From 45c2868d4cb8f36a610b8deb37c5519d267827cb Mon Sep 17 00:00:00 2001
From: sk89q
Date: Wed, 26 Mar 2014 23:09:55 -0700
Subject: [PATCH] Added various visitors (BFS, Downward, Recursive, Region).
---
.../operation/BreadthFirstSearch.java | 172 ++++++++++++++++++
.../worldedit/operation/DownwardVisitor.java | 66 +++++++
.../worldedit/operation/RecursiveVisitor.java | 49 +++++
.../worldedit/operation/RegionVisitor.java | 65 +++++++
4 files changed, 352 insertions(+)
create mode 100644 src/main/java/com/sk89q/worldedit/operation/BreadthFirstSearch.java
create mode 100644 src/main/java/com/sk89q/worldedit/operation/DownwardVisitor.java
create mode 100644 src/main/java/com/sk89q/worldedit/operation/RecursiveVisitor.java
create mode 100644 src/main/java/com/sk89q/worldedit/operation/RegionVisitor.java
diff --git a/src/main/java/com/sk89q/worldedit/operation/BreadthFirstSearch.java b/src/main/java/com/sk89q/worldedit/operation/BreadthFirstSearch.java
new file mode 100644
index 000000000..47d9feaa5
--- /dev/null
+++ b/src/main/java/com/sk89q/worldedit/operation/BreadthFirstSearch.java
@@ -0,0 +1,172 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q
+ * 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 .
+ */
+
+package com.sk89q.worldedit.operation;
+
+import com.sk89q.worldedit.BlockVector;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEditException;
+
+import java.util.*;
+
+/**
+ * Performs a breadth-first search starting from points added with
+ * {@link #visit(com.sk89q.worldedit.Vector)}. The search continues
+ * to a certain adjacent point provided that the method
+ * {@link #isVisitable(com.sk89q.worldedit.Vector, com.sk89q.worldedit.Vector)}
+ * returns true for that point.
+ *
+ * As an abstract implementation, this class can be used to implement
+ * functionality that starts at certain points and extends outward from
+ * those points.
+ */
+public abstract class BreadthFirstSearch implements Operation {
+
+ private final RegionFunction function;
+ private final Queue queue = new ArrayDeque();
+ private final Set visited = new HashSet();
+ private final List directions = new ArrayList();
+ private int affected = 0;
+
+ /**
+ * Create a new instance.
+ *
+ * @param function the function to apply to visited blocks
+ */
+ public BreadthFirstSearch(RegionFunction function) {
+ this.function = function;
+ addAxes();
+ }
+
+ /**
+ * Get the list of directions will be visited.
+ *
+ * Directions are {@link com.sk89q.worldedit.Vector}s that determine
+ * what adjacent points area available. Vectors should not be
+ * unit vectors. An example of a valid direction is {@code new Vector(1, 0, 1)}.
+ *
+ * The list of directions can be cleared.
+ *
+ * @return the list of directions
+ */
+ protected List getDirections() {
+ return directions;
+ }
+
+ /**
+ * Add the directions along the axes as directions to visit.
+ */
+ protected void addAxes() {
+ directions.add(new Vector(0, -1, 0));
+ directions.add(new Vector(0, 1, 0));
+ 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));
+ }
+
+ /**
+ * Add the diagonal directions as directions to visit.
+ */
+ protected void addDiagonal() {
+ directions.add(new Vector(1, 0, 1));
+ directions.add(new Vector(-1, 0, -1));
+ directions.add(new Vector(1, 0, -1));
+ directions.add(new Vector(-1, 0, 1));
+ }
+
+ /**
+ * Add the given location to the list of locations to visit, provided
+ * that it has not been visited. The position passed to this method
+ * will still be visited even if it fails
+ * {@link #isVisitable(com.sk89q.worldedit.Vector, com.sk89q.worldedit.Vector)}.
+ *
+ * This method should be used before the search begins, because if
+ * the position does fail the test, and the search has already
+ * visited it (because it is connected to another root point),
+ * the search will mark the position as "visited" and a call to this
+ * method will do nothing.
+ *
+ * @param position the position
+ */
+ public void visit(Vector position) {
+ BlockVector blockVector = position.toBlockVector();
+ if (!visited.contains(blockVector)) {
+ queue.add(blockVector);
+ visited.add(blockVector);
+ }
+ }
+
+ /**
+ * Try to visit the given 'to' location.
+ *
+ * @param from the origin block
+ * @param to the block under question
+ */
+ private void visit(Vector from, Vector to) {
+ BlockVector blockVector = to.toBlockVector();
+ if (!visited.contains(blockVector)) {
+ visited.add(blockVector);
+ if (isVisitable(from, to)) {
+ queue.add(blockVector);
+ }
+ }
+ }
+
+ /**
+ * Return whether the given 'to' block should be visited, starting from the
+ * 'from' block.
+ *
+ * @param from the origin block
+ * @param to the block under question
+ * @return true if the 'to' block should be visited
+ */
+ protected abstract boolean isVisitable(Vector from, Vector to);
+
+ /**
+ * Get the number of affected objects.
+ *
+ * @return the number of affected
+ */
+ public int getAffected() {
+ return affected;
+ }
+
+ @Override
+ public Operation resume() throws WorldEditException {
+ Vector position;
+
+ while ((position = queue.poll()) != null) {
+ if (function.apply(position)) {
+ affected++;
+ }
+
+ for (Vector dir : directions) {
+ visit(position, position.add(dir));
+ }
+ }
+
+ return null;
+ }
+
+ @Override
+ public void cancel() {
+ }
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/sk89q/worldedit/operation/DownwardVisitor.java b/src/main/java/com/sk89q/worldedit/operation/DownwardVisitor.java
new file mode 100644
index 000000000..393ca35c7
--- /dev/null
+++ b/src/main/java/com/sk89q/worldedit/operation/DownwardVisitor.java
@@ -0,0 +1,66 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q
+ * 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 .
+ */
+
+package com.sk89q.worldedit.operation;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.masks.Mask;
+
+import java.util.List;
+
+/**
+ * Visits adjacent points on the same X-Z plane as long as the points
+ * pass the given mask, and then executes the provided region
+ * function on the entire column.
+ *
+ * This is used by //fill
.
+ */
+public class DownwardVisitor extends RecursiveVisitor {
+
+ private int baseY;
+
+ /**
+ * Create a new visitor.
+ *
+ * @param editSession the edit session
+ * @param mask the mask
+ * @param function the function
+ * @param baseY the base Y
+ */
+ public DownwardVisitor(EditSession editSession, Mask mask, RegionFunction function, int baseY) {
+ super(editSession, mask, function);
+
+ this.baseY = baseY;
+
+ List 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));
+ }
+
+ @Override
+ protected boolean isVisitable(Vector from, Vector to) {
+ int fromY = from.getBlockY();
+ return (fromY == baseY || to.subtract(from).getBlockY() < 0) && super.isVisitable(from, to);
+ }
+}
diff --git a/src/main/java/com/sk89q/worldedit/operation/RecursiveVisitor.java b/src/main/java/com/sk89q/worldedit/operation/RecursiveVisitor.java
new file mode 100644
index 000000000..7bc6eb82c
--- /dev/null
+++ b/src/main/java/com/sk89q/worldedit/operation/RecursiveVisitor.java
@@ -0,0 +1,49 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q
+ * 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 .
+ */
+
+package com.sk89q.worldedit.operation;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.masks.Mask;
+
+/**
+ * An implementation of an {@link BreadthFirstSearch} that uses a mask to
+ * determine where a block should be visited.
+ */
+public class RecursiveVisitor extends BreadthFirstSearch {
+
+ private final EditSession editSession;
+ private final Mask mask;
+
+ public RecursiveVisitor(EditSession editSession, Mask mask, RegionFunction function) {
+ super(function);
+ this.editSession = editSession;
+ this.mask = mask;
+ }
+
+ @Override
+ protected boolean isVisitable(Vector from, Vector to) {
+ int y = to.getBlockY();
+ if (y < 0 || y > editSession.getWorld().getMaxY()) {
+ return false;
+ }
+ return mask.matches(editSession, to);
+ }
+}
diff --git a/src/main/java/com/sk89q/worldedit/operation/RegionVisitor.java b/src/main/java/com/sk89q/worldedit/operation/RegionVisitor.java
new file mode 100644
index 000000000..51772d57b
--- /dev/null
+++ b/src/main/java/com/sk89q/worldedit/operation/RegionVisitor.java
@@ -0,0 +1,65 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q
+ * 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 .
+ */
+
+package com.sk89q.worldedit.operation;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.regions.Region;
+
+/**
+ * Utility class to apply region functions to {@link com.sk89q.worldedit.regions.Region}.
+ */
+public class RegionVisitor implements Operation {
+
+ private final Region region;
+ private final RegionFunction function;
+ private int affected = 0;
+
+ public RegionVisitor(Region region, RegionFunction function) {
+ this.region = region;
+ this.function = function;
+ }
+
+ /**
+ * Get the number of affected objects.
+ *
+ * @return the number of affected
+ */
+ public int getAffected() {
+ return affected;
+ }
+
+ @Override
+ public Operation resume() throws WorldEditException {
+ for (Vector pt : region) {
+ if (function.apply(pt)) {
+ affected++;
+ }
+ }
+
+ return null;
+ }
+
+ @Override
+ public void cancel() {
+ }
+
+}
+