Add some experimental brush commands.

/br set <shape> <radius> <pattern>
/br deform <shape> <expression>
/br scatter <shape> <density> <generator>
/br apply <shape> <generator>

<shape> can be: cuboid, cyl[inder], sphere

<density> is 0-100

<generator> can be:
forest|tree <type>
item <item>[:<data>] (ONLY WORKS ON FORGE)

Examples:

/br deform cuboid 5 y-=0.2
/br scatter sphere 5 100 minecraft:dye:15

worldedit-core/src/main/java/com/sk89q/worldedit/function/EditContext.java

@@ -0,0 +1,62 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.blocks.BlockID;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.extent.NullExtent;
+import com.sk89q.worldedit.function.pattern.BlockPattern;
+import com.sk89q.worldedit.function.pattern.Pattern;
+import com.sk89q.worldedit.regions.CuboidRegion;
+import com.sk89q.worldedit.regions.Region;
+
+public class EditContext {
+
+    private Extent destination = new NullExtent();
+    private Region region = new CuboidRegion(Vector.ZERO, Vector.ZERO);
+    private Pattern fill = new BlockPattern(new BaseBlock(BlockID.AIR));
+
+    public Extent getDestination() {
+        return destination;
+    }
+
+    public void setDestination(Extent destination) {
+        this.destination = destination;
+    }
+
+    public Region getRegion() {
+        return region;
+    }
+
+    public void setRegion(Region region) {
+        this.region = region;
+    }
+
+    public Pattern getFill() {
+        return fill;
+    }
+
+    public void setFill(Pattern fill) {
+        this.fill = fill;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Deform.java

@@ -0,0 +1,144 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.operation.RunContext;
+import com.sk89q.worldedit.internal.expression.ExpressionException;
+import com.sk89q.worldedit.regions.Region;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public class Deform implements OperationFactory {
+
+    private String expression;
+    private Mode mode = Mode.UNIT_CUBE;
+    private Vector offset = new Vector();
+
+    public Deform(String expression) {
+        checkNotNull(expression, "expression");
+        this.expression = expression;
+    }
+
+    public String getExpression() {
+        return expression;
+    }
+
+    public void setExpression(String expression) {
+        checkNotNull(expression, "expression");
+        this.expression = expression;
+    }
+
+    public Mode getMode() {
+        return mode;
+    }
+
+    public void setMode(Mode mode) {
+        checkNotNull(mode, "mode");
+        this.mode = mode;
+    }
+
+    public Vector getOffset() {
+        return offset;
+    }
+
+    public void setOffset(Vector offset) {
+        checkNotNull(offset, "offset");
+        this.offset = offset;
+    }
+
+    @Override
+    public String toString() {
+        return "deformation of " + expression;
+    }
+
+    @Override
+    public Operation createOperation(final EditContext context) {
+        final Vector zero;
+        Vector unit;
+
+        switch (mode) {
+            case UNIT_CUBE:
+                final Vector min = context.getRegion().getMinimumPoint();
+                final Vector max = context.getRegion().getMaximumPoint();
+
+                zero = max.add(min).multiply(0.5);
+                unit = max.subtract(zero);
+
+                if (unit.getX() == 0) unit = unit.setX(1.0);
+                if (unit.getY() == 0) unit = unit.setY(1.0);
+                if (unit.getZ() == 0) unit = unit.setZ(1.0);
+                break;
+            case RAW_COORD:
+                zero = Vector.ZERO;
+                unit = Vector.ONE;
+                break;
+            case OFFSET:
+            default:
+                zero = offset;
+                unit = Vector.ONE;
+        }
+
+        return new DeformOperation(context.getDestination(), context.getRegion(), zero, unit, expression);
+    }
+
+    private static final class DeformOperation implements Operation {
+        private final Extent destination;
+        private final Region region;
+        private final Vector zero;
+        private final Vector unit;
+        private final String expression;
+
+        private DeformOperation(Extent destination, Region region, Vector zero, Vector unit, String expression) {
+            this.destination = destination;
+            this.region = region;
+            this.zero = zero;
+            this.unit = unit;
+            this.expression = expression;
+        }
+
+        @Override
+        public Operation resume(RunContext run) throws WorldEditException {
+            try {
+                // TODO: Move deformation code
+                ((EditSession) destination).deformRegion(region, zero, unit, expression);
+                return null;
+            } catch (ExpressionException e) {
+                throw new RuntimeException("Failed to execute expression", e); // TODO: Better exception to throw here?
+            }
+        }
+
+        @Override
+        public void cancel() {
+        }
+    }
+
+    public enum Mode {
+        RAW_COORD,
+        OFFSET,
+        UNIT_CUBE
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/OperationFactory.java

@@ -0,0 +1,29 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.operation.Operation;
+
+public interface OperationFactory {
+
+    Operation createOperation(EditContext context);
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/RegionApply.java

@@ -0,0 +1,49 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.google.common.base.Function;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.RegionFunction;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.visitor.RegionVisitor;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public class RegionApply implements OperationFactory {
+
+    private final Function<EditContext, ? extends RegionFunction> regionFunctionFactory;
+
+    public RegionApply(Function<EditContext, ? extends RegionFunction> regionFunctionFactory) {
+        checkNotNull(regionFunctionFactory, "regionFunctionFactory");
+        this.regionFunctionFactory = regionFunctionFactory;
+    }
+
+    @Override
+    public Operation createOperation(EditContext context) {
+        return new RegionVisitor(context.getRegion(), regionFunctionFactory.apply(context));
+    }
+
+    @Override
+    public String toString() {
+        return "set " + regionFunctionFactory;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/RegionReplace.java

@@ -0,0 +1,40 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.block.BlockReplace;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.visitor.RegionVisitor;
+
+public class RegionReplace implements OperationFactory {
+
+    @Override
+    public Operation createOperation(EditContext context) {
+        BlockReplace replace = new BlockReplace(context.getDestination(), context.getFill());
+        return new RegionVisitor(context.getRegion(), replace);
+    }
+
+    @Override
+    public String toString() {
+        return "set blocks";
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Scatter.java

@@ -0,0 +1,60 @@
+/*
+ * 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/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.google.common.base.Function;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.GroundFunction;
+import com.sk89q.worldedit.function.RegionFunction;
+import com.sk89q.worldedit.function.mask.ExistingBlockMask;
+import com.sk89q.worldedit.function.mask.NoiseFilter2D;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.visitor.LayerVisitor;
+import com.sk89q.worldedit.math.noise.RandomNoise;
+import com.sk89q.worldedit.regions.Region;
+
+import static com.sk89q.worldedit.regions.Regions.*;
+
+public class Scatter implements OperationFactory {
+
+    private final Function<EditContext, ? extends RegionFunction> regionFunctionFactory;
+    private final double density;
+
+    public Scatter(Function<EditContext, ? extends RegionFunction> regionFunctionFactory, double density) {
+        this.regionFunctionFactory = regionFunctionFactory;
+        this.density = density;
+        new NoiseFilter2D(new RandomNoise(), density); // Check validity density argument
+    }
+
+    @Override
+    public Operation createOperation(EditContext context) {
+        Region region = context.getRegion();
+        GroundFunction ground = new GroundFunction(new ExistingBlockMask(context.getDestination()), regionFunctionFactory.apply(context));
+        LayerVisitor visitor = new LayerVisitor(asFlatRegion(region), minimumBlockY(region), maximumBlockY(region), ground);
+        visitor.setMask(new NoiseFilter2D(new RandomNoise(), density));
+        return visitor;
+    }
+
+    @Override
+    public String toString() {
+        return "scatter " + regionFunctionFactory;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/generator/ForestGenerator.java

@@ -55,6 +55,10 @@ public class ForestGenerator implements RegionFunction {
         if (t == BlockID.GRASS || t == BlockID.DIRT) {
             treeGenerator.generate(editSession, position.add(0, 1, 0));
             return true;
+        } else if (t == BlockID.LONG_GRASS || t == BlockID.DEAD_BUSH || t == BlockID.RED_FLOWER || t == BlockID.YELLOW_FLOWER) { // TODO: This list needs to be moved
+            editSession.setBlock(position, new BaseBlock(0));
+            treeGenerator.generate(editSession, position);
+            return true;
         } else if (t == BlockID.SNOW) {
             editSession.setBlock(position, new BaseBlock(BlockID.AIR));
             return false;