +1,47 @@
+/*
+ * 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.regions.search;
+
+import com.sk89q.worldedit.Vector;
+
+/**
+ * Given a column of blocks in the world, finds the first ground block
+ * starting from a given Y.
+ */
+public interface GroundSearch {
+
+    /**
+     * Find the ground block starting from the given position and traversing
+     * downward until reaching minY (inclusive).
+     * </p>
+     * The highest ground block that may be returned is at the location of
+     * the origin location. The lowest ground block that may be returned is
+     * in the same column as the origin but with y = minY.
+     * </p>
+     * It is possible for no ground block to be found if the given origin
+     * block is underground.
+     *
+     * @param origin the origin
+     * @param minY the minimum Y to end the search at
+     * @return the location of a ground block, or null if none was found
+     */
+    Vector findGround(Vector origin, int minY);
+
+}

src/main/java/com/sk89q/worldedit/regions/search/MaskingGroundSearch.java

@@ -0,0 +1,68 @@
+/*
+ * 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.regions.search;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.masks.Mask;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * A ground finder that uses a {@link com.sk89q.worldedit.masks.Mask} to determine
+ * ground blocks.
+ */
+public class MaskingGroundSearch extends AbstractGroundSearch {
+
+    private final EditSession editSession;
+    private final Mask mask;
+
+    /**
+     * Create a new instance.
+     * </p>
+     * If a mask that matches non-ground blocks is available, it can be inverted with
+     * {@link com.sk89q.worldedit.masks.InvertedMask}.
+     *
+     * @param editSession an edit session
+     * @param mask a mask that matches ground blocks
+     */
+    public MaskingGroundSearch(EditSession editSession, Mask mask) {
+        checkNotNull(editSession);
+        checkNotNull(mask);
+
+        this.editSession = editSession;
+        this.mask = mask;
+    }
+
+    /**
+     * Get the mask that matches ground blocks.
+     *
+     * @return the mask
+     */
+    public Mask getMask() {
+        return mask;
+    }
+
+    @Override
+    protected boolean isGround(Vector position) {
+        return mask.matches(editSession, position);
+    }
+
+}