libopenvdb-dev 2.1.0-1ubuntu1 / usr / include / openvdb / tree / LeafNode.h

///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2012-2013 DreamWorks Animation LLC
//
// All rights reserved. This software is distributed under the
// Mozilla Public License 2.0 ( http://www.mozilla.org/MPL/2.0/ )
//
// Redistributions of source code must retain the above copyright
// and license notice and the following restrictions and disclaimer.
//
// *     Neither the name of DreamWorks Animation nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// IN NO EVENT SHALL THE COPYRIGHT HOLDERS' AND CONTRIBUTORS' AGGREGATE
// LIABILITY FOR ALL CLAIMS REGARDLESS OF THEIR BASIS EXCEED US$250.00.
//
///////////////////////////////////////////////////////////////////////////

#ifndef OPENVDB_TREE_LEAFNODE_HAS_BEEN_INCLUDED
#define OPENVDB_TREE_LEAFNODE_HAS_BEEN_INCLUDED

#include <iostream>
#include <algorithm> // for std::swap
#include <cstring> // for std::memcpy()
#include <boost/shared_ptr.hpp>
#include <boost/static_assert.hpp>
#include <boost/bind.hpp>
#include <tbb/blocked_range.h>
#include <tbb/parallel_for.h>
#include <openvdb/Types.h>
#include <openvdb/util/NodeMasks.h>
#include <openvdb/io/Compression.h> // for io::readData(), etc.
#include "Iterator.h"
#include "Util.h"


class TestLeaf;
template<typename> class TestLeafIO;

namespace openvdb {
OPENVDB_USE_VERSION_NAMESPACE
namespace OPENVDB_VERSION_NAME {
namespace tree {

/// @brief Templated block class to hold specific data types and a fixed
/// number of values determined by Log2Dim. The actual coordinate
/// dimension of the block is 2^Log2Dim, i.e. Log2Dim=3 corresponds to
/// a LeafNode that spans a 8^3 block.
template<typename T, Index Log2Dim>
class LeafNode
{
public:
    typedef T                            ValueType;
    typedef LeafNode<ValueType, Log2Dim> LeafNodeType;
    typedef boost::shared_ptr<LeafNode>  Ptr;
    typedef util::NodeMask<Log2Dim>      NodeMaskType;

    static const Index
        LOG2DIM     = Log2Dim,      // needed by parent nodes
        TOTAL       = Log2Dim,      // needed by parent nodes
        DIM         = 1 << TOTAL,   // dimension along one coordinate direction
        NUM_VALUES  = 1 << 3 * Log2Dim,
        NUM_VOXELS  = NUM_VALUES,   // total number of voxels represented by this node
        SIZE        = NUM_VALUES,
        LEVEL       = 0;            // level 0 = leaf

    /// @brief ValueConverter<T>::Type is the type of a LeafNode having the same
    /// child hierarchy and dimensions as this node but a different value type, T.
    template<typename OtherValueType>
    struct ValueConverter {
        typedef LeafNode<OtherValueType, Log2Dim> Type;
    };

    /// @brief Stores the actual values in the LeafNode. Its dimension
    /// it fixed to 2^(3*Log2Dim)
    class Buffer
    {
    public:
        /// @brief Empty default constructor
        Buffer(): mData(new ValueType[SIZE]) {}
        /// @brief Constructs a buffer populated with the specified value
        Buffer(const ValueType& val) :  mData(new ValueType[SIZE]) { this->fill(val); }
        /// @brief Copy constructor
        Buffer(const Buffer& other)   : mData(new ValueType[SIZE]) { *this = other; }
        /// @brief Destructor
        ~Buffer() { delete [] mData; }
        /// @brief Populates the buffer with a constant value
        void fill(const ValueType& val)
        {
            ValueType* target = mData;
            Index n = SIZE;
            while (n--) *target++ = val;
        }
        /// Return a const reference to the i'th element of the Buffer
        const ValueType& getValue(Index i) const { assert(i < SIZE); return mData[i]; }
        /// Return a const reference to the i'th element of the Buffer
        const ValueType& operator[](Index i) const { return this->getValue(i); }
        /// Set the i'th value of the Buffer to the specified value
        void setValue(Index i, const ValueType& val) { assert(i < SIZE); mData[i] = val; }
        /// Assigns the values in the other Buffer to this Buffer
        Buffer& operator=(const Buffer& other)
        {
            ValueType* target = mData;
            const ValueType* source = other.mData;
            Index n = SIZE;
            while (n--) *target++ = *source++;
            return *this;
        }
        /// Return true if the values in the other buffer exactly
        /// equates the values in this buffer
        bool operator==(const Buffer& other) const
        {
            const ValueType* target = mData;
            const ValueType* source = other.mData;
            Index n = SIZE;
            while (n && math::isExactlyEqual(*target++, *source++)) --n;
            return n == 0;
        }
        /// Return true if any of the values in the other buffer do
        /// not exactly equate the values in this buffer
        bool operator!=(const Buffer& other) const { return !(other == *this); }
        /// Replace the values in this Buffer with the values in the other Buffer
        void swap(Buffer& other)
        {
            ValueType* tmp = mData;
            mData = other.mData;
            other.mData = tmp;
        }
        /// Return the memory-footprint of this Buffer in units of bytes
        static Index memUsage() { return sizeof(ValueType*) + SIZE * sizeof(ValueType); }
        /// Return the number of values represented in this Buffer
        static Index size() { return SIZE; }

    private:
        /// This direct access method is private since it makes
        /// assumptions about the implementations of the memory layout.
        ValueType& operator[](Index i) { assert(i < SIZE); return mData[i]; }

        friend class ::TestLeaf;
        // Allow the parent LeafNode to access this Buffer's data pointer.
        friend class LeafNode;

        ValueType* mData;
    }; // class Buffer


    /// Default constructor
    LeafNode();

    /// @brief Constructor
    /// @param coords  the grid index coordinates of a voxel
    /// @param value   a value with which to fill the buffer
    /// @param active  the active state to which to initialize all voxels
    explicit LeafNode(const Coord& coords,
                      const ValueType& value = zeroVal<ValueType>(),
                      bool active = false);

    /// Deep copy constructor
    LeafNode(const LeafNode&);

    /// Topology copy constructor
    template<typename OtherValueType>
    LeafNode(const LeafNode<OtherValueType, Log2Dim>& other,
             const ValueType& offValue, const ValueType& onValue, TopologyCopy);

    /// Topology copy constructor
    template<typename OtherValueType>
    LeafNode(const LeafNode<OtherValueType, Log2Dim>& other,
             const ValueType& background, TopologyCopy);

    /// Destructor.
    ~LeafNode();

    //
    // Statistics
    //
    /// Return log2 of the dimension of this LeafNode, e.g. 3 if dimensions are 8^3
    static Index log2dim() { return Log2Dim; }
    /// Return the number of voxels in each coordinate dimension.
    static Index dim() { return DIM; }
    /// Return the total number of voxels represented by this LeafNode
    static Index size() { return SIZE; }
    /// Return the total number of voxels represented by this LeafNode
    static Index numValues() { return SIZE; }
    /// Return the level of this node, which by definition is zero for LeafNodes
    static Index getLevel() { return LEVEL; }
    /// Append the Log2Dim of this LeafNode to the specified vector
    static void getNodeLog2Dims(std::vector<Index>& dims) { dims.push_back(Log2Dim); }
    /// Return the dimension of child nodes of this LeafNode, which is one for voxels.
    static Index getChildDim() { return 1; }
    /// Return the leaf count for this node, which is one.
    static Index32 leafCount() { return 1; }
    /// Return the non-leaf count for this node, which is zero.
    static Index32 nonLeafCount() { return 0; }

    /// Return the number of voxels marked On.
    Index64 onVoxelCount() const { return mValueMask.countOn(); }
    /// Return the number of voxels marked Off.
    Index64 offVoxelCount() const { return mValueMask.countOff(); }
    Index64 onLeafVoxelCount() const { return onVoxelCount(); }
    Index64 offLeafVoxelCount() const { return offVoxelCount(); }
    static Index64 onTileCount()  { return 0; }
    static Index64 offTileCount() { return 0; }
    /// Return @c true if this node has no active voxels.
    bool isEmpty() const { return mValueMask.isOff(); }
    /// Return @c true if this node contains only active voxels.
    bool isDense() const { return mValueMask.isOn(); }

    /// Return the memory in bytes occupied by this node.
    Index64 memUsage() const;

    /// Expand the given bounding box so that it includes this leaf node's active voxels.
    /// If visitVoxels is false this LeafNode will be approximated as dense, i.e. with all
    /// voxels active. Else the individual active voxels are visited to produce a tight bbox.
    void evalActiveBoundingBox(CoordBBox&, bool visitVoxels = true) const;
    OPENVDB_DEPRECATED void evalActiveVoxelBoundingBox(CoordBBox&) const;

    /// @brief Return the bounding box of this node, i.e., the full index space
    /// spanned by this leaf node.
    CoordBBox getNodeBoundingBox() const { return CoordBBox::createCube(mOrigin, DIM); }

    /// Set the grid index coordinates of this node's local origin.
    void setOrigin(const Coord& origin) { mOrigin = origin; }
    /// @brief Return the grid index coordinates of this node's local origin.
    /// @deprecated Use origin() instead.
    OPENVDB_DEPRECATED const Coord& getOrigin() const { return mOrigin; }
    //@{
    /// Return the grid index coordinates of this node's local origin.
    const Coord& origin() const { return mOrigin; }
    void getOrigin(Coord& origin) const { origin = mOrigin; }
    void getOrigin(Int32& x, Int32& y, Int32& z) const { mOrigin.asXYZ(x, y, z); }
    //@}

    /// Return the linear table offset of the given global or local coordinates.
    static Index coordToOffset(const Coord& xyz);
    /// @brief Return the local coordinates for a linear table offset,
    /// where offset 0 has coordinates (0, 0, 0).
    static Coord offsetToLocalCoord(Index n);
    OPENVDB_DEPRECATED static void offsetToLocalCoord(Index n, Coord& xyz);
    /// Return the global coordinates for a linear table offset.
    Coord offsetToGlobalCoord(Index n) const;

    /// Return a string representation of this node.
    std::string str() const;

    /// @brief Return @c true if the given node (which may have a different @c ValueType
    /// than this node) has the same active value topology as this node.
    template<typename OtherType, Index OtherLog2Dim>
    bool hasSameTopology(const LeafNode<OtherType, OtherLog2Dim>* other) const;

    /// Check for buffer, state and origin equivalence.
    bool operator==(const LeafNode& other) const;
    bool operator!=(const LeafNode& other) const { return !(other == *this); }

protected:
    typedef typename NodeMaskType::OnIterator    MaskOnIterator;
    typedef typename NodeMaskType::OffIterator   MaskOffIterator;
    typedef typename NodeMaskType::DenseIterator MaskDenseIterator;

    // Type tags to disambiguate template instantiations
    struct ValueOn {}; struct ValueOff {}; struct ValueAll {};
    struct ChildOn {}; struct ChildOff {}; struct ChildAll {};

    template<typename MaskIterT, typename NodeT, typename ValueT, typename TagT>
    struct ValueIter:
        // Derives from SparseIteratorBase, but can also be used as a dense iterator,
        // if MaskIterT is a dense mask iterator type.
        public SparseIteratorBase<
            MaskIterT, ValueIter<MaskIterT, NodeT, ValueT, TagT>, NodeT, ValueT>
    {
        typedef SparseIteratorBase<MaskIterT, ValueIter, NodeT, ValueT> BaseT;

        ValueIter() {}
        ValueIter(const MaskIterT& iter, NodeT* parent): BaseT(iter, parent) {}

        ValueT& getItem(Index pos) const { return this->parent().getValue(pos); }
        ValueT& getValue() const { return this->parent().getValue(this->pos()); }

        // Note: setItem() can't be called on const iterators.
        void setItem(Index pos, const ValueT& value) const
        {
            this->parent().setValueOnly(pos, value);
        }
        // Note: setValue() can't be called on const iterators.
        void setValue(const ValueT& value) const
        {
            this->parent().setValueOnly(this->pos(), value);
        }

        // Note: modifyItem() can't be called on const iterators.
        template<typename ModifyOp>
        void modifyItem(Index n, const ModifyOp& op) const { this->parent().modifyValue(n, op); }
        // Note: modifyValue() can't be called on const iterators.
        template<typename ModifyOp>
        void modifyValue(const ModifyOp& op) const { this->parent().modifyValue(this->pos(), op); }
    };

    /// Leaf nodes have no children, so their child iterators have no get/set accessors.
    template<typename MaskIterT, typename NodeT, typename TagT>
    struct ChildIter:
        public SparseIteratorBase<MaskIterT, ChildIter<MaskIterT, NodeT, TagT>, NodeT, ValueType>
    {
        ChildIter() {}
        ChildIter(const MaskIterT& iter, NodeT* parent): SparseIteratorBase<
            MaskIterT, ChildIter<MaskIterT, NodeT, TagT>, NodeT, ValueType>(iter, parent) {}
    };

    template<typename NodeT, typename ValueT, typename TagT>
    struct DenseIter: public DenseIteratorBase<
        MaskDenseIterator, DenseIter<NodeT, ValueT, TagT>, NodeT, /*ChildT=*/void, ValueT>
    {
        typedef DenseIteratorBase<MaskDenseIterator, DenseIter, NodeT, void, ValueT> BaseT;
        typedef typename BaseT::NonConstValueType NonConstValueT;

        DenseIter() {}
        DenseIter(const MaskDenseIterator& iter, NodeT* parent): BaseT(iter, parent) {}

        bool getItem(Index pos, void*& child, NonConstValueT& value) const
        {
            value = this->parent().getValue(pos);
            child = NULL;
            return false; // no child
        }

        // Note: setItem() can't be called on const iterators.
        //void setItem(Index pos, void* child) const {}

        // Note: unsetItem() can't be called on const iterators.
        void unsetItem(Index pos, const ValueT& value) const
        {
            this->parent().setValueOnly(pos, value);
        }
    };

public:
    typedef ValueIter<MaskOnIterator, LeafNode, const ValueType, ValueOn>        ValueOnIter;
    typedef ValueIter<MaskOnIterator, const LeafNode, const ValueType, ValueOn>  ValueOnCIter;
    typedef ValueIter<MaskOffIterator, LeafNode, const ValueType, ValueOff>      ValueOffIter;
    typedef ValueIter<MaskOffIterator,const LeafNode,const ValueType,ValueOff>   ValueOffCIter;
    typedef ValueIter<MaskDenseIterator, LeafNode, const ValueType, ValueAll>    ValueAllIter;
    typedef ValueIter<MaskDenseIterator,const LeafNode,const ValueType,ValueAll> ValueAllCIter;
    typedef ChildIter<MaskOnIterator, LeafNode, ChildOn>                         ChildOnIter;
    typedef ChildIter<MaskOnIterator, const LeafNode, ChildOn>                   ChildOnCIter;
    typedef ChildIter<MaskOffIterator, LeafNode, ChildOff>                       ChildOffIter;
    typedef ChildIter<MaskOffIterator, const LeafNode, ChildOff>                 ChildOffCIter;
    typedef DenseIter<LeafNode, ValueType, ChildAll>                             ChildAllIter;
    typedef DenseIter<const LeafNode, const ValueType, ChildAll>                 ChildAllCIter;

    ValueOnCIter  cbeginValueOn() const { return ValueOnCIter(mValueMask.beginOn(), this); }
    ValueOnCIter   beginValueOn() const { return ValueOnCIter(mValueMask.beginOn(), this); }
    ValueOnIter    beginValueOn() { return ValueOnIter(mValueMask.beginOn(), this); }
    ValueOffCIter cbeginValueOff() const { return ValueOffCIter(mValueMask.beginOff(), this); }
    ValueOffCIter  beginValueOff() const { return ValueOffCIter(mValueMask.beginOff(), this); }
    ValueOffIter   beginValueOff() { return ValueOffIter(mValueMask.beginOff(), this); }
    ValueAllCIter cbeginValueAll() const { return ValueAllCIter(mValueMask.beginDense(), this); }
    ValueAllCIter  beginValueAll() const { return ValueAllCIter(mValueMask.beginDense(), this); }
    ValueAllIter   beginValueAll() { return ValueAllIter(mValueMask.beginDense(), this); }

    ValueOnCIter  cendValueOn() const { return ValueOnCIter(mValueMask.endOn(), this); }
    ValueOnCIter   endValueOn() const { return ValueOnCIter(mValueMask.endOn(), this); }
    ValueOnIter    endValueOn() { return ValueOnIter(mValueMask.endOn(), this); }
    ValueOffCIter cendValueOff() const { return ValueOffCIter(mValueMask.endOff(), this); }
    ValueOffCIter  endValueOff() const { return ValueOffCIter(mValueMask.endOff(), this); }
    ValueOffIter   endValueOff() { return ValueOffIter(mValueMask.endOff(), this); }
    ValueAllCIter cendValueAll() const { return ValueAllCIter(mValueMask.endDense(), this); }
    ValueAllCIter  endValueAll() const { return ValueAllCIter(mValueMask.endDense(), this); }
    ValueAllIter   endValueAll() { return ValueAllIter(mValueMask.endDense(), this); }

    // Note that [c]beginChildOn() and [c]beginChildOff() actually return end iterators,
    // because leaf nodes have no children.
    ChildOnCIter  cbeginChildOn() const { return ChildOnCIter(mValueMask.endOn(), this); }
    ChildOnCIter   beginChildOn() const { return ChildOnCIter(mValueMask.endOn(), this); }
    ChildOnIter    beginChildOn() { return ChildOnIter(mValueMask.endOn(), this); }
    ChildOffCIter cbeginChildOff() const { return ChildOffCIter(mValueMask.endOff(), this); }
    ChildOffCIter  beginChildOff() const { return ChildOffCIter(mValueMask.endOff(), this); }
    ChildOffIter   beginChildOff() { return ChildOffIter(mValueMask.endOff(), this); }
    ChildAllCIter cbeginChildAll() const { return ChildAllCIter(mValueMask.beginDense(), this); }
    ChildAllCIter  beginChildAll() const { return ChildAllCIter(mValueMask.beginDense(), this); }
    ChildAllIter   beginChildAll() { return ChildAllIter(mValueMask.beginDense(), this); }

    ChildOnCIter  cendChildOn() const { return ChildOnCIter(mValueMask.endOn(), this); }
    ChildOnCIter   endChildOn() const { return ChildOnCIter(mValueMask.endOn(), this); }
    ChildOnIter    endChildOn() { return ChildOnIter(mValueMask.endOn(), this); }
    ChildOffCIter cendChildOff() const { return ChildOffCIter(mValueMask.endOff(), this); }
    ChildOffCIter  endChildOff() const { return ChildOffCIter(mValueMask.endOff(), this); }
    ChildOffIter   endChildOff() { return ChildOffIter(mValueMask.endOff(), this); }
    ChildAllCIter cendChildAll() const { return ChildAllCIter(mValueMask.endDense(), this); }
    ChildAllCIter  endChildAll() const { return ChildAllCIter(mValueMask.endDense(), this); }
    ChildAllIter   endChildAll() { return ChildAllIter(mValueMask.endDense(), this); }

    //
    // Buffer management
    //
    /// @brief Exchange this node's data buffer with the given data buffer
    /// without changing the active states of the values.
    void swap(Buffer& other) { mBuffer.swap(other); }
    const Buffer& buffer() const { return mBuffer; }
    Buffer& buffer() { return mBuffer; }

    //
    // I/O methods
    //
    /// @brief Read in just the topology.
    /// @param is        the stream from which to read
    /// @param fromHalf  if true, floating-point input values are assumed to be 16-bit
    void readTopology(std::istream& is, bool fromHalf = false);
    /// @brief Write out just the topology.
    /// @param os      the stream to which to write
    /// @param toHalf  if true, output floating-point values as 16-bit half floats
    void writeTopology(std::ostream& os, bool toHalf = false) const;

    /// @brief Read buffers from a stream.
    /// @param is        the stream from which to read
    /// @param fromHalf  if true, floating-point input values are assumed to be 16-bit
    void readBuffers(std::istream& is, bool fromHalf = false);
    /// @brief Write buffers to a stream.
    /// @param os      the stream to which to write
    /// @param toHalf  if true, output floating-point values as 16-bit half floats
    void writeBuffers(std::ostream& os, bool toHalf = false) const;

    size_t streamingSize(bool toHalf = false) const;

    //
    // Accessor methods
    //
    /// Return the value of the voxel at the given coordinates.
    const ValueType& getValue(const Coord& xyz) const;
    /// Return the value of the voxel at the given linear offset.
    const ValueType& getValue(Index offset) const;

    /// @brief Return @c true if the voxel at the given coordinates is active.
    /// @param xyz       the coordinates of the voxel to be probed
    /// @param[out] val  the value of the voxel at the given coordinates
    bool probeValue(const Coord& xyz, ValueType& val) const;
    /// @brief Return @c true if the voxel at the given offset is active.
    /// @param offset    the linear offset of the voxel to be probed
    /// @param[out] val  the value of the voxel at the given coordinates
    bool probeValue(Index offset, ValueType& val) const;

    /// Return the level (i.e., 0) at which leaf node values reside.
    static Index getValueLevel(const Coord&) { return LEVEL; }

    /// Set the active state of the voxel at the given coordinates but don't change its value.
    void setActiveState(const Coord& xyz, bool on);
    /// Set the active state of the voxel at the given offset but don't change its value.
    void setActiveState(Index offset, bool on) { assert(offset<SIZE); mValueMask.set(offset, on); }

    /// Set the value of the voxel at the given coordinates but don't change its active state.
    void setValueOnly(const Coord& xyz, const ValueType& val);
    /// Set the value of the voxel at the given offset but don't change its active state.
    void setValueOnly(Index offset, const ValueType& val);

    /// Mark the voxel at the given coordinates as inactive but don't change its value.
    void setValueOff(const Coord& xyz) { mValueMask.setOff(LeafNode::coordToOffset(xyz)); }
    /// Mark the voxel at the given offset as inactive but don't change its value.
    void setValueOff(Index offset) { assert(offset < SIZE); mValueMask.setOff(offset); }

    /// Set the value of the voxel at the given coordinates and mark the voxel as inactive.
    void setValueOff(const Coord& xyz, const ValueType& val);
    /// Set the value of the voxel at the given offset and mark the voxel as inactive.
    void setValueOff(Index offset, const ValueType& val);

    /// Mark the voxel at the given coordinates as active but don't change its value.
    void setValueOn(const Coord& xyz) { mValueMask.setOn(LeafNode::coordToOffset(xyz)); }
    /// Mark the voxel at the given offset as active but don't change its value.
    void setValueOn(Index offset) { assert(offset < SIZE); mValueMask.setOn(offset); }
    /// Set the value of the voxel at the given coordinates and mark the voxel as active.
    void setValueOn(const Coord& xyz, const ValueType& val) {
        this->setValueOn(LeafNode::coordToOffset(xyz), val);
    }
    /// Set the value of the voxel at the given coordinates and mark the voxel as active.
    void setValue(const Coord& xyz, const ValueType& val) { this->setValueOn(xyz, val); };
    /// Set the value of the voxel at the given offset and mark the voxel as active.
    void setValueOn(Index offset, const ValueType& val) {
        mBuffer[offset] = val;
        mValueMask.setOn(offset);
    }

    /// @brief Apply a functor to the value of the voxel at the given offset
    /// and mark the voxel as active.
    template<typename ModifyOp>
    void modifyValue(Index offset, const ModifyOp& op)
    {
        op(mBuffer[offset]);
        mValueMask.setOn(offset);
    }
    /// @brief Apply a functor to the value of the voxel at the given coordinates
    /// and mark the voxel as active.
    template<typename ModifyOp>
    void modifyValue(const Coord& xyz, const ModifyOp& op)
    {
        this->modifyValue(this->coordToOffset(xyz), op);
    }

    /// Apply a functor to the voxel at the given coordinates.
    template<typename ModifyOp>
    void modifyValueAndActiveState(const Coord& xyz, const ModifyOp& op)
    {
        const Index offset = this->coordToOffset(xyz);
        bool state = mValueMask.isOn(offset);
        op(mBuffer[offset], state);
        mValueMask.set(offset, state);
    }

    /// Mark all voxels as active but don't change their values.
    void setValuesOn() { mValueMask.setOn(); }
    /// Mark all voxels as inactive but don't change their values.
    void setValuesOff() { mValueMask.setOff(); }

    /// Return @c true if the voxel at the given coordinates is active.
    bool isValueOn(const Coord& xyz) const {return this->isValueOn(LeafNode::coordToOffset(xyz));}
    /// Return @c true if the voxel at the given offset is active.
    bool isValueOn(Index offset) const { return mValueMask.isOn(offset); }

    /// Return @c false since leaf nodes never contain tiles.
    static bool hasActiveTiles() { return false; }

    /// Set all voxels within an axis-aligned box to the specified value and active state.
    void fill(const CoordBBox& bbox, const ValueType&, bool active = true);

    /// Set all voxels to the specified value but don't change their active states.
    void fill(const ValueType& value);
    /// Set all voxels to the specified value and active state.
    void fill(const ValueType& value, bool active);

    /// @brief Copy into a dense grid the values of the voxels that lie within
    /// a given bounding box.
    ///
    /// @param bbox   inclusive bounding box of the voxels to be copied into the dense grid
    /// @param dense  dense grid with a stride in @e z of one (see tools::Dense
    ///               in tools/Dense.h for the required API)
    ///
    /// @note @a bbox is assumed to be identical to or contained in the coordinate domains
    /// of both the dense grid and this node, i.e., no bounds checking is performed.
    /// @note Consider using tools::CopyToDense in tools/Dense.h
    /// instead of calling this method directly.
    template<typename DenseT>
    void copyToDense(const CoordBBox& bbox, DenseT& dense) const;

    /// @brief Copy from a dense grid into this node the values of the voxels
    /// that lie within a given bounding box.
    /// @details Only values that are different (by more than the given tolerance)
    /// from the background value will be active.  Other values are inactive
    /// and truncated to the background value.
    ///
    /// @param bbox        inclusive bounding box of the voxels to be copied into this node
    /// @param dense       dense grid with a stride in @e z of one (see tools::Dense
    ///                    in tools/Dense.h for the required API)
    /// @param background  background value of the tree that this node belongs to
    /// @param tolerance   tolerance within which a value equals the background value
    ///
    /// @note @a bbox is assumed to be identical to or contained in the coordinate domains
    /// of both the dense grid and this node, i.e., no bounds checking is performed.
    /// @note Consider using tools::CopyFromDense in tools/Dense.h
    /// instead of calling this method directly.
    template<typename DenseT>
    void copyFromDense(const CoordBBox& bbox, const DenseT& dense,
                       const ValueType& background, const ValueType& tolerance);

    /// @brief Return the value of the voxel at the given coordinates.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    const ValueType& getValueAndCache(const Coord& xyz, AccessorT&) const
    {
        return this->getValue(xyz);
    }

    /// @brief Return @c true if the voxel at the given coordinates is active.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    bool isValueOnAndCache(const Coord& xyz, AccessorT&) const { return this->isValueOn(xyz); }

    /// @brief Change the value of the voxel at the given coordinates and mark it as active.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    void setValueAndCache(const Coord& xyz, const ValueType& val, AccessorT&)
    {
        this->setValueOn(xyz, val);
    }

    /// @brief Change the value of the voxel at the given coordinates
    /// but preserve its state.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    void setValueOnlyAndCache(const Coord& xyz, const ValueType& val, AccessorT&)
    {
        this->setValueOnly(xyz, val);
    }

    /// @brief Apply a functor to the value of the voxel at the given coordinates
    /// and mark the voxel as active.
    /// @note Used internally by ValueAccessor.
    template<typename ModifyOp, typename AccessorT>
    void modifyValueAndCache(const Coord& xyz, const ModifyOp& op, AccessorT&)
    {
        this->modifyValue(xyz, op);
    }

    /// Apply a functor to the voxel at the given coordinates.
    /// @note Used internally by ValueAccessor.
    template<typename ModifyOp, typename AccessorT>
    void modifyValueAndActiveStateAndCache(const Coord& xyz, const ModifyOp& op, AccessorT&)
    {
        this->modifyValueAndActiveState(xyz, op);
    }

    /// @brief Change the value of the voxel at the given coordinates and mark it as inactive.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    void setValueOffAndCache(const Coord& xyz, const ValueType& value, AccessorT&)
    {
        this->setValueOff(xyz, value);
    }

    /// @brief Set the active state of the voxel at the given coordinates
    /// without changing its value.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    void setActiveStateAndCache(const Coord& xyz, bool on, AccessorT&)
    {
        this->setActiveState(xyz, on);
    }

    /// @brief Return @c true if the voxel at the given coordinates is active
    /// and return the voxel value in @a val.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    bool probeValueAndCache(const Coord& xyz, ValueType& val, AccessorT&) const
    {
        return this->probeValue(xyz, val);
    }

    /// @brief Return the value of the voxel at the given coordinates and return
    /// its active state and level (i.e., 0) in @a state and @a level.
    /// @note Used internally by ValueAccessor.
    template<typename AccessorT>
    const ValueType& getValue(const Coord& xyz, bool& state, int& level, AccessorT&) const
    {
        const Index offset = this->coordToOffset(xyz);
        state = mValueMask.isOn(offset);
        level = LEVEL;
        return mBuffer[offset];
    }

    /// @brief Return the LEVEL (=0) at which leaf node values reside.
    /// @note Used internally by ValueAccessor (note last argument is a dummy).
    template<typename AccessorT>
    static Index getValueLevelAndCache(const Coord&, AccessorT&) { return LEVEL; }

    /// @brief Return a const reference to the first value in the buffer.
    /// @note Though it is potentially risky you can convert this
    /// to a non-const pointer by means of const_case<ValueType*>&.
    const ValueType& getFirstValue() const { return mBuffer[0]; }
    /// Return a const reference to the last value in the buffer.
    const ValueType& getLastValue() const { return mBuffer[SIZE - 1]; }

    /// @brief Replace inactive occurrences of @a oldBackground with @a newBackground,
    /// and inactive occurrences of @a -oldBackground with @a -newBackground.
    void resetBackground(const ValueType& oldBackground, const ValueType& newBackground);

    /// @brief Overwrite each inactive value in this node and in any child nodes with
    /// a new value whose magnitude is equal to the specified background value and whose
    /// sign is consistent with that of the lexicographically closest active value.
    /// @details This is primarily useful for propagating the sign from the (active) voxels
    /// in a narrow-band level set to the inactive voxels outside the narrow band.
    void signedFloodFill(const ValueType& background);

    /// @brief Overwrite each inactive value in this node and in any child nodes with
    /// either @a outside or @a inside, depending on the sign of the lexicographically
    /// closest active value.
    /// @details Specifically, an inactive value is set to @a outside if the closest active
    /// value in the lexicographic direction is positive, otherwise it is set to @a inside.
    void signedFloodFill(const ValueType& outside, const ValueType& inside);

    void negate();

    void voxelizeActiveTiles() {};

    template<MergePolicy Policy> void merge(const LeafNode&);
    template<MergePolicy Policy> void merge(const ValueType& tileValue, bool tileActive);
    template<MergePolicy Policy>
    void merge(const LeafNode& other, const ValueType& /*bg*/, const ValueType& /*otherBG*/);

    /// @brief Union this node's set of active values with the active values
    /// of the other node, whose @c ValueType may be different. So a
    /// resulting voxel will be active if either of the original voxels
    /// were active.
    ///
    /// @note This operation modifies only active states, not values.
    template<typename OtherType>
    void topologyUnion(const LeafNode<OtherType, Log2Dim>& other);

    /// @brief Intersect this node's set of active values with the active values
    /// of the other node, whose @c ValueType may be different. So a
    /// resulting voxel will be active only if both of the original voxels
    /// were active.
    ///
    /// @details The last dummy argument is required to match the signature
    /// for InternalNode::topologyIntersection.
    ///
    /// @note This operation modifies only active states, not
    /// values. Also note that this operation can result in all voxels
    /// being inactive so consider subsequnetly calling prune.
    template<typename OtherType>
    void topologyIntersection(const LeafNode<OtherType, Log2Dim>& other, const ValueType&);

    /// @brief Difference this node's set of active values with the active values
    /// of the other node, whose @c ValueType may be different. So a
    /// resulting voxel will be active only if the original voxel is
    /// active in this LeafNode and inactive in the other LeafNode.
    ///
    /// @details The last dummy argument is required to match the signature
    /// for InternalNode::topologyDifference.
    ///
    /// @note This operation modifies only active states, not
    /// values. Also note that this operation can result in all voxels
    /// being inactive so consider subsequnetly calling prune.
    template<typename OtherType>
    void topologyDifference(const LeafNode<OtherType, Log2Dim>& other, const ValueType&);

    template<typename CombineOp>
    void combine(const LeafNode& other, CombineOp& op);
    template<typename CombineOp>
    void combine(const ValueType& value, bool valueIsActive, CombineOp& op);

    template<typename CombineOp>
    void combine2(const LeafNode& other, const ValueType&, bool valueIsActive, CombineOp&);
    template<typename CombineOp>
    void combine2(const ValueType&, const LeafNode& other, bool valueIsActive, CombineOp&);
    template<typename CombineOp>
    void combine2(const LeafNode& b0, const LeafNode& b1, CombineOp&);

    /// @brief Calls the templated functor BBoxOp with bounding box
    /// information. An additional level argument is provided to the
    /// callback.
    ///
    /// @note The bounding boxes are guarenteed to be non-overlapping.
    template<typename BBoxOp> void visitActiveBBox(BBoxOp&) const;

    template<typename VisitorOp> void visit(VisitorOp&);
    template<typename VisitorOp> void visit(VisitorOp&) const;

    template<typename OtherLeafNodeType, typename VisitorOp>
    void visit2Node(OtherLeafNodeType& other, VisitorOp&);
    template<typename OtherLeafNodeType, typename VisitorOp>
    void visit2Node(OtherLeafNodeType& other, VisitorOp&) const;
    template<typename IterT, typename VisitorOp>
    void visit2(IterT& otherIter, VisitorOp&, bool otherIsLHS = false);
    template<typename IterT, typename VisitorOp>
    void visit2(IterT& otherIter, VisitorOp&, bool otherIsLHS = false) const;

    //@{
    /// This function exists only to enable template instantiation.
    template<typename PruneOp> void pruneOp(PruneOp&) {}
    void prune(const ValueType& /*tolerance*/ = zeroVal<ValueType>()) {}
    void pruneInactive(const ValueType&) {}
    void addLeaf(LeafNode*) {}
    template<typename AccessorT>
    void addLeafAndCache(LeafNode*, AccessorT&) {}
    template<typename NodeT>
    NodeT* stealNode(const Coord&, const ValueType&, bool) { return NULL; }
    template<typename NodeT>
    NodeT* probeNode(const Coord&) { return NULL; }
    template<typename NodeT>
    const NodeT* probeConstNode(const Coord&) const { return NULL; }
    //@}

    void addTile(Index level, const Coord&, const ValueType&, bool);
    void addTile(Index offset, const ValueType&, bool);
    template<typename AccessorT>
    void addTileAndCache(Index, const Coord&, const ValueType&, bool, AccessorT&);

    //@{
    /// @brief Return a pointer to this node.
    LeafNode* touchLeaf(const Coord&) { return this; }
    template<typename AccessorT>
    LeafNode* touchLeafAndCache(const Coord&, AccessorT&) { return this; }
    template<typename NodeT, typename AccessorT>
    NodeT* probeNodeAndCache(const Coord&, AccessorT&)
    {
        OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
        if (!(boost::is_same<NodeT,LeafNode>::value)) return NULL;
        return reinterpret_cast<NodeT*>(this);
        OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
    }
    LeafNode* probeLeaf(const Coord&) { return this; }
    template<typename AccessorT>
    LeafNode* probeLeafAndCache(const Coord&, AccessorT&) { return this; }
    //@}
    //@{
    /// @brief Return a @const pointer to this node.
    const LeafNode* probeConstLeaf(const Coord&) const { return this; }
    template<typename AccessorT>
    const LeafNode* probeConstLeafAndCache(const Coord&, AccessorT&) const { return this; }
    template<typename AccessorT>
    const LeafNode* probeLeafAndCache(const Coord&, AccessorT&) const { return this; }
    const LeafNode* probeLeaf(const Coord&) const { return this; }
    template<typename NodeT, typename AccessorT>
    const NodeT* probeConstNodeAndCache(const Coord&, AccessorT&) const
    {
        OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
        if (!(boost::is_same<NodeT,LeafNode>::value)) return NULL;
        return reinterpret_cast<const NodeT*>(this);
        OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
    }
    //@}

    /// Return @c true if all of this node's values have the same active state
    /// and are equal to within the given tolerance, and return the value in @a constValue
    /// and the active state in @a state.
    bool isConstant(ValueType& constValue, bool& state,
                    const ValueType& tolerance = zeroVal<ValueType>()) const;
    /// Return @c true if all of this node's values are inactive.
    bool isInactive() const { return mValueMask.isOff(); }

protected:
    friend class ::TestLeaf;
    template<typename> friend class ::TestLeafIO;

    // During topology-only construction, access is needed
    // to protected/private members of other template instances.
    template<typename, Index> friend class LeafNode;

    friend struct ValueIter<MaskOnIterator, LeafNode, ValueType, ValueOn>;
    friend struct ValueIter<MaskOffIterator, LeafNode, ValueType, ValueOff>;
    friend struct ValueIter<MaskDenseIterator, LeafNode, ValueType, ValueAll>;
    friend struct ValueIter<MaskOnIterator, const LeafNode, ValueType, ValueOn>;
    friend struct ValueIter<MaskOffIterator, const LeafNode, ValueType, ValueOff>;
    friend struct ValueIter<MaskDenseIterator, const LeafNode, ValueType, ValueAll>;

    // Allow iterators to call mask accessor methods (see below).
    /// @todo Make mask accessors public?
    friend class IteratorBase<MaskOnIterator, LeafNode>;
    friend class IteratorBase<MaskOffIterator, LeafNode>;
    friend class IteratorBase<MaskDenseIterator, LeafNode>;

    /// Buffer containing the actual data values
    Buffer mBuffer;
    /// Bitmask that determines which voxels are active
    NodeMaskType mValueMask;
    /// Global grid index coordinates (x,y,z) of the local origin of this node
    Coord mOrigin;

    // Mask accessors
public:
    bool isValueMaskOn(Index n) const { return mValueMask.isOn(n); }
    bool isValueMaskOn() const { return mValueMask.isOn(); }
    bool isValueMaskOff(Index n) const { return mValueMask.isOff(n); }
    bool isValueMaskOff() const { return mValueMask.isOff(); }
    const NodeMaskType& getValueMask() const { return mValueMask; }
    NodeMaskType& getValueMask() { return mValueMask; }
    void setValueMask(const NodeMaskType& mask) { mValueMask = mask; }
    bool isChildMaskOn(Index) const { return false; } // leaf nodes have no children
    bool isChildMaskOff(Index) const { return true; }
    bool isChildMaskOff() const { return true; }
protected:
    void setValueMask(Index n, bool on) { mValueMask.set(n, on); }
    void setValueMaskOn(Index n)  { mValueMask.setOn(n); }
    void setValueMaskOff(Index n) { mValueMask.setOff(n); }

    /// Compute the origin of the leaf node that contains the voxel with the given coordinates.
    static void evalNodeOrigin(Coord& xyz) { xyz &= ~(DIM - 1); }

    template<typename NodeT, typename VisitorOp, typename ChildAllIterT>
    static inline void doVisit(NodeT&, VisitorOp&);

    template<typename NodeT, typename OtherNodeT, typename VisitorOp,
             typename ChildAllIterT, typename OtherChildAllIterT>
    static inline void doVisit2Node(NodeT& self, OtherNodeT& other, VisitorOp&);

    template<typename NodeT, typename VisitorOp,
             typename ChildAllIterT, typename OtherChildAllIterT>
    static inline void doVisit2(NodeT& self, OtherChildAllIterT&, VisitorOp&, bool otherIsLHS);

}; // end of LeafNode class


////////////////////////////////////////

template<typename T, Index Log2Dim>
inline
LeafNode<T, Log2Dim>::LeafNode():
    mValueMask(),//default is off!
    mOrigin(0, 0, 0)
{
}


template<typename T, Index Log2Dim>
inline
LeafNode<T, Log2Dim>::LeafNode(const Coord& xyz, const ValueType& val, bool active):
    mBuffer(val),
    mValueMask(active),
    mOrigin(xyz & (~(DIM - 1)))
{
}

template<typename T, Index Log2Dim>
template<typename OtherValueType>
inline
LeafNode<T, Log2Dim>::LeafNode(const LeafNode<OtherValueType, Log2Dim>& other,
                               const ValueType& background, TopologyCopy):
    mBuffer(background),
    mValueMask(other.mValueMask),
    mOrigin(other.mOrigin)
{
}

template<typename T, Index Log2Dim>
template<typename OtherValueType>
inline
LeafNode<T, Log2Dim>::LeafNode(const LeafNode<OtherValueType, Log2Dim>& other,
    const ValueType& offValue, const ValueType& onValue, TopologyCopy):
    mValueMask(other.mValueMask),
    mOrigin(other.mOrigin)
{
    for (Index i = 0; i < SIZE; ++i) {
        mBuffer[i] = (mValueMask.isOn(i) ? onValue : offValue);
    }
}

template<typename T, Index Log2Dim>
inline
LeafNode<T, Log2Dim>::LeafNode(const LeafNode &other):
    mBuffer(other.mBuffer),
    mValueMask(other.mValueMask),
    mOrigin(other.mOrigin)
{
}


template<typename T, Index Log2Dim>
inline
LeafNode<T, Log2Dim>::~LeafNode()
{
}

template<typename T, Index Log2Dim>
inline std::string
LeafNode<T, Log2Dim>::str() const
{
    std::ostringstream ostr;
    ostr << "LeafNode @" << mOrigin << ": " << mBuffer;
    return ostr.str();
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline Index
LeafNode<T, Log2Dim>::coordToOffset(const Coord& xyz)
{
    assert ((xyz[0] & (DIM-1u)) < DIM && (xyz[1] & (DIM-1u)) < DIM && (xyz[2] & (DIM-1u)) < DIM);
    return ((xyz[0] & (DIM-1u)) << 2*Log2Dim)
        +  ((xyz[1] & (DIM-1u)) <<  Log2Dim)
        +   (xyz[2] & (DIM-1u));
}

template<typename T, Index Log2Dim>
inline Coord
LeafNode<T, Log2Dim>::offsetToLocalCoord(Index n)
{
    assert(n<(1<< 3*Log2Dim));
    Coord xyz;
    xyz.setX(n >> 2*Log2Dim);
    n &= ((1<<2*Log2Dim)-1);
    xyz.setY(n >> Log2Dim);
    xyz.setZ(n & ((1<<Log2Dim)-1));
    return xyz;
}

//deprecated
template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::offsetToLocalCoord(Index n, Coord &xyz)
{
    assert(n<(1<< 3*Log2Dim));
    xyz.setX(n >> 2*Log2Dim);
    n &= ((1<<2*Log2Dim)-1);
    xyz.setY(n >> Log2Dim);
    xyz.setZ(n & ((1<<Log2Dim)-1));
}


template<typename T, Index Log2Dim>
inline Coord
LeafNode<T, Log2Dim>::offsetToGlobalCoord(Index n) const
{
    return (this->offsetToLocalCoord(n) + this->origin());
}


////////////////////////////////////////


template<typename ValueT, Index Log2Dim>
inline const ValueT&
LeafNode<ValueT, Log2Dim>::getValue(const Coord& xyz) const
{
    return this->getValue(LeafNode::coordToOffset(xyz));
}

template<typename ValueT, Index Log2Dim>
inline const ValueT&
LeafNode<ValueT, Log2Dim>::getValue(Index offset) const
{
    assert(offset < SIZE);
    return mBuffer[offset];
}


template<typename T, Index Log2Dim>
inline bool
LeafNode<T, Log2Dim>::probeValue(const Coord& xyz, ValueType& val) const
{
    return this->probeValue(LeafNode::coordToOffset(xyz), val);
}

template<typename T, Index Log2Dim>
inline bool
LeafNode<T, Log2Dim>::probeValue(Index offset, ValueType& val) const
{
    assert(offset < SIZE);
    val = mBuffer[offset];
    return mValueMask.isOn(offset);
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::setValueOff(const Coord& xyz, const ValueType& val)
{
    this->setValueOff(LeafNode::coordToOffset(xyz), val);
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::setValueOff(Index offset, const ValueType& val)
{
    assert(offset < SIZE);
    mBuffer[offset] = val;
    mValueMask.setOff(offset);
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::setActiveState(const Coord& xyz, bool on)
{
    mValueMask.set(this->coordToOffset(xyz), on);
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::setValueOnly(const Coord& xyz, const ValueType& val)
{
    this->setValueOnly(LeafNode::coordToOffset(xyz), val);
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::setValueOnly(Index offset, const ValueType& val)
{
    assert(offset<SIZE); mBuffer[offset] = val;
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::fill(const CoordBBox& bbox, const ValueType& value, bool active)
{
    for (Int32 x = bbox.min().x(); x <= bbox.max().x(); ++x) {
        const Index offsetX = (x & (DIM-1u)) << 2*Log2Dim;
        for (Int32 y = bbox.min().y(); y <= bbox.max().y(); ++y) {
            const Index offsetXY = offsetX + ((y & (DIM-1u)) << Log2Dim);
            for (Int32 z = bbox.min().z(); z <= bbox.max().z(); ++z) {
                const Index offset = offsetXY + (z & (DIM-1u));
                mBuffer[offset] = value;
                mValueMask.set(offset, active);
            }
        }
    }
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::fill(const ValueType& value)
{
    mBuffer.fill(value);
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::fill(const ValueType& value, bool active)
{
    mBuffer.fill(value);
    mValueMask.set(active);
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename DenseT>
inline void
LeafNode<T, Log2Dim>::copyToDense(const CoordBBox& bbox, DenseT& dense) const
{
    typedef typename DenseT::ValueType DenseValueType;

    const size_t xStride = dense.xStride(), yStride = dense.yStride(), zStride = dense.zStride();
    const Coord& min = dense.bbox().min();
    DenseValueType* t0 = dense.data() + zStride * (bbox.min()[2] - min[2]); // target array
    const T* s0 = &mBuffer[bbox.min()[2] & (DIM-1u)]; // source array
    for (Int32 x = bbox.min()[0], ex = bbox.max()[0] + 1; x < ex; ++x) {
        DenseValueType* t1 = t0 + xStride * (x - min[0]);
        const T* s1 = s0 + ((x & (DIM-1u)) << 2*Log2Dim);
        for (Int32 y = bbox.min()[1], ey = bbox.max()[1] + 1; y < ey; ++y) {
            DenseValueType* t2 = t1 + yStride * (y - min[1]);
            const T* s2 = s1 + ((y & (DIM-1u)) << Log2Dim);
            for (Int32 z = bbox.min()[2], ez = bbox.max()[2] + 1; z < ez; ++z, t2 += zStride) {
                *t2 = DenseValueType(*s2++);
            }
        }
    }
}


template<typename T, Index Log2Dim>
template<typename DenseT>
inline void
LeafNode<T, Log2Dim>::copyFromDense(const CoordBBox& bbox, const DenseT& dense,
                                    const ValueType& background, const ValueType& tolerance)
{
    typedef typename DenseT::ValueType DenseValueType;

    const size_t xStride = dense.xStride(), yStride = dense.yStride(), zStride = dense.zStride();
    const Coord& min = dense.bbox().min();

    const DenseValueType* s0 = dense.data() + zStride * (bbox.min()[2] - min[2]); // source
    const Int32 n0 = bbox.min()[2] & (DIM-1u);
    for (Int32 x = bbox.min()[0], ex = bbox.max()[0]+1; x < ex; ++x) {
        const DenseValueType* s1 = s0 + xStride * (x - min[0]);
        const Int32 n1 = n0 + ((x & (DIM-1u)) << 2*LOG2DIM);
        for (Int32 y = bbox.min()[1], ey = bbox.max()[1]+1; y < ey; ++y) {
            const DenseValueType* s2 = s1 + yStride * (y - min[1]);
            Int32 n2 = n1 + ((y & (DIM-1u)) << LOG2DIM);
            for (Int32 z = bbox.min()[2], ez = bbox.max()[2]+1; z < ez; ++z, ++n2, s2 += zStride) {
                if (math::isApproxEqual(background, ValueType(*s2), tolerance)) {
                    mValueMask.setOff(n2);
                    mBuffer[n2] = background;
                } else {
                    mValueMask.setOn(n2);
                    mBuffer[n2] = ValueType(*s2);
                }
            }
        }
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::readTopology(std::istream& is, bool /*fromHalf*/)
{
    mValueMask.load(is);
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::writeTopology(std::ostream& os, bool /*toHalf*/) const
{
    mValueMask.save(os);
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline void
LeafNode<T,Log2Dim>::readBuffers(std::istream& is, bool fromHalf)
{
    // Read in the value mask.
    mValueMask.load(is);

    int8_t numBuffers = 1;
    if (io::getFormatVersion(is) < OPENVDB_FILE_VERSION_NODE_MASK_COMPRESSION) {
        // Read in the origin.
        is.read(reinterpret_cast<char*>(&mOrigin), sizeof(Coord::ValueType) * 3);

        // Read in the number of buffers, which should now always be one.
        is.read(reinterpret_cast<char*>(&numBuffers), sizeof(int8_t));
    }

    io::readCompressedValues(is, mBuffer.mData, SIZE, mValueMask, fromHalf);

    if (numBuffers > 1) {
        // Read in and discard auxiliary buffers that were created with earlier
        // versions of the library.  (Auxiliary buffers are not mask compressed.)
        const bool zipped = io::getDataCompression(is) & io::COMPRESS_ZIP;
        Buffer temp;
        for (int i = 1; i < numBuffers; ++i) {
            if (fromHalf) {
                io::HalfReader<io::RealToHalf<T>::isReal, T>::read(is, temp.mData, SIZE, zipped);
            } else {
                io::readData<T>(is, temp.mData, SIZE, zipped);
            }
        }
    }
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::writeBuffers(std::ostream& os, bool toHalf) const
{
    // Write out the value mask.
    mValueMask.save(os);

    io::writeCompressedValues(os, mBuffer.mData, SIZE,
        mValueMask, /*childMask=*/NodeMaskType(), toHalf);
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline bool
LeafNode<T, Log2Dim>::operator==(const LeafNode& other) const
{
    return mOrigin == other.mOrigin &&
           mValueMask == other.mValueMask &&
           mBuffer == other.mBuffer;
}


template<typename T, Index Log2Dim>
inline Index64
LeafNode<T, Log2Dim>::memUsage() const
{
    return mBuffer.memUsage() + sizeof(mOrigin) + mValueMask.memUsage();
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::evalActiveVoxelBoundingBox(CoordBBox& bbox) const
{
    CoordBBox this_bbox = this->getNodeBoundingBox();
    if (bbox.isInside(this_bbox)) return;//this LeafNode is already enclosed in the bbox
    if (ValueOnCIter iter = this->cbeginValueOn()) {//any active values?
        this_bbox.reset();
        for(; iter; ++iter) this_bbox.expand(this->offsetToLocalCoord(iter.pos()));
        this_bbox.translate(this->origin());
        bbox.expand(this_bbox);
    }
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::evalActiveBoundingBox(CoordBBox& bbox, bool visitVoxels) const
{
    CoordBBox this_bbox = this->getNodeBoundingBox();
    if (bbox.isInside(this_bbox)) return;//this LeafNode is already enclosed in the bbox
    if (ValueOnCIter iter = this->cbeginValueOn()) {//any active values?
        if (visitVoxels) {//use voxel granularity?
            this_bbox.reset();
            for(; iter; ++iter) this_bbox.expand(this->offsetToLocalCoord(iter.pos()));
            this_bbox.translate(this->origin());
        }
        bbox.expand(this_bbox);
    }
}


template<typename T, Index Log2Dim>
template<typename OtherType, Index OtherLog2Dim>
inline bool
LeafNode<T, Log2Dim>::hasSameTopology(const LeafNode<OtherType, OtherLog2Dim>* other) const
{
    assert(other);
    return (Log2Dim == OtherLog2Dim && mValueMask == other->getValueMask());
}


template<typename T, Index Log2Dim>
inline bool
LeafNode<T, Log2Dim>::isConstant(ValueType& constValue,
                                 bool& state, const ValueType& tolerance) const
{
    state = mValueMask.isOn();

    if (!(state || mValueMask.isOff())) return false;

    bool allEqual = true;
    const T value = mBuffer[0];
    for (Index i = 1; allEqual && i < SIZE; ++i) {
        /// @todo Alternatively, allEqual = !((maxVal - minVal) > (2 * tolerance))
        allEqual = math::isApproxEqual(mBuffer[i], value, tolerance);
    }
    if (allEqual) constValue = value; ///< @todo return average/median value?
    return allEqual;
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::addTile(Index level, const Coord& xyz, const ValueType& val, bool active)
{
    assert(level == 0);
    this->addTile(this->coordToOffset(xyz), val, active);
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::addTile(Index offset, const ValueType& val, bool active)
{
    assert(offset < SIZE);
    setValueOnly(offset, val);
    setActiveState(offset, active);
}

template<typename T, Index Log2Dim>
template<typename AccessorT>
inline void
LeafNode<T, Log2Dim>::addTileAndCache(Index level, const Coord& xyz,
    const ValueType& val, bool active, AccessorT&)
{
    this->addTile(level, xyz, val, active);
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::signedFloodFill(const ValueType& background)
{
    this->signedFloodFill(background, math::negative(background));
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::signedFloodFill(const ValueType& outsideValue,
                                      const ValueType& insideValue)
{
    const Index first = mValueMask.findFirstOn();
    if (first < SIZE) {
        bool xInside = math::isNegative(mBuffer[first]), yInside = xInside, zInside = xInside;
        for (Index x = 0; x != (1 << Log2Dim); ++x) {
            const Index x00 = x << (2 * Log2Dim);
            if (mValueMask.isOn(x00)) {
                xInside = math::isNegative(mBuffer[x00]); // element(x, 0, 0)
            }
            yInside = xInside;
            for (Index y = 0; y != (1 << Log2Dim); ++y) {
                const Index xy0 = x00 + (y << Log2Dim);
                if (mValueMask.isOn(xy0)) {
                    yInside = math::isNegative(mBuffer[xy0]); // element(x, y, 0)
                }
                zInside = yInside;
                for (Index z = 0; z != (1 << Log2Dim); ++z) {
                    const Index xyz = xy0 + z; // element(x, y, z)
                    if (mValueMask.isOn(xyz)) {
                        zInside = math::isNegative(mBuffer[xyz]);
                    } else {
                        mBuffer[xyz] = zInside ? insideValue : outsideValue;
                    }
                }
            }
        }
    } else {// if no active voxels exist simply use the sign of the first value
        mBuffer.fill(math::isNegative(mBuffer[0]) ? insideValue : outsideValue);
    }
}


template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::resetBackground(const ValueType& oldBackground,
                                      const ValueType& newBackground)
{
    typename NodeMaskType::OffIterator iter;
    // For all inactive values...
    for (iter = this->mValueMask.beginOff(); iter; ++iter) {
        ValueType &inactiveValue = mBuffer[iter.pos()];
        if (math::isApproxEqual(inactiveValue, oldBackground)) {
            inactiveValue = newBackground;
        } else if (math::isApproxEqual(inactiveValue, math::negative(oldBackground))) {
            inactiveValue = math::negative(newBackground);
        }
    }
}


template<typename T, Index Log2Dim>
template<MergePolicy Policy>
inline void
LeafNode<T, Log2Dim>::merge(const LeafNode& other)
{
    OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
    if (Policy == MERGE_NODES) return;
    typename NodeMaskType::OnIterator iter = other.mValueMask.beginOn();
    for (; iter; ++iter) {
        const Index n = iter.pos();
        if (mValueMask.isOff(n)) {
            mBuffer[n] = other.mBuffer[n];
            mValueMask.setOn(n);
        }
    }
    OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
}

template<typename T, Index Log2Dim>
template<MergePolicy Policy>
inline void
LeafNode<T, Log2Dim>::merge(const LeafNode& other,
    const ValueType& /*bg*/, const ValueType& /*otherBG*/)
{
    this->template merge<Policy>(other);
}

template<typename T, Index Log2Dim>
template<MergePolicy Policy>
inline void
LeafNode<T, Log2Dim>::merge(const ValueType& tileValue, bool tileActive)
{
    OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN
    if (Policy != MERGE_ACTIVE_STATES_AND_NODES) return;
    if (!tileActive) return;
    // Replace all inactive values with the active tile value.
    for (typename NodeMaskType::OffIterator iter = mValueMask.beginOff(); iter; ++iter) {
        const Index n = iter.pos();
        mBuffer[n] = tileValue;
        mValueMask.setOn(n);
    }
    OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
}


template<typename T, Index Log2Dim>
template<typename OtherType>
inline void
LeafNode<T, Log2Dim>::topologyUnion(const LeafNode<OtherType, Log2Dim>& other)
{
    mValueMask |= other.getValueMask();
}

template<typename T, Index Log2Dim>
template<typename OtherType>
inline void
LeafNode<T, Log2Dim>::topologyIntersection(const LeafNode<OtherType, Log2Dim>& other,
                                           const ValueType&)
{
    mValueMask &= other.getValueMask();
}

template<typename T, Index Log2Dim>
template<typename OtherType>
inline void
LeafNode<T, Log2Dim>::topologyDifference(const LeafNode<OtherType, Log2Dim>& other,
                                         const ValueType&)
{
    mValueMask &= !other.getValueMask();
}

template<typename T, Index Log2Dim>
inline void
LeafNode<T, Log2Dim>::negate()
{
    for (Index i = 0; i < SIZE; ++i) {
        mBuffer[i] = -mBuffer[i];
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename CombineOp>
inline void
LeafNode<T, Log2Dim>::combine(const LeafNode& other, CombineOp& op)
{
    CombineArgs<T> args;
    for (Index i = 0; i < SIZE; ++i) {
        op(args.setARef(mBuffer[i])
            .setAIsActive(mValueMask.isOn(i))
            .setBRef(other.mBuffer[i])
            .setBIsActive(other.mValueMask.isOn(i))
            .setResultRef(mBuffer[i]));
        mValueMask.set(i, args.resultIsActive());
    }
}


template<typename T, Index Log2Dim>
template<typename CombineOp>
inline void
LeafNode<T, Log2Dim>::combine(const ValueType& value, bool valueIsActive, CombineOp& op)
{
    CombineArgs<T> args;
    args.setBRef(value).setBIsActive(valueIsActive);
    for (Index i = 0; i < SIZE; ++i) {
        op(args.setARef(mBuffer[i])
            .setAIsActive(mValueMask.isOn(i))
            .setResultRef(mBuffer[i]));
        mValueMask.set(i, args.resultIsActive());
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename CombineOp>
inline void
LeafNode<T, Log2Dim>::combine2(const LeafNode& other, const ValueType& value,
    bool valueIsActive, CombineOp& op)
{
    CombineArgs<T> args;
    args.setBRef(value).setBIsActive(valueIsActive);
    for (Index i = 0; i < SIZE; ++i) {
        op(args.setARef(other.mBuffer[i])
            .setAIsActive(other.mValueMask.isOn(i))
            .setResultRef(mBuffer[i]));
        mValueMask.set(i, args.resultIsActive());
    }
}


template<typename T, Index Log2Dim>
template<typename CombineOp>
inline void
LeafNode<T, Log2Dim>::combine2(const ValueType& value, const LeafNode& other,
    bool valueIsActive, CombineOp& op)
{
    CombineArgs<T> args;
    args.setARef(value).setAIsActive(valueIsActive);
    for (Index i = 0; i < SIZE; ++i) {
        op(args.setBRef(other.mBuffer[i])
            .setBIsActive(other.mValueMask.isOn(i))
            .setResultRef(mBuffer[i]));
        mValueMask.set(i, args.resultIsActive());
    }
}


template<typename T, Index Log2Dim>
template<typename CombineOp>
inline void
LeafNode<T, Log2Dim>::combine2(const LeafNode& b0, const LeafNode& b1, CombineOp& op)
{
    CombineArgs<T> args;
    for (Index i = 0; i < SIZE; ++i) {
        mValueMask.set(i, b0.mValueMask.isOn(i) || b1.mValueMask.isOn(i));
        op(args.setARef(b0.mBuffer[i])
            .setAIsActive(b0.mValueMask.isOn(i))
            .setBRef(b1.mBuffer[i])
            .setBIsActive(b1.mValueMask.isOn(i))
            .setResultRef(mBuffer[i]));
        mValueMask.set(i, args.resultIsActive());
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename BBoxOp>
inline void
LeafNode<T, Log2Dim>::visitActiveBBox(BBoxOp& op) const
{
    if (op.template descent<LEVEL>()) {
        for (ValueOnCIter i=this->cbeginValueOn(); i; ++i) {
#ifdef _MSC_VER
            op.operator()<LEVEL>(CoordBBox::createCube(i.getCoord(), 1));
#else
            op.template operator()<LEVEL>(CoordBBox::createCube(i.getCoord(), 1));
#endif
        }
    } else {
#ifdef _MSC_VER
        op.operator()<LEVEL>(this->getNodeBoundingBox());
#else
        op.template operator()<LEVEL>(this->getNodeBoundingBox());
#endif
    }
}


template<typename T, Index Log2Dim>
template<typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit(VisitorOp& op)
{
    doVisit<LeafNode, VisitorOp, ChildAllIter>(*this, op);
}


template<typename T, Index Log2Dim>
template<typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit(VisitorOp& op) const
{
    doVisit<const LeafNode, VisitorOp, ChildAllCIter>(*this, op);
}


template<typename T, Index Log2Dim>
template<typename NodeT, typename VisitorOp, typename ChildAllIterT>
inline void
LeafNode<T, Log2Dim>::doVisit(NodeT& self, VisitorOp& op)
{
    for (ChildAllIterT iter = self.beginChildAll(); iter; ++iter) {
        op(iter);
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename OtherLeafNodeType, typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit2Node(OtherLeafNodeType& other, VisitorOp& op)
{
    doVisit2Node<LeafNode, OtherLeafNodeType, VisitorOp, ChildAllIter,
        typename OtherLeafNodeType::ChildAllIter>(*this, other, op);
}


template<typename T, Index Log2Dim>
template<typename OtherLeafNodeType, typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit2Node(OtherLeafNodeType& other, VisitorOp& op) const
{
    doVisit2Node<const LeafNode, OtherLeafNodeType, VisitorOp, ChildAllCIter,
        typename OtherLeafNodeType::ChildAllCIter>(*this, other, op);
}


template<typename T, Index Log2Dim>
template<
    typename NodeT,
    typename OtherNodeT,
    typename VisitorOp,
    typename ChildAllIterT,
    typename OtherChildAllIterT>
inline void
LeafNode<T, Log2Dim>::doVisit2Node(NodeT& self, OtherNodeT& other, VisitorOp& op)
{
    // Allow the two nodes to have different ValueTypes, but not different dimensions.
    BOOST_STATIC_ASSERT(OtherNodeT::SIZE == NodeT::SIZE);
    BOOST_STATIC_ASSERT(OtherNodeT::LEVEL == NodeT::LEVEL);

    ChildAllIterT iter = self.beginChildAll();
    OtherChildAllIterT otherIter = other.beginChildAll();

    for ( ; iter && otherIter; ++iter, ++otherIter) {
        op(iter, otherIter);
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
template<typename IterT, typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit2(IterT& otherIter, VisitorOp& op, bool otherIsLHS)
{
    doVisit2<LeafNode, VisitorOp, ChildAllIter, IterT>(
        *this, otherIter, op, otherIsLHS);
}


template<typename T, Index Log2Dim>
template<typename IterT, typename VisitorOp>
inline void
LeafNode<T, Log2Dim>::visit2(IterT& otherIter, VisitorOp& op, bool otherIsLHS) const
{
    doVisit2<const LeafNode, VisitorOp, ChildAllCIter, IterT>(
        *this, otherIter, op, otherIsLHS);
}


template<typename T, Index Log2Dim>
template<
    typename NodeT,
    typename VisitorOp,
    typename ChildAllIterT,
    typename OtherChildAllIterT>
inline void
LeafNode<T, Log2Dim>::doVisit2(NodeT& self, OtherChildAllIterT& otherIter,
    VisitorOp& op, bool otherIsLHS)
{
    if (!otherIter) return;

    if (otherIsLHS) {
        for (ChildAllIterT iter = self.beginChildAll(); iter; ++iter) {
            op(otherIter, iter);
        }
    } else {
        for (ChildAllIterT iter = self.beginChildAll(); iter; ++iter) {
            op(iter, otherIter);
        }
    }
}


////////////////////////////////////////


template<typename T, Index Log2Dim>
inline std::ostream&
operator<<(std::ostream& os, const typename LeafNode<T, Log2Dim>::Buffer& buf)
{
    for (Index32 i = 0, N = buf.size(); i < N; ++i) os << buf.mData[i] << ", ";
    return os;
}

} // namespace tree
} // namespace OPENVDB_VERSION_NAME
} // namespace openvdb


////////////////////////////////////////


// Specialization for LeafNodes of type bool
#include "LeafNodeBool.h"

#endif // OPENVDB_TREE_LEAFNODE_HAS_BEEN_INCLUDED

// Copyright (c) 2012-2013 DreamWorks Animation LLC
// All rights reserved. This software is distributed under the
// Mozilla Public License 2.0 ( http://www.mozilla.org/MPL/2.0/ )