Example: maps_gmrf_map_example

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2021, 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 <mrpt/gui.h>
#include <mrpt/maps/CGasConcentrationGridMap2D.h>
#include <mrpt/opengl/CPointCloud.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/random.h>

#include <iostream>

using namespace mrpt;
using namespace mrpt::maps;
using namespace mrpt::math;
using namespace mrpt::random;
using namespace std;

// Example of custom connectivity pattern:
struct MyConnectivityVisitor
    : public mrpt::maps::CRandomFieldGridMap2D::ConnectivityDescriptor
{
    bool getEdgeInformation(
        const CRandomFieldGridMap2D* parent,
        size_t icx, size_t icy,
        size_t jcx, size_t jcy,
        double& out_edge_information) override
    {
        out_edge_information = 1.0 / (1.0 + icx + icy);
        return true;
    }
};

void Example_GMRF()
{
    const double X_SIZE = 10.0;
    const double Y_SIZE = 10.0;
    const double RESOLUTION = 0.5;

    mrpt::maps::CGasConcentrationGridMap2D gasmap(
        CRandomFieldGridMap2D::mrGMRF_SD /*map type*/, 0, X_SIZE, 0, Y_SIZE,
        RESOLUTION /* resolution */
    );

    auto conn =
        mrpt::maps::CGasConcentrationGridMap2D::ConnectivityDescriptor::Ptr(
            new MyConnectivityVisitor);
    gasmap.setMinLoggingLevel(mrpt::system::LVL_DEBUG);
    gasmap.setCellsConnectivity(conn);
    gasmap.clear();  // for the connectivity to be taken into account.

    auto gl_data = mrpt::opengl::CPointCloud::Create();
    gl_data->setPointSize(3.0f);

    for (int i = 0; i < 20; i++)
    {
        const double value = getRandomGenerator().drawUniform(0.01, 0.99);
        const double x = getRandomGenerator().drawUniform(0.1, 0.95 * X_SIZE);
        const double y = getRandomGenerator().drawUniform(0.1, 0.95 * Y_SIZE);

        printf(
            "Observation: (x,y)=(%6.02f,%6.02f,)  => value: %6.03f\n", x, y,
            value);
        gl_data->insertPoint(x, y, value);

        gasmap.insertIndividualReading(
            value, TPoint2D(x, y), false /*dont update map now*/);
    }

    // Update only once now:
    gasmap.updateMapEstimation();

    // 3D view:
    auto glObj = mrpt::opengl::CSetOfObjects::Create();
    gasmap.getAs3DObject(glObj);

    mrpt::gui::CDisplayWindow3D win("Map", 640, 480);

    mrpt::opengl::COpenGLScene::Ptr& scene = win.get3DSceneAndLock();
    scene->insert(mrpt::opengl::stock_objects::CornerXYZSimple(1.0f, 4.0f));
    scene->insert(gl_data);
    scene->insert(glObj);
    win.unlockAccess3DScene();
    win.repaint();

    win.waitForKey();
}

int main(int argc, char** argv)
{
    try
    {
        Example_GMRF();
        return 0;
    }
    catch (exception& e)
    {
        cout << "MRPT exception caught: " << e.what() << endl;
        return -1;
    }
    catch (...)
    {
        printf("Another exception!!");
        return -1;
    }
}