VelodyneCalibration.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 "obs-precomp.h"  // Precompiled headers

#include <mrpt/core/bits_math.h>
#include <mrpt/core/exceptions.h>
#include <mrpt/obs/VelodyneCalibration.h>
#include <cmath>
#include <fstream>
#include <iostream>
#include <map>
#include <sstream>

#include <mrpt/config.h>
#if MRPT_HAS_YAMLCPP
#include <yaml-cpp/yaml.h>
#endif
#if MRPT_HAS_TINYXML2
#include <tinyxml2.h>
#endif

// ======= Default calibration files ========================
#include "velodyne_default_calib_HDL-32.h"
#include "velodyne_default_calib_VLP-16.h"
#include "velodyne_default_calib_hdl64e-s3.h"
// ======= End of default calibration files =================

using namespace std;
using namespace mrpt::obs;

VelodyneCalibration::PerLaserCalib::PerLaserCalib() = default;

#if MRPT_HAS_TINYXML2
static const tinyxml2::XMLElement* get_xml_children(
    const tinyxml2::XMLNode* e, const char* name)
{
    ASSERT_(e != nullptr);
    // It's ok if name is nullptr for tinyxml2

    auto ret = e->FirstChildElement(name);
    if (!ret)
        throw std::runtime_error(
            mrpt::format("Cannot find XML tag `%s`", name));
    return ret;
}
static const char* get_xml_children_as_str(
    const tinyxml2::XMLNode* e, const char* name)
{
    auto n = get_xml_children(e, name);
    ASSERTMSG_(n, mrpt::format("Cannot find XML tag `%s`", name));
    const char* txt = n->GetText();
    ASSERTMSG_(
        txt, mrpt::format("Cannot convert XML tag `%s` to string", name));
    return txt;
}
static double get_xml_children_as_double(
    const tinyxml2::XMLNode* e, const char* name)
{
    return ::atof(get_xml_children_as_str(e, name));
}
static int get_xml_children_as_int(const tinyxml2::XMLNode* e, const char* name)
{
    return ::atoi(get_xml_children_as_str(e, name));
}
#endif

VelodyneCalibration::VelodyneCalibration() : laser_corrections(0) {}
bool VelodyneCalibration::internal_loadFromXMLNode(void* node_ptr)
{
#if MRPT_HAS_TINYXML2

    ASSERT_(node_ptr != nullptr);

    const tinyxml2::XMLDocument& root =
        *reinterpret_cast<tinyxml2::XMLDocument*>(node_ptr);

    auto node_bs = get_xml_children(&root, "boost_serialization");
    auto node_DB = get_xml_children(node_bs, "DB");
    auto node_enabled_ = get_xml_children(node_DB, "enabled_");

    // Clear previous contents:
    clear();

    const int nEnabled = get_xml_children_as_int(node_enabled_, "count");
    ASSERT_ABOVE_(nEnabled, 0);
    ASSERT_BELOW_(nEnabled, 10000);

    int enabledCount = 0;
    const tinyxml2::XMLElement* node_enabled_ith = nullptr;
    for (int i = 0; i < nEnabled; i++)
    {
        if (node_enabled_ith)
            node_enabled_ith = node_enabled_ith->NextSiblingElement("item");
        else
        {
            ASSERT_EQUAL_(i, 0);
            node_enabled_ith = node_enabled_->FirstChildElement("item");
        }

        if (!node_enabled_ith)
            throw std::runtime_error(
                "Cannot find the expected number of XML nodes: "
                "'enabled_::item'");
        const int enable_val = atoi(node_enabled_ith->GetText());
        if (enable_val) ++enabledCount;
    }

    // enabledCount = number of lasers in the LIDAR
    this->laser_corrections.resize(enabledCount);

    auto node_points_ = get_xml_children(node_DB, "points_");
    const tinyxml2::XMLElement* node_points_item = nullptr;

    for (int i = 0;; ++i)
    {
        if (!node_points_item)
            node_points_item = node_points_->FirstChildElement("item");
        else
            node_points_item = node_points_item->NextSiblingElement("item");

        if (!node_points_item) break;

        auto node_px = get_xml_children(node_points_item, "px");
        auto node_px_id = get_xml_children(node_px, "id_");
        const int id = atoi(node_px_id->GetText());
        ASSERT_ABOVEEQ_(id, 0);
        if (id >= enabledCount) continue;  // ignore

        PerLaserCalib& plc = laser_corrections[id];

        plc.azimuthCorrection =
            get_xml_children_as_double(node_px, "rotCorrection_");
        plc.verticalCorrection =
            get_xml_children_as_double(node_px, "vertCorrection_");

        plc.distanceCorrection =
            0.01 * get_xml_children_as_double(node_px, "distCorrection_");
        plc.verticalOffsetCorrection =
            0.01 * get_xml_children_as_double(node_px, "vertOffsetCorrection_");
        plc.horizontalOffsetCorrection =
            0.01 *
            get_xml_children_as_double(node_px, "horizOffsetCorrection_");

        plc.sinVertCorrection = std::sin(mrpt::DEG2RAD(plc.verticalCorrection));
        plc.cosVertCorrection = std::cos(mrpt::DEG2RAD(plc.verticalCorrection));

        plc.sinVertOffsetCorrection =
            plc.sinVertCorrection * plc.sinVertOffsetCorrection;
        plc.cosVertOffsetCorrection =
            plc.cosVertCorrection * plc.sinVertOffsetCorrection;
    }

    return true;  // Ok
#else
    return false;
#endif
}

bool VelodyneCalibration::loadFromXMLText(const std::string& xml_file_contents)
{
    try
    {
#if MRPT_HAS_TINYXML2
        tinyxml2::XMLDocument doc;
        const auto err = doc.Parse(xml_file_contents.c_str());

        if (err != tinyxml2::XML_SUCCESS)
        {
            std::cerr
                << "[VelodyneCalibration::loadFromXMLText] Error parsing XML "
                   "content: "
#if TIXML2_MAJOR_VERSION >= 7 || \
    (TIXML2_MAJOR_VERSION >= 6 && TIXML2_MINOR_VERSION >= 2)
                << tinyxml2::XMLDocument::ErrorIDToName(err)
#else
                << doc.ErrorName()
#endif
                << std::endl;
            return false;
        }

        return internal_loadFromXMLNode(reinterpret_cast<void*>(&doc));
#else
        THROW_EXCEPTION("MRPT built without tinyxml2");
#endif
    }
    catch (exception& e)
    {
        cerr << "[VelodyneCalibration::loadFromXMLFile] Exception:" << endl
             << e.what() << endl;
        return false;
    }
}

/** Loads calibration from file. \return false on any error, true on success */
// See reference code in:
// vtkVelodyneHDLReader::vtkInternal::LoadCorrectionsFile()
bool VelodyneCalibration::loadFromXMLFile(
    const std::string& velodyne_calibration_xml_fil)
{
    try
    {
#if MRPT_HAS_TINYXML2
        tinyxml2::XMLDocument doc;
        const auto err = doc.LoadFile(velodyne_calibration_xml_fil.c_str());

        if (err != tinyxml2::XML_SUCCESS)
        {
            std::cerr << "[VelodyneCalibration::loadFromXMLFile] Error loading "
                         "XML file: "
#if TIXML2_MAJOR_VERSION >= 7 || \
    (TIXML2_MAJOR_VERSION >= 6 && TIXML2_MINOR_VERSION >= 2)
                      << tinyxml2::XMLDocument::ErrorIDToName(err)
#else
                      << doc.ErrorName()
#endif
                      << std::endl;
            return false;
        }
        return internal_loadFromXMLNode(reinterpret_cast<void*>(&doc));
#else
        THROW_EXCEPTION("MRPT built without tinyxml2");
#endif
    }
    catch (exception& e)
    {
        cerr << "[VelodyneCalibration::loadFromXMLFile] Exception:" << endl
             << e.what() << endl;
        return false;
    }
}

bool VelodyneCalibration::loadFromYAMLText(const std::string& str)
{
#if MRPT_HAS_YAMLCPP
    try
    {
        YAML::Node root = YAML::Load(str);

        // Clear previous contents:
        clear();

        const auto num_lasers = root["num_lasers"].as<unsigned int>(0);
        ASSERT_(num_lasers > 0);

        this->laser_corrections.resize(num_lasers);

        auto lasers = root["lasers"];
        ASSERT_EQUAL_(lasers.size(), num_lasers);

        for (auto item : lasers)
        {
            const auto id = item["laser_id"].as<unsigned int>(9999999);
            ASSERT_(id < num_lasers);

            PerLaserCalib& plc = laser_corrections[id];

            plc.azimuthCorrection = item["rot_correction"].as<double>();
            plc.verticalCorrection = item["vert_correction"].as<double>();

            plc.distanceCorrection = item["dist_correction"].as<double>();
            plc.verticalOffsetCorrection =
                item["vert_offset_correction"].as<double>();
            plc.horizontalOffsetCorrection =
                item["horiz_offset_correction"].as<double>();

            plc.sinVertCorrection = std::sin(plc.verticalCorrection);
            plc.cosVertCorrection = std::cos(plc.verticalCorrection);

            plc.sinVertOffsetCorrection =
                plc.sinVertCorrection * plc.sinVertOffsetCorrection;
            plc.cosVertOffsetCorrection =
                plc.cosVertCorrection * plc.sinVertOffsetCorrection;
        }

        return true;  // all ok
    }
    catch (const std::exception& e)
    {
        std::cerr << "[VelodyneCalibration::loadFromYAMLText]" << e.what()
                  << "\n";
        return false;
    }
#else
    THROW_EXCEPTION("This method requires building MRPT with YAML-CPP.");
#endif
}

bool VelodyneCalibration::loadFromYAMLFile(const std::string& filename)
{
#if MRPT_HAS_YAMLCPP
    try
    {
        std::ifstream f(filename);
        if (!f.is_open())
            THROW_EXCEPTION_FMT("Cannot open file: '%s'", filename.c_str());

        // Load file:
        std::string str(
            (std::istreambuf_iterator<char>(f)),
            std::istreambuf_iterator<char>());

        return loadFromYAMLText(str);
    }
    catch (const std::exception& e)
    {
        std::cerr << "[VelodyneCalibration::loadFromYAMLFile]" << e.what()
                  << "\n";
        return false;
    }
#else
    THROW_EXCEPTION("This method requires building MRPT with YAML-CPP.");
#endif
}

bool VelodyneCalibration::empty() const { return laser_corrections.empty(); }
void VelodyneCalibration::clear() { laser_corrections.clear(); }
static std::map<std::string, VelodyneCalibration> cache_default_calibs;

// It always return a calibration structure, but it may be empty if the model
// name is unknown.
const VelodyneCalibration& VelodyneCalibration::LoadDefaultCalibration(
    const std::string& lidar_model)
{
    // Cached calib data?
    auto it = cache_default_calibs.find(lidar_model);
    if (it != cache_default_calibs.end()) return it->second;

    VelodyneCalibration result;  // Leave empty to indicate unknown model
    std::string xml_contents, yaml_contents;

    if (lidar_model == "VLP16")
        xml_contents = velodyne_default_calib_VLP16;
    else if (lidar_model == "HDL32")
        xml_contents = velodyne_default_calib_HDL32;
    else if (lidar_model == "HDL64")
        yaml_contents = velodyne_default_calib_HDL64E_S3;

    if (!xml_contents.empty())
    {
        if (!result.loadFromXMLText(xml_contents))
            std::cerr << "[VelodyneCalibration::LoadDefaultCalibration] Error "
                         "parsing default XML calibration file for model '"
                      << lidar_model << "'\n";
    }
    else if (!yaml_contents.empty())
    {
        if (!result.loadFromYAMLText(yaml_contents))
            std::cerr << "[VelodyneCalibration::LoadDefaultCalibration] Error "
                         "parsing default YAML calibration file for model '"
                      << lidar_model << "'\n";
    }

    cache_default_calibs[lidar_model] = result;
    return cache_default_calibs[lidar_model];
}