Ported block tracing code to WorldEdit.

src/com/sk89q/worldedit/util/TargetBlock.java

@@ -0,0 +1,174 @@
+// $Id$
+/*
+ * Copyright (c) 2011 toi
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+*/
+
+package com.sk89q.worldedit.util;
+
+import com.sk89q.worldedit.BlockWorldVector;
+import com.sk89q.worldedit.LocalPlayer;
+import com.sk89q.worldedit.LocalWorld;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BlockType;
+
+/**
+ * This class uses an inefficient method to figure out what block a player
+ * is looking towards.
+ * 
+ * Originally written by toi. It was ported to WorldEdit and trimmed down by
+ * sk89q. Thanks to Raphfrk for optimization of toi's original class.
+ * 
+ * @author toi
+ */
+public class TargetBlock {
+    private LocalWorld world;
+    private int maxDistance;
+    private double checkDistance, curDistance;
+    private Vector targetPos = new Vector();
+    private Vector targetPosDouble = new Vector();
+    private Vector prevPos = new Vector();
+    private Vector offset = new Vector();
+
+    /**
+     * Constructor requiring a player, uses default values
+     * 
+     * @param player player to work with
+     */
+    public TargetBlock(LocalPlayer player) {
+        this.world = player.getWorld();
+        this.setValues(player.getPosition(), player.getYaw(), player.getPitch(),
+                300, 1.65, 0.2);
+    }
+
+    /**
+     * Constructor requiring a player, max distance and a checking distance
+     * 
+     * @param player LocalPlayer to work with
+     * @param maxDistance how far it checks for blocks
+     * @param checkDistance how often to check for blocks, the smaller the more precise
+     */
+    public TargetBlock(LocalPlayer player, int maxDistance, double checkDistance) {
+        this.world = player.getWorld();
+        this.setValues(player.getPosition(), player.getYaw(), player.getPitch(),
+                maxDistance, 1.65, checkDistance);
+    }
+
+    /**
+     * Set the values, all constructors uses this function
+     * 
+     * @param loc location of the view
+     * @param xRotation
+     * @param yRotation
+     * @param maxDistance how far it checks for blocks
+     * @param viewPos where the view is positioned in y-axis
+     * @param checkDistance how often to check for blocks, the smaller the more precise
+     */
+    private void setValues(Vector loc, double xRotation, double yRotation,
+            int maxDistance, double viewHeight, double checkDistance) {
+        this.maxDistance = maxDistance;
+        this.checkDistance = checkDistance;
+        this.curDistance = 0;
+        xRotation = (xRotation + 90) % 360;
+        yRotation = yRotation * -1;
+
+        double h = (checkDistance * Math.cos(Math.toRadians(yRotation)));
+        
+        offset = new Vector((h * Math.cos(Math.toRadians(xRotation))),
+                            (checkDistance * Math.sin(Math.toRadians(yRotation))),
+                            (h * Math.sin(Math.toRadians(xRotation))));
+
+        targetPosDouble = loc.add(0, viewHeight, 0);
+        targetPos = targetPosDouble.toBlockPoint();
+        prevPos = targetPos;
+    }
+
+    /**
+     * Returns the block at the sight. Returns null if out of range or if no
+     * viable target was found
+     * 
+     * @return Block
+     */
+    public BlockWorldVector getTargetBlock() {
+        while ((getNextBlock() != null)
+                && (world.getBlockType(getCurrentBlock()) == 0));
+        return getCurrentBlock();
+    }
+
+    /**
+     * Returns the block at the sight. Returns null if out of range or if no
+     * viable target was found
+     * 
+     * @return Block
+     */
+    public BlockWorldVector getSolidTargetBlock() {
+        while ((getNextBlock() != null)
+                && BlockType.canPassThrough(world.getBlockType(getCurrentBlock())));
+        return getCurrentBlock();
+    }
+
+    /**
+     * Get next block
+     * 
+     * @return next block position
+     */
+    public BlockWorldVector getNextBlock() {
+        prevPos = targetPos;
+        do {
+            curDistance += checkDistance;
+            
+            targetPosDouble = offset.add(targetPosDouble.getX(),
+                                         targetPosDouble.getY(),
+                                         targetPosDouble.getZ());
+            targetPos = targetPosDouble.toBlockPoint();
+        } while (curDistance <= maxDistance
+                && targetPos.getBlockX() == prevPos.getBlockX()
+                && targetPos.getBlockY() == prevPos.getBlockY()
+                && targetPos.getBlockZ() == prevPos.getBlockZ());
+        
+        if (curDistance > maxDistance) {
+            return null;
+        }
+
+        return new BlockWorldVector(world, targetPos);
+    }
+
+    /**
+     * Returns the current block along the line of vision
+     * 
+     * @return block position
+     */
+    public BlockWorldVector getCurrentBlock() {
+        if (curDistance > maxDistance) {
+            return null;
+        } else {
+            return new BlockWorldVector(world, targetPos);
+        }
+    }
+
+    /**
+     * Returns the previous block in the aimed path
+     * 
+     * @return block position
+     */
+    public BlockWorldVector getPreviousBlock() {
+        return new BlockWorldVector(world, prevPos);
+    }
+}