CColouredPointsMap.cpp

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/* +------------------------------------------------------------------------+
|                     Mobile Robot Programming Toolkit (MRPT)            |
|                          https://www.mrpt.org/                         |
|                                                                        |
| Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
| See: https://www.mrpt.org/Authors - All rights reserved.               |
| Released under BSD License. See: https://www.mrpt.org/License          |
+------------------------------------------------------------------------+ */

#include "maps-precomp.h"  // Precomp header

#include <mrpt/core/bits_mem.h>
#include <mrpt/img/color_maps.h>
#include <mrpt/maps/CColouredPointsMap.h>
#include <mrpt/maps/CSimplePointsMap.h>
#include <mrpt/obs/CObservation3DRangeScan.h>
#include <mrpt/opengl/CPointCloudColoured.h>
#include <mrpt/serialization/aligned_serialization.h>
#include <mrpt/system/os.h>

#include "CPointsMap_crtp_common.h"

using namespace std;
using namespace mrpt;
using namespace mrpt::maps;
using namespace mrpt::obs;
using namespace mrpt::img;
using namespace mrpt::poses;
using namespace mrpt::system;
using namespace mrpt::math;
using namespace mrpt::config;

//  =========== Begin of Map definition ============
MAP_DEFINITION_REGISTER(
    "mrpt::maps::CColouredPointsMap,colourPointsMap",
    mrpt::maps::CColouredPointsMap)

CColouredPointsMap::TMapDefinition::TMapDefinition() = default;
void CColouredPointsMap::TMapDefinition::loadFromConfigFile_map_specific(
    const CConfigFileBase& source, const std::string& sectionNamePrefix)
{
    insertionOpts.loadFromConfigFile(
        source, sectionNamePrefix + string("_insertOpts"));
    likelihoodOpts.loadFromConfigFile(
        source, sectionNamePrefix + string("_likelihoodOpts"));
    colourOpts.loadFromConfigFile(
        source, sectionNamePrefix + string("_colorOpts"));
}

void CColouredPointsMap::TMapDefinition::dumpToTextStream_map_specific(
    std::ostream& out) const
{
    this->insertionOpts.dumpToTextStream(out);
    this->likelihoodOpts.dumpToTextStream(out);
    this->colourOpts.dumpToTextStream(out);
}

mrpt::maps::CMetricMap* CColouredPointsMap::internal_CreateFromMapDefinition(
    const mrpt::maps::TMetricMapInitializer& _def)
{
    const CColouredPointsMap::TMapDefinition& def =
        *dynamic_cast<const CColouredPointsMap::TMapDefinition*>(&_def);
    auto* obj = new CColouredPointsMap();
    obj->insertionOptions = def.insertionOpts;
    obj->likelihoodOptions = def.likelihoodOpts;
    obj->colorScheme = def.colourOpts;
    return obj;
}
//  =========== End of Map definition Block =========

IMPLEMENTS_SERIALIZABLE(CColouredPointsMap, CPointsMap, mrpt::maps)

void CColouredPointsMap::reserve(size_t newLength)
{
    m_x.reserve(newLength);
    m_y.reserve(newLength);
    m_z.reserve(newLength);
    m_color_R.reserve(newLength);
    m_color_G.reserve(newLength);
    m_color_B.reserve(newLength);
}

// Resizes all point buffers so they can hold the given number of points: newly
// created points are set to default values,
//  and old contents are not changed.
void CColouredPointsMap::resize(size_t newLength)
{
    m_x.resize(newLength, 0);
    m_y.resize(newLength, 0);
    m_z.resize(newLength, 0);
    m_color_R.resize(newLength, 1);
    m_color_G.resize(newLength, 1);
    m_color_B.resize(newLength, 1);
    mark_as_modified();
}

// Resizes all point buffers so they can hold the given number of points,
// *erasing* all previous contents
//  and leaving all points to default values.
void CColouredPointsMap::setSize(size_t newLength)
{
    m_x.assign(newLength, 0);
    m_y.assign(newLength, 0);
    m_z.assign(newLength, 0);
    m_color_R.assign(newLength, 1);
    m_color_G.assign(newLength, 1);
    m_color_B.assign(newLength, 1);
    mark_as_modified();
}

void CColouredPointsMap::impl_copyFrom(const CPointsMap& obj)
{
    // This also does a ::resize(N) of all data fields.
    CPointsMap::base_copyFrom(obj);

    const auto* pCol = dynamic_cast<const CColouredPointsMap*>(&obj);
    if (pCol)
    {
        m_color_R = pCol->m_color_R;
        m_color_G = pCol->m_color_G;
        m_color_B = pCol->m_color_B;
    }
}

uint8_t CColouredPointsMap::serializeGetVersion() const { return 9; }
void CColouredPointsMap::serializeTo(mrpt::serialization::CArchive& out) const
{
    uint32_t n = m_x.size();

    // First, write the number of points:
    out << n;

    if (n > 0)
    {
        out.WriteBufferFixEndianness(&m_x[0], n);
        out.WriteBufferFixEndianness(&m_y[0], n);
        out.WriteBufferFixEndianness(&m_z[0], n);
    }
    out << m_color_R << m_color_G << m_color_B;  // added in v4

    out << genericMapParams;  // v9
    insertionOptions.writeToStream(
        out);  // version 9?: insert options are saved with its own method
    likelihoodOptions.writeToStream(out);  // Added in version 5
}

void CColouredPointsMap::serializeFrom(
    mrpt::serialization::CArchive& in, uint8_t version)
{
    switch (version)
    {
        case 8:
        case 9:
        {
            mark_as_modified();

            // Read the number of points:
            uint32_t n;
            in >> n;

            this->resize(n);

            if (n > 0)
            {
                in.ReadBufferFixEndianness(&m_x[0], n);
                in.ReadBufferFixEndianness(&m_y[0], n);
                in.ReadBufferFixEndianness(&m_z[0], n);
            }
            in >> m_color_R >> m_color_G >> m_color_B;

            if (version >= 9)
                in >> genericMapParams;
            else
            {
                bool disableSaveAs3DObject;
                in >> disableSaveAs3DObject;
                genericMapParams.enableSaveAs3DObject = !disableSaveAs3DObject;
            }
            insertionOptions.readFromStream(in);
            likelihoodOptions.readFromStream(in);
        }
        break;

        case 0:
        case 1:
        case 2:
        case 3:
        case 4:
        case 5:
        case 6:
        case 7:
        {
            mark_as_modified();

            // Read the number of points:
            uint32_t n;
            in >> n;

            this->resize(n);

            if (n > 0)
            {
                in.ReadBufferFixEndianness(&m_x[0], n);
                in.ReadBufferFixEndianness(&m_y[0], n);
                in.ReadBufferFixEndianness(&m_z[0], n);

                // Version 1: weights are also stored:
                // Version 4: Type becomes long int -> uint32_t for
                // portability!!
                if (version >= 1)
                {
                    if (version >= 4)
                    {
                        if (version >= 7)
                        {
                            // Weights were removed from this class in v7 (MRPT
                            // 0.9.5),
                            //  so nothing else to do.
                        }
                        else
                        {
                            // Go on with old serialization format, but discard
                            // weights:
                            std::vector<uint32_t> dummy_pointWeight(n);
                            in.ReadBufferFixEndianness(
                                &dummy_pointWeight[0], n);
                        }
                    }
                    else
                    {
                        std::vector<uint32_t> dummy_pointWeight(n);
                        in.ReadBufferFixEndianness(&dummy_pointWeight[0], n);
                    }
                }
            }

            if (version >= 2)
            {
                // version 2: options saved too
                in >> insertionOptions.minDistBetweenLaserPoints >>
                    insertionOptions.addToExistingPointsMap >>
                    insertionOptions.also_interpolate >>
                    insertionOptions.disableDeletion >>
                    insertionOptions.fuseWithExisting >>
                    insertionOptions.isPlanarMap;

                if (version < 6)
                {
                    bool old_matchStaticPointsOnly;
                    in >> old_matchStaticPointsOnly;
                }

                in >> insertionOptions.maxDistForInterpolatePoints;
                {
                    bool disableSaveAs3DObject;
                    in >> disableSaveAs3DObject;
                    genericMapParams.enableSaveAs3DObject =
                        !disableSaveAs3DObject;
                }
            }

            if (version >= 3)
            {
                in >> insertionOptions.horizontalTolerance;
            }

            if (version >= 4)  // Color data
            {
                in >> m_color_R >> m_color_G >> m_color_B;
                if (version >= 7)
                {
                    // Removed: in >> m_min_dist;
                }
                else
                {
                    std::vector<float> dummy_dist;
                    in >> dummy_dist;
                }
            }
            else
            {
                m_color_R.assign(m_x.size(), 1.0f);
                m_color_G.assign(m_x.size(), 1.0f);
                m_color_B.assign(m_x.size(), 1.0f);
                // m_min_dist.assign(x.size(),2000.0f);
            }

            if (version >= 5)  // version 5: added likelihoodOptions
                likelihoodOptions.readFromStream(in);

            if (version >= 8)  // version 8: added insertInvalidPoints
                in >> insertionOptions.insertInvalidPoints;
        }
        break;
        default:
            MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version);
    };
}

/*---------------------------------------------------------------
Clear
---------------------------------------------------------------*/
void CColouredPointsMap::internal_clear()
{
    // This swap() thing is the only way to really deallocate the memory.
    vector_strong_clear(m_x);
    vector_strong_clear(m_y);
    vector_strong_clear(m_z);

    vector_strong_clear(m_color_R);
    vector_strong_clear(m_color_G);
    vector_strong_clear(m_color_B);

    mark_as_modified();
}

/** Changes a given point from map. First index is 0.
 * \exception Throws std::exception on index out of bound.
 */
void CColouredPointsMap::setPointRGB(
    size_t index, float x, float y, float z, float R, float G, float B)
{
    if (index >= m_x.size()) THROW_EXCEPTION("Index out of bounds");
    m_x[index] = x;
    m_y[index] = y;
    m_z[index] = z;
    this->m_color_R[index] = R;
    this->m_color_G[index] = G;
    this->m_color_B[index] = B;
    mark_as_modified();
}

/** Changes just the color of a given point from the map. First index is 0.
 * \exception Throws std::exception on index out of bound.
 */
void CColouredPointsMap::setPointColor(size_t index, float R, float G, float B)
{
    if (index >= m_x.size()) THROW_EXCEPTION("Index out of bounds");
    this->m_color_R[index] = R;
    this->m_color_G[index] = G;
    this->m_color_B[index] = B;
    // mark_as_modified();  // No need to rebuild KD-trees, etc...
}

void CColouredPointsMap::insertPointFast(float x, float y, float z)
{
    m_x.push_back(x);
    m_y.push_back(y);
    m_z.push_back(z);
    m_color_R.push_back(1);
    m_color_G.push_back(1);
    m_color_B.push_back(1);

    // mark_as_modified(); -> Fast
}

void CColouredPointsMap::insertPointRGB(
    float x, float y, float z, float R, float G, float B)
{
    m_x.push_back(x);
    m_y.push_back(y);
    m_z.push_back(z);
    m_color_R.push_back(R);
    m_color_G.push_back(G);
    m_color_B.push_back(B);

    mark_as_modified();
}

/*---------------------------------------------------------------
getAs3DObject
---------------------------------------------------------------*/
void CColouredPointsMap::getAs3DObject(
    mrpt::opengl::CSetOfObjects::Ptr& outObj) const
{
    ASSERT_(outObj);

    if (!genericMapParams.enableSaveAs3DObject) return;

    opengl::CPointCloudColoured::Ptr obj =
        std::make_shared<opengl::CPointCloudColoured>();

    obj->loadFromPointsMap(this);
    obj->setColor(1, 1, 1, 1.0);

    obj->setPointSize(this->renderOptions.point_size);

    outObj->insert(obj);
}

/*---------------------------------------------------------------
TColourOptions
---------------------------------------------------------------*/
CColouredPointsMap::TColourOptions::TColourOptions()

    = default;

void CColouredPointsMap::TColourOptions::loadFromConfigFile(
    const CConfigFileBase& source, const std::string& section)
{
    scheme = source.read_enum(section, "scheme", scheme);
    MRPT_LOAD_CONFIG_VAR(z_min, float, source, section)
    MRPT_LOAD_CONFIG_VAR(z_max, float, source, section)
    MRPT_LOAD_CONFIG_VAR(d_max, float, source, section)
}

void CColouredPointsMap::TColourOptions::dumpToTextStream(
    std::ostream& out) const
{
    out << "\n----------- [CColouredPointsMap::TColourOptions] ------------ "
           "\n\n";

    out << "scheme                                  = " << scheme << endl;
    out << "z_min                                   = " << z_min << endl;
    out << "z_max                                   = " << z_max << endl;
    out << "d_max                                   = " << d_max << endl;
}

void CColouredPointsMap::getPointRGB(
    size_t index, float& x, float& y, float& z, float& R, float& G,
    float& B) const
{
    if (index >= m_x.size()) THROW_EXCEPTION("Index out of bounds");

    x = m_x[index];
    y = m_y[index];
    z = m_z[index];
    R = m_color_R[index];
    G = m_color_G[index];
    B = m_color_B[index];
}

/** Retrieves a point color (colors range is [0,1])
 */
void CColouredPointsMap::getPointColor(
    size_t index, float& R, float& G, float& B) const
{
    if (index >= m_x.size()) THROW_EXCEPTION("Index out of bounds");

    R = m_color_R[index];
    G = m_color_G[index];
    B = m_color_B[index];
}

// This function is duplicated from
// "mrpt::vision::pinhole::projectPoint_with_distortion", to avoid
//  a dependency on mrpt-vision.
static void aux_projectPoint_with_distortion(
    const mrpt::math::TPoint3D& P, const TCamera& params, TPixelCoordf& pixel,
    bool accept_points_behind)
{
    MRPT_UNUSED_PARAM(accept_points_behind);
    // Pinhole model:
    const double x = P.x / P.z;
    const double y = P.y / P.z;

    // Radial distortion:
    const double r2 = square(x) + square(y);
    const double r4 = square(r2);
    const double r6 = r2 * r4;

    pixel.x = params.cx() +
              params.fx() * (x * (1 + params.dist[0] * r2 +
                                  params.dist[1] * r4 + params.dist[4] * r6) +
                             2 * params.dist[2] * x * y +
                             params.dist[3] * (r2 + 2 * square(x)));
    pixel.y = params.cy() +
              params.fy() * (y * (1 + params.dist[0] * r2 +
                                  params.dist[1] * r4 + params.dist[4] * r6) +
                             2 * params.dist[3] * x * y +
                             params.dist[2] * (r2 + 2 * square(y)));
}

/*---------------------------------------------------------------
getPoint
---------------------------------------------------------------*/
bool CColouredPointsMap::colourFromObservation(
    const CObservationImage& obs, const CPose3D& robotPose)
{
    // Check if image is not grayscale
    ASSERT_(obs.image.isColor());

    CPose3D cameraPoseR;  // Get Camera Pose on the Robot(B) (CPose3D)
    CPose3D cameraPoseW;  // World Camera Pose

    obs.getSensorPose(cameraPoseR);
    cameraPoseW = robotPose + cameraPoseR;  // Camera Global Coordinates

    // Image Information
    unsigned int imgW = obs.image.getWidth();
    unsigned int imgH = obs.image.getHeight();

    // Projection related variables
    std::vector<TPixelCoordf>
        projectedPoints;  // The set of projected points in the image
    std::vector<TPixelCoordf>::iterator
        itProPoints;  // Iterator for projectedPoints
    std::vector<size_t> p_idx;
    std::vector<float> p_dist;
    std::vector<unsigned int> p_proj;

    // Get the N closest points
    kdTreeNClosestPoint2DIdx(
        cameraPoseW.x(), cameraPoseW.y(),  // query point
        200000,  // number of points to search
        p_idx, p_dist);  // indexes and distances of the returned points

    // Fill p3D vector
    for (size_t k = 0; k < p_idx.size(); k++)
    {
        float d = sqrt(p_dist[k]);
        size_t idx = p_idx[k];
        if (d < colorScheme.d_max)  //  && d < m_min_dist[idx] )
        {
            TPixelCoordf px;
            aux_projectPoint_with_distortion(
                TPoint3D(m_x[idx], m_y[idx], m_z[idx]), obs.cameraParams, px,
                true);
            projectedPoints.push_back(px);
            p_proj.push_back(k);
        }  // end if
    }  // end for

    // Get channel order
    unsigned int chR, chG, chB;
    if (obs.image.getChannelsOrder()[0] == 'B')
    {
        chR = 2;
        chG = 1;
        chB = 0;
    }
    else
    {
        chR = 0;
        chG = 1;
        chB = 2;
    }

    unsigned int n_proj = 0;
    const float factor = 1.0f / 255;  // Normalize pixels:

    // Get the colour of the projected points
    size_t k;
    for (itProPoints = projectedPoints.begin(), k = 0;
         itProPoints != projectedPoints.end(); ++itProPoints, ++k)
    {
        // Only get the points projected inside the image
        if (itProPoints->x >= 0 && itProPoints->x < imgW &&
            itProPoints->y > 0 && itProPoints->y < imgH)
        {
            unsigned int ii = p_idx[p_proj[k]];
            uint8_t* p = obs.image(
                (unsigned int)itProPoints->x, (unsigned int)itProPoints->y);

            m_color_R[ii] = p[chR] * factor;  // R
            m_color_G[ii] = p[chG] * factor;  // G
            m_color_B[ii] = p[chB] * factor;  // B
            // m_min_dist[ii]   = p_dist[p_proj[k]];

            n_proj++;
        }
    }  // end for

    return true;
}  // end colourFromObservation

void CColouredPointsMap::resetPointsMinDist(float defValue)
{
    MRPT_UNUSED_PARAM(defValue);
    // m_min_dist.assign(x.size(),defValue);
}

bool CColouredPointsMap::save3D_and_colour_to_text_file(
    const std::string& file) const
{
    FILE* f = os::fopen(file.c_str(), "wt");
    if (!f) return false;

    for (size_t i = 0; i < m_x.size(); i++)
        os::fprintf(
            f, "%f %f %f %d %d %d\n", m_x[i], m_y[i], m_z[i],
            (uint8_t)(255 * m_color_R[i]), (uint8_t)(255 * m_color_G[i]),
            (uint8_t)(255 * m_color_B[i]));

    os::fclose(f);
    return true;
}

// ================================ PLY files import & export virtual methods
// ================================

/** In a base class, reserve memory to prepare subsequent calls to
 * PLY_import_set_vertex */
void CColouredPointsMap::PLY_import_set_vertex_count(const size_t N)
{
    this->setSize(N);
}

/** In a base class, will be called after PLY_import_set_vertex_count() once for
 * each loaded point.
 *  \param pt_color Will be nullptr if the loaded file does not provide color
 * info.
 */
void CColouredPointsMap::PLY_import_set_vertex(
    const size_t idx, const mrpt::math::TPoint3Df& pt, const TColorf* pt_color)
{
    if (pt_color)
        this->setPointRGB(
            idx, pt.x, pt.y, pt.z, pt_color->R, pt_color->G, pt_color->B);
    else
        this->setPoint(idx, pt.x, pt.y, pt.z);
}

/** In a base class, will be called after PLY_export_get_vertex_count() once for
 * each exported point.
 *  \param pt_color Will be nullptr if the loaded file does not provide color
 * info.
 */
void CColouredPointsMap::PLY_export_get_vertex(
    const size_t idx, mrpt::math::TPoint3Df& pt, bool& pt_has_color,
    TColorf& pt_color) const
{
    pt_has_color = true;

    pt.x = m_x[idx];
    pt.y = m_y[idx];
    pt.z = m_z[idx];

    pt_color.R = m_color_R[idx];
    pt_color.G = m_color_G[idx];
    pt_color.B = m_color_B[idx];
}

/*---------------------------------------------------------------
addFrom_classSpecific
---------------------------------------------------------------*/
void CColouredPointsMap::addFrom_classSpecific(
    const CPointsMap& anotherMap, const size_t nPreviousPoints)
{
    const size_t nOther = anotherMap.size();

    // Specific data for this class:
    const auto* anotheMap_col =
        dynamic_cast<const CColouredPointsMap*>(&anotherMap);

    if (anotheMap_col)
    {
        for (size_t i = 0, j = nPreviousPoints; i < nOther; i++, j++)
        {
            m_color_R[j] = anotheMap_col->m_color_R[i];
            m_color_G[j] = anotheMap_col->m_color_G[i];
            m_color_B[j] = anotheMap_col->m_color_B[i];
        }
    }
}

namespace mrpt::maps::detail
{
using mrpt::maps::CColouredPointsMap;

template <>
struct pointmap_traits<CColouredPointsMap>
{
    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called only once before inserting
     * points - this is the place to reserve memory in lric for extra working
     * variables. */
    inline static void internal_loadFromRangeScan2D_init(
        CColouredPointsMap& me,
        mrpt::maps::CPointsMap::TLaserRange2DInsertContext& lric)
    {
        // Vars:
        //  [0] -> pR
        //  [1] -> pG
        //  [2] -> pB
        //  [3] -> Az_1_color
        lric.fVars.resize(4);

        ASSERT_NOT_EQUAL_(me.colorScheme.z_max, me.colorScheme.z_min);
        lric.fVars[3] = 1.0 / (me.colorScheme.z_max - me.colorScheme.z_min);
    }

    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called once per range data */
    inline static void internal_loadFromRangeScan2D_prepareOneRange(
        CColouredPointsMap& me, const float gx, const float gy, const float gz,
        mrpt::maps::CPointsMap::TLaserRange2DInsertContext& lric)
    {
        MRPT_UNUSED_PARAM(gx);
        MRPT_UNUSED_PARAM(gy);
        // Relative height of the point wrt the sensor:
        const float rel_z = gz - lric.HM(2, 3);  // m23;

        // Variable renaming:
        float& pR = lric.fVars[0];
        float& pG = lric.fVars[1];
        float& pB = lric.fVars[2];
        float Az_1_color = lric.fVars[3];

        // Compute color:
        switch (me.colorScheme.scheme)
        {
            // case cmFromHeightRelativeToSensor:
            case CColouredPointsMap::cmFromHeightRelativeToSensorJet:
            case CColouredPointsMap::cmFromHeightRelativeToSensorGray:
            {
                float q = (rel_z - me.colorScheme.z_min) * Az_1_color;
                if (q < 0)
                    q = 0;
                else if (q > 1)
                    q = 1;

                if (me.colorScheme.scheme ==
                    CColouredPointsMap::cmFromHeightRelativeToSensorGray)
                {
                    pR = pG = pB = q;
                }
                else
                {
                    jet2rgb(q, pR, pG, pB);
                }
            }
            break;
            case CColouredPointsMap::cmFromIntensityImage:
            {
                // In 2D scans we don't have this channel.
                pR = pG = pB = 1.0;
            }
            break;
            default:
                THROW_EXCEPTION("Unknown color scheme");
        }
    }
    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called after each
     * "{x,y,z}.push_back(...);" */
    inline static void internal_loadFromRangeScan2D_postPushBack(
        CColouredPointsMap& me,
        mrpt::maps::CPointsMap::TLaserRange2DInsertContext& lric)
    {
        float& pR = lric.fVars[0];
        float& pG = lric.fVars[1];
        float& pB = lric.fVars[2];
        me.m_color_R.push_back(pR);
        me.m_color_G.push_back(pG);
        me.m_color_B.push_back(pB);
        // m_min_dist.push_back(1e4);
    }

    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called only once before inserting
     * points - this is the place to reserve memory in lric for extra working
     * variables. */
    inline static void internal_loadFromRangeScan3D_init(
        CColouredPointsMap& me,
        mrpt::maps::CPointsMap::TLaserRange3DInsertContext& lric)
    {
        // Vars:
        //  [0] -> pR
        //  [1] -> pG
        //  [2] -> pB
        //  [3] -> Az_1_color
        //  [4] -> K_8u
        //  [5] -> cx
        //  [6] -> cy
        //  [7] -> fx
        //  [8] -> fy
        lric.fVars.resize(9);
        float& cx = lric.fVars[5];
        float& cy = lric.fVars[6];
        float& fx = lric.fVars[7];
        float& fy = lric.fVars[8];

        // unsigned int vars:
        //  [0] -> imgW
        //  [1] -> imgH
        //  [2] -> img_idx_x
        //  [3] -> img_idx_y
        lric.uVars.resize(4);
        unsigned int& imgW = lric.uVars[0];
        unsigned int& imgH = lric.uVars[1];
        unsigned int& img_idx_x = lric.uVars[2];
        unsigned int& img_idx_y = lric.uVars[3];

        // bool vars:
        //  [0] -> hasValidIntensityImage
        //  [1] -> hasColorIntensityImg
        //  [2] -> simple_3d_to_color_relation
        lric.bVars.resize(3);
        uint8_t& hasValidIntensityImage = lric.bVars[0];
        uint8_t& hasColorIntensityImg = lric.bVars[1];
        uint8_t& simple_3d_to_color_relation = lric.bVars[2];

        ASSERT_NOT_EQUAL_(me.colorScheme.z_max, me.colorScheme.z_min);
        lric.fVars[3] = 1.0 / (me.colorScheme.z_max -
                               me.colorScheme.z_min);  // Az_1_color = ...
        lric.fVars[4] = 1.0f / 255;  // K_8u

        hasValidIntensityImage = false;
        imgW = 0;
        imgH = 0;

        if (lric.rangeScan.hasIntensityImage)
        {
            // assure the size matches:
            if (lric.rangeScan.points3D_x.size() ==
                lric.rangeScan.intensityImage.getWidth() *
                    lric.rangeScan.intensityImage.getHeight())
            {
                hasValidIntensityImage = true;
                imgW = lric.rangeScan.intensityImage.getWidth();
                imgH = lric.rangeScan.intensityImage.getHeight();
            }
        }

        hasColorIntensityImg =
            hasValidIntensityImage && lric.rangeScan.intensityImage.isColor();

        // running indices for the image pixels for the gray levels:
        // If both range & intensity images coincide (e.g. SwissRanger), then we
        // can just
        // assign 3D points to image pixels one-to-one, but that's not the case
        // if
        //
        simple_3d_to_color_relation =
            (std::abs(lric.rangeScan.relativePoseIntensityWRTDepth.norm()) <
             1e-5);
        img_idx_x = 0;
        img_idx_y = 0;

        // Will be used just if simple_3d_to_color_relation=false
        cx = lric.rangeScan.cameraParamsIntensity.cx();
        cy = lric.rangeScan.cameraParamsIntensity.cy();
        fx = lric.rangeScan.cameraParamsIntensity.fx();
        fy = lric.rangeScan.cameraParamsIntensity.fy();
    }

    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called once per range data */
    inline static void internal_loadFromRangeScan3D_prepareOneRange(
        CColouredPointsMap& me, const float gx, const float gy, const float gz,
        mrpt::maps::CPointsMap::TLaserRange3DInsertContext& lric)
    {
        MRPT_UNUSED_PARAM(gx);
        MRPT_UNUSED_PARAM(gy);
        // Rename variables:
        float& pR = lric.fVars[0];
        float& pG = lric.fVars[1];
        float& pB = lric.fVars[2];
        float& Az_1_color = lric.fVars[3];
        float& K_8u = lric.fVars[4];
        float& cx = lric.fVars[5];
        float& cy = lric.fVars[6];
        float& fx = lric.fVars[7];
        float& fy = lric.fVars[8];

        unsigned int& imgW = lric.uVars[0];
        unsigned int& imgH = lric.uVars[1];
        unsigned int& img_idx_x = lric.uVars[2];
        unsigned int& img_idx_y = lric.uVars[3];

        const uint8_t& hasValidIntensityImage = lric.bVars[0];
        const uint8_t& hasColorIntensityImg = lric.bVars[1];
        const uint8_t& simple_3d_to_color_relation = lric.bVars[2];

        // Relative height of the point wrt the sensor:
        const float rel_z = gz - lric.HM(2, 3);  // m23;

        // Compute color:
        switch (me.colorScheme.scheme)
        {
            // case cmFromHeightRelativeToSensor:
            case CColouredPointsMap::cmFromHeightRelativeToSensorJet:
            case CColouredPointsMap::cmFromHeightRelativeToSensorGray:
            {
                float q = (rel_z - me.colorScheme.z_min) * Az_1_color;
                if (q < 0)
                    q = 0;
                else if (q > 1)
                    q = 1;

                if (me.colorScheme.scheme ==
                    CColouredPointsMap::cmFromHeightRelativeToSensorGray)
                {
                    pR = pG = pB = q;
                }
                else
                {
                    jet2rgb(q, pR, pG, pB);
                }
            }
            break;
            case CColouredPointsMap::cmFromIntensityImage:
            {
                // Do we have to project the 3D point into the image plane??
                bool hasValidColor = false;
                if (simple_3d_to_color_relation)
                {
                    hasValidColor = true;
                }
                else
                {
                    // Do projection:
                    TPoint3D pt;  // pt_wrt_colorcam;
                    lric.rangeScan.relativePoseIntensityWRTDepth
                        .inverseComposePoint(
                            lric.scan_x, lric.scan_y, lric.scan_z, pt.x, pt.y,
                            pt.z);

                    // Project to image plane:
                    if (pt.z)
                    {
                        img_idx_x = cx + fx * pt.x / pt.z;
                        img_idx_y = cy + fy * pt.y / pt.z;

                        hasValidColor = img_idx_x < imgW &&  // img_idx_x>=0
                                                             // isn't needed for
                                                             // unsigned.
                                        img_idx_y < imgH;
                    }
                }

                const auto& ii = lric.rangeScan.intensityImage;
                if (hasValidColor && hasColorIntensityImg)
                {
                    const auto* c = ii.ptr<uint8_t>(img_idx_x, img_idx_y);
                    pR = c[2] * K_8u;
                    pG = c[1] * K_8u;
                    pB = c[0] * K_8u;
                }
                else if (hasValidColor && hasValidIntensityImage)
                {
                    const auto c = ii.at<uint8_t>(img_idx_x, img_idx_y);
                    pR = pG = pB = c * K_8u;
                }
                else
                {
                    pR = pG = pB = 1.0;
                }
            }
            break;
            default:
                THROW_EXCEPTION("Unknown color scheme");
        }
    }

    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called after each
     * "{x,y,z}.push_back(...);" */
    inline static void internal_loadFromRangeScan3D_postPushBack(
        CColouredPointsMap& me,
        mrpt::maps::CPointsMap::TLaserRange3DInsertContext& lric)
    {
        float& pR = lric.fVars[0];
        float& pG = lric.fVars[1];
        float& pB = lric.fVars[2];

        me.m_color_R.push_back(pR);
        me.m_color_G.push_back(pG);
        me.m_color_B.push_back(pB);

        // m_min_dist.push_back(1e4);
    }

    /** Helper method fot the generic implementation of
     * CPointsMap::loadFromRangeScan(), to be called once per range data, at the
     * end */
    inline static void internal_loadFromRangeScan3D_postOneRange(
        CColouredPointsMap& me,
        mrpt::maps::CPointsMap::TLaserRange3DInsertContext& lric)
    {
        MRPT_UNUSED_PARAM(me);
        unsigned int& imgW = lric.uVars[0];
        unsigned int& img_idx_x = lric.uVars[2];
        unsigned int& img_idx_y = lric.uVars[3];

        const uint8_t& hasValidIntensityImage = lric.bVars[0];
        const uint8_t& simple_3d_to_color_relation = lric.bVars[2];

        // Advance the color pointer (just for simple cases, e.g. SwissRanger,
        // not for Kinect)
        if (simple_3d_to_color_relation && hasValidIntensityImage)
        {
            if (++img_idx_x >= imgW)
            {
                img_idx_y++;
                img_idx_x = 0;
            }
        }
    }
};
}  // namespace mrpt::maps::detail
/** See CPointsMap::loadFromRangeScan() */
void CColouredPointsMap::loadFromRangeScan(
    const CObservation2DRangeScan& rangeScan, const CPose3D* robotPose)
{
    mrpt::maps::detail::loadFromRangeImpl<CColouredPointsMap>::
		templ_loadFromRangeScan(*this, rangeScan, robotPose);
}

/** See CPointsMap::loadFromRangeScan() */
void CColouredPointsMap::loadFromRangeScan(
    const CObservation3DRangeScan& rangeScan, const CPose3D* robotPose)
{
    mrpt::maps::detail::loadFromRangeImpl<CColouredPointsMap>::
		templ_loadFromRangeScan(*this, rangeScan, robotPose);
}