Various

Optimize spline
Translate spline brush
Add various new patterns (#nox #noy #noz #rel `[stone,wood,blah`
#existing
Can now use percentages with patterns, not just blocks e.g.
50%#clipboard,50%stone
Add resettable patterns

core/src/main/java/com/boydti/fawe/Fawe.java

@@ -41,6 +41,7 @@ import com.sk89q.worldedit.command.tool.RecursivePickaxe;
 import com.sk89q.worldedit.command.tool.brush.GravityBrush;
 import com.sk89q.worldedit.event.extent.EditSessionEvent;
 import com.sk89q.worldedit.extension.factory.DefaultMaskParser;
+import com.sk89q.worldedit.extension.factory.HashTagPatternParser;
 import com.sk89q.worldedit.extension.platform.CommandManager;
 import com.sk89q.worldedit.extension.platform.PlatformManager;
 import com.sk89q.worldedit.extent.AbstractDelegateExtent;
@@ -71,6 +72,7 @@ import com.sk89q.worldedit.function.visitor.RecursiveVisitor;
 import com.sk89q.worldedit.function.visitor.RegionVisitor;
 import com.sk89q.worldedit.history.change.EntityCreate;
 import com.sk89q.worldedit.history.change.EntityRemove;
+import com.sk89q.worldedit.math.interpolation.KochanekBartelsInterpolation;
 import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.regions.selector.CuboidRegionSelector;
 import com.sk89q.worldedit.session.SessionManager;
@@ -386,6 +388,7 @@ public class Fawe {
             Patterns.inject(); // Optimizations (reduce object creation)
             RandomPattern.inject(); // Optimizations
             ClipboardPattern.inject(); // Optimizations
+            HashTagPatternParser.inject(); // Add new patterns
             // Mask
             BlockMask.inject(); // Optimizations
             SolidBlockMask.inject(); // Optimizations
@@ -403,6 +406,8 @@ public class Fawe {
             // NBT
             NBTInputStream.inject(); // Add actual streaming + Optimizations + New methods
             NBTOutputStream.inject(); // New methods
+            // Math
+            KochanekBartelsInterpolation.inject(); // Optimizations
             try {
                 CommandManager.inject(); // Async commands
                 PlatformManager.inject(); // Async brushes / tools

core/src/main/java/com/boydti/fawe/config/BBC.java

@@ -93,7 +93,10 @@ public enum BBC {
     BRUSH_SMOOTH("Smooth brush equipped (%s0 x %s1 using %s2).", "WorldEdit.Brush"),
     BRUSH_SPHERE("Sphere brush shape equipped (%s0).", "WorldEdit.Brush"),
     BRUSH_LINE("Line brush shape equipped (%s0).", "WorldEdit.Brush"),
-    BRUSH_SPLINE("Line brush shape equipped (%s0). Right click to select points, left click to execute.", "WorldEdit.Brush"),
+    BRUSH_SPLINE("Line brush shape equipped (%s0). Right click an end to add a shape", "WorldEdit.Brush"),
+    BRUSH_SPLINE_PRIMARY("Added position, left click to spline them together!", "WorldEdit.Brush"),
+    BRUSH_SPLINE_SECONDARY_ERROR("Not enough positions set!", "WorldEdit.Brush"),
+    BRUSH_SPLINE_SECONDARY("Created spline", "WorldEdit.Brush"),
     BRUSH_BLEND_BALL("Blend ball brush equipped (%s0).", "WorldEdit.Brush"),
     BRUSH_ERODE("Erode brush equipped (%s0).", "WorldEdit.Brush"),
     BRUSH_PASTE_NONE("Nothing to paste", "WorldEdit.Brush"),

core/src/main/java/com/boydti/fawe/object/brush/SplineBrush.java

@@ -68,12 +68,12 @@ public class SplineBrush implements DoubleActionBrush {
                     numSplines = points.size();
                 }
                 this.positionSets.add(points);
-                player.print("Added position, right click to spline them together!");
+                BBC.BRUSH_SPLINE_PRIMARY.send(player);
                 break;
             }
             case SECONDARY: {
                 if (positionSets.size() < 2) {
-                    player.print("Not enough positions set!");
+                    BBC.BRUSH_SPLINE_SECONDARY_ERROR.send(player);
                     return;
                 }
                 List<Vector> centroids = new ArrayList<>();
@@ -112,7 +112,7 @@ public class SplineBrush implements DoubleActionBrush {
                     }
                     editSession.drawSpline(Patterns.wrap(pattern), currentSpline, 0, 0, 0, 10, 0, true);
                 }
-                player.print("Created spline");
+                BBC.BRUSH_SPLINE_SECONDARY.send(player);
                 positionSets.clear();
                 numSplines = 0;
                 break;

core/src/main/java/com/boydti/fawe/object/pattern/ExistingPattern.java

@@ -0,0 +1,19 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+
+public class ExistingPattern extends AbstractPattern {
+    private final Extent extent;
+
+    public ExistingPattern(Extent extent) {
+        this.extent = extent;
+    }
+
+    @Override
+    public BaseBlock apply(Vector position) {
+        return extent.getBlock(position);
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/LinearBlockPattern.java

@@ -0,0 +1,23 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+
+public class LinearBlockPattern extends AbstractPattern {
+
+    private final BaseBlock[] blocks;
+    private int index;
+
+    public LinearBlockPattern(BaseBlock[] blocks) {
+        this.blocks = blocks;
+    }
+
+    @Override
+    public BaseBlock apply(Vector position) {
+        if (index == blocks.length) {
+            index = 0;
+        }
+        return blocks[index++];
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/NoXPattern.java

@@ -0,0 +1,24 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+
+public class NoXPattern extends AbstractPattern {
+
+    private final Pattern pattern;
+
+    public NoXPattern(Pattern pattern) {
+        this.pattern = pattern;
+    }
+
+    private Vector mutable = new Vector();
+
+    @Override
+    public BaseBlock apply(Vector pos) {
+        mutable.y = pos.y;
+        mutable.z = pos.z;
+        return pattern.apply(mutable);
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/NoYPattern.java

@@ -0,0 +1,24 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+
+public class NoYPattern extends AbstractPattern {
+
+    private final Pattern pattern;
+
+    public NoYPattern(Pattern pattern) {
+        this.pattern = pattern;
+    }
+
+    private Vector mutable = new Vector();
+
+    @Override
+    public BaseBlock apply(Vector pos) {
+        mutable.x = pos.x;
+        mutable.z = pos.z;
+        return pattern.apply(mutable);
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/NoZPattern.java

@@ -0,0 +1,24 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+
+public class NoZPattern extends AbstractPattern {
+
+    private final Pattern pattern;
+
+    public NoZPattern(Pattern pattern) {
+        this.pattern = pattern;
+    }
+
+    private Vector mutable = new Vector();
+
+    @Override
+    public BaseBlock apply(Vector pos) {
+        mutable.x = pos.x;
+        mutable.y = pos.y;
+        return pattern.apply(mutable);
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/PatternTraverser.java

@@ -0,0 +1,58 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import java.lang.reflect.Field;
+import java.util.Collection;
+
+public class PatternTraverser {
+    private final Object pattern;
+
+    public PatternTraverser(Object start) {
+        this.pattern = start;
+    }
+
+    public void reset(Extent newExtent) {
+        reset(pattern, newExtent);
+    }
+
+    private void reset(Object pattern, Extent newExtent) {
+        if (pattern == null) {
+            return;
+        }
+        if (pattern instanceof ResettablePattern) {
+            ((ResettablePattern) pattern).reset();
+        }
+        Class<?> current = pattern.getClass();
+        while(current.getSuperclass() != null) {
+            if (newExtent != null) {
+                try {
+                    Field field = current.getDeclaredField("extent");
+                    field.setAccessible(true);
+                    field.set(pattern, newExtent);
+                } catch (NoSuchFieldException | IllegalAccessException ignore) {}
+            }
+            try {
+                Field field = current.getDeclaredField("pattern");
+                field.setAccessible(true);
+                Pattern next = (Pattern) field.get(pattern);
+                reset(next, newExtent);
+            } catch (NoSuchFieldException | IllegalAccessException ignore) {}
+            try {
+                Field field = current.getDeclaredField("material");
+                field.setAccessible(true);
+                Pattern next = (Pattern) field.get(pattern);
+                reset(next, newExtent);
+            } catch (NoSuchFieldException | IllegalAccessException ignore) {}
+            try {
+                Field field = current.getDeclaredField("patterns");
+                field.setAccessible(true);
+                Collection<Pattern> patterns = (Collection<Pattern>) field.get(pattern);
+                for (Pattern next : patterns) {
+                    reset(next, newExtent);
+                }
+            } catch (NoSuchFieldException | IllegalAccessException ignore) {}
+            current = current.getSuperclass();
+        }
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/RelativePattern.java

@@ -0,0 +1,34 @@
+package com.boydti.fawe.object.pattern;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.function.pattern.AbstractPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+
+public class RelativePattern extends AbstractPattern implements ResettablePattern {
+
+    private final Pattern pattern;
+
+    public RelativePattern(Pattern pattern) {
+        this.pattern = pattern;
+    }
+
+    private Vector origin;
+    private Vector mutable = new Vector();
+
+    @Override
+    public BaseBlock apply(Vector pos) {
+        if (origin == null) {
+            origin = new Vector(pos);
+        }
+        mutable.x = pos.x - origin.x;
+        mutable.y = pos.y - origin.y;
+        mutable.z = pos.z - origin.z;
+        return pattern.apply(mutable);
+    }
+
+    @Override
+    public void reset() {
+        origin = null;
+    }
+}

core/src/main/java/com/boydti/fawe/object/pattern/ResettablePattern.java

@@ -0,0 +1,5 @@
+package com.boydti.fawe.object.pattern;
+
+public interface ResettablePattern {
+    void reset();
+}

core/src/main/java/com/boydti/fawe/util/MaskTraverser.java

@@ -18,6 +18,9 @@ public class MaskTraverser {
     }
 
     private void reset(Mask mask, Extent newExtent) {
+        if (mask == null) {
+            return;
+        }
         if (mask instanceof ResettableMask) {
             ((ResettableMask) mask).reset();
         }

core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -2700,14 +2700,20 @@ public class EditSession extends AbstractWorld implements HasFaweQueue {
             final int tipx = (int) Math.round(tipv.getX());
             final int tipy = (int) Math.round(tipv.getY());
             final int tipz = (int) Math.round(tipv.getZ());
-            vset.add(new Vector(tipx, tipy, tipz));
+            if (radius == 0) {
+                setBlock(tipx, tipy, tipz, pattern.next(tipx, tipy, tipz));
+            }  else {
+                vset.add(new Vector(tipx, tipy, tipz));
+            }
         }
-
-        vset = this.getBallooned(vset, radius);
-        if (!filled) {
-            vset = this.getHollowed(vset);
+        if (radius != 0) {
+            vset = this.getBallooned(vset, radius);
+            if (!filled) {
+                vset = this.getHollowed(vset);
+            }
+            return this.setBlocks(vset, pattern);
         }
-        return this.setBlocks(vset, pattern);
+        return changes;
     }
 
     private double hypot(final double... pars) {

core/src/main/java/com/sk89q/worldedit/extension/factory/HashTagPatternParser.java

@@ -0,0 +1,123 @@
+package com.sk89q.worldedit.extension.factory;
+
+import com.boydti.fawe.object.pattern.ExistingPattern;
+import com.boydti.fawe.object.pattern.LinearBlockPattern;
+import com.boydti.fawe.object.pattern.NoXPattern;
+import com.boydti.fawe.object.pattern.NoYPattern;
+import com.boydti.fawe.object.pattern.NoZPattern;
+import com.boydti.fawe.object.pattern.RelativePattern;
+import com.sk89q.worldedit.EmptyClipboardException;
+import com.sk89q.worldedit.LocalSession;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.extension.input.InputParseException;
+import com.sk89q.worldedit.extension.input.ParserContext;
+import com.sk89q.worldedit.extent.clipboard.Clipboard;
+import com.sk89q.worldedit.function.pattern.BlockPattern;
+import com.sk89q.worldedit.function.pattern.ClipboardPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import com.sk89q.worldedit.function.pattern.RandomPattern;
+import com.sk89q.worldedit.internal.registry.InputParser;
+import com.sk89q.worldedit.session.ClipboardHolder;
+import java.util.ArrayList;
+
+public class HashTagPatternParser extends InputParser<Pattern> {
+
+    public HashTagPatternParser(WorldEdit worldEdit) {
+        super(worldEdit);
+    }
+
+    @Override
+    public Pattern parseFromInput(String input, ParserContext context) throws InputParseException {
+        switch (input.toLowerCase().charAt(0)) {
+            case '#': {
+                switch (input) {
+                    case "#existing": {
+                        return new ExistingPattern(context.requireExtent());
+                    }
+                    case "#clipboard":
+                    case "#copy": {
+                        LocalSession session = context.requireSession();
+                        if (session != null) {
+                            try {
+                                ClipboardHolder holder = session.getClipboard();
+                                Clipboard clipboard = holder.getClipboard();
+                                return new ClipboardPattern(clipboard);
+                            } catch (EmptyClipboardException e) {
+                                throw new InputParseException("To use #clipboard, please first copy something to your clipboard");
+                            }
+                        } else {
+                            throw new InputParseException("No session is available, so no clipboard is available");
+                        }
+                    }
+                }
+                String[] split2 = input.split(":");
+                if (split2.length > 1) {
+                    switch (split2[0]) {
+                        case "#relative":
+                        case "#rel": {
+                            String rest = input.substring(5);
+                            return new RelativePattern(parseFromInput(rest, context));
+                        }
+                        case "#nox": {
+                            String rest = input.substring(5);
+                            return new NoXPattern(parseFromInput(rest, context));
+                        }
+                        case "#noy": {
+                            String rest = input.substring(5);
+                            return new NoYPattern(parseFromInput(rest, context));
+                        }
+                        case "#noz": {
+                            String rest = input.substring(5);
+                            return new NoZPattern(parseFromInput(rest, context));
+                        }
+                    }
+                }
+                throw new InputParseException("Invalid, see: https://github.com/boy0001/FastAsyncWorldedit/wiki/WorldEdit-and-FAWE-patterns");
+            }
+            case '[': {
+                ArrayList<BaseBlock> blocks = new ArrayList<>();
+                for (String token : input.substring(1).split(",")) {
+                    BlockFactory blockRegistry = worldEdit.getBlockFactory();
+                    BaseBlock block = blockRegistry.parseFromInput(token, context);
+                    blocks.add(block);
+                }
+                if (blocks.isEmpty()) {
+                    throw new InputParseException("No blocks provided for linear pattern e.g. [stone,wood");
+                }
+                return new LinearBlockPattern(blocks.toArray(new BaseBlock[blocks.size()]));
+            }
+            default:
+                String[] items = input.split(",");
+                if (items.length == 1) {
+                    return new BlockPattern(worldEdit.getBlockFactory().parseFromInput(items[0], context));
+                }
+                BlockFactory blockRegistry = worldEdit.getBlockFactory();
+                RandomPattern randomPattern = new RandomPattern();
+                for (String token : input.split(",")) {
+                    Pattern pattern;
+                    double chance;
+                    // Parse special percentage syntax
+                    if (token.matches("[0-9]+(\\.[0-9]*)?%.*")) {
+                        String[] p = token.split("%");
+                        if (p.length < 2) {
+                            throw new InputParseException("Missing the pattern after the % symbol for '" + input + "'");
+                        } else {
+                            chance = Double.parseDouble(p[0]);
+                            pattern = parseFromInput(p[1], context);
+                        }
+                    } else {
+                        chance = 1;
+                        pattern = parseFromInput(token, context);
+                    }
+                    randomPattern.add(pattern, chance);
+                }
+                return randomPattern;
+
+        }
+    }
+
+    public static Class<?> inject() {
+        return HashTagPatternParser.class;
+    }
+}

core/src/main/java/com/sk89q/worldedit/extension/platform/PlatformManager.java

@@ -22,6 +22,7 @@ package com.sk89q.worldedit.extension.platform;
 import com.boydti.fawe.config.BBC;
 import com.boydti.fawe.object.FawePlayer;
 import com.boydti.fawe.object.exception.FaweException;
+import com.boydti.fawe.object.pattern.PatternTraverser;
 import com.boydti.fawe.util.MainUtil;
 import com.boydti.fawe.wrappers.PlayerWrapper;
 import com.sk89q.worldedit.LocalConfiguration;
@@ -330,6 +331,11 @@ public class PlatformManager {
         }
     }
 
+    private <T extends Tool> T reset(T tool) {
+        new PatternTraverser(tool).reset(null);
+        return tool;
+    }
+
     @SuppressWarnings("deprecation")
     @Subscribe
     public void handleBlockInteract(BlockInteractEvent event) {
@@ -371,7 +377,7 @@ public class PlatformManager {
                             fp.runAction(new Runnable() {
                                 @Override
                                 public void run() {
-                                    superPickaxe.actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
+                                    reset(superPickaxe).actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
                                 }
                             }, true, true);
                             event.setCancelled(true);
@@ -385,7 +391,7 @@ public class PlatformManager {
                             fp.runAction(new Runnable() {
                                 @Override
                                 public void run() {
-                                    ((DoubleActionBlockTool) tool).actSecondary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
+                                    reset(((DoubleActionBlockTool) tool)).actSecondary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
                                 }
                             }, true, true);
                             event.setCancelled(true);
@@ -417,7 +423,7 @@ public class PlatformManager {
                             fp.runAction(new Runnable() {
                                 @Override
                                 public void run() {
-                                    ((BlockTool) tool).actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
+                                    reset((BlockTool) tool).actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session, location);
                                 }
                             }, true, true);
                             event.setCancelled(true);
@@ -443,6 +449,7 @@ public class PlatformManager {
         // Create a proxy actor with a potentially different world for
         // making changes to the world
         final Player player = PlayerWrapper.wrap(createProxyActor(event.getPlayer()));
+
         try {
             switch (event.getInputType()) {
                 case PRIMARY: {
@@ -475,7 +482,7 @@ public class PlatformManager {
                             fp.runAsyncIfFree(new Runnable() {
                                 @Override
                                 public void run() {
-                                    ((DoubleActionTraceTool) tool).actSecondary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session);
+                                    reset((DoubleActionTraceTool) tool).actSecondary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session);
                                 }
                             });
                             event.setCancelled(true);
@@ -513,7 +520,7 @@ public class PlatformManager {
                             fp.runAsyncIfFree(new Runnable() {
                                 @Override
                                 public void run() {
-                                    ((TraceTool) tool).actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session);
+                                    reset((TraceTool) tool).actPrimary(queryCapability(Capability.WORLD_EDITING), getConfiguration(), player, session);
                                 }
                             });
                             event.setCancelled(true);

core/src/main/java/com/sk89q/worldedit/function/pattern/ClipboardPattern.java

@@ -12,7 +12,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 public class ClipboardPattern extends AbstractPattern {
 
     private final Clipboard clipboard;
-    private final Vector size;
+    private final int sx, sy, sz;
     private final Vector min;
 
     /**
@@ -23,7 +23,10 @@ public class ClipboardPattern extends AbstractPattern {
     public ClipboardPattern(Clipboard clipboard) {
         checkNotNull(clipboard);
         this.clipboard = clipboard;
-        this.size = clipboard.getMaximumPoint().subtract(clipboard.getMinimumPoint()).add(1, 1, 1);
+        Vector size = clipboard.getMaximumPoint().subtract(clipboard.getMinimumPoint()).add(1, 1, 1);
+        this.sx = size.getBlockX();
+        this.sy = size.getBlockY();
+        this.sz = size.getBlockZ();
         this.min = clipboard.getMinimumPoint();
     }
 
@@ -31,9 +34,12 @@ public class ClipboardPattern extends AbstractPattern {
 
     @Override
     public BaseBlock apply(Vector position) {
-        int xp = Math.abs(position.getBlockX()) % size.getBlockX();
-        int yp = Math.abs(position.getBlockY()) % size.getBlockY();
-        int zp = Math.abs(position.getBlockZ()) % size.getBlockZ();
+        int xp = position.getBlockX() % sx;
+        int yp = position.getBlockY() % sy;
+        int zp = position.getBlockZ() % sz;
+        if (xp < 0) xp += sx;
+        if (yp < 0) yp += sy;
+        if (zp < 0) zp += sz;
         mutable.x = min.x + xp;
         mutable.y = min.y + yp;
         mutable.z = min.z + zp;

core/src/main/java/com/sk89q/worldedit/function/pattern/RandomPattern.java

@@ -5,6 +5,7 @@ import com.sk89q.worldedit.Vector;
 import com.sk89q.worldedit.blocks.BaseBlock;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -16,6 +17,7 @@ public class RandomPattern extends AbstractPattern {
 
     private Map<Pattern, Double> weights = new HashMap<>();
     private RandomCollection<Pattern> collection;
+    private Set<Pattern> patterns;
 
     /**
      * Add a pattern to the weight list of patterns.
@@ -30,6 +32,7 @@ public class RandomPattern extends AbstractPattern {
         checkNotNull(pattern);
         weights.put(pattern, chance);
         collection = RandomCollection.of(weights);
+        this.patterns = weights.keySet();
     }
 
     @Override

core/src/main/java/com/sk89q/worldedit/math/interpolation/KochanekBartelsInterpolation.java

@@ -0,0 +1,262 @@
+/*
+ * 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/>.
+ */
+
+// $Id$
+
+package com.sk89q.worldedit.math.interpolation;
+
+import com.sk89q.worldedit.Vector;
+
+import java.util.Collections;
+import java.util.List;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * A Kochanek-Bartels interpolation; continuous in the 2nd derivative.
+ *
+ * <p>Supports {@link Node#tension tension}, {@link Node#bias bias} and
+ * {@link Node#continuity continuity} parameters per {@link Node}.</p>
+ */
+public class KochanekBartelsInterpolation implements Interpolation {
+
+    private List<Node> nodes;
+    private Vector[] coeffA;
+    private Vector[] coeffB;
+    private Vector[] coeffC;
+    private Vector[] coeffD;
+    private double scaling;
+
+    public KochanekBartelsInterpolation() {
+        setNodes(Collections.<Node>emptyList());
+    }
+
+    @Override
+    public void setNodes(List<Node> nodes) {
+        checkNotNull(nodes);
+
+        this.nodes = nodes;
+        recalc();
+    }
+
+    private void recalc() {
+        final int nNodes = nodes.size();
+        coeffA = new Vector[nNodes];
+        coeffB = new Vector[nNodes];
+        coeffC = new Vector[nNodes];
+        coeffD = new Vector[nNodes];
+
+        if (nNodes == 0)
+            return;
+
+        Node nodeB = nodes.get(0);
+        double tensionB = nodeB.getTension();
+        double biasB = nodeB.getBias();
+        double continuityB = nodeB.getContinuity();
+        for (int i = 0; i < nNodes; ++i) {
+            final double tensionA = tensionB;
+            final double biasA = biasB;
+            final double continuityA = continuityB;
+
+            if (i + 1 < nNodes) {
+                nodeB = nodes.get(i + 1);
+                tensionB = nodeB.getTension();
+                biasB = nodeB.getBias();
+                continuityB = nodeB.getContinuity();
+            }
+
+            // Kochanek-Bartels tangent coefficients
+            final double ta = (1-tensionA)*(1+biasA)*(1+continuityA)/2; // Factor for lhs of d[i]
+            final double tb = (1-tensionA)*(1-biasA)*(1-continuityA)/2; // Factor for rhs of d[i]
+            final double tc = (1-tensionB)*(1+biasB)*(1-continuityB)/2; // Factor for lhs of d[i+1]
+            final double td = (1-tensionB)*(1-biasB)*(1+continuityB)/2; // Factor for rhs of d[i+1]
+
+            coeffA[i] = linearCombination(i,  -ta,    ta-  tb-tc+2,    tb+tc-td-2,  td);
+            coeffB[i] = linearCombination(i, 2*ta, -2*ta+2*tb+tc-3, -2*tb-tc+td+3, -td);
+            coeffC[i] = linearCombination(i,  -ta,    ta-  tb     ,    tb        ,   0);
+            //coeffD[i] = linearCombination(i,    0,               1,             0,   0);
+            coeffD[i] = retrieve(i); // this is an optimization
+        }
+
+        scaling = nodes.size() - 1;
+    }
+
+    /**
+     * Returns the linear combination of the given coefficients with the nodes adjacent to baseIndex.
+     *
+     * @param baseIndex node index
+     * @param f1 coefficient for baseIndex-1
+     * @param f2 coefficient for baseIndex
+     * @param f3 coefficient for baseIndex+1
+     * @param f4 coefficient for baseIndex+2
+     * @return linear combination of nodes[n-1..n+2] with f1..4
+     */
+    private Vector linearCombination(int baseIndex, double f1, double f2, double f3, double f4) {
+        final Vector r1 = retrieve(baseIndex - 1).multiply(f1);
+        final Vector r2 = retrieve(baseIndex    ).multiply(f2);
+        final Vector r3 = retrieve(baseIndex + 1).multiply(f3);
+        final Vector r4 = retrieve(baseIndex + 2).multiply(f4);
+
+        return r1.add(r2).add(r3).add(r4);
+    }
+
+    /**
+     * Retrieves a node. Indexes are clamped to the valid range.
+     *
+     * @param index node index to retrieve
+     * @return nodes[clamp(0, nodes.length-1)]
+     */
+    private Vector retrieve(int index) {
+        if (index < 0)
+            return fastRetrieve(0);
+
+        if (index >= nodes.size())
+            return fastRetrieve(nodes.size()-1);
+
+        return fastRetrieve(index);
+    }
+
+    private Vector fastRetrieve(int index) {
+        return nodes.get(index).getPosition();
+    }
+
+    private Vector mutable = new Vector();
+
+    @Override
+    public Vector getPosition(double position) {
+        if (coeffA == null)
+            throw new IllegalStateException("Must call setNodes first.");
+
+        if (position > 1)
+            return null;
+
+        position *= scaling;
+
+        final int index = (int) Math.floor(position);
+        final double remainder = position - index;
+
+        final Vector a = coeffA[index];
+        final Vector b = coeffB[index];
+        final Vector c = coeffC[index];
+        final Vector d = coeffD[index];
+
+        double r2 = remainder * remainder;
+        double r3 = r2 * remainder;
+        mutable.x = a.x * r3 + b.x * r2 + c.x * remainder + d.x;
+        mutable.y = a.y * r3 + b.y * r2 + c.y * remainder + d.y;
+        mutable.z = a.z * r3 + b.z * r2 + c.z * remainder + d.z;
+        return mutable;
+    }
+
+    @Override
+    public Vector get1stDerivative(double position) {
+        if (coeffA == null)
+            throw new IllegalStateException("Must call setNodes first.");
+
+        if (position > 1)
+            return null;
+
+        position *= scaling;
+
+        final int index = (int) Math.floor(position);
+        //final double remainder = position - index;
+
+        final Vector a = coeffA[index];
+        final Vector b = coeffB[index];
+        final Vector c = coeffC[index];
+
+        return a.multiply(1.5*position - 3.0*index).add(b).multiply(2.0*position).add(a.multiply(1.5*index).subtract(b).multiply(2.0*index)).add(c).multiply(scaling);
+    }
+
+    @Override
+    public double arcLength(double positionA, double positionB) {
+        if (coeffA == null)
+            throw new IllegalStateException("Must call setNodes first.");
+
+        if (positionA > positionB)
+            return arcLength(positionB, positionA);
+
+        positionA *= scaling;
+        positionB *= scaling;
+
+        final int indexA = (int) Math.floor(positionA);
+        final double remainderA = positionA - indexA;
+
+        final int indexB = (int) Math.floor(positionB);
+        final double remainderB = positionB - indexB;
+
+        return arcLengthRecursive(indexA, remainderA, indexB, remainderB);
+    }
+
+    /**
+     * Assumes a < b
+     */
+    private double arcLengthRecursive(int indexLeft, double remainderLeft, int indexRight, double remainderRight) {
+        switch (indexRight - indexLeft) {
+            case 0:
+                return arcLengthRecursive(indexLeft, remainderLeft, remainderRight);
+
+            case 1:
+                // This case is merely a speed-up for a very common case
+                return
+                        arcLengthRecursive(indexLeft, remainderLeft, 1.0) +
+                                arcLengthRecursive(indexRight, 0.0, remainderRight);
+
+            default:
+                return
+                        arcLengthRecursive(indexLeft, remainderLeft, indexRight - 1, 1.0) +
+                                arcLengthRecursive(indexRight, 0.0, remainderRight);
+        }
+    }
+
+    private double arcLengthRecursive(int index, double remainderLeft, double remainderRight) {
+        final Vector a = coeffA[index].multiply(3.0);
+        final Vector b = coeffB[index].multiply(2.0);
+        final Vector c = coeffC[index];
+
+        final int nPoints = 8;
+
+        double accum = a.multiply(remainderLeft).add(b).multiply(remainderLeft).add(c).length() / 2.0;
+        for (int i = 1; i < nPoints-1; ++i) {
+            double t = ((double) i) / nPoints;
+            t = (remainderRight-remainderLeft)*t + remainderLeft;
+            accum += a.multiply(t).add(b).multiply(t).add(c).length();
+        }
+
+        accum += a.multiply(remainderRight).add(b).multiply(remainderRight).add(c).length() / 2.0;
+        return accum * (remainderRight - remainderLeft) / nPoints;
+    }
+
+    @Override
+    public int getSegment(double position) {
+        if (coeffA == null)
+            throw new IllegalStateException("Must call setNodes first.");
+
+        if (position > 1)
+            return Integer.MAX_VALUE;
+
+        position *= scaling;
+
+        return (int) Math.floor(position);
+    }
+
+    public static Class<?> inject() {
+        return KochanekBartelsInterpolation.class;
+    }
+}