// Copyright Contributors to the OpenVDB Project
// SPDX-License-Identifier: MPL-2.0

/// @file SOP_OpenVDB_Filter_Level_Set.cc
///
/// @author FX R&D OpenVDB team
///
/// @brief Performs various types of level set deformations with
/// interface tracking. These unrestricted deformations include
/// surface smoothing (e.g., Laplacian flow), filtering (e.g., mean
/// value) and morphological operations (e.g., morphological opening).
/// All these operations can optionally be masked with another grid that
/// acts as an alpha-mask.
///
/// @note Works with level set grids of floating point type (float/double).

#include <houdini_utils/ParmFactory.h>

#include <openvdb_houdini/Utils.h>
#include <openvdb_houdini/SOP_NodeVDB.h>
#include <openvdb/tools/LevelSetFilter.h>

#include <OP/OP_AutoLockInputs.h>
#include <UT/UT_Interrupt.h>

#include <hboost/algorithm/string/case_conv.hpp>
#include <hboost/algorithm/string/trim.hpp>

#include <algorithm>
#include <iostream>
#include <stdexcept>
#include <string>
#include <vector>



#undef DWA_DEBUG_MODE
//#define DWA_DEBUG_MODE


namespace hvdb = openvdb_houdini;
namespace hutil = houdini_utils;


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

// Utilities

namespace {

// Add new items to the *end* of this list, and update NUM_OPERATOR_TYPES.
enum OperatorType {
    OP_TYPE_RENORM = 0,
    OP_TYPE_RESHAPE,
    OP_TYPE_SMOOTH,
    OP_TYPE_RESIZE
};

enum { NUM_OPERATOR_TYPES = OP_TYPE_RESIZE + 1 };


// Add new items to the *end* of this list, and update NUM_FILTER_TYPES.
enum FilterType {
    FILTER_TYPE_NONE = -1,
    FILTER_TYPE_RENORMALIZE = 0,
    FILTER_TYPE_MEAN_VALUE,
    FILTER_TYPE_MEDIAN_VALUE,
    FILTER_TYPE_MEAN_CURVATURE,
    FILTER_TYPE_LAPLACIAN_FLOW,
    FILTER_TYPE_DILATE,
    FILTER_TYPE_ERODE,
    FILTER_TYPE_OPEN,
    FILTER_TYPE_CLOSE,
    FILTER_TYPE_TRACK,
    FILTER_TYPE_GAUSSIAN,
    FILTER_TYPE_RESIZE
};

enum { NUM_FILTER_TYPES = FILTER_TYPE_RESIZE + 1 };


std::string
filterTypeToString(FilterType filter)
{
    std::string ret;
    switch (filter) {
        case FILTER_TYPE_NONE:           ret = "none";                  break;
        case FILTER_TYPE_RENORMALIZE:    ret = "renormalize";           break;
        case FILTER_TYPE_RESIZE:         ret = "resize narrow band";    break;
        case FILTER_TYPE_GAUSSIAN:       ret = "gaussian";              break;
        case FILTER_TYPE_DILATE:         ret = "dilate";                break;
        case FILTER_TYPE_ERODE:          ret = "erode";                 break;
        case FILTER_TYPE_OPEN:           ret = "open";                  break;
        case FILTER_TYPE_CLOSE:          ret = "close";                 break;
        case FILTER_TYPE_TRACK:          ret = "track";                 break;
#ifndef SESI_OPENVDB
        case FILTER_TYPE_MEAN_VALUE:     ret = "mean value";            break;
        case FILTER_TYPE_MEDIAN_VALUE:   ret = "median value";          break;
        case FILTER_TYPE_MEAN_CURVATURE: ret = "mean curvature";        break;
        case FILTER_TYPE_LAPLACIAN_FLOW: ret = "laplacian flow";        break;
#else
        case FILTER_TYPE_MEAN_VALUE:     ret = "meanvalue";             break;
        case FILTER_TYPE_MEDIAN_VALUE:   ret = "medianvalue";           break;
        case FILTER_TYPE_MEAN_CURVATURE: ret = "meancurvature";         break;
        case FILTER_TYPE_LAPLACIAN_FLOW: ret = "laplacianflow";         break;
#endif
    }
    return ret;
}

std::string
filterTypeToMenuName(FilterType filter)
{
    std::string ret;
    switch (filter) {
        case FILTER_TYPE_NONE: ret           = "None";                  break;
        case FILTER_TYPE_RENORMALIZE: ret    = "Renormalize";           break;
        case FILTER_TYPE_RESIZE: ret         = "Resize Narrow Band";    break;
        case FILTER_TYPE_MEAN_VALUE: ret     = "Mean Value";            break;
        case FILTER_TYPE_GAUSSIAN: ret       = "Gaussian";              break;
        case FILTER_TYPE_MEDIAN_VALUE: ret   = "Median Value";          break;
        case FILTER_TYPE_MEAN_CURVATURE: ret = "Mean Curvature Flow";   break;
        case FILTER_TYPE_LAPLACIAN_FLOW: ret = "Laplacian Flow";        break;
        case FILTER_TYPE_DILATE: ret         = "Dilate";                break;
        case FILTER_TYPE_ERODE: ret          = "Erode";                 break;
        case FILTER_TYPE_OPEN: ret           = "Open";                  break;
        case FILTER_TYPE_CLOSE: ret          = "Close";                 break;
        case FILTER_TYPE_TRACK: ret          = "Track Narrow Band";     break;
    }
    return ret;
}


FilterType
stringToFilterType(const std::string& s)
{
    FilterType ret = FILTER_TYPE_NONE;

    std::string str = s;
    hboost::trim(str);
    hboost::to_lower(str);

    if (str == filterTypeToString(FILTER_TYPE_RENORMALIZE)) {
        ret = FILTER_TYPE_RENORMALIZE;
    } else if (str == filterTypeToString(FILTER_TYPE_RESIZE)) {
        ret = FILTER_TYPE_RESIZE;
    } else if (str == filterTypeToString(FILTER_TYPE_MEAN_VALUE)) {
        ret = FILTER_TYPE_MEAN_VALUE;
    } else if (str == filterTypeToString(FILTER_TYPE_GAUSSIAN)) {
        ret = FILTER_TYPE_GAUSSIAN;
    } else if (str == filterTypeToString(FILTER_TYPE_MEDIAN_VALUE)) {
        ret = FILTER_TYPE_MEDIAN_VALUE;
    } else if (str == filterTypeToString(FILTER_TYPE_MEAN_CURVATURE)) {
        ret = FILTER_TYPE_MEAN_CURVATURE;
    } else if (str == filterTypeToString(FILTER_TYPE_LAPLACIAN_FLOW)) {
        ret = FILTER_TYPE_LAPLACIAN_FLOW;
    } else if (str == filterTypeToString(FILTER_TYPE_DILATE)) {
        ret = FILTER_TYPE_DILATE;
    } else if (str == filterTypeToString(FILTER_TYPE_ERODE)) {
        ret = FILTER_TYPE_ERODE;
    } else if (str == filterTypeToString(FILTER_TYPE_OPEN)) {
        ret = FILTER_TYPE_OPEN;
    } else if (str == filterTypeToString(FILTER_TYPE_CLOSE)) {
        ret = FILTER_TYPE_CLOSE;
    } else if (str == filterTypeToString(FILTER_TYPE_TRACK)) {
        ret = FILTER_TYPE_TRACK;
    }

    return ret;
}


// Add new items to the *end* of this list, and update NUM_ACCURACY_TYPES.
enum Accuracy {
    ACCURACY_UPWIND_FIRST = 0,
    ACCURACY_UPWIND_SECOND,
    ACCURACY_UPWIND_THIRD,
    ACCURACY_WENO,
    ACCURACY_HJ_WENO
};

enum { NUM_ACCURACY_TYPES = ACCURACY_HJ_WENO + 1 };

std::string
accuracyToString(Accuracy ac)
{
    std::string ret;
    switch (ac) {
        case ACCURACY_UPWIND_FIRST: ret     = "upwind first";       break;
        case ACCURACY_UPWIND_SECOND: ret    = "upwind second";      break;
        case ACCURACY_UPWIND_THIRD: ret     = "upwind third";       break;
        case ACCURACY_WENO: ret             = "weno";               break;
        case ACCURACY_HJ_WENO: ret          = "hj weno";            break;
    }
    return ret;
}

std::string
accuracyToMenuName(Accuracy ac)
{
    std::string ret;
    switch (ac) {
        case ACCURACY_UPWIND_FIRST: ret     = "First-order upwinding";      break;
        case ACCURACY_UPWIND_SECOND: ret    = "Second-order upwinding";     break;
        case ACCURACY_UPWIND_THIRD: ret     = "Third-order upwinding";      break;
        case ACCURACY_WENO: ret             = "Fifth-order WENO";           break;
        case ACCURACY_HJ_WENO: ret          = "Fifth-order HJ-WENO";        break;
    }
    return ret;
}


Accuracy
stringToAccuracy(const std::string& s)
{
    Accuracy ret = ACCURACY_UPWIND_FIRST;

    std::string str = s;
    hboost::trim(str);
    hboost::to_lower(str);

    if (str == accuracyToString(ACCURACY_UPWIND_SECOND)) {
        ret = ACCURACY_UPWIND_SECOND;
    } else if (str == accuracyToString(ACCURACY_UPWIND_THIRD)) {
        ret = ACCURACY_UPWIND_THIRD;
    } else if (str == accuracyToString(ACCURACY_WENO)) {
        ret = ACCURACY_WENO;
    } else if (str == accuracyToString(ACCURACY_HJ_WENO)) {
        ret = ACCURACY_HJ_WENO;
    }

    return ret;
}


void
buildFilterMenu(std::vector<std::string>& items, OperatorType op)
{
    items.clear();

    if (OP_TYPE_SMOOTH == op) {

        items.push_back(filterTypeToString(FILTER_TYPE_MEAN_VALUE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_MEAN_VALUE));

        items.push_back(filterTypeToString(FILTER_TYPE_GAUSSIAN));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_GAUSSIAN));

        items.push_back(filterTypeToString(FILTER_TYPE_MEDIAN_VALUE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_MEDIAN_VALUE));

        items.push_back(filterTypeToString(FILTER_TYPE_MEAN_CURVATURE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_MEAN_CURVATURE));

        items.push_back(filterTypeToString(FILTER_TYPE_LAPLACIAN_FLOW));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_LAPLACIAN_FLOW));

    } else if (OP_TYPE_RESHAPE == op) {

        items.push_back(filterTypeToString(FILTER_TYPE_DILATE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_DILATE));

        items.push_back(filterTypeToString(FILTER_TYPE_ERODE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_ERODE));

        items.push_back(filterTypeToString(FILTER_TYPE_OPEN));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_OPEN));

        items.push_back(filterTypeToString(FILTER_TYPE_CLOSE));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_CLOSE));

#ifdef DWA_DEBUG_MODE
        items.push_back(filterTypeToString(FILTER_TYPE_TRACK));
        items.push_back(filterTypeToMenuName(FILTER_TYPE_TRACK));
#endif

    }
}


struct FilterParms
{
    using TrimMode = openvdb::tools::lstrack::TrimMode;

    std::string mGroup;
    std::string mMaskName;
    bool        mSecondInputConnected = false;
    FilterType  mFilterType           = FILTER_TYPE_NONE;
    int         mIterations           = 0;
    int         mHalfWidth            = 3;
    int         mStencilWidth         = 0;
    float       mVoxelOffset          = 0.0f;
    float       mHalfWidthWorld       = 0.1f;
    float       mStencilWidthWorld    = 0.1f;
    bool        mWorldUnits           = false;
    float       mMinMask              = 0;
    float       mMaxMask              = 1;
    bool        mInvertMask           = false;
    Accuracy    mAccuracy             = ACCURACY_UPWIND_FIRST;
    TrimMode    mTrimMode             = TrimMode::kAll;
    bool        mMaskInputNode        = false;
};

} // namespace


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

// SOP Declaration

class SOP_OpenVDB_Filter_Level_Set: public hvdb::SOP_NodeVDB
{
public:
    SOP_OpenVDB_Filter_Level_Set(OP_Network*, const char* name, OP_Operator*, OperatorType);
    ~SOP_OpenVDB_Filter_Level_Set() override {}

    static OP_Node* factoryRenormalize(OP_Network*, const char* name, OP_Operator*);
    static OP_Node* factorySmooth(OP_Network*, const char* name, OP_Operator*);
    static OP_Node* factoryReshape(OP_Network*, const char* name, OP_Operator*);
    static OP_Node* factoryNarrowBand(OP_Network*, const char* name, OP_Operator*);

    int isRefInput(unsigned input) const override { return (input == 1); }

protected:
    bool updateParmsFlags() override;
    void resolveObsoleteParms(PRM_ParmList*) override;

public:
    class Cache: public SOP_VDBCacheOptions
    {
    public:
        Cache(OperatorType op): mOpType{op} {}

    protected:
        OP_ERROR cookVDBSop(OP_Context&) override;

    private:
        using BossT = openvdb::util::NullInterrupter;

        OP_ERROR evalFilterParms(OP_Context&, FilterParms&);

        template<typename GridT>
        bool applyFilters(GU_PrimVDB*, std::vector<FilterParms>&, BossT&,
            OP_Context&, GU_Detail&, bool verbose);

        template<typename FilterT>
        void filterGrid(OP_Context&, FilterT&, const FilterParms&, BossT&, bool verbose);

        template<typename FilterT>
        void offset(const FilterParms&, FilterT&, const float offset, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void mean(const FilterParms&, FilterT&, BossT&, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void gaussian(const FilterParms&, FilterT&, BossT&, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void median(const FilterParms&, FilterT&, BossT&, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void meanCurvature(const FilterParms&, FilterT&, BossT&, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void laplacian(const FilterParms&, FilterT&, BossT&, bool verbose,
            const typename FilterT::MaskType* mask = nullptr);

        template<typename FilterT>
        void renormalize(const FilterParms&, FilterT&, BossT&, bool verbose = false);

        template<typename FilterT>
        void resizeNarrowBand(const FilterParms&, FilterT&, BossT&, bool verbose = false);

        template<typename FilterT>
        void track(const FilterParms&, FilterT&, BossT&, bool verbose);

    private:
        const OperatorType mOpType;
    };

private:
    const OperatorType mOpType;
};//SOP_OpenVDB_Filter_Level_Set


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

// Build UI

void
newSopOperator(OP_OperatorTable* table)
{
    if (table == nullptr) return;

    for (int n = 0; n < NUM_OPERATOR_TYPES; ++n) {

        OperatorType op = OperatorType(n);

        hutil::ParmList parms;

        parms.add(hutil::ParmFactory(PRM_STRING, "group", "Group")
            .setChoiceList(&hutil::PrimGroupMenuInput1)
            .setTooltip("Specify a subset of the input VDB grids to be processed.")
            .setDocumentation(
                "A subset of the input VDBs to be processed"
                " (see [specifying volumes|/model/volumes#group])"));

        if (OP_TYPE_RENORM != op && OP_TYPE_RESIZE != op) { // Filter menu

            parms.add(hutil::ParmFactory(PRM_TOGGLE, "mask", "")
                .setDefault(PRMoneDefaults)
                .setTypeExtended(PRM_TYPE_TOGGLE_JOIN)
                .setTooltip("Enable / disable the mask."));

            parms.add(hutil::ParmFactory(PRM_STRING, "maskname", "Alpha Mask")
                .setChoiceList(&hutil::PrimGroupMenuInput2)
                .setTooltip("Optional VDB used for alpha masking. Assumes values 0->1.")
                .setDocumentation(
                    "If enabled, operate on the input VDBs using the given VDB"
                    " from the second input as an alpha mask.\n\n"
                    "The mask VDB is assumed to be scalar, with values between zero and one."
                    " Where the mask is zero, no processing occurs.  Where the mask is one,"
                    " the operation is applied at full strength.  For intermediate mask values,"
                    " the strength varies linearly."));

            std::vector<std::string> items;

            buildFilterMenu(items, op);

            parms.add(hutil::ParmFactory(PRM_STRING, "operation", "Operation")
                .setDefault(items[0])
                .setChoiceListItems(PRM_CHOICELIST_SINGLE, items)
                .setTooltip("The operation to be applied"));
        }

        parms.add(hutil::ParmFactory(PRM_TOGGLE, "useworldspaceunits", "Use World Space Units")
            .setTooltip("If enabled, use world-space units, otherwise use voxels."));

        parms.add(hutil::ParmFactory(PRM_INT_J, "radius", "Filter Voxel Radius")
            .setDefault(PRMoneDefaults)
            .setRange(PRM_RANGE_RESTRICTED, 1, PRM_RANGE_UI, 5)
            .setDocumentation(nullptr));

        parms.add(hutil::ParmFactory(PRM_FLT_J, "radiusworld", "Filter Radius")
            .setDefault(0.1)
            .setRange(PRM_RANGE_RESTRICTED, 1e-5, PRM_RANGE_UI, 10)
            .setDocumentation("The desired radius of the filter"));

        parms.add(hutil::ParmFactory(PRM_INT_J, "iterations", "Iterations")
            .setDefault(PRMfourDefaults)
            .setRange(PRM_RANGE_RESTRICTED, 0, PRM_RANGE_UI, 10)
            .setTooltip("The number of times to apply the operation"));

        parms.add(hutil::ParmFactory(PRM_INT_J, "halfwidth", "Half Width")
            .setDefault(PRMthreeDefaults)
            .setRange(PRM_RANGE_RESTRICTED, 1, PRM_RANGE_UI, 10)
            .setTooltip(
                "Half the width of the narrow band, in voxels\n\n"
                "(Many level set operations require this to be a minimum of three voxels.)"));

        parms.add(hutil::ParmFactory(PRM_FLT_J, "halfwidthworld", "Half Width")
            .setDefault(0.1)
            .setRange(PRM_RANGE_RESTRICTED, 1e-5, PRM_RANGE_UI, 10)
            .setTooltip("Half the width of the narrow band, in world units")
            .setDocumentation(nullptr));

        parms.add(hutil::ParmFactory(PRM_FLT_J, "voxeloffset", "Offset")
            .setDefault(PRMoneDefaults)
            .setRange(PRM_RANGE_RESTRICTED, 0.0, PRM_RANGE_UI, 10.0)
            .setTooltip(
                "The distance in voxels by which to offset the level set surface"
                " along its normals"));

        {
            std::vector<std::string> items;
            for (int i = 0; i < NUM_ACCURACY_TYPES; ++i) {
                Accuracy ac = Accuracy(i);
#ifndef DWA_DEBUG_MODE // Exclude some of the menu options
                if (ac == ACCURACY_UPWIND_THIRD || ac == ACCURACY_WENO) continue;
#endif
                items.push_back(accuracyToString(ac)); // token
                items.push_back(accuracyToMenuName(ac)); // label
            }

            parms.add(hutil::ParmFactory(PRM_STRING, "accuracy", "Renorm Accuracy")
                .setDefault(items[0])
                .setChoiceListItems(PRM_CHOICELIST_SINGLE, items));
        }

        parms.add(hutil::ParmFactory(PRM_TOGGLE, "invert", "Invert Alpha Mask")
            .setTooltip("Invert the optional alpha mask, mapping 0 to 1 and 1 to 0."));

        parms.add(hutil::ParmFactory(PRM_FLT_J, "minmask", "Min Mask Cutoff")
            .setDefault(PRMzeroDefaults)
            .setRange(PRM_RANGE_UI, 0.0, PRM_RANGE_UI, 1.0)
            .setTooltip("Threshold below which voxel values in the mask map to zero"));

        parms.add(hutil::ParmFactory(PRM_FLT_J, "maxmask", "Max Mask Cutoff")
            .setDefault(PRMoneDefaults)
            .setRange(PRM_RANGE_UI, 0.0, PRM_RANGE_UI, 1.0)
            .setTooltip("Threshold above which voxel values in the mask map to one"));

        parms.add(hutil::ParmFactory(PRM_STRING, "trim", "Trim")
            .setChoiceListItems(PRM_CHOICELIST_SINGLE, {
                "none",     "None",
                "interior", "Interior",
                "exterior", "Exterior",
                "all",      "All",
            })
            .setDefault("all")
            .setTooltip("Set voxels that lie outside the narrow band to the background value.")
            .setDocumentation(
                "Optionally set interior, exterior, or all voxels that lie outside"
                " the narrow band to the background value.\n\n"
                "Trimming reduces memory usage, but it also reduces dense SDFs\n"
                "to narrow-band level sets."));

#ifndef SESI_OPENVDB
        parms.add(hutil::ParmFactory(PRM_TOGGLE, "verbose", "Verbose")
            .setTooltip("If enabled, print the sequence of operations to the terminal."));
#endif

        // Obsolete parameters
        hutil::ParmList obsoleteParms;
        obsoleteParms.add(hutil::ParmFactory(PRM_SEPARATOR, "sep1", "Sep"));
        obsoleteParms.add(hutil::ParmFactory(PRM_SEPARATOR, "sep2", "Sep"));
        obsoleteParms.add(hutil::ParmFactory(PRM_TOGGLE, "worldSpaceUnits", ""));
        obsoleteParms.add(hutil::ParmFactory(PRM_INT_J, "stencilWidth", "Filter Voxel Radius")
            .setDefault(PRMoneDefaults));
        obsoleteParms.add(hutil::ParmFactory(PRM_FLT_J, "stencilWidthWorld", "").setDefault(0.1));
        obsoleteParms.add(hutil::ParmFactory(PRM_INT_J, "halfWidth", "Half-Width")
            .setDefault(PRMthreeDefaults));
        obsoleteParms.add(hutil::ParmFactory(PRM_FLT_J, "halfWidthWorld", "").setDefault(0.1));
        obsoleteParms.add(hutil::ParmFactory(PRM_FLT_J, "voxelOffset", "Offset")
            .setDefault(PRMoneDefaults));
        obsoleteParms.add(hutil::ParmFactory(PRM_FLT_J, "minMask", "").setDefault(PRMzeroDefaults));
        obsoleteParms.add(hutil::ParmFactory(PRM_FLT_J, "maxMask", "").setDefault(PRMoneDefaults));

        auto cacheAllocator = [op]() { return new SOP_OpenVDB_Filter_Level_Set::Cache{op}; };

        // Register operator
        if (OP_TYPE_RENORM == op) {

            hvdb::OpenVDBOpFactory("VDB Renormalize SDF",
                SOP_OpenVDB_Filter_Level_Set::factoryRenormalize, parms, *table)
#ifndef SESI_OPENVDB
                .setInternalName("DW_OpenVDBRenormalizeLevelSet")
#endif
                .setObsoleteParms(obsoleteParms)
                .addInput("Input with VDB grids to process")
                .setVerb(SOP_NodeVerb::COOK_INPLACE, cacheAllocator)
                .setDocumentation("\
#icon: COMMON/openvdb\n\
#tags: vdb\n\
\n\
\"\"\"Repair level sets represented by VDB volumes.\"\"\"\n\
\n\
@overview\n\
\n\
Certain operations on a level set volume can cause the signed distances\n\
to its zero crossing to become invalid.\n\
This node iteratively adjusts voxel values to restore proper distances.\n\
\n\
NOTE:\n\
    If the level set departs significantly from a proper signed distance field,\n\
    it might be necessary to rebuild it completely.\n\
    That can be done with the\
 [OpenVDB Rebuild Level Set node|Node:sop/DW_OpenVDBRebuildLevelSet],\n\
    which converts an input level set to polygons and then back to a level set.\n\
\n\
@related\n\
- [OpenVDB Offset Level Set|Node:sop/DW_OpenVDBOffsetLevelSet]\n\
- [OpenVDB Rebuild Level Set|Node:sop/DW_OpenVDBRebuildLevelSet]\n\
- [OpenVDB Smooth Level Set|Node:sop/DW_OpenVDBSmoothLevelSet]\n\
\n\
@examples\n\
\n\
See [openvdb.org|http://www.openvdb.org/download/] for source code\n\
and usage examples.\n");

        } else if (OP_TYPE_RESHAPE == op) {

            hvdb::OpenVDBOpFactory("VDB Reshape SDF",
                SOP_OpenVDB_Filter_Level_Set::factoryReshape, parms, *table)
#ifndef SESI_OPENVDB
                .setInternalName("DW_OpenVDBOffsetLevelSet")
#endif
                .setObsoleteParms(obsoleteParms)
                .addInput("Input with VDBs to process")
                .addOptionalInput("Optional VDB Alpha Mask")
                .setVerb(SOP_NodeVerb::COOK_INPLACE, cacheAllocator)
                .setDocumentation("\
#icon: COMMON/openvdb\n\
#tags: vdb\n\
\n\
\"\"\"Offset level sets represented by VDB volumes.\"\"\"\n\
\n\
@overview\n\
\n\
This node changes the shape of a level set by moving the surface in or out\n\
along its normals.\n\
Unlike just adding an offset to a signed distance field, this node properly\n\
updates the active voxels to account for the transformation.\n\
\n\
@related\n\
- [OpenVDB Renormalize Level Set|Node:sop/DW_OpenVDBRenormalizeLevelSet]\n\
- [OpenVDB Smooth Level Set|Node:sop/DW_OpenVDBSmoothLevelSet]\n\
\n\
@examples\n\
\n\
See [openvdb.org|http://www.openvdb.org/download/] for source code\n\
and usage examples.\n");

        } else if (OP_TYPE_SMOOTH == op) {

            hvdb::OpenVDBOpFactory("VDB Smooth SDF",
                SOP_OpenVDB_Filter_Level_Set::factorySmooth, parms, *table)
#ifndef SESI_OPENVDB
                .setInternalName("DW_OpenVDBSmoothLevelSet")
#endif
                .setObsoleteParms(obsoleteParms)
                .addInput("Input with VDBs to process")
                .addOptionalInput("Optional VDB Alpha Mask")
                .setVerb(SOP_NodeVerb::COOK_INPLACE, cacheAllocator)
                .setDocumentation("\
#icon: COMMON/openvdb\n\
#tags: vdb\n\
\n\
\"\"\"Smooth the surface of a level set represented by a VDB volume.\"\"\"\n\
\n\
@overview\n\
\n\
This node applies a simulated flow operation, moving the surface of a\n\
signed distance field according to some local property.\n\
\n\
For example, if you move along the normal by an amount dependent on the curvature,\n\
you will flatten out dimples and hills and leave flat areas unchanged.\n\
\n\
Unlike the [OpenVDB Filter|Node:sop/DW_OpenVDBFilter] node,\n\
this node ensures that the level set remains a valid signed distance field.\n\
\n\
@related\n\
- [OpenVDB Filter|Node:sop/DW_OpenVDBFilter]\n\
- [OpenVDB Offset Level Set|Node:sop/DW_OpenVDBOffsetLevelSet]\n\
- [OpenVDB Renormalize Level Set|Node:sop/DW_OpenVDBRenormalizeLevelSet]\n\
\n\
@examples\n\
\n\
See [openvdb.org|http://www.openvdb.org/download/] for source code\n\
and usage examples.\n");

        } else if (OP_TYPE_RESIZE == op) {

            hvdb::OpenVDBOpFactory("VDB Activate SDF",
                SOP_OpenVDB_Filter_Level_Set::factoryNarrowBand, parms, *table)
#ifndef SESI_OPENVDB
                .setInternalName("DW_OpenVDBResizeNarrowBand")
#endif
                .setObsoleteParms(obsoleteParms)
                .addInput("Input with VDBs to process")
                .setVerb(SOP_NodeVerb::COOK_INPLACE, cacheAllocator)
                .setDocumentation("\
#icon: COMMON/openvdb\n\
#tags: vdb\n\
\n\
\"\"\"Change the width of the narrow band of a VDB signed distance field.\"\"\"\n\
\n\
@overview\n\
\n\
This node adjusts the width of the narrow band of a signed distance field\n\
represented by a VDB volume.\n\
\n\
@related\n\
- [OpenVDB Offset Level Set|Node:sop/DW_OpenVDBOffsetLevelSet]\n\
- [OpenVDB Rebuild Level Set|Node:sop/DW_OpenVDBRebuildLevelSet]\n\
- [OpenVDB Renormalize Level Set|Node:sop/DW_OpenVDBRenormalizeLevelSet]\n\
\n\
@examples\n\
\n\
See [openvdb.org|http://www.openvdb.org/download/] for source code\n\
and usage examples.\n");
        }
    }
}


void
SOP_OpenVDB_Filter_Level_Set::resolveObsoleteParms(PRM_ParmList* obsoleteParms)
{
    if (!obsoleteParms) return;

    resolveRenamedParm(*obsoleteParms, "halfWidth", "halfwidth");
    resolveRenamedParm(*obsoleteParms, "halfWidthWorld", "halfwidthworld");
    resolveRenamedParm(*obsoleteParms, "maxMask", "maxmask");
    resolveRenamedParm(*obsoleteParms, "minMask", "minmask");
    resolveRenamedParm(*obsoleteParms, "stencilWidth", "radius");
    resolveRenamedParm(*obsoleteParms, "stencilWidthWorld", "radiusworld");
    resolveRenamedParm(*obsoleteParms, "voxelOffset", "voxeloffset");
    resolveRenamedParm(*obsoleteParms, "worldSpaceUnits", "useworldspaceunits");

    // Delegate to the base class.
    hvdb::SOP_NodeVDB::resolveObsoleteParms(obsoleteParms);
}


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

// Operator registration

OP_Node*
SOP_OpenVDB_Filter_Level_Set::factoryRenormalize(
    OP_Network* net, const char* name, OP_Operator* op)
{
    return new SOP_OpenVDB_Filter_Level_Set(net, name, op, OP_TYPE_RENORM);
}

OP_Node*
SOP_OpenVDB_Filter_Level_Set::factoryReshape(
    OP_Network* net, const char* name, OP_Operator* op)
{
    return new SOP_OpenVDB_Filter_Level_Set(net, name, op, OP_TYPE_RESHAPE);
}

OP_Node*
SOP_OpenVDB_Filter_Level_Set::factorySmooth(
    OP_Network* net, const char* name, OP_Operator* op)
{
    return new SOP_OpenVDB_Filter_Level_Set(net, name, op, OP_TYPE_SMOOTH);
}

OP_Node*
SOP_OpenVDB_Filter_Level_Set::factoryNarrowBand(
    OP_Network* net, const char* name, OP_Operator* op)
{
    return new SOP_OpenVDB_Filter_Level_Set(net, name, op, OP_TYPE_RESIZE);
}

SOP_OpenVDB_Filter_Level_Set::SOP_OpenVDB_Filter_Level_Set(
    OP_Network* net, const char* name, OP_Operator* op, OperatorType opType)
    : hvdb::SOP_NodeVDB(net, name, op)
    , mOpType(opType)
{
}

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

// Disable UI Parms.
bool
SOP_OpenVDB_Filter_Level_Set::updateParmsFlags()
{
    bool changed = false, stencil = false;
    const bool renorm = mOpType == OP_TYPE_RENORM;
    const bool smooth = mOpType == OP_TYPE_SMOOTH;
    const bool reshape = mOpType == OP_TYPE_RESHAPE;
    const bool resize = mOpType == OP_TYPE_RESIZE;

    if (renorm || resize) {
        changed |= setVisibleState("invert", false);
        changed |= setVisibleState("minmask",false);
        changed |= setVisibleState("maxmask",false);
    } else {
        const FilterType operation = stringToFilterType(evalStdString("operation", 0));
        stencil = operation == FILTER_TYPE_MEAN_VALUE ||
                  operation == FILTER_TYPE_GAUSSIAN   ||
                  operation == FILTER_TYPE_MEDIAN_VALUE;
        const bool hasMask = (this->nInputs() == 2);
        changed |= enableParm("mask", hasMask);
        const bool useMask = hasMask && bool(evalInt("mask", 0, 0));
        changed |= enableParm("invert",   useMask);
        changed |= enableParm("minmask",  useMask);
        changed |= enableParm("maxmask",  useMask);
        changed |= enableParm("maskname", useMask);
    }

    const bool worldUnits = bool(evalInt("useworldspaceunits", 0, 0));

    changed |= setVisibleState("halfwidth", resize && !worldUnits);
    changed |= setVisibleState("halfwidthworld", resize && worldUnits);

    changed |= enableParm("iterations", smooth || renorm);
    changed |= enableParm("radius", stencil && !worldUnits);
    changed |= enableParm("radiusworld", stencil && worldUnits);

    changed |= setVisibleState("radius", getEnableState("radius"));
    changed |= setVisibleState("radiusworld", getEnableState("radiusworld"));

    changed |= setVisibleState("iterations", getEnableState("iterations"));

    changed |= setVisibleState("useworldspaceunits", !renorm);
    changed |= setVisibleState("voxeloffset", reshape);

    return changed;
}


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

// Cook

OP_ERROR
SOP_OpenVDB_Filter_Level_Set::Cache::cookVDBSop(
    OP_Context& context)
{
    try {
        hvdb::HoudiniInterrupter boss("Processing level sets");

        const fpreal time = context.getTime();

#ifndef SESI_OPENVDB
        const bool verbose = bool(evalInt("verbose", 0, time));
#else
        const bool verbose = false;
#endif

        // Collect filter parameters starting from the topmost node.
        std::vector<FilterParms> filterParms;
        filterParms.resize(1);
        evalFilterParms(context, filterParms[0]);

        // Filter grids
        const GA_PrimitiveGroup* group = matchGroup(*gdp, evalStdString("group", time));
        for (hvdb::VdbPrimIterator it(gdp, group); it; ++it) {

            // Check grid class
            const openvdb::GridClass gridClass = it->getGrid().getGridClass();
            if (gridClass != openvdb::GRID_LEVEL_SET) {
                std::string s = it.getPrimitiveNameOrIndex().toStdString();
                s = "VDB primitive " + s + " was skipped because it is not a level-set grid.";
                addWarning(SOP_MESSAGE, s.c_str());
                continue;
            }

            // Appply filters

            bool wasFiltered = applyFilters<openvdb::FloatGrid>(
                *it, filterParms, boss.interrupter(), context, *gdp, verbose);

            if (boss.wasInterrupted()) break;

            if (!wasFiltered) {
                wasFiltered = applyFilters<openvdb::DoubleGrid>(
                    *it, filterParms, boss.interrupter(), context, *gdp, verbose);
            }

            if (boss.wasInterrupted()) break;

            if (!wasFiltered) {
                std::string msg = "VDB primitive "
                    + it.getPrimitiveNameOrIndex().toStdString()
                    + " is not of floating point type.";
                addWarning(SOP_MESSAGE, msg.c_str());
                continue;
            }

            if (boss.wasInterrupted()) break;
        }

        if (boss.wasInterrupted()) addWarning(SOP_MESSAGE, "processing was interrupted");
        boss.end();

    } catch (std::exception& e) {
        addError(SOP_MESSAGE, e.what());
    }
    return error();
}


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


OP_ERROR
SOP_OpenVDB_Filter_Level_Set::Cache::evalFilterParms(
    OP_Context& context, FilterParms& parms)
{
    fpreal now = context.getTime();

    parms.mIterations   = static_cast<int>(evalInt("iterations", 0, now));
    parms.mHalfWidth    = static_cast<int>(evalInt("halfwidth", 0, now));
    parms.mHalfWidthWorld = float(evalFloat("halfwidthworld", 0, now));
    parms.mStencilWidth = static_cast<int>(evalInt("radius", 0, now));
    parms.mStencilWidthWorld = float(evalFloat("radiusworld", 0, now));
    parms.mVoxelOffset  = static_cast<float>(evalFloat("voxeloffset", 0, now));
    parms.mMinMask      = static_cast<float>(evalFloat("minmask", 0, now));
    parms.mMaxMask      = static_cast<float>(evalFloat("maxmask", 0, now));
    parms.mInvertMask   = bool(evalInt("invert", 0, now));
    parms.mWorldUnits   = bool(evalInt("useworldspaceunits", 0, now));
    parms.mAccuracy     = stringToAccuracy(evalStdString("accuracy", now));
    parms.mGroup        = evalStdString("group", now);

    {
        const auto trimMode = evalStdString("trim", now);
        if (trimMode == "none")          { parms.mTrimMode = FilterParms::TrimMode::kNone; }
        else if (trimMode == "interior") { parms.mTrimMode = FilterParms::TrimMode::kInterior; }
        else if (trimMode == "exterior") { parms.mTrimMode = FilterParms::TrimMode::kExterior; }
        else if (trimMode == "all")      { parms.mTrimMode = FilterParms::TrimMode::kAll; }
        else {
            addError(SOP_MESSAGE,
                ("Expected \"none\", \"interior\", \"exterior\" or \"all\" for \"trim\", got \""
                     + trimMode + "\".").c_str());
        }
    }

    if (OP_TYPE_RENORM == mOpType) {
        parms.mFilterType = FILTER_TYPE_RENORMALIZE;
    } else if (OP_TYPE_RESIZE == mOpType) {
        parms.mFilterType = FILTER_TYPE_RESIZE;
    } else {
        parms.mFilterType = stringToFilterType(evalStdString("operation", now));
    }

    if (OP_TYPE_SMOOTH == mOpType || OP_TYPE_RESHAPE == mOpType) {
        if (evalInt("mask", 0, now)) {
            parms.mMaskInputNode = hasInput(1);
            parms.mMaskName = evalStdString("maskname", now);
        }
    }

    return error();
}


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

// Filter callers

template<typename GridT>
bool
SOP_OpenVDB_Filter_Level_Set::Cache::applyFilters(
    GU_PrimVDB* vdbPrim,
    std::vector<FilterParms>& filterParms,
    BossT& boss,
    OP_Context& context,
    GU_Detail&,
    bool verbose)
{
    vdbPrim->makeGridUnique();
    typename GridT::Ptr grid = openvdb::gridPtrCast<GridT>(vdbPrim->getGridPtr());

    if (!grid) return false;

    using ValueT = typename GridT::ValueType;
    using MaskT = openvdb::FloatGrid;
    using FilterT = openvdb::tools::LevelSetFilter<GridT, MaskT, BossT>;

    const float voxelSize = static_cast<float>(grid->voxelSize()[0]);
    FilterT filter(*grid, &boss);
    filter.setTemporalScheme(openvdb::math::TVD_RK1);

    if (grid->background() < ValueT(openvdb::LEVEL_SET_HALF_WIDTH * voxelSize)) {
        std::string msg = "VDB primitive '"
            + std::string(vdbPrim->getGridName())
            + "' has a narrow band width that is less than 3 voxel units. ";
        addWarning(SOP_MESSAGE, msg.c_str());
    }

    for (size_t n = 0, N = filterParms.size(); n < N; ++n) {

        const GA_PrimitiveGroup *group = matchGroup(*gdp, filterParms[n].mGroup);

        // Skip this node if it doesn't operate on this primitive
        if (group && !group->containsOffset(vdbPrim->getMapOffset())) continue;

        filterGrid(context, filter, filterParms[n], boss, verbose);

        if (boss.wasInterrupted()) break;
    }

    return true;
}


template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::filterGrid(
    OP_Context& /*context*/,
    FilterT& filter,
    const FilterParms& parms,
    BossT& boss,
    bool verbose)
{
    // Alpha-masking
    using MaskT = typename FilterT::MaskType;
    typename MaskT::ConstPtr maskGrid;

    if (parms.mMaskInputNode) {
        const GU_Detail* maskGeo = inputGeo(1);

        if (maskGeo) {
            const GA_PrimitiveGroup* maskGroup =
                parsePrimitiveGroups(parms.mMaskName.c_str(), GroupCreator(maskGeo));
            if (!maskGroup && !parms.mMaskName.empty()) {
                addWarning(SOP_MESSAGE, "Mask not found.");
            } else {
                hvdb::VdbPrimCIterator maskIt(maskGeo, maskGroup);
                if (maskIt) {
                    if (maskIt->getStorageType() == UT_VDB_FLOAT) {
                        maskGrid = openvdb::gridConstPtrCast<MaskT>(maskIt->getGridPtr());
                    } else {
                        addWarning(SOP_MESSAGE, "The mask grid has to be a FloatGrid.");
                    }
                } else {
                    addWarning(SOP_MESSAGE, "The mask input is empty.");
                }
            }
        }
        filter.setMaskRange(parms.mMinMask, parms.mMaxMask);
        filter.invertMask(parms.mInvertMask);
    }

    filter.setTrimming(parms.mTrimMode);

    switch (parms.mAccuracy) {
        case ACCURACY_UPWIND_FIRST:  filter.setSpatialScheme(openvdb::math::FIRST_BIAS);   break;
        case ACCURACY_UPWIND_SECOND: filter.setSpatialScheme(openvdb::math::SECOND_BIAS);  break;
        case ACCURACY_UPWIND_THIRD:  filter.setSpatialScheme(openvdb::math::THIRD_BIAS);   break;
        case ACCURACY_WENO:          filter.setSpatialScheme(openvdb::math::WENO5_BIAS);   break;
        case ACCURACY_HJ_WENO:       filter.setSpatialScheme(openvdb::math::HJWENO5_BIAS); break;
    }

    const float voxelSize = float(filter.grid().voxelSize()[0]);

    const float ds = (parms.mWorldUnits ? 1.0f : voxelSize) * parms.mVoxelOffset;

    switch (parms.mFilterType) {

        case FILTER_TYPE_NONE:
            break;
        case FILTER_TYPE_RENORMALIZE:
            renormalize(parms, filter, boss, verbose);
            break;
        case FILTER_TYPE_RESIZE:
            resizeNarrowBand(parms, filter, boss, verbose);
            break;
        case FILTER_TYPE_MEAN_VALUE:
            mean(parms, filter, boss, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_GAUSSIAN:
            gaussian(parms, filter, boss, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_MEDIAN_VALUE:
            median(parms, filter, boss, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_MEAN_CURVATURE:
            meanCurvature(parms, filter, boss, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_LAPLACIAN_FLOW:
            laplacian(parms, filter, boss, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_TRACK:
            track(parms, filter, boss, verbose);
            break;
        case FILTER_TYPE_DILATE:
            offset(parms, filter, -ds, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_ERODE:
            offset(parms, filter,  ds, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_OPEN:
            offset(parms, filter,  ds, verbose, maskGrid.get());
            offset(parms, filter, -ds, verbose, maskGrid.get());
            break;
        case FILTER_TYPE_CLOSE:
            offset(parms, filter, -ds, verbose, maskGrid.get());
            offset(parms, filter,  ds, verbose, maskGrid.get());
            break;
    }
}


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

// Filter operations

template<typename FilterT>
inline void
SOP_OpenVDB_Filter_Level_Set::Cache::offset(
    const FilterParms&,
    FilterT& filter,
    const float offset,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    if (verbose) {
        std::cout << "Morphological " << (offset>0 ? "erosion" : "dilation")
            << " by the offset " << offset << std::endl;
    }

    filter.offset(offset, mask);
}

template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::mean(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    const double voxelScale = 1.0 / filter.grid().voxelSize()[0];

    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        int radius = parms.mStencilWidth;

        if (parms.mWorldUnits) {
            double voxelRadius = double(parms.mStencilWidthWorld) * voxelScale;
            radius = std::max(1, int(voxelRadius));
        }

        if (verbose) {
            std::cout << "Mean filter of radius " << radius << std::endl;
        }

        filter.mean(radius, mask);
    }
}

template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::gaussian(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    const double voxelScale = 1.0 / filter.grid().voxelSize()[0];

    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        int radius = parms.mStencilWidth;

        if (parms.mWorldUnits) {
            double voxelRadius = double(parms.mStencilWidthWorld) * voxelScale;
            radius = std::max(1, int(voxelRadius));
        }

        if (verbose) {
            std::cout << "Gaussian filter of radius " << radius << std::endl;
        }

        filter.gaussian(radius, mask);
    }
}

template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::median(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    const double voxelScale = 1.0 / filter.grid().voxelSize()[0];

    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        int radius = parms.mStencilWidth;

        if (parms.mWorldUnits) {
            double voxelRadius = double(parms.mStencilWidthWorld) * voxelScale;
            radius = std::max(1, int(voxelRadius));
        }

        if (verbose) {
            std::cout << "Median filter of radius " << radius << std::endl;
        }

        filter.median(radius, mask);
    }
}

template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::meanCurvature(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        if (verbose) std::cout << "Mean-curvature flow" << (n+1) << std::endl;

        filter.meanCurvature(mask);
    }
}

template<typename FilterT>
void
SOP_OpenVDB_Filter_Level_Set::Cache::laplacian(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose,
    const typename FilterT::MaskType* mask)
{
    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        if (verbose) std::cout << "Laplacian flow" << (n+1) << std::endl;

        filter.laplacian(mask);
    }
}

template<typename FilterT>
inline void
SOP_OpenVDB_Filter_Level_Set::Cache::renormalize(
    const FilterParms& parms,
    FilterT& filter,
    BossT&,
    bool verbose)
{
    // We will restore the old state since it is important to level set tracking
    const typename FilterT::State s = filter.getState();

    filter.setNormCount(parms.mIterations);

    filter.setTemporalScheme(openvdb::math::TVD_RK3);

    if (verbose) std::cout << "Renormalize #" << parms.mIterations << std::endl;

    filter.normalize();

    filter.prune();

    filter.setState(s);
}

template<typename FilterT>
inline void
SOP_OpenVDB_Filter_Level_Set::Cache::resizeNarrowBand(
    const FilterParms& parms,
    FilterT& filter,
    BossT&,
    bool /*verbose*/)
{
    // The filter is a statemachine so we will restore the old
    // state since it is important to subsequent level set tracking
    const typename FilterT::State s = filter.getState();

    filter.setNormCount(1); // only one normalization per iteration

    int width = parms.mHalfWidth;

    if (parms.mWorldUnits) {
        double voxelWidth = double(parms.mHalfWidthWorld) / filter.grid().voxelSize()[0];
        width = std::max(1, int(voxelWidth));
    }

    filter.resize(width);

    filter.prune();

    filter.setState(s);
}

template<typename FilterT>
inline void
SOP_OpenVDB_Filter_Level_Set::Cache::track(
    const FilterParms& parms,
    FilterT& filter,
    BossT& boss,
    bool verbose)
{
    for (int n = 0, N = parms.mIterations; n < N && !boss.wasInterrupted(); ++n) {

        if (verbose) std::cout << "Tracking #" << (n+1) << std::endl;
        filter.track();
    }
}
